Question : 1994 3.1 Oldsmobile LIM question

[Jesuscookies]

I have a late 93 early 94 3.1 engine in my oldmobile supreme. I'm in the middle of replacing the LIM gasket. I ordered the metal gasket from Dorman but the ports appear to be much bigger than the original plastic version. The metal gasket has the correct mounting tabs but again, the port sizes on the gasket look to be way too big.

In doing some research it appears that the only version gasket that is available for my car is the plastic version. is this true?

Does Fel-Pro or anyone else make a metal perma-dry type gasket with the smaller port size that will fit my engine, or am I stuck with the plastic piece of crap?

[pocket-rocket]

Since the roller style rockers started in 95 I think it was, I believe you are stuck with the crap gaskets. Mainly because the gaskets for the roller rocker heads were the metal ones, not the ball pivots. If you wanted to swap to a better set of heads later, you could go with the later style heads and get the roller rockers and get the metal LIM gaskets then.

[Jesuscookies]

I should have signed up on this forum about a week ago, and saved myself the headache..lol. Anyway that is what I figured. The car only has 26k original miles and is pristine aside from the leaking plastic valve covers and the LIM issue. I am swapping out the valve covers to the aluminum version, and will just use the plastic gasket for right now.

Thanks for your speedy response....

[pocket-rocket]

No problem, and welcome to the site

I just happened to be on and see your post, not so much that I was speedy about it. The aluminum valve covers would be a good move. In my opinion, plastic should have very limited uses on an engine since they get so hot, and valve covers aren't one of them.

26k miles, holay-crap, lol. Sounds like you got yourself a really nice car

[Jesuscookies]

Yep, 26K estate sale find

I guess with the plastic gaskets the revised torque specs are going to be important too. Anyone know what those are?

No problem, and welcome to the site

I just happened to be on and see your post, not so much that I was speedy about it. The aluminum valve covers would be a good move. In my opinion, plastic should have very limited uses on an engine since they get so hot, and valve covers aren't one of them.

26k miles, holay-crap, lol. Sounds like you got yourself a really nice car

[Penglii]

Which Dorman LIM gasket set did you purchase?
#615-206 says it fits the Ball & Stud Rocker heads...

[Jesuscookies]

Which Dorman LIM gasket set did you purchase?
#615-206 says it fits the Ball & Stud Rocker heads...

This is the one I purchased. All the little mounting tabs match up fine, but the port sizes on the gasket are much larger than the original gasket. They are roughly 1/4 of an inch larger than the actual port. Won't this cause a problem with sealing?

[Penglii]

This is the one I purchased. All the little mounting tabs match up fine, but the port sizes on the gasket are much larger than the original gasket. They are roughly 1/4 of an inch larger than the actual port. Won't this cause a problem with sealing?

Interesting, my understanding is that the intake ports are the same size on the 94-99 3100's regardless of Rocker type... so I don't see how they can be selling a part that claims to fit the Ball & Stud rocker motors if the ports are the wrong size.

Granted, I have been told that the Dorman kit includes the wrong Upper Intake gasket (no big deal).... but this is the first I've heard that they might not even include the correct Lower gasket. If true, this is not good.

I am planning a LIM gasket change on my '94 3100 this weekend and have the #615-206 kit... so I am very interested in finding out what's going on here.

[Jesuscookies]

When you get the LIM off, compare your original gasket with the dorman one. you will see the size difference that I'm taking about.

Interesting, my understanding is that the intake ports are the same size on the 94-99 3100's regardless of Rocker type... so I don't see how they can be selling a part that claims to fit the Ball & Stud rocker motors if the ports are the wrong size.

Granted, I have been told that the Dorman kit includes the wrong Upper Intake gasket (no big deal).... but this is the first I've heard that they might not even include the correct Lower gasket. If true, this is not good.

I am planning a LIM gasket change on my '94 3100 this weekend and have the #615-206 kit... so I am very interested in finding out what's going on here.

[Penglii]

Well... I did some research and according to this PDF (http://www.fme-cat.com/Docs/1430.pdf) as long as the mounting tab is CENTERED above the middle intake port, then it is the correct gasket for the job. It also includes measurements of the port size.

I'll check my own Dorman gasket when I get home... but unless Dorman really messed up their design it should work A-OK.

I also learned that as long as the LIM gasket is the metal variety it will work for either type of Rocker, so if worse comes to worse the Felpro MS98004T will work for us.

[Jesuscookies]

Yeah, Im not going to risk the dorman gasket. The ports are gynormus. I will be interested to see what you find out when you get home and measure yours. Please post up the results. I found a local shop with the 98004t. I think I am just going to pick that set up on the way home today. I now offically own 3 sets of gaskets for this dumb ass car!!!!!

Well... I did some research and according to this PDF (http://www.fme-cat.com/Docs/1430.pdf) as long as the mounting tab is CENTERED above the middle intake port, then it is the correct gasket for the job. It also includes measurements of the port size.

I'll check my own Dorman gasket when I get home... but unless Dorman really messed up their design it should work A-OK.

I also learned that as long as the LIM gasket is the metal variety it will work for either type of Rocker, so if worse comes to worse the Felpro MS98004T will work for us.

[Penglii]

Yeah, Im not going to risk the dorman gasket. The ports are gynormus. I will be interested to see what you find out when you get home and measure yours. Please post up the results. I found a local shop with the 98004t. I think I am just going to pick that set up on the way home today. I now offically own 3 sets of gaskets for this dumb ass car!!!!!

I will definitely post my measurement results.
Likewise I would like you to compare the 98004T gasket you pick up with the Dorman gasket you have and post the results.
Thanks.

[bszopi]

Set the gasket on the head and take a picture, then post it on here.

[Penglii]

OK... I think the PDF that I linked to has innacurate measurement info, but it's still useful.
The Dorman gaskets that I posess have the locating pin in the center of the middle port... just like the Small Port gaskets are supposed to.

The PDF says that the Small Ports are 0.75 inches tall and the Large Ports would be .85 inches tall
I think that is wrong because mine measured out to exactly 1.75 inches tall.... but that DOES jive with the .75 measurement.

I cannot find anything that indicates the Dorman gaskets are wrong.

I look forward to your comparison of the Dorman and FelPro gaskets... I suspect that they are the same.
And of course a picture of the gasket laid on top of the head would be great.

[Jesuscookies]

Okay, I measured each gasket with a caliper, and as I suspected, the Dorman 615-206 is bigger than any of the others. The Dorman measures in at 1.83 inches. The Fel-Pro 89