Swapping the SII Heads onto the SI 3800-INFO-not 56K safe...

[Turbocharged400sbc]

OK fer the fellow psychotic gearheads out there....

The rear 90 3800 LN3 Vin C engine in our twin engine 94 Olds Cutlass 442 will be getting Turbocharged this winter and get a Mega Squirt EFI setup (90 non PCM controlled trans) and we have already swapped to the Delco ignition, there are plans for an intercooler to be plumbed into the mix to feed a TB located on the belt side of the engine for better plumbing.

One of my goals is to swap the SII cam, heads, intake onto the SI 3800, and have the specific modifications required to make this Hybrid, available to anyone else who might be interested in getting more power from their SI 3800.

 

All references to SI are taken from a 90 Vin C 3800 and all SII are in reference to a 95 Vin K 3800 engine, these may also correlate to other SI and SII engine years.

 

SI & SII 3800 differences/similarities: They seem to have the same bolt pattern on the ends of the heads, but different accessory mounts, this would allow the use of the SI accessory’s and belt drive with the SII heads. The 90 LN3 block (all SI) has a taller deck height which with using the series II Lower intake manifold will require spacers with the SII heads on the SI block. The different looking coolant bosses from the block into the heads is not a big deal, the head gaskets will still seal them... at least the SII V6 isn’t reverse flow and have the massive differences like the Gen I (regular) small block Chevy V8 vs. LT1/LS1 Gen II/III V8’s though more than a couple of people have put LT1 heads on the Gen I SBC with just a couple of modifications. Here is a side by side comparison of the SI and SII block surfaces.

The camshaft lifters are hydraulic roller for both engines but the series II has shorter pushrods for its lower deck height, there is a possibility the stock LN3 pushrods will work with the SII heads, but custom length pushrods are not expensive, if they are required. The valve arrangement is different between the SI and SII, i.e. the cam lobe timing events are tailored for the I-E-I-E-I-E valve positions of the SII and not the E-I-I-E-I-E of the LN3, this is one of the only things that I have found different between the cams. The other major change concerns the balance shaft bearings, the sleeve bearings (SII) that got changed from roller bearings (SI) on the balance shaft. The SI & SII cams have identical bearing journal spacing as well as the lobes, so they would line up correctly with the lifter bores. In one manual I found that there are differences in the SI and SII bearing journal diameters, but it also states that it is 97 and later SII that has the larger diameter, whether or not this is the case still remains to be seen.

Series I:

Camshaft Journal Diameter = 1.785-1.786 in

Bearing-to-Journal Clearance = 0.0005-0.0025 in

Series II:

Journal Diameter = 1.8462-1.8448 in

Bearing-to-Journal Clearance = 0.0016-0.0047 in

 

If this is the case, then it would require the early SII cam to slide into the SI cam bearings or the later SII cam would have to be chucked in a Lathe and cut the journals down and polish them to the correct diameter for proper bearing clearances. The other difference between the SI & SII cams is the snout and timing chain differences. The SI cam (in the 2 SI blocks I have looked at) uses a flange on the front of the cam to keep it from walking back in the block and uses a cam button on a spring to keep it from walking forward into the T chain cover. This pic is of a non balance shaft equipped SI.

The SII cam however (has no front flange and can slid back and forth no problem) slips into the block and has a flat retainer/thrust plate that bolts on with two flush head torx bolts, this keeps the cam from being able to walk forward in the block.

Then after the plate the balance shaft gear slips over the snout of the cam with the cam Timing chain gear going on right after and tightened with a single bolt, and with the Thrust plate behind the balance shaft gear/T chain gear this prevents the cam from walking backward in the block. And yes the SI and SII do have the same cam journal diameters if it's a 95 (and some/all 96?) SII blocks then the cam bearing part #'s change... to the larger ones....no wonder my manual said that the 97+ have the larger cam bearing journal diameters-and this is also shown by the 95 and 96 SII blocks using the same part # cam bearings as the SI blocks. The Cam specs are as follows for a 90 Vin C 3800 duration at .050 is 188 deg on the intake and 191 deg on the exhaust with the lobe separation angle of 114 degrees (no valve lift #’s found-yet). The 95 Vin K SII cam specs out at 180 deg intake and 191 degrees on the exhaust at .050, and the lobe separation of 115 degree’s, the SII cam also lists valve lift at .411/.408, on the intake/exhaust valves respectively.

 

 

The other difference that I can see is that the pushrods will have more of a tilt to them than the SI pushrods when the SII heads are placed on the SI block but this shouldn’t be a problem as plenty of engines have been designed with pushrods that are not directly in line with the axis of the lifter bore, the only side effect would be a little more thrust loading on the lifter to bore surface. Did you know the SI and SII use the same lifters? Same part #’s! The pushrods on the SI are 7.965 inches in overall length where the SII pushrods are 6.959 inches in length. This would seem to indicate that the shorter deck height is approx 1 inch on the SII block (presumably for a smaller engine package that will fit into smaller engine bays) but I have yet to verify this through specs or through measurements. This hybrid engine may still require custom length pushrods for proper lifter preload and valvetrain geometry

 

The SII exhaust manifolds would have to be used with the SII heads, however it seems possible that the SI tubular log manifolds can be cut and modified to fit the SII head, however with the plethora of aftermarket SII headers this wouldn’t be necessary, though the X-over pipe would be a little longer due to the SI blocks taller deck height. Here are pics of the SII front (cast) and rear (tube steel) exhaust manifolds.

SI front manifold made of tubular steel

 

The pistons in the SI are listed as having two 1.5 mm and one 3 mm ring grooves with a 1.377 compression height rated at 8.5 to 1 Compression ratio with a dish of .260 inch deep x 3.050 inches in diameter. The SII pistons spec out as having, one 1.2 mm, one 1.5 mm, and one 2 mm ring grooves, with a 1.090 inch compression height and having a dish of .050 inch deep x 2.9 inch diameter.

