Intake manifold...
Thread Starter
Drifting
Joined: Jun 2001
Posts: 1,625
Likes: 1
From: Zagreb, Croatia
Intake manifold...
I've got few questions about intake manifold and gaskets.
1. How much should screws on intake manifold be tightened?
2. In what order should they be tightened?
3. Should I put some sort of seal on gaskets or just bare gaskets?
I took the whole intake down again, so I would like to do it
right this time.
If anybody have any tips feel free to share them with me.
Thank You!
[Modified by Sliding, 4:13 PM 6/1/2002]
1. How much should screws on intake manifold be tightened?
2. In what order should they be tightened?
3. Should I put some sort of seal on gaskets or just bare gaskets?
I took the whole intake down again, so I would like to do it
right this time.
If anybody have any tips feel free to share them with me.
Thank You!
[Modified by Sliding, 4:13 PM 6/1/2002]
Le Mans Master
Joined: Jun 1999
Posts: 6,272
Likes: 2
From: Chino Valley AZ
Cruise-In I Veteran
Cruise-In II Veteran
Currently Corvette-less
Re: Intake manifold... (Sliding)
Generally speaking, the intake manifold bolts should be progressively tightened from the middle to the ends, crisscrossing the manifold from bolt-to-bolt. If you have a torque wrench, tighten the bolts to 25 ft. lbs ~ or 300 in. lbs.
You will achieve the best results if you take a vibrating palm sander with 50 grit sandpaper, and rough the gasket surfaces on the heads. The key here is to not remove metal, just rough and shine the surface.
As far as sealant is concerned, I prefer an oxygen sensor safe RTV. Make sure that you put an extra bubble in each corner of the end rails, as that is where it is most prone to leak.
Lastly, it never hurts to re-torque the bolts after the engine has heated up and all parts are normalized in temperature.
~ Purp
[Modified by PurpleC4, 8:35 AM 6/1/2002]
You will achieve the best results if you take a vibrating palm sander with 50 grit sandpaper, and rough the gasket surfaces on the heads. The key here is to not remove metal, just rough and shine the surface.
As far as sealant is concerned, I prefer an oxygen sensor safe RTV. Make sure that you put an extra bubble in each corner of the end rails, as that is where it is most prone to leak.
Lastly, it never hurts to re-torque the bolts after the engine has heated up and all parts are normalized in temperature.
~ Purp
[Modified by PurpleC4, 8:35 AM 6/1/2002]
Team Owner
Joined: Sep 2001
Posts: 62,140
Likes: 1,728
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
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Re: Intake manifold... (Sliding)
there is a tightening order sequence in any vette engine manual, even Haynes has it
do the middle ones, then the front, then the back but in a crossing pattern (one on left-one on right-back to the left side)
do the middle ones, then the front, then the back but in a crossing pattern (one on left-one on right-back to the left side)
Safety Car
Joined: Oct 2001
Posts: 4,763
Likes: 1
From: Connectivette
Re: Intake manifold... (vader86)
My corvette shop swears by this stuff that Permatex makes called "Right Stuff". The packaging resembles cheese wiz. I just finished pulling, cleaning and re-attching my intake, in fact i'm in the process of putting it back together right now.
Make sure you clean out the bolts and bolt holes before reattaching intake manifold and put thread sealer on them. I used a liquid tephlon. Again recommended by my corvette shop.
Make sure you clean out the bolts and bolt holes before reattaching intake manifold and put thread sealer on them. I used a liquid tephlon. Again recommended by my corvette shop.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: Intake manifold... (Sliding)
My '88 GM Shop Manual says 34 ft-lb; go in three stages. I started with 20, then 25-30 and finally 34.
Get a thread cleaning set from Sears and clean the bolt holes & the bolt threads. Apply gasket sealer to the clean bolt threads.
I put a little Black RTV around each water hole on the head, laid the gasket in place and then put a little around each water hole on the gasket top side. Then I put a 3/16" bead of Black RTV along each end rail, tailing a little up onto the gaskets.
When you lower the base be sure the bolt holes are aligned before setting it onto the RTV. Do NOT slide the base fore/aft after it's resting on the gaskets & RTV.
Get a very good Torx bit from Sears or other quality tool supplier as they can be stripped when going to even 34psi.
Get a thread cleaning set from Sears and clean the bolt holes & the bolt threads. Apply gasket sealer to the clean bolt threads.
I put a little Black RTV around each water hole on the head, laid the gasket in place and then put a little around each water hole on the gasket top side. Then I put a 3/16" bead of Black RTV along each end rail, tailing a little up onto the gaskets.
When you lower the base be sure the bolt holes are aligned before setting it onto the RTV. Do NOT slide the base fore/aft after it's resting on the gaskets & RTV.
Get a very good Torx bit from Sears or other quality tool supplier as they can be stripped when going to even 34psi.
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Safety Car
Joined: Oct 2001
Posts: 4,763
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From: Connectivette
Re: Intake manifold... (65Z01)
Jim,
You seem to be the resident intake consultant. You definetly help me tear down and re-assemble my manifold.
It's back together....no leaks......no codes......no extra parts left over :lol:
Thanks,
Chuck
You seem to be the resident intake consultant. You definetly help me tear down and re-assemble my manifold.
It's back together....no leaks......no codes......no extra parts left over :lol:
Thanks,
Chuck
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: Intake manifold... (chucks88)
Chck, though not an expert by any stretch, you are quite welcome for any help I could provide. No parts left over is always a good thing.
I recently went through the "learning curve" in this area and my L98 survived with help from good friends on the Forum and others.
I recently went through the "learning curve" in this area and my L98 survived with help from good friends on the Forum and others.
