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3.1 MPFI lower intake & timing cover gasket? (RTV?)


Guest TurboSedan

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Guest TurboSedan

should i use any RTV around the coolant passages when installing the lower intake manifold? i know i'm supposed to use it on the both ends but i'm not sure if i should use some around the four corner coolant passages or not?

 

also, should i use any RTV on the timing cover or install it dry?

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When I popped my LIM off a couple weeks ago, the shop that did it last went by the book, used a Fel-pro gasket and the included RTV in the space in between on both sides between the heads....it was a slight challenge to get it off and the rubber mallet helped but I also needed to strategically place my pry bar a few times...I'm still going to use the RTV tomorrow when I put it back on, just because it made me feel a bit safer...thats what the online factory service manual says to do as well, i'm pretty sure.

 

YK

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Guest TurboSedan

crap, i have the lower intake all cleaned and ready to go on but it's only 5* freakin degrees outside....i'm worried the RTV won't set right at that temperature. i wish my garage had a heater :?

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crap, i have the lower intake all cleaned and ready to go on but it's only 5* freakin degrees outside....i'm worried the RTV won't set right at that temperature. i wish my garage had a heater :?
:lol: Fun ain't it! At least you don't have to drive a piece of shit dodge around in this snow. :leaving: (work truck hehe)

 

You should get one of those space heaters if the garage is insulated well.

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Guest TurboSedan
Didn't use any on mine, 70k miles later no leaks!

 

how is that even possible? the lower intake gasket doesn't even cover the area between the heads on both ends. with no RTV it would be metal-to-metal, ie. iron block surface to aluminum lower intake manifold surface. i don't see how that could possibly seal without the use of RTV.

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Didn't use any on mine, 70k miles later no leaks!

 

how is that even possible? the lower intake gasket doesn't even cover the area between the heads on both ends. with no RTV it would be metal-to-metal, ie. iron block surface to aluminum lower intake manifold surface. i don't see how that could possibly seal without the use of RTV.

 

You might get away w/ that if you have gasket inserts there like some lower intakes...but always use the rtv on the intake manifold corners where they meet the block, you'll thank me later when your lower intake manifold isn't pissing oil like a geyser. I've never had a problem removing intakes, etc. from anything w/ rtv, some of you guys must be using super glue instead. :wink:

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OK to clarify, this is talking about the 3.1L Vin V, T/2.8L W. Can we keep ONTO that topic and leave the other engines out of it?

Edit: Clean :)

Felpro gives you the RTV to make a bead between the heads, on the block. This is what GM does (obviously) I never used RTV around the coolant ports, but using it won't necessarily hurt it.

 

However, when I installed the timing cover gasket, I put RTV around the large coolant passages (just a thin layer) and a small dab on both sides where the block ends and the timing cover meets the oil pan.

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Guest TurboSedan

thanks Brian. i was looking forward to getting the entire top half of my engine together today but the weather went to shit. i'm going to have to wait until i'm back in town next week i guess :?

 

well at least i got the heads back from the machine shop and i have them installed. not as much progress as i was hoping to make but oh well. hopefully next week the weather will be better and i can get the rest of the engine buttoned up, install the clutch & slide the 282 on, and then i can drop this sucker back into the Cutty.

 

one question though - when you put RTV around the coolant passages on the timing cover, did you put RTV on both sides of the gasket or?

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one question though - when you put RTV around the coolant passages on the timing cover, did you put RTV on both sides of the gasket or?

 

I put rtv on the block, and the timing cover, so technically yes. Like I said, I put a thin layer just to have a little extra insurance.

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Forget RTV.

 

Get this stuff (AKA GMS)......

GMS.jpg

 

Apply a good sized drop where the head meets the block near the oil gallery...do this on all four corners. Also apply a pile of it to the ends of the oil gallery. The valve cover gaskets will seal better if you put a dap where the head meets the lower intake manifold.....the triangle in the valve cover gasket does a shitty job.

 

Don't forget to get new lower intake bolts, EGR gasket, coolant nipple (or o-ring if the motor is newer), distributor drive ring, and water pump o-ring.

 

Buy all your parts from a GM dealership if you want the intake to stay sealed. Use the torque specs included with the gasket set.

 

If you want to save yourself some time....but not replace the rear valve cover....don't. You can still get the rocker arms loose to pull the gasket with the valve cover on and the lower intake off. This way you don't have to pull the alternator or coil packs off (handy if you are resealing a Venture van). Just becareful you don't roll the valve cover gasket when you set the lower intake down.

 

Another thing....clean everything. A sanding block works best to clean the intake manifolds. Razor blades on the heads and block. A vacuum cleaner works well for the debri.

 

REMEMBER......the EXHAUST is the long pushrod (6.0"). Intake is short (5.75"). If you mix them up, the longer rod will open the intake valve sooner and earlier....slamming it into the face of the piston. Bending the pushrod and valve. You could also destory the pison and block. Do not mix them up.