 

Now for the cylinder heads, the primary difference between the SI and SII heads are the intake and exhaust valve and port locations/order, with the SI head having a EIIEIE arrangement and the SII having a “symmetrical port†design of IEIEIE, these differences are why the Camshaft from the SII must be used as it has the correct lobe phasing/order. Now besides the fact that the SII heads have much better engineering of the port design and excellent crossectional area/flow the SII heads feature 1.8 and 1.52 inch intake and exhaust valves, and they measure 4.7212/4.7133 inches overall length on the intake and exhaust respectively. While the SI heads have 1.71 and 1.487 inch diameter intake and exhaust valves, and measure 4.727 inches overall length each. I have yet to determine the SI and SII combustion chamber volume but the differences in the dishes of the pistons would lead me to believe that there is a possibility that the SII heads have a slightly larger chamber than the SI heads, but this has yet to be verified by me. Also the SII roller rockers are lighter than the L27 roller rockers, just by handling them. From the look of things I can make the roller rockers a different ratio with the Bridgeport and a 300 amp TIG welder, here is a side by side pic of the SII and the SI rockers.

 

 

From the looks of things the Timing chain from the SII will work with the SI block as they use the same chain tensioner part # between the SI and SII setup, however you cannot use the SI chain with the SII cam gear because the spacing (pitch) of the teeth are different and will not work. This should not pose a problem since the SII timing chain crank sprocket will fit on the SI crank snout; however one of the things I have to check is whether the splines on it are the same as the SI splines that drive the oil pump that is in the Timing chain cover, but I would think that they wouldn’t have changed, and if they did then you would also require the SII sun gear (and maybe the ring gear) of the gerotor type oil pump.

 

I think that covers most of the differences and/or similarities.

 

Now for what I am trying to accomplish with this Hybrid project on our 90 Vin C 3800 in the rear of the twin engine Olds 442:

I am looking to swap the SII L67 heads with the injector bosses in the heads (this means that yes, you can put a L67 supercharged top end onto a SI block-with the L67 intake- SI guys can say goodbye to the M62.....HELLO M90!) with a modified factory fuel rail. Along with the L36 NA lower intake manifold (with spacers…) with it’s 6 injector bosses and modified factory fuel rails, so that we can run 12 30lb hr injectors at 50 psi with a boost referenced pressure regulator (Quad 4 injectors-free from J yards….) with the Mega Squirt DIY EFI system controlling them with custom fuel tables for the Mitsubishi TD06-17c-8cm^2 Turbocharger from a 4.3L Cyclone/Typhoon, this Turbocharger is capable of enough flow to support 400Hp which would require ~ 60 lb hr injector per cylinder, it’s much cheaper for us to use two 30 lb hr injectors. The L36 NA lower intake would receive bell mouthing of the intake runners, and we would Fabricate a sheet metal aluminum Upper intake plenum that would have a N* or LS1 TB located on the belt drive side of the engine to allow for better plumbing of the Turbocharger to Intercooler to TB ductwork without any flow robbing bends. There is no big deal with this as our rear engine has crank, WP, alt, and tensioner only and wouldn’t interfere with the TB. Mega Squirt EFI will work with MAF or MAP based EFI setups but I think we will go with a 3 bar MAP sensor and use speed density tables and forgo the LS1 MAF etc and its associated cost, though it’s not out of the question. The SII exhaust manifolds will be used with the rear manifolds normal outlet removed and the crossover pipe that is (now) too short will be cut in half to facilitate the fabrication of the Turbocharger mount/flange.

Besides the benefits of factory SII parts on the SI block you can then use the aftermarket SII performance parts, an IC under a L67 supercharger etc you name it…the possibilities would be endless, at least it’s possible.

 

Modifications required:

 

Here is a pic of the SII cam gear, balance shaft gear, and the thrust plate, from left to right. The balance shaft gears are identical between the SI and SII tooth pattern wise so you can still keep your SI balance shaft and the SII cam gears will mesh perfectly. Here is a pick of the SI and SII balance shaft gears-identical

The thrust plate on the far right is the part that will have to be centered over the cam hole and the two small torx flush head screw holes will need to be center punched, drilled ~5/16 of an inch deep and tapped for the thread of the bolts...this looks like the hardest part of the whole swap.

But I still have some measuring to do in the Junkyard I have to compare the SI crank sprocket (timing chain) to the SII one and make sure that both have the same oil pump drive splines, as in this picture of the SII crank sprocket which has the same crank snout diameter as the SI. However you cannot use the SI crank sprocket with SII cam sprocket and or chain because of the differences in the tooth pitch of the SI and SII timing chains.

So far it looks like all we have to do is drill and tap two holes in the front of the SI and use the SII cam thrust plate....with a SII T chain set... here you can see the difference between the SII and SI cam gear tooth pitch, the SII gear is on the top.

 

Now, bolting the Lower L36 or L67 intake on the hybrid, as the intake bolts are perpendicular to the intake port surfaces all that you need are longer bolts to account for the spacers thickness. The Spacers can be cut from Aluminum stock of the correct thickness with a plasma cutter and milled with the correct size coolant and intake port patterns with the intake bolt holes drilled into it, this is also an easy task as I have access to a Bridgeport mill and alum stock of varying thicknesses. Then the spacers need to be bolted to the intake and a few more small holes drilled and the spacer needs to be countersunk for flush head screws to hold the spacers to the Intake with just a paper gasket material between them then tap the small holes for the correct thread that your flush head bolts have and bolt the spacers to the intake. Then you would just use the factory SII intake gaskets between the intake (and its spacers) and the heads, and fasten it down with the longer intake bolts. The spacers would be cut to the same shape etc as the intake port flange such as the L36 Lower intake in this pic of the Lower intake with the intake gasket on it, you could basically copy the intake gasket.

