Hi all,
I need to replace my oil pan with the engine in the car. I bought a new oil pan and a Felpro 1 piece gasket (both locally, from a very reliable Parts Authority) after reading how happy everyone is who used it. I made sure to measure the height of the timing chain side to make sure it matches the Felpro gasket. As indicated by the posts I read here, the timing chain lip to the top of the pan is 2-3/8 which means I need the 'thick' Felpro gasket. When I test fit the gasket to the pan, the timing chain side fit perfect, but the rear main side wasn't even close! AAARRRRGGGG! I never read about anyone having THIS problem., In the pics that follow, I show measurements for the rear oil pan lip and the gasket. Please don't take the absolute number you see to heart; I'm not measuring for accuracy. Just look at the relative difference in size. The gasket is smaller than the rear lip on the oil pan. So small, it sits on top of the lip. Over on the timing chain side, the gasket is a perfect fit over the lip. I double checked the application of the oil pan and gasket and both are for a 1979 350 corvette (my car) per the manufacturer web sites.

So the first question you probably have is whats on the the car now? How big is the rear lip? I dunno. I'm trying to gather all the parts I need to make this a few hour job before I take the oil pan off. Maybe I have to take the oil pan off first, but if Felpo and the oil pan manufacturer both say I have the correct parts, which one is wrong? Are there different size oil pan lips????

Thank for reading.....



Rear lip thickness. Don't mind the actual number; I'm not measuring for accuracy.

Rear gasket thickness. Much smaller than the lip. So much smaller, it sits on top of the lip.

Inside measurement of the rear gasket. This is supposed to fit over the 0.55" lip.

Timing chain side lip

Timing chain side gasket thickness. Fits over the lip perfectly.

Oil pan

Felpro Gasket set

 

Is the rear lip curved? If so....install it and move on......if not, if it is flat.....get a different pan.....quite a few repops now have a flat lip in the rear and that is about useless....
The gasket will squash and spread as you torque it down.....

Jebby

 

Jebbysan,
Thanks for the confirmation. Yeah, its square and like you said, the gasket will most definitely squish and absolutely leak. Fortunately, I can return the pan and hopefully find one with rolled edges. Any suggestions on where to find the correct one?

Thanks again...

 

I recently bought a Dorman pan and it was as good as it gets......installed on a 1982 block in 20 minutes after it was determined a stock Vette pan was not going to work.....

Jebby

 

Thanks!

 

So, I returned the oil pan with the square lips and got one from National Parts Depot. I called them first to verify the lips were 'rolled' and not square. I'm happy to say the gasket fits perfectly. I haven't installed the pan yet, but hopefully, I'm starting out with the right parts.

 

Hi All,
Just wanted to update and close out this thread with good news. I installed the new oil pan this weekend and it went well. I only had to remove the idler arm (just unbolt it from the chassis), oil filter and the inspection cover (I have side pipes so I didn't have to get involved with exhaust). The felpro one piece gasket kit was great. Those little blue dowels that hold the gasket in place worked out great, especially doing this job lying on your back. I made sure to remove all remnants of the old gasket, cleaned the block, new pan and timing chain cover with acetone and washed my hands before installing the gasket. Per the directions that came with the gasket, I put some "Right Stuff" in the corners of the rear main and timing chain cover and no where else. Drove it around a bit and so far, no leaks.
In reading about changing the oil pan gasket on this forum, I learned there are two variations of the felpro gasket; think and thin. And within those two variations, you can buy either the kit that includes new bolts and the blue dowels or just the gasket by itself. I read threads where people talked about the dowels and replies that they didn't get dowels or bolts. If you want the new, longer bolts, lock washers and dowels, make sure you buy the kit, not just the gasket. I needed the thick gasket for my application. That kit is felpro OS-34510T. The thin kit is OS-34509T. If you don't get those part numbers, you'll only get the gasket. Look around of the forum to find out how to determine if you need a thick or thin gasket.
Good luck with your projects.