Just got an L67 - dare I top swap?

[Krieger]

Hey everyone. Looking to get some input and I figured this was as good a place as any.

 

I recently got my hands on an L67 block for next to nothing. And I do mean next to nothing: $50. It came out of a working '99 GTP and the friend just wants it out of his garage where it has hung from a cherry picker.

 

Now, my first thought was "Oh, let's swap that supercharger onto the 3800 in my Impala!" And then I started to do the research....wow, not a bolt-on. So, I've been going through thread after thread on this forum as well as the 3800pro boards and found all sorts of instructions, lists, warnings, pros/cons, etc. Bottom line is that my situation is different than most seeing as I am getting 80% of the parts for (basically) free so the cost aspect is nearly nill and I still cannot find a good, concise list of what I will need from the old engine and what I will need to buy new. A few other things to add in and keep in mind are the fact that the Impala has 180k on it; when I bought it 6 months ago, I had the intake and oil pan gaskets done; this would be a side project just for fun and because I like to mod/tinker with stuff.

 

So, W-Body'ers, these are my questions to you: 1)Given the fact that I am getting a 'donor' L67 block for nothing - is a top swap a logical choice and 2)When I pull this motor out of the guy's garage what is my pick list going to look like and what will my shopping list be in order to get this puppy running correctly?

 

Some more background on me: I took automotive all through High School and 2 years of college, I work at a police equipment install shop and have access to most basic hand/air tools and enjoy projects where I can lay out all my tools/bolts/parts on a table and take my time to do things right. In other words: I'm fairly certain that if you sat me down in front of a motor with some tools, I could tear it down completely and put it back together without any extra parts and it would still run.

[Andrew]

if you are getting a complete good running engine from flywheel to pulleys, supercharger to oil pan, i would just swap the complete motor. It would actually be faster than top swapping IMO.

 

then you'd need your pcm to be tuned, a couple additions to the wiring harness, and i think thats it.

http://www.wbodystore.com/L36-to-L67-Wiring-Conversion-Kit-p-61.html

[Addicted to eaton]

1 yes

 

Coil bracket

Blower

LIM

Heads

Rocker arms

push rods

Fuel rail

Crank pulley

 

Parts to buy

idler pulleys if the other motor has higher miles

Supercharger gasket

LIMG

2 coolant elbo's

injectors

 

Antifreeze

Oil

Oil filter

belts (unless he has the blower belt

 

(change oil after the job is done

 

You can buy the wiring harness from zzp (very little needed) then have ur computer tuned

 

There is probably some im missing its been some time since i did a top swap.

[Addicted to eaton]

And andrew a top swapped 3800 is Faster then a normal l67 Due to compression ratio

 

the stock 3.8 pulley on a top swapped 3800 is equal to a 3.4 pulley on a l67

 

That reminded me. if you want to run the stock 3.8 pulley Grab a set of headers from ebay (speed daddy are known and trusted and for 200 shipped to your door you can't go wrong (l67's LOVE headers!) Or get a 4.0 pulley from zzp.

[Andrew]

i realize this. However, you need to mod them right away to be safe to run(ie your advise to run a 4.0 pulley or headers). And i wouldnt recommend those headers, they certainly dont fit right out of the box from all the reviews ive read. i'd pony up the bucks for the wbodystore headers.

 

also, the stall speed of the l36 converter is a bit higher than you'd want with a l67. so i would re use your l36 flexplate and get a aftermarket converter. https://www.zzperformance.com/grand_prix/products1.php?id=133&catid=105

[Addicted to eaton]

Why wouldnt you recommend them? I didnt know you had a set be for? I Installed a set on my 1997 GTP Fit Great. i installed a set on my 1999 GTP fit Great. I also installed a set in a friends Nick car. All fit Great. The ones that did not fit were the first design but luckly they found out real quick gave everyone there money back and redesigned them. Ever since then they have been great. The 02 needs relocated or the firewall waked 2 times with a sledge. it cost 5 dollars at the shop i went to when i got it relocated. 205 Bucks for headers that are the quality they were. Its a no Brainer.

[Krieger]

I am hesitant on doing a complete motor swap. First, I have no idea what this car went through and I'm almost positive it had more miles than my current car. Also, I have a complete service history on the Impala and know that it was looked after as a single driver patrol vehicle plus the maintenance I've already done to it. I'd be looking at a near complete rebuild on the L67.

 

Is there a downside to using the stock headers? I realize that I will have them off so it would make sense to upgrade them but I am looking at this from a budget perspective as well so I have to at least weigh that in if it's not 100% needed.

[Krieger]

Also, do I need to grab any of the sensors? Links to any mentioned parts would be extremely helpful. Starting my bookmark folder now...

 

I do plan on documenting on how this goes (if it does go down). Thanks for the lightning fast replies so far. I'll be sure to post up any stumbling blocks I hit along the way.

[Addicted to eaton]

well headers are a kinda on the fence of a must unless you Buy the 4.0 Pulley.

