Thread: Intake gaksets blowing out....

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i too thought they are talking about 3M 1300 vinyl adhesive. AKA 'monkey snot' It is a GOOD gasket adhesive, but I have never heard of it being used for gasket replacement as is silicone.

Blows the seals out or sucks them in???

Do you run a vacume/pressure guage hooked into your valley???

do you have mufflers on the car??? Crankcase evac won't work with mufflers, you'll just pressurize the crankcase instead

do you have your intake hooked up to vacume your crankcase??? My tunnel ram engine would pull a strong vacume at idle and the headers evac system would then take over and pull 18-20 inches in the traps at 9500rpm

this wasn't just an intake manifold swap---it was a vechicle swap---different everything
anyone running a crankcase evac should have a vacume/pressure guage plumbed into the valley--tells a lot of what is going on


on a more serious note-----if you are blowing the gaskets OUT, you have a serious problem in that all that pressure is acting as a head of pressure that your oil system must overcome----for example----30 lbs of crankcase pressure, 40 pounds of oil pressure equals 10 lbs of lubrication!!!!!!

We pull over 20 inches of crankcase vacume at 10400rpm----we could run without a oil pump!!!!!

for those of you who want a better product than rtv---try right stuff by permatex, available at Napa---a little more expensive , but lives up to its name

No exhaust system on the car....open headers only. But, I didn't know that the evac hoses to the headers would not work with mufflers. In fact, I have a similar engine, sbc421 c.i., 13.5:1, solid roller w/ .765 lift in another vehicle that I have mufflers on, and am using the same evac system. Have had no problems.... similar, but stronger motor. Should I be knocking on wood as I type this?

Originally Posted by lodilobo

No exhaust system on the car....open headers only. But, I didn't know that the evac hoses to the headers would not work with mufflers. In fact, I have a similar engine, sbc421 c.i., 13.5:1, solid roller w/ .765 lift in another vehicle that I have mufflers on, and am using the same evac system. Have had no problems.... similar, but stronger motor. Should I be knocking on wood as I type this?

well i have tried using a evac system on a 462.468 .548. 572. 632. with a 3.inch 3 1/2 and a 4 inch with a X pipe EX it just did not work on my 50 chevy or my GTO and it was not for lack of trying

so have you checked crankcase vacume/pressure yet???

Originally Posted by jerry clayton

so have you checked crankcase vacume/pressure yet???

WHO ?

lodilobo----

I have not put any type of gauge on the crank case pressure, but I have blown air through the breathers and lines to determine that they are functioning. While excessive crank case pressure may be the source of the problem, I did have a severe crank case pressure problem with a sbc a couple years ago. However, the difference was, that it would constantly blow out oil pan and timing cover gaskets.....not intake gaskets. I am in the process of removing the intake, at the moment. I suppopse I could put the original intake back on the motor, and check the results. If the problem is corrected, that tells me 2 things....the new intake has problems...and never buy an intake at a swap meet.

Originally Posted by lodilobo

I have not put any type of gauge on the crank case pressure, but I have blown air through the breathers and lines to determine that they are functioning. While excessive crank case pressure may be the source of the problem, I did have a severe crank case pressure problem with a sbc a couple years ago. However, the difference was, that it would constantly blow out oil pan and timing cover gaskets.....not intake gaskets. I am in the process of removing the intake, at the moment. I suppopse I could put the original intake back on the motor, and check the results. If the problem is corrected, that tells me 2 things....the new intake has problems...and never buy an intake at a swap meet.

if you blow thru the hose at the valve covers that not going to tell you that the check valves are bad you need to know at ex pressure can not get in the engine this needs to be check on the other end

Even if you find the intake don't fit, that doesn't solve the crankcase pressure issue

Jerry....I'm not sure there is a crankcase pressure issue. This vehicle....as it sits....with the exception of the intake, and switched from trick flow rockers to harland sharp, ran 9.80's and never had that problem before.

its got that problem now if its blowing out the seals

I have already done the compression test......close to 180 in every cylinder. I will know shortly if the problem is the new intake, or something else. I'm betting on the intake.