Topic: Intake gaskets
in Forum: C3 Engines
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I am in the middle of a clutch job and noticed the bell housing had a little to much oil on it and in it for my liking. The clutch was not wet, but worn on the outside pretty well and enough to cause slippage.
Looking at the oil pan and behind the intake rear seal, they both were wet with oil, so I decided to replace both oil pan and intake with new gaskets, while the drive train was out of the car.
I have a FELPRO 1 piece for the oil pan, and the old 4 part intake set for the top end.
The car did burn some oil at times and a bit smokey when at idle, so I had decided to just redo the intake during the off driving season, then the clutch slipped so here I am.
Anyway, today I pulled the top end off and noticed that the INTAKE gaskets all had RTV applied end to end. I know the front and back rubber seals get that treatment and are a classic leak point on these small blocks, but never have I seen RTV on everything. I have always applied the intake side gaskets dry.
I am thinking that over time and heat cycles that RTV begins to break down and allow seepage to occur thus allowing oil to be pulled into the cylinders. Not a large amount, but enough to burn some oil to cause it to smoke from BOTH side pipes.
When I bought the car in 2009, it had been rebuilt with only 500 miles on the motor so guess it was done this way in the build.
BTW I got a Mcleod performance clutch kit, new flywheel,and associated other parts and some New Foose Nitrous R/T chrome wheels.
Looking at the oil pan and behind the intake rear seal, they both were wet with oil, so I decided to replace both oil pan and intake with new gaskets, while the drive train was out of the car.
I have a FELPRO 1 piece for the oil pan, and the old 4 part intake set for the top end.
The car did burn some oil at times and a bit smokey when at idle, so I had decided to just redo the intake during the off driving season, then the clutch slipped so here I am.
Anyway, today I pulled the top end off and noticed that the INTAKE gaskets all had RTV applied end to end. I know the front and back rubber seals get that treatment and are a classic leak point on these small blocks, but never have I seen RTV on everything. I have always applied the intake side gaskets dry.
I am thinking that over time and heat cycles that RTV begins to break down and allow seepage to occur thus allowing oil to be pulled into the cylinders. Not a large amount, but enough to burn some oil to cause it to smoke from BOTH side pipes.
When I bought the car in 2009, it had been rebuilt with only 500 miles on the motor so guess it was done this way in the build.
BTW I got a Mcleod performance clutch kit, new flywheel,and associated other parts and some New Foose Nitrous R/T chrome wheels.
Gary
79 Coupe, rare 4spd.L-48,Edlebrock intake and Performer Carb,Mcleoad Street performer clutch, Hooker Super Comp chrome headers/side-pipes, Foose wheels,mild cam.Custom leather interior.
http://www.C3VR.com/member_uploads/14601_14700/14664/test-011201272163337r.jpg
79 Coupe, rare 4spd.L-48,Edlebrock intake and Performer Carb,Mcleoad Street performer clutch, Hooker Super Comp chrome headers/side-pipes, Foose wheels,mild cam.Custom leather interior.
http://www.C3VR.com/member_uploads/14601_14700/14664/test-011201272163337r.jpg
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Got to love RTV..not sure why thy would have put it all over but maybe there is something to this..maybe the intake is warped and they were trying to seal it..or they just do that..can't really say why..sounds like you got a good bit apart..seal it up good and be done with it! Mcloed clutch sounds good also!
Rich
Rich

My first parade at Carlisle 2010

HOWELL, NJ - USA
Joined: 5/18/2004
Posts: 6812
Vette(s): 1979, Targa Blue (72 Color), Pace Car rear spoiler, L88 hood, Dark blue factory interior, 525HP 406, HD 700R4, 370 gears,Steeroids, composite rear spring, TT IIs wrapped in T/A Radials.
Typically the rubber front and rear rubber intake gaskets are prone to leaking. I have had tons of small blocks and most of my friends do the same, where the robber gaskets go in the dumper and are replaced by a 1/4" bead of RTV or "Right Stuff" (black sealant in a cheese whiz-like can - much better that RTV IMHO) with an extra blob on the corners where the side gaskets /heads / front and rear block rails meet.
We also "glaze" the water passages on the heads with a light skim of sealant before putting the side gaskets in place.
You'll find most experienced engine builders use a similar process. I know a rare few that elect the original rubber gaskets over sealer these days...
Good luck! 