 

You may be able to use the stock SI pushrods if they will work but if not a pair of adjustable checking pushrods can be used to determine the correct length and purchase new custom length pushrods from Manley/Comp Cams etc. A pair of checking pushrods is 25$ and a set of high end custom pushrods goes for 80-100$ for a V8 and you don’t need that many except for maybe spares…

 

The Upper intake (L36) or supercharger (L67) would bolt right onto the Lower intake with no changes however the supercharged fuel rail will need to be fit for the wider head spacing of the taller block. And the belt routing will need some work but would seem to be a possibility that it would work with a SI or SII accessory/belt system no problem, but as I am not attempting this I cannot say for sure…

 

Why the hell am I doing this instead of swapping in an L67:

 

Lowbuck Redneck Modern Hotrodding! We is Rednecks, we is cheap! We already have the 3800 SI drive train in the rear of the 442 and since we are going to be Turbocharging it we will be running MS EFI, as the trans isn’t computer controlled the MS system will work so we don’t have to spend tons of $$ to get a custom PCM/ECM, and because I can tune the MS to run it just fine-even with 12 injectors using peak and hold drivers for the low impedance Quad4 injectors. It is well worth spending a day at the J yard tearing down a couple engines to check/compare dimensions and feasibility of the swap. I have the time and the energy as well as the tools to try this out for nothing, it will just be a little investment of time, if it doesn’t work because of massive cam differences (doesn’t seem likely...) at least someone will have taken time to prove it's not possible and document the proceedings. But like Gearheads of old who put a blower from a diesel on their V8’s or swapped Flathead fords into T bucket roadsters, blazing new trails, I am doing it for the fun and challenge, and of course to go faster!

.

We are trying this because for the price of a set of SI roller rockers we can put the SII heads with factory roller rockers, and it's better flowing ports and larger valves, and the lower NA intake on with machined spacers, and fabricate an upper plenum that would allow use of a N* TB or equivalent. Along with the SII exhaust manifolds and fabricate the crossover for the turbo flange, ourselves saving $, who can argue with that?

 

You can do anything with a Plasma cutter, welder, Bridgeport mill, and lathe…

Case in point…Twin engine 94 Olds Cutlass 442 New Pic of the rear engine bay....

 

More to come…stay tuned….

Regards, James

[5speedz34]

Damn, long post; got the cliff notes?

[Turbocharged400sbc]

sorry it's so long but I was intending fer a Mod to be able to turn it into a techinfo piece...

 

Cliff notes:

Yes it can happen, needs a little work, less work than swapping an SII in place of a SI/3x00 engine.

 

James

[digitaloutsider]

Yes it can happen, needs a little work, less work than swapping an SII in place of a SI/3x00 engine.

How in the hell do you figure? This was discussed to great lengths in your BonnevilleClub posts.

[Turbocharged400sbc]

I meant in terms of modifications required, overall it looks like you have to drill two holes and tap them so the SII cam thrust plate will bolt on. use the SII timing chain and gears. a set of pushrods that may or may not need to be custom length. and Intake manifold spacers. the Cam journals are not a problem if you use a pre 97 cam.

 

I shouldnt have put the 3xoo in there, basically with all the work to put a SII L67 harness, trans, halfshafts etc you would spend less time putting the SII top end on the vehicles SI block and even the L67 top end and supercharger.

 

it's still an option for those who want more power from their SI and dont want to swap the engine, harness, trans etc.

[Turbocharged400sbc]

in this project the biggest question was whether i could put the early SII cam (in 97 they went to a larger cam bearing journal size) into the SI block to actuate the valves in the proper sequence (the SI has a valve arangment like this...EIIEIE where the SII is IEIEIE) well i can now say without a doubt...nope the lifter bore spacing is dead on on the middle 4 lifters but has one lifter in a radically different spot on each opposite end...

so in order to have this project continue I would need a custom SI camshaft with the SII lobe phasing (but i can wick up the duration and do a couple other turbo friendly changes to the lobe profiles)

 

heheheh now fer the redneck part....I have identified the 4 lobes that need to be rephased...and since i can weld...cast iron even. I can weld up the surfaces that need to be off base circle and have a cam company grind the lobe profiles...however i have found out that a friend with a lathe has a pattern follower.... so it would be possible to take the camshaft lobe profile from my Turbocharged 400 sbc aftermarket camshaft....and grind this camshaft with it... :green: though it would probably be wayy too big for the 3800...though since i will be keeping the stock (SII) rockers i can machine the heads to handle much higher lift (at the valve)

 

so yeah i can still doit! woot!

now the SII cam is close enough that i can use it to mock the engine up with (the rollers on the hyraulic lifters not being 100% on the camshat lobes but since i will just be mocking it up to determin intake spacer thickness and custom pushrod length...this is no problem...

 

ahhh redneck lowbuck hotroddin'

 

at least its not a flat tappet camshaft....then it would be harder for me to grind it on my own...and hell i dont really need a lathe...i could do it on the Bridgport at my old buddy's house...but a lathe would be more repeatable...

 

sooo how many of ya have ground your own custom cam...lol

 

(BTW sooo many people say that nothing will interchange between the SI/SII...they have NO clue how similar these two engines really are...)

 

that is all... stay tuned... more to come

 

James

[99RegalGS]

Good luck on your custom regrind.

 

Good info James.

[Turbocharged400sbc]

well it looks like it will be easier to modify the SII cam (redneck wise) and get it to work than just changing 4 lobes on the SI cam (cast iron-4 lobes are out of phase)

the SII billet steel would be easily (fairly) made to work by welding alongside the lobes that need to be "Moved" over to line up with the SI block lifter bore spacing pattern, and then using a simple follower jig with a belt sander/grinder grind the extension to the same pattern as the original next to it, polish it and grind away the old (original) portion of the lobe to maintain lobe to adjacent lifter clearance....

and this cam can easily be made into an aftermarket billet steel camshaft with any custom lobe profile you desire...we may eventually get one but fer now...it's Lowbuck

annnnd.... the lifters are identical in every way...and look very similar to the sbc/ or 3x00 seried hydraulic roller cam engines (will hopefully confirm... and there may be a factory lifter out there with a larger roller that can handle a faster opening lobe ramp)

I may have to use the SI timing shain but that isnt an issue at this point (i believe that the cam/crank centerline measurments are identical (well i could have been .010 off)

i could use either...but i wil be deleting the balance shaft in the lifter valley (block oil holes) and will be cutting down the balance shaft gear to just a spacer...if you notice there are thickness differences in the SI vs SII timing compnents...they are different but stacking the parts together SI and SII components are the same thickness....as a unit...the SII chain and gears have a smaller tooth pitch pattern but share a nearly identical Tchain tensioner...

the cam retainer plates are the same thickness and opening diameter, just different bolt pattern...no problem there

and here is the SII crank gear (didnt have the SI on me) besides the smaller tooth pitch it is identical to the SI unit...however the SII drives the oil pump by 6 splines as opposed the the SI's two flats design...this is irelevant as the pump assemblys and Timing chain covers are nearly identical...just swap the pumps from the SII cover to the SI T chain cover....