 

The timing cover should just require some GMS in the lower corners and a new gasket.

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Guest TurboSedan

Don't forget to get new lower intake bolts

 

why new lower intake bolts? i simply cleaned & chased the threads on the old bolts and was planning on reusing them.

 

right now the motor is on the engine stand in my garage. i just bolted the heads on yesterday with Fel-Pro gaskets and new Fel-Pro head bolts. i still need to do everything else. i kept all valvetrain parts in their own labeled bags(1I,1E,2I,2E, etc), and made sure everything went right back where it came from....i did notice the difference in pushrod length and was cautious to not mix them up.

 

i already have the Fel-Pro lower intake gasket and black RTV, so i'm going to use them. this project is very much a low budget ordeal, although i have been taking alot of time to get all gasket surfaces very clean. i've been through quite a few razor blades and several cans of Brakleen already.

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why new lower intake bolts?

 

I guess it applies more to the 3x00 line up (as does my entire post).......but its mainly because of the red shit they got on the end of the bolts.

 

I'd still go get a tube of GMS......its a lot better.

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The updated instructions from GM specify adding some thread lock to the bolts, so I'm sure you'll be ok with the original ones if you clean them up. With the light amount of torque needed they sure as hell aren't going to stretch on you.

 

Interesting theory on not taking off the rear valve cover, that would save a pile of time. I hate that damn ign. module bracket, it's in the way of everything.

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When I did my topend swap, I couldn't get the front of the blcok clean. I cleaned it off for about an hour, but there was some shit just caked on there, so since I knew the gasket wasn't going to seal, I just used RTV on the whole thing instead and no leaks yet. It only has ~1500-2000 miles on it since then, so I can't tell you if it will last or not, but it should, and its been fine so far.

 

Shawn

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Guest TurboSedan
When I did my topend swap, I couldn't get the front of the blcok clean. I cleaned it off for about an hour, but there was some shit just caked on there, so since I knew the gasket wasn't going to seal, I just used RTV on the whole thing instead and no leaks yet. It only has ~1500-2000 miles on it since then, so I can't tell you if it will last or not, but it should, and its been fine so far.

 

Shawn

 

i've done the timing gasket once before a couple years ago and i used RTV on the whole thing. mine didn't leak either, but this time i'm going to just use a minimal amount of RTV around the coolant passages and the bottom corners where it meets the oil pan gasket. Shawn, i bet that was a PITA to get that area clean with the engine still in the car! i have mine on the stand in my garage so i have easy access. i think i got the surfaces clean enough:

 

DSC01434.JPG

 

DSC01432.JPG

 

DSC01433.JPG

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Those surfaces look pretty clean to me, it should seal pretty well. It really wasn't that bad getting to it in the car, because I could get to most of it from the wheelwell, and what I couldn't get there, I could from the top, so it really wasn't bad.

 

Did you leave the stock cam in there? It doesn't look like you replaced the timing chain or anything, so I'm assuming thats still the stock cam right? Also, those pistons don't look very smooth...is that just the reflection of the light, or are they all beat up on top like that, or did you clean them off with a wire brush or something? They look weird...

 

Shawn

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Guest TurboSedan

Did you leave the stock cam in there? It doesn't look like you replaced the timing chain or anything, so I'm assuming thats still the stock cam right? Also, those pistons don't look very smooth...is that just the reflection of the light, or are they all beat up on top like that, or did you clean them off with a wire brush or something? They look weird...

 

Shawn

 

yup, the stock 227,000 mile camshaft, lifters & timing chain are being re-used. i'm not touching the rotating assembly either. this high mileage shortblock is only getting a new Melling 95HV oil pump, new gaskets, seals & o-rings everywhere & new head bolts....and of course a bunch of TGP parts. every lobe on the camshaft looks great, and the timing chain isn't stretched that much so i feel i can get by for now leaving that stuff alone. i don't have very high hopes for this engine; if it blows up so be it. i figure i don't have room to store it nor the need for it so i might as well have fun learning from it and blowing it up. i didn't want to spend much money on this 'T' engine because i'd rather put money into the 'V' engine i have sitting in my garage. fwiw this 'T' engine will probably only see 8psi max via MBC & a custom TGP/5-speed chip from Jay.

 

the pistons are actually pefectly fine. what you see is 227,000 miles worth of gunk that built up and caked onto the top of the piston. i very carefully shaved as much of it away as possible with a razor blade - you can see the marks (the camera flash does make it look kinda wierd). i got as much of the gunk scraped off as possible without digging into or scratching the top of the piston. the pistons are all snug in their bores and i can turn the engine over very easily. it ran awesome when i pulled the motor last November (i quit driving the car late last summer because the clutch was toasted).

 

i had the TGP heads hot tanked, bead blasted, 3-angle valve job, new valve seals, new expansion plugs and the heads were slightly resurfaced. the only reason i spent money on the heads was because i can use them with the 'V' engine when it gets built up next summer.

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