Dejavet

I purchased the new one piece gasket for my original 1965, 327, 350 horse engine. With the engine out it was easy to put the gasket on and see that the front end did not fit right. With the pan on the seal was not tight. I called Summit Racing and found that there is another size gasket for this engine, but it was intended for "aftermarket" oil pans which have a bigger gap at the front. This is what the Summit Racing Technical staff told me. I do not have an aftermarket pan, but it is a reproduction original, so I ordered the larger gasket. When I put that one on it was so think at the front that the pan would not reach down to the gasket on the sides. This was clearly not the correct gasket, so I exchanged it with Summit for the thinner one. I put the thiner one on, but put a thick coating of RTV on both sides of the front. I was a bit concerned when I did not get much RTV out from around the seal when torqued. The engine is now back in and I have a serious oil leak from the front of the pan.

I know I can solve this with the older 4 piece gasket, but why will this new gasket not work for me? I have seen some other threads on this forum that are similar, but their leaks were at the rear of the pan and mine is the front. Does anyone know what is going on here?

Dejavet

JohnZ

Here's the story on the oil pan front seal. Production pans through 1974 used a "thin" (0.22") front seal. Chevy increased the front seal radius on the pan in 1975 for the "thick" (0.41") front seal, and all Service pans manufactured from 1975-on (regardless of their application) also got the increased seal radius, and those Service pans came with a "thick" front seal.

To determine which one you need, flip the pan upside-down on a flat surface (with no gasket) and measure from the surface to 12 o'clock on the seal radius; if it measures 2-1/4", it takes the early "thin" seal - if it measures 2-3/8", it takes the later "thick" seal. Fel-Pro makes the one-piece gasket for each condition. See photo below.

Aftermarket Taiwan timing covers can also cause a front seal leak, as the seal channel on those chrome covers is usually spot-welded to the cover (instead of roller-welded like the originals), and they leak between the spot welds.

Westlotorn

Great explanation John.

aafadca

I had a leak and when I took the pan off and measured it, it was a later model one. I got the correct gasket and now have no more leaks.

DZAUTO

John Z above is 100% on the money!
It is MANDATORY that you KNOW which pan you have (NOT which pan you THINK you have). If you're not sure, make the measurement, it's toooooooooooooo easy to do.
I've never used an import, spot welded, timing cover because there are 87 bazillion stock covers just lying around. The instructions that come with the one piece pan gaskets say not to use a sealant/RTV------------------------well, I do anyway (front/back only) with ZERO problems---------------especially in the corners.
A perfect example of what John's talking about regarding service replacement pans is the 57-62 style replacement pans with the trap door (LONG discontinued now). A person would think a replacement pan for the 57-62 cars would use the thin front seal. WRONG! As John mentioned, if the replacement pans were made AFTER 1974 (or thereabouts), then the front radius was larger and required the thick front seal (been down this road before-------------the hard way).

Tom Parsons

Dejavet

Thanks for the response John. I have to take the oil pan off anyway, so I will do the measurement. I purchased this oil pan from Long Island Corvette back in 1995 as a correct replacement for my original oil pan. The receipt describes it as correct for the 350 horse 1965 327. It has been my experience that Long Island Corvette has the most correct parts, so I will be surprised if this is not the correct oil pan.

Thanks for your help.

Dejavet

JohnZ

There were no correct reproduction SB Corvette oil pans available in 1995, so LICS was most likely selling the GM Service replacement pans at the time; unless they'd been sitting in a box on the shelf for over 20 years, they were the later design with the large front seal radius.

VetteRed1965

Not to hijack...Can the gasket be replaced with out removing the engine. It looked good until startup. Amazing what .019 can do !

JohnZ

Yes, it can - fortunately, the Corvette is probably the easiest Chevy to drop the oil pan in. Unbolt the steering idler arm from the frame, pull the steering linkage down out of the way, and drop the pan. It helps to set the engine so the timing index line on the balancer ring is at 5 o'clock (as viewed from the front) - that gets the front crankshaft counterweight up out of the way and provides more clearance at the front of the pan.

corvette95

What is the correct size gasket for 95 LT1 - thick or thin? Thanks!

Hitch

Right church WRONG pew... You should try the forum your car has more of a following in and great job on digging up a thread from last year...

corvette95

What does that mean, this thread isn't that old, thought the OP got it resolved and could provide the info. That's what the search function is for, if you know the answer, would it have been that much more trouble for you to post the right size gasket instead of what you did geez !

SpartyGW

Corvette95:

I think you are looking for felpro 1886:

http://www.summitracing.com/parts/fe...et?prefilter=1

http://www.oreillyauto.com/site/c/de...2296&ppt=C0026

FastEddy

Yea, I've never understood that attitude either... you will get it every once and while. Some people seem to think threads have an expiration date, whereas I would rather jumpstart an old one instead of starting a new one on the same exact subject... fewer threads are easier track, store, research...etc....

MikeM

Lotsa' self appointed hall monitors here. Reminds me of junior high school.

Ironcross

On parts that are universal to Chevrolet, I would suggest to buy the part from a local parts store...both by experience and price...they normally sell more gaskets in a day than the Corvette specialists do in a month...and the OP`s situation could have been handled in a few minutes


even a old thread like this is useful

LB66383

I very recently got a new Felpro one-piece oil pan gasket (thin front seal, if I remember correctly, although it doesn't matter). My point with this is that it came not only with all new bolts and lockwashers, it also had four plastic pieces in it that screw into the block to hold the gasket in place while you get the pan in position and start the other bolts. Having installed these gaskets while lying in my back, I think it's those plastic pieces are a great addition. (Sorry if this is old news to everyone else, it was a pleasant surprise to me.

cordova67

Good information. Been having same problem with oil pan leaking at the timing cover. Tried red RTV, the 34509 Fel-Pro one piece gasket and nothing worked.

saw this thread and just checked the dimensions my pan as noted in the view above and mine is 2.384". Went to Auto-Zone and purchased the larger 34510 Fel-Pro gasket. As soon as I get everything all cleaned up, I'll give it a try and post the results.

Hitch

So that would make you the play ground bully.. right? Just wanting to get it straight...

corvette95

I have tried three of the same fel pro thick gaskets with and without rtv, still have a good drip from the middle of the passenger side, even sent it out for a shop to do it the third time, let them chose their own gasket, still leaks. Thinking of getting some good (Mercedes OE - its great stuff) and just using that and no gasket.....thoughts?