 

i was talking to my buddy down under, (Locksmiff on Streetcommodores.com,) who started a seperate invite only tech site for holden commodores...but too the case at hand...

 

I have some pics of the SII stuff mocked up on his Holden SI (same as ours but has different intakes and exhaust (they got RWD but not quite the same stuff as the F body 3800 stuff...)

 

here are the SII heads on the SI block...

The cover over the balance shaft kinda hides the lifter bores but here is a valley view (btw i have never seen that blance shaft cover on an american engine...we think this is because of the high temps of the Au market...keep oil from coking on the underside of the intake)

And the money shot...here is the SII Holden intake bolted to the head...you can see the 1 inch gap that would have to be filled with spacers...or the SII intake widened...

and here are a couple of shots of the holden SII upper and lower intake manifold...similar to the F body setup but not quite...

 

now if you look at the lower holden intake it might be easy to cut it in half down the middle and widen it (cut zigzag between the runners and straight down the middle on the bottom) and then weld in filler for the coolant "T" and just fabricate a sheetmetal common plenum for the top...

alteernatly we have been talking about just making a custom (sheet aluminum) lower intake as a tunnel ram...which would be great for a NA engine but on our turbocharged setup ahort runners would work just as well...

 

well i hope that gives ya'll some more stuff to chew on....

 

I hope to get my own SII heads here soon so that i can start mocking up pushrod angles etc...but the heads bolt on nooo problem

 

 

OK here we go...

the SII cover on the left and the SI cover is on the right...essentially the covers are the same but Al's fingers are pointing to the major difference...the SII cover has one bolt hole deleted and the other moved...

by now you have rfigured that the cleaner piece is the SII cover...the filthy one the SI unit...here are the two oil filter mount units...both are interchangable between covers (W body unit on the filthy SI cover.)

here is a side by side view of the SII and SI covers near the oil filter adapter mountings here also you can see the (minor) differences between the two units

here are the fronts of the covers...you can see that the cam sensors are in the same spots as well as the small differences between the two water pumps...and the same mounting points for the crank sensors between the two covers.

Here you can see the identical oil pump assemblies...the SI cover pump driven by two flats on the crank gear...and the SII unit driven by 6 splines, the pumps are identical otherwise...

here is a crappy shot of the SII deck height measurment/timing chain area

and here is Al in front of the 442 and his V8 S10

and a quick shot of the drivers cockpit

and here is the empty engine compartment of the (formerly) 4wd S10 Blazer...That is getting a 400cid SBC

[brianteel]

I have a question why mod the heads so they go instead of just using a series 2 motor with your harness

[Turbocharged400sbc]

I have a question why mod the heads so they go instead of just using a series 2 motor with your harness

 

OK i get this alot from people...(no it doesn't piss me off..we are all here for learning...)

 

OK as i have established...the SI/SII blocks are nearly identical...small differences being a few accessory bolt boss's...and the 2 bolt vs 4 bolt mains (no the SI two bolt mains are not weak...remember plenty of factory buick 3.8 GN's have run well over 900Hp on a factory 2bolt shortblock)

and i like to point out that because the SI block has a tall deck height...the front and rear main block bulkheads are taller and seem to be slightly thicker making for a stronger block (torsionally)

the big difference is also the MOST Beneficial

the SI shortblock has a 1 inch taller deck height! as well as correspondingly longer connecting rods which gives the engine mechanicals a better rod/stroke ratio (less thrust loading on the cylinder walls,) as well as a noticable improvement in TDC dwell

 

going farther into this...with the SI tall deck block..you can get short compression height pistons (as far as narrowing the ringpack to an acceptable amount using narrow/low friction rings) and get a set of aftermarket conecting rods that (as well as being stronger than the SI/SII factory rods...) can now be even longer further improving Rod/Stroke ratio...

also take this into account...when stroking an engine (ANY engine) a tall deck block is better....as the rods length will still yeild an acceptable rod/stroke ratio as oposed to the SII short deck block...

 

all in all what i am trying to accomplish is to use factory parts to make a (More) mechanically efficient engine

a SI shortblock, with the larger valve/symetrical port SII heads on it...

and since the biggest snarl seems to be the need for the modified camshaft...people will also at the same time be able to put a nicer camshaft in (from 150-300$) the engine to make even more power...

 

now ya dig?

 

doing it all for the same reason i would take a 10.200 inch tall deck BBC over a 9.800 inch factory deck height BBC...

better in more ways than one...

 

Regards, James

[brianteel]

i understand that but the GN motor is not a series 1 motor

[Turbocharged400sbc]

Ahhh but you see, their first cousins, the SI 3800 (and the SII and SIII) 3800's as are closely related in the block casting...though changes have occured in the oiling system flat tappet to roller lifter valvetrains, balance shafts added, etc...the pre SI 3800's (the LN3, LG3 back to 88) are even more closely related...

 

we have a Turbo 3.8L GN engine in the shop basement and i have done a few comparisons...though the blocks do differ somewhat (belhousing patern etc) the main caps and bolts are the same size (though the GN is SAE thread) the base of the block/oil pan rails look very similar (except for the engine mount boss's RWD vs FWD)

 

basically the Buick 3.8L V6 that borrowed heavily from the buick V8, in all of its oddfire, evenfire, DIS changes and the rest of its evolution from a RWD platform engine to the FWD platform, its evolution as a short block, I believe, peaked at the tall deck SI 3800...it is in all ways a better shortblock when you consider the benifits (when the 3800 FWD's get into the 8's and start for the 7's i bet youll see alot more stroker 3800's and the SI block is much better suited...