[Addicted to eaton]

• L67 Balancer
  
• L67 idler pulley standoff
  
• Supercharger belt
  
• L67 throttlebody
  
• Gen3 blower w/pulley
  
• Gen3 lower intake
  
• L67 heads w/ valve covers
  
• Fuel rails
  
• Injectors (01+ will also need injector connectors)
  
  • Felpro head gaskets (2)
    
  • Felpro head bolts (set) ( i reuse them but w/e)
    
  • GM aluminum lower intake gasket set
    
  • Gen3 supercharger gasket
    
  • L67 throttlebody gasket
    
  • L67 valve cover gaskets
    
  • Coolant O Rings
    
  • Fuel Injector O Rings
    

[Addicted to eaton]

can buy it all here

 

http://www.zzperformance.com/grand_prix/products1.php?id=1090&catid=103

 

Or just go to your local parts store tell them what u need.

 

http://www.zzperformance.com/grand_prix/products1.php?id=173&catid=108

to put it in simple u need

What u need

Heads from SC motor (Either Series will do, all the blocks are the came so all the heads can be interchanged)

Head Bolts, can be OEM replacements or Studs, up to you(Stock are Torque to Yield(one time use)

Thread Sealer (the head bolts go into the coolant jacket, and if they aren't sealed, they will weap coolant out)

Head Gaskets

Rocker boltsSame reason as the head bolts

Valve Cover Gaskets

Harmonic Balancer From the SC motor

Tensioner for SC belt

Idlers for Sc beltThese require bolts that aren't on the L26/L36

Coil Pack BracketThe tensioner and one of the idlers bolt to the SC Coil bracket (some 97 and 98 cars may not need a different bracket)

Lower Intake Manifold from the SC motor(The bolts are the same, so you can use your old LIM bolts if needed)

Lower intake Manifold Gaskets(the Aluminum ones are the Best)

Fuel Rail(you need the one that matches your fuel system, 97-03 gets the standard rail, while 04+ needs the return-less)

Fuel InjectorsAre not a requirement, but you should run the SC injectors or better flowing units

**Injector connectors may be required on some years

Supercharger

Supercharger Gasket(If you use a Gen III M90 you need O-rings as well)

Supercharger Belt

Throttle Body from SC motor(This isn't required but recommended)

Throttle Body Gasket

Colder Thermostat I Recommend 180*, but that is all personal preference

1 Step Cooler Spark PlugsUsually recommended for the Top Swap

Fluids Oil(a change needs to be done after Swap and before engine is started) Coolant(you will loose a good amount doing the Swap

Oil FilterFor above change

Tunned PCM Stock Gt settings are way too aggressive for a SC application, I suggest a tuner, but if you don't have time, a Canned tune can work

Exhaust Manifold Gaskets (optional)

[Krieger]

Or basically this: http://www.wbodystore.com/Supercharger-Conversion-Accessory-Kit-p-311.html

 

I'm confused on the injector conversion. Mainly because I haven't looked that closely at the L67 setup. What do I need there?

[Krieger]

I think I will get a price list together with some of my parts suppliers. I get them at cost through work so I can shop around the parts stores/dealerships for a better price.

[Addicted to eaton]

on the injectors Im not sure never had to deal with it i guess the clip is different.

[Krieger]

on the injectors Im not sure never had to deal with it i guess the clip is different.

I'll take a look at them and compare with pictures from the adapter kits sold online.

[Krieger]

Also, what kinds of signs of wear/damage am I looking for on the SC?

[Addicted to eaton]

teflon on the Supercharger rotors. wears off alot. Also if you want, You could slap a cupler in it (20 bucks from zzp) there known to go bad and make a lot of noise when they do.

[White93z34]

If you feel your existing engine is healthy I see no problem with top swapping it. everything is total bolt on.

 

Headers are now cheap enough that I could justify doing those at the same time, probably not necessary though if using a stock tune/pulley

 

you will have to get a tune modified for the gear ratio of the transmission in your car now

 

wiring is super easy to overcome. don't bother buying the map extension kit just extend those wires yourself, you will have to get a different MAP plug so the L67 map will plug in since L36 is different, any 3.1/3100/ almost any gm will have that though so its a easy junkyard part.

 

the BBV harness if you choose to use it is cheap from Casper's electronics, and pretty easy to wire in.

[GtpKo]

I just had my M90 open last week. Open it up, take the rotor packs out carefully. Check the bearings in the case by the intake, maybe clean/regrease. I can't remember what kind at the moment, I know its blue.

 

It's ok to leave some carbonization on the rotors IMO, helps seal between rotors. They rely on tight clearances for compression. If you clean the heck out of it you might lose the teflon coating. What I did was clean out any heavy carbon buildup. But definitely clean the intake side of the case.

 

Also, check the rotor gears for wear. After replacing the coupler, bolt it back together and rotate(wiggle) the pulley back and forth to see if there's any play. Of the 2 I have, one I felt a tiny bit of play and the other was solid.

[Krieger]

Well, seems my plan has changed. My motor just developed a rod knock and is getting worse by the day. Had it in for an oil change and they confirmed my suspicion that it is not just lifter noise but indeed the rods. Calling around to my sources at junkyards, I can get an L67 with 100k and a 1yr warranty for $650. I have a garage and the tools to do the swap so instead of rebuilding my current motor with 185k, I'm just going to do a complete swap.

 

Few questions: will the engine fit coming out and going in through the top or do I need to drop the whole cradle? Also, what parts besides a matching PCM will I need to get? All I can think of beyond the oil pan gasket and LIM (as preventative measures) and basic fluids are the harness adapters for the injectors. Anything else I am missing?