Paul
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Early 4th gen Camaros were notorious for the rear intake leak and when I installed the Hot Cam kit on mine, it was suggested to dimple the intake and use RTV Copper which worked great.
The idea of a thin coat around the water ports sounds like a good idea/
Early 4th gen Camaros were notorious for the rear intake leak and when I installed the Hot Cam kit on mine, it was suggested to dimple the intake and use RTV Copper which worked great.
The idea of a thin coat around the water ports sounds like a good idea/
Gary
79 Coupe, rare 4spd.L-48,Edlebrock intake and Performer Carb,Mcleoad Street performer clutch, Hooker Super Comp chrome headers/side-pipes, Foose wheels,mild cam.Custom leather interior.
http://www.C3VR.com/member_uploads/14601_14700/14664/test-011201272163337r.jpg
79 Coupe, rare 4spd.L-48,Edlebrock intake and Performer Carb,Mcleoad Street performer clutch, Hooker Super Comp chrome headers/side-pipes, Foose wheels,mild cam.Custom leather interior.
http://www.C3VR.com/member_uploads/14601_14700/14664/test-011201272163337r.jpg

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Sealant on both sides of the intake gaskets is a sign of a Bubba mek-a-neck...
There is no need for any type of sealer on the intake side gaskets at all, except, as Paul mentioned, a smidgen around the water passages. The ends of the intake/engine block should be sealed with RTV(or similar)...not the goofy rubber seals that will spit out as soon as they get oil on them.
I have, on occasion, used a spray-on copper gasket sealer on intake gaskets on our race engines in the past, but that was more to allow us to remove/replace the intakes without tearing the gaskets than sealing them, tho it does help them seal. But sillycone on the gaskets themselves? Never!

There is no need for any type of sealer on the intake side gaskets at all, except, as Paul mentioned, a smidgen around the water passages. The ends of the intake/engine block should be sealed with RTV(or similar)...not the goofy rubber seals that will spit out as soon as they get oil on them.
I have, on occasion, used a spray-on copper gasket sealer on intake gaskets on our race engines in the past, but that was more to allow us to remove/replace the intakes without tearing the gaskets than sealing them, tho it does help them seal. But sillycone on the gaskets themselves? Never!

Joel Adams
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I am a firm believer in if you want something done right, then do it yourself. I do not like guessing what someone else did,or did not do on my cars. I only entertain taking a car to a shop is if there is something special that needs to be done and I don't have the proper tools to do the work.
Keeps Bubba from installing some time bomb fix it quick deal not to mention the cost.
I still have to finish pulling the oil pan (gotta undo that steering linkage) then clean some parts, repaint the Pan then start re-assembly. Seems you spend more time cleaning things than installation, but at least I will know its done right and I am the only one to blame if its not.
Keeps Bubba from installing some time bomb fix it quick deal not to mention the cost.
I still have to finish pulling the oil pan (gotta undo that steering linkage) then clean some parts, repaint the Pan then start re-assembly. Seems you spend more time cleaning things than installation, but at least I will know its done right and I am the only one to blame if its not.
Gary
79 Coupe, rare 4spd.L-48,Edlebrock intake and Performer Carb,Mcleoad Street performer clutch, Hooker Super Comp chrome headers/side-pipes, Foose wheels,mild cam.Custom leather interior.
http://www.C3VR.com/member_uploads/14601_14700/14664/test-011201272163337r.jpg
79 Coupe, rare 4spd.L-48,Edlebrock intake and Performer Carb,Mcleoad Street performer clutch, Hooker Super Comp chrome headers/side-pipes, Foose wheels,mild cam.Custom leather interior.
http://www.C3VR.com/member_uploads/14601_14700/14664/test-011201272163337r.jpg
in Forum: C3 Engines
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