 

while i believe the block design peaked in the SI engines, the SII/SII 3800's recieved much better flowing heads...MUCH better in many ways...valve size, combustion chamber design, port design...

 

so i would like to put these heads on the SI block....and make her run...

that in its simplicity is the reason why i am doing this...(that and everyone thinks its not worth it, a challenge i cannot deny )

 

Regards, James

[White93z34]

alright, i'll keep asking questions, but i'm not trrying to flame you, just trying to understnad your choices.

 

you seem very determined to use this old LN3 with alot of series 1 3800 stuff, now after all this would it not have been far more efficent and cost effective to use a L36 or L67 block and the corosponding heads.

 

now when you refer to series 1 / 2 i can only assume you are refering to the LN3 as a series 1 and a L27 as a series 2 rather then a L27 as a series 1 and a L36 as a series 2

 

now compared to a LN3, what are the base differences in the block that makes it more worthwhile to use over a L36 block?

[Turbocharged400sbc]

*Cracks knuckles*

 

alright, i'll keep asking questions, but i'm not trrying to flame you, just trying to understnad your choices.

 

good that (and your other questions) shows you are interested in learning more...that makes my time well spent responding. I know you arent trying to flame...your questions are logical, to the point. now let me rattle my brain fer a few...

 

you seem very determined to use this old LN3 with alot of series 1 3800 stuff, now after all this would it not have been far more efficent and cost effective to use a L36 or L67 block and the corosponding heads.

 

OK the LN3 currently in the 442 was the precurser to the SI 3800's...and is identical except for missing the two holes for the cam retainer plate bolts...that and the head/egr/intakes are different (because of this all LN3/SI shortblocks are nearly identical...for my needs)but this does not matter since SII heads/modified intakes will be used.

efficient...maybe for some, cost effective...no

in short the cost to "buy an L67" is more than what we can build ourselves...

beyond this factor...i have 2 SI (L27) engines, 1 LN3 (in the 442), and one L36 SII short block.

and the means to aquire good SII top end parts for my project for cheap, and since the engines' will be getting turbocharged we will be getting aftermarket Turbocharger friendly grinds, it is nothing for the cam company to move a few lobes laterally a few tenths of an inch. also the early SII engines (97 and later got the large cam bearing journals) have the same camshaft bearing journal diameters.

but mainly this is for building a more efficient engine, and because no one's ever done it before, the challenge is irresistable, and because the info will be out there, so that someone who decides to build a 4.2L stroker 3800 can look at the benefits of the SI block over the SII block in stroker applications

 

now when you refer to series 1 / 2 i can only assume you are refering to the LN3 as a series 1 and a L27 as a series 2 rather then a L27 as a series 1 and a L36 as a series 2

 

no, i kinda mess people up on this one...but when i loock at the shortblocks...i lump the LN3 in with the SI (L27) engines as they are for all intensive purposes the same...and when i say "bolting on SII heads to SI Shortblock"...i am including the LN3, the LG3 has more differences that i cant lump its shortblock in with the SI engines (though theoretically all of this would work on an LG3...but for the hassle of extra machining its better to get a SI shortblock (or LN3 if you dont mind drilling and tapping two 8mm holes)

to clarify...My "SI shortblock" designation covers the LN3, L27 (SI), L67 (SI) and these were produced into the begining of the 95 model year, late 95 on are the "SII engines" L36 L67 (and now the SII L32 etc)

 

when i refer to the SI...i am mainly talking about the shortblock

 

now compared to a LN3, what are the base differences in the block that makes it more worthwhile to use over a L36 block?

 

compared to the SI (LN3/L27/L67) shortblock the SII Shortblock (L36/67)

has a shorter deck height by one inch, this means shorter connecting rods to fit the same stroke crank (both are 3.8 bores and 3.4 stroke) this means more rod angularity which means more cylinder wall thrust loading

now when you stroke the SII engine...because of the short deck height you need pistons with a shorter compression height to use the same length rods or stock compression height pistons with shorter rods...

 

Now with the SI block...if it were stroked to a larger displacment you can fit longer rods with the short compression height pistons and have a much better rod/stroke ratio...which reduces the power losses due to friction from thrust loading etc.

even in a stock stroke 3800 being able to put really long rods with short compression height pistons will make for some very favorable rod/stroke figures...

 

ALL engine builders agree that when you build an engine to minimize drag/friction you get more power...on top of this a long rod engine has other inherent benefits to the combustion process of a thermodynamic engine, increased piston dwell at TDC/BDC a big one.

 

(what) makes it (SI shortblock) more worthwhile to use over a L36 block?

 

in the end it all comes down to going faster...face it at some point to get these FWD cars (and our Twin engine, 4 WD 442) to go faster (say to hit the 8's or 7's) they will start to stroke the 3800...4.1L, 4.2L, 4.3L whatever it is they will start to see some major issues with the rod/stroke ratio and piston thrust loading in the SII block...so at some point they will look to the SI Tall deck block to ease their woes...and go faster all with GM Factory parts, without needing custon CNC billet alum blocks/heads etc ($$$ :shock: )

 

And I will be right there to help them

 

Regards, James

[99RegalGS]

Good info Again James. I for one can't wait untill you get this done.

 

By any chance did you get the "Pre-series 1" LN3 thing from Bonneville Club??

I've seen the LN3 called "pre-series 1" on there before.

 

I don't agree with them on this thought. To me the Pre-Series 1 is the old FWD Buick 3.8.

Then the LN3 "3800" came out in 88, so how can it be a Pre 3800, if it's called a 3800??

Doesn't make sence to me.

 

To me the Series 1 3800's are 88-95, and just differentiate by the RPO if I need to get specific.

[Turbocharged400sbc]

Dude! hows it goin?!? i'll give ya 200 bux for the front half of yur regal....

