dewhurstaj

I just completed a HEI upgrade on my 1966 427 390 HP Vette.
The distributor was tuned to Lars specs & performed well during the 10 mile test run.
When I arrived home, it was discovered that a significant amount of oil was leaking from the rear of the intake @ the distributor gasket!
The HEI was installed with the gasket that came with the distributor.
I thought it was a special gasket & would serve as a GND for the HEI.
I did not measure the diameter of the base of the HEI & compare it to the original Corvette distributor.
Are the above distributor bases that exact same size?
The stock intake manifold has room for a much larger outside diameter gasket when compare to the HEI gasket that came with the distributor.
Has anyone else experienced oil leaking @ the distributor base after a HEI upgrade when using the gasket that came with the distributor?
How is the HEI GRD to the Block?
Can anyone recommend the correct distributor gasket for the HEI?
Thanks in advance for helping!
Andy

redred65cpe

It isn't much of a gasket to begin with. Are the surfaces clean and flat with no gouges or such? I'm also assuming the obvious - the dist hold down clamp is properly installed and was tightened. Also, it would be nice if you updated the thread you started about not getting spark in case others have similar problems. Looks like you solved that problem.

larry

kbuhagiar

dewhurstaj,

Did you resolve your problem with the HEI distributor oil leak?
Did you use the thick "gasket" (looks more like a spacer to me) that came with the distributor, or did you use a standard gasket?

Thanks!

dewhurstaj

I used the thick non-flexible gasket that came w/ the HEI! I assumed that it was required to help gnd the HEI to the block. You have to tighten the dist clamp much tighter then you would a stock gasket.
Mind stopped leaking after it was tighten twice.

Good Luck & let me know how you like the HEI!

Andy

drewdog66vette

my intake has two places to put the hold down clip and i fabricated an extra one, cause two will not fit, they will overlap. i just ground an extra one down a bit. then i was able to hit it from both sides. it stopped my problem. that and a thick gasket. no, it is not a stock intake, but you may have two bolt holes as well. try that.

MikeM

I'm having more than a little trouble trying to understand why an HEI distributor would need a thick gasket or two hold down clamps or even overtightening a single clamp to keep it from leaking at the intake manifold. That is, just because it's an HEI distributor.

redred65cpe

My HEI uses the same (type) gasket that went on my non-HEI distributor. No leaks even with the hold down bolt lose enough to play with timing.

larry

kbuhagiar

MikeM,

I agree completely with you; that is the reason for my original inquiry. My distributor came with no instructions. I found two different instruction sheets on the web; one says to install the distributor with NO GASKET; the other makes no reference to the use of a gasket.

Is the electrical ground path at the base of the unit even an issue?

The "gasket" that came with the distributor doesn't appear to have any sealing qualities; it is quite thick and more like a spacer or shim, or a phenolic disk.

My inclination at this point is to just use a conventional gasket, unless I see or hear evidence to the contrary...

redcliff

I'm also concerned that there is proper distributor to oil pump driveshaft clearance.

MikeM

Well, that's where I was going with this. Somebody may have shimmed the distributor gear clearance too tight and the oil pump shaft is bottoming out on the distributor gear.

Drop the distributor in the engine WITHOUT a gasket and see if there is a gap at the manifold as measured with a feeler gauge. If there is no gap (none) you are probably okay as the thickness of the gasket when present will give some clearance. If there is a gap there, remove shims from the shaft equal to the gap plus .010, put the gasket on and drop the distributor back in the engine. You should be good to go.

dewhurstaj

I recently installed a stock distributor gasket because the thick one that came w/ the HEI continued to leak! The stock gasket works perfect! No excessive tightening & no leaks! Felpro purchased from auto Zone < a buck!

Andy

ghostrider20

If the intake has been decked or milled, and or the dist shimmed, this could add to the dist not seating all the way on the intake. You need to shim the dist at the intake/base with either extra gaskets or actual shim. I use 2 gaskets.

Set the dist in there with no gaskets, and take a feeler gauge to determine the height.

Mark