 

Good info Again James. I for one can't wait untill you get this done.

 

Thanks, Neither can I

 

By any chance did you get the "Pre-series 1" LN3 thing from Bonneville Club??

I've seen the LN3 called "pre-series 1" on there before.

 

I don't agree with them on this thought. To me the Pre-Series 1 is the old FWD Buick 3.8.

Then the LN3 "3800" came out in 88, so how can it be a Pre 3800, if it's called a 3800??

Doesn't make sence to me.

 

To me the Series 1 3800's are 88-95, and just differentiate by the RPO if I need to get specific.

 

I'm with you on the last statement...as far as shortblocks go....

 

now if your looking at the whole engine the LN3 isnt really a SI 3800, too many diferences on the top end...

soooo we have

 

SIII (L32), the SII's (L67/L36), the SI's (L27/L67), 3800 (88-90 LN3), Buick 3800 (LG3), and the Buick (3.8L/4.1L/231 cid etc)

 

i guess its all in what your looking at/talking about in relation to the top end parts/long/short block

 

I tend to use the RPO's as well as the Series designation in most of my posts (which can get confusing as the Holden guys refer to the SI 3800 as "the buick" and the SII and newer "ecotec"

 

they also do not include the LN3 into the SI designation as what they consider SI are the 3800 blocks with EV6 cast into the sides...they also tend to refer to the SI "Buick" also as the "EV6"

 

they love talking to us "Yank's" lol

 

James

[Turbocharged400sbc]

Update!

 

i have a set of 00 impalla heads and misc pieces (w body SII rear manifold LIM etc) and have done a prelim mockup...boy does it look good it looks like 8 of the pushrods (SI, the SII are way to short by the same amount the SII deck was shortened) are able to preload the lifters to spec 2 more pushrods will be close and the last two may need a little more length for proper lifter preload, also it looks like i need to grind the pushrod passthrough holes for those 4 oddball pushrods but thankfully this engine doesnt use guidplates etc and has pedestal mount rockers that makes my job easier

 

i'll tell you this much...it sure is lonely from here on out as i am now at the point that Locksmiff stopped his to persue other work...

 

one cool thing i have found is that the smaller cam journal blocks (SI and supposedly 95-96 SII) can be turned into roller cam bearing by some small cam tunnel machining and just a hair off the cam journals to fit and use the "off the shelf" roller bearings i found...dont know about the large journal SII stuff but it is an interesting way to further reduce cam bearing friction as well as (with restricters) making sure the bottom end gets all the oil it needs as the roller cam bearings will require less oil. yes i have been looking at alot of ways to make a better "mouse trap" lol, including minimizing windage to free up more power...

 

I guess thats the majority of the update...James

[Turbocharged400sbc]

i honestly cant belive no one has done this before...there is no way that some GM tech/engineer hasent figured out that you could put the SII heads on the tall deck/long rod block with a custom cam and intake spacers...oh and lengthening the exhaust manifold crosover pipe...

 

ask and ye shale recieve...i have 58 new pics....

 

Just a tease....fer now ...these are the hot ones

 

8-)

 

10 pic flash strip of SI tall deck/long rod block/pushrods with SII DE larger valve/symetrical port heads

[Turbocharged400sbc]

so far the longblock looks like all it needs:

is the ~13mm (1/2 inch) phenolic or alum intake port spacers (and the end oil seals will need spacers) phenolic would def be better

 

a custom grind camshaft SI bearing journal diameter and SI lifter bore spacing but with the SII lobe phasing...and since most with a tall deck stroker/turbo high performance engine would want a custom cam to get the most out of the engine this is a very minor cost (~250-350 USD dep on lobe pattern)

 

4 pushrods approx ~.010-.020 longer than stock SI pushrods for the higher angle pushrods (for proper lifter preload), which clear the head casting just fine after just a hair over 1mm was ground away from the outer edge of the port wall (see in pics below)

 

you will have to use wither the SI or SII balance shaft gear/Timing chain, Cam and crank gears on the SI crank/block, the cam retainer plates are identical thickness (3 bolts in SI only 2 in SII) and the cam snouts are the same, just different journnal diameters.

One thing to make clear, if if your deleting the balance shaft, or not, you have to use the SII cam gear with the SII balance shaft drive gear as the cam gear and balance shaft gear from either set are the same thickness you cannot mix the SI cam gear with the SII balance shaft drive gear or vis-a-ersa as they with be thicker/thinner than the required thickness.

 

also if your using the better smaller pitch SII Tchain/balance shaft gear, cam gear, crank gear you will have to install the SII oil pump into the SI cover (the drive arangment between the oil pump in the cover and the Tchain crank gears are different from SI to the SII.

 

accesory brackets look like you will be able to use all of the SI brackets with the SII heads with some minor customizing (and making a few parts "factory optional" )

 

Ok lets start with the obvious stuff...

here are two pics of the different deck heights SI (1 inch taller) vs SII measured from the coolant port for the nearly identical timing chain covers....

SII

In these pics you will see a 93 EV6 SI short block next to a SII shortblock

in this pic you will notice the same skirt mount holes for the accesory brackets and other bolt locations and then you will see the other differences in bolt hole locations and the extra knock sensor boss.

SI block face:

SII block face

now to the headgaskets Here are some pics...try to guess which is which...lol

the SII is identical except for the slightly different valve reliefs in the combustion chamber fire-ring in the SII HG as well as it has the large area with triangles cutout for the pushrods to pass through.

Here you wil see the SII headgasket on the SI block

Here you see the lifter offset from the SII lifter bore locations

And here is the SI gasket on the SI block

so far it looks like the SII gasket will have to be used as the SI gasket, though nearly identical, might shroud the valves and hinder flow.

 

Here the 2000 SII head is bolted onto the SI EV6 block...those symetrical ports look right at home dont they...

Here is a 3/4 view:

and a rocker arm buisness end view

 

To further show the slight differences in lifter bore locations between the SI and SII blocks here is a SII lifter carrier above a SI carrier notice the center two are in perfect alignment

And here you see the two end lifter locations notice on the SII where the lifter bores were moved inward more on the inner lifter than the outer (end) lifter.

 

And here are the SI pushrods installed center two are at 0 degree's and the outboard 4 pushrods are at slight inward angles, the ones on the ends are at ~ 1.5-2 degree's and the ones inboard of the ends are at ~3.5 degree's and just slightly graze the edges of the intake port casting. This neccesitates grinding just a hair over 1mm from the outter port wall.

Lifter guide left off for clarity:

In this pic my buddy Donald is pointing to the two outter pushrods which are at the ~1.5-2 degree angle

here he is pointing to the pushrods that are at ~ 3.5-4 degree's and that hit the outer port casting, this was fixed by removing just a bit over 1mm of metal about 1 cm tall from the outer port wall...

 

now the oilpans are even more interesting as the SI sump height is a little deeper and has a larger front sump section...both have identical bolt hole locations and pan rail widths...the major difference is the SI pan has an integral windage tray and the SII pan has the windage tray integral to the pan gasket carrier... (SI pan is on the right and bottom of the pics)

 

and the rods are next the SI rod being a longer rod by ~5/8ths of an inch (I have seen specs saying its .64 inches shorter) but i have to pull the pistons off the rods for more comparison. the SI rod has a thicker main beam and also has more material around the big end capscrew locations, besides being equipped with a larger dia piston wrist pin, this could be bushed to work for a floating pin application and probably use the SII wrist pin diameter. Also note where the SI piston also has a tall compression height that if the SII piston were put into a SI block you would be able to get the rod even longer by ~1/4 inch of an inch for an even better rod/stroke ratio

 

so if you used the SII piston (or an aftermarket) with the SI rod in a SI shortblock you could throw in a ~3.6 inch stroker crank and have all factory components without custom length rods etc.

 

 

the SI piston on the right has a deeper dish with a top ring located lower and a taller oil scrapper ring, than the L36 piston on the left

 

and a through the bore view of the head/valves

 

thats enough fer now...more to come...

 

Regards, James

[99RegalGS]

as always James. Very good info.

[Turbocharged400sbc]

I have been thinking of using aluminum for the intake spacers i need for the SI/SII (EV6/Eco) hybrid, and this weekend while i was cutting 1/2 inch plywood for the mockup spacers...why not use phenolic material here to reduce intake temps?, i doubt the plywood would seal well without getting rid of the oring style gaskets and going to a thicker paper/felt type gasket etc.

 

where are some good places to get 18 inch x 4 inch sheets of phenolic material in ~9/16ths to 1/2 inch thickness's??? i have searched the web and some companies want 145$ US for a 24x48 sheet of the stuff that is rated to 280* and 375$ US for 350* plus stuff!!!

 

i dont think that this aplication needs a temp rating over 280* but the phenolic material must have a low moisture absorbtion factor (mostly glass fiber based phenolics...and special composits fit these needs but $$$$$$$)

 

should i just stick with my idea of aluminum spacers and just using 2 SII intake gasket sets? or thickeralum spacer and swapping to hand made paper gaskets? or should i try to find some phenoilic material and use OE or handmade gaskets?

 

i have the L36 (NA) SII lower intake but it def would suxor to cut it down the middle and widden it....which at that point would def require a custom sheet alum upper...prob best to stick with making spacers...

 

I should have more pics once i am done with these mockup spacers and old intake gaskets... for proper thickness of the spacers (yes i have considered "Raising" the port angle to give the air a more direct shot at the back of the valve) in the final build

 

I sent an email in regards, to this project to Outlawengineering.com

WoW! talk about fast response!

 

James,

 

You guys are nuts! I mean that in the best of ways. The twin engine Cutlass is too much! Talk about a double-edged sword!

 

Send a gasket over here and we'll see what we can do. We use a standard 1/4" thick composite, but we can certainly stack them to whatever thickness you may need. Just place another gasket between the spacers for now. I think we can fit you in for ~$100.

 

The composite will be fine, we run other spacers that have coolant passing through. I would suggest bypassing the coolant through the LIM if you can. With coolant going through the manifold, it will still get to ~180 degrees F.

 

Best regards,

Sean Morgan

Outlaw Engineering

now this represents and interesting idea...dep on how thick exactly the spacers have to be, you would have to use some paper gaskets between the seperate 1/4inch plates (like bolt a stack together with a couple 4-40 screws and then put it on the engine...or maybe since you'd have to get two sets of LIM gaskets, just stack 4 of em... lol i almost might be better off with using 3 oem replacment gaskets and two 1/4 inch aluminum pieces...use the gaskets as the phenolic insulators...of course this provides packaging/instalation problems and possibility of more leaks

 

I hope i can find someone to give me an estimate on an actual 1/2 inch phenolic material to have the spacers made from.

 

what are some of your opinions?

 

just go with some ~ 1/2 inch thick aluminum spacers and the two LIM gaskets "acting" as phenolic insulators or should i see about some 1/2 phenolic material...what do you think would be the best, would the aluminum be that much less efficient than the phenolic that it would benifit to any large degree? maybe if i did remove the coolant passages from the intake (I have looked at the room available for running dedicated reverse cooling lines (AN8) from the front cover to the head coolant port and then into the blockseperate AN lines and use a thin blockoff plate at the W/P or and external mounted W/P) this would let the phenolics do their job better and i bet you could get U/LIM temps nearly ambient

 

The other option is to go farther than just making my sheet alum UIM for the L36 LIM, and make the whole damn mess from sheet aluminum, i have acess to a Tig and have a bridgport, so i could do it...but i'd like to do it using as many factory parts as possible to keep costs down. (as well as to keep from spending 30+ hrs on an intake)

 

thoughts?, comments?

 

Regards, James

[br]Posted on: April 01, 2006, 06:56:20 PM_________________________________________________OK i admit it I goofed...when measuring the intake manifold spacer thickness...i set the intake on the block...the real thickness (surface to surface) is ~ 1 5/32's inches!!! the end oil seals would have to be 1 inch (redid my math and this is fer sure since the head's are now 1 inch higher due to the tall deck block)

 

sooo i have to make some reaallly thick intake spacers or i just go ahead and section the L36 LIM into two port flanges, run my own coolant hose path's and weld a plate down the center for the new "Floor" of the intake plenum, now this may be the best way to go about this, though i would loose the benifite of over 1 inch phenolic spacers, going over 1/2 inch thickness with that stuff gets expensive reallly quick, and i can get 1/4 inch alumin sheet and TIG it fer less than that fer sure, my labor comes cheap to me

 

the other thing i noted other than the UIM being really tall with the spacer method is thet the bolt holes in the LIM would have to be slotted because of the bolt angle to the head face. this problem goes away if i just fabricate a wider LIM using as much of the factory unit as i can (but believe me i would run external coolant lines, that would seriously reduce LIM temps in and of itself)

 

I have a crapload of pics of my mockups with SI brackets and SII brackets...guess what other than some tomfoolery with coolant routing (aka the SII alternator bracket vs the SI) almost all the brackets interchange...and the 00 impalla L36 alternator/tensioner bracket bolted onto teh head shows that the tensioner pulley lines up perfectly with the SI T chain cover Water pump pulley...so belt routing may not be as bad as i think.

 

I would appreciate pics of any of your cars that are similar to these makes/models 00 impalla L36, 00 L67 (W and H bodies) and 93 regal's 3800 SI, so that i may see what brackets would be the best, as far as the compressor, alternator, P/S mounting brackets as well as the belt routings, i will be looking in Mitchell OnDemand when i get to work but usable pics would be appreciated.

 

Wait till ya'll see the pics (soon!)

 

Regards, James[br]Posted on: April 02, 2006, 11:42:05 PM_________________________________________________Right now i am trying to locate a factory rod (from another application) to allow the use of SII short compression height pistons with a rod longer than the factory SI/EV6 i havent gotten an exact measurement but the SI rod is dam near 5.9 inches c to c and using the SI piston means i need to find a factory rod ~ 6.1-6.15 in length

 

SII guys only wish they could fit a rod that long in a short deck...

 

on this same note a SI guy could get a crank with a larger stroke while using the factory SI rod with a factory or forged aftermarket SII piston, cheap stroker...

 

well onto the pics...

this is the SI/SII Hybrid (by now ya'll know i'm talking about the EV6/Ecotec) the end gaps under the intake is 1 inch, the sides are approx 1 5/32 inches

awww yeah SII alternator bracket, SI front lower mount, with SI cover and pump, pulley's all line up all good there.

a high res view of the cylinder bore/head alignment, anyone ever scribe the heads with the bore, my one head needs a .010 ofset pin to move it up, but i want to check more.

nice view of the pushrods...

here's the two coolant ports...these will play into my work on a custom fabb'd intake manifold, i will section out the middle and weld in aluminum to widen it as well as i am looking into external plumbing for the cooling system...i am wanting to see how dificult it would be to make it a reverse flow system, sending the cool coolant straight to the heads and then into the block to prevent hot spots.

Yup it's def an EV6 with symetrical port heads...

crankcase pics:

and this is the main reason i have figured it easier and better to widen the LIM than spacers and the problem shown in these pics, bolt angles, you could slot the LIM but that thick of spacers is pretty excessive as are the other problems, this is why i have settled on widening the manifold.

Here i played with flipping the manifold backwards to see if it would be better for external plumbing access to the needed coolant ports in the heads with some work to the T chain cover i could make a bypass for coolant leaving the water pump to the head passages and from there into the block and exiting the front to a remote thermostat/restricter plate.

SII FWD front engine mount adaptor bolted on

[br]Posted on: April 16, 2006, 06:32:55 PM_________________________________________________SI FWD front engine mount bracket and AC comp bracket. either could be used in the final engine, the questions arise for RWD differences, but i'll leave that to ya'll.

I have yet to finish sorting this all out but it looks like the SII alternator bracket can be used with some work or the SI stuff can be retained, i do not have a clue (yet!) what this means as for using the dual belt drive setup on a SII L67 on the SI/SII Hybrid.

a few more pics:

The SII EGR could be used in this setup, but i don’t have smog test's... what? like the guy will ever even think to check for a rear engine...:dancingna

one of the issues of a spacer for the intake...alternator bracket clearance...

the SII tensioner lines up perfectly with the SI pump with SI pulley

for the FWD crowd...now that the SII heads are 1 inch higher there is now an issue with the rear manifold, for turbo vehicles with headers...i dont see an issue but with the firewall on a W body this would probably require rewelding of the rear manifold to lower the angle.

and now to the rods and pistons, i have finally pressed the SI apart and hope to have pics here in the near future (uh yeah the SI rod is a good bit meatier in many ways..but as i said i am looking for longer rods from a different engine/application so that the aftermarket forged SII pistons can be used with an even longer rod at stock stroke is 1.80 rod/stroke angle vs 1.73 for a stock rod SI, which is still way better than a factory SII

but before i go nuts with numbers i have been checking an it would seem that there are different compression height SI pistons...which means several different incarnations of SI (EV6/L27/LN3/LG3) connecting rod length

I'll let your imagination wander...i bet ya can figure which is which..

and the turbo's i'd love to have on the 442...now if i can only steal them off my pop's 07 Peterbilt 13.5L Detroit compound turbocharged diesel

 

[99RegalGS]

Keep it coming!!!

 

Also, That's not a Detroit Diesel. That's a Cat engine.

[Turbocharged400sbc]

Keep it coming!!!

 

Also, That's not a Detroit Diesel. That's a Cat engine.

 

lol i know...his old truck's been a detroit and i messed up....

 

i havent even seen it in person yet...only has 3800 miles....his old truck got traded in at 780,000mi

 

he's wrather have his old super 10 trans than "this damn fuller 13"

 

we're going on the road next week, closest thing to a vacation fer me I've driven alot of big trucks but i've never been in a semi going faster than 4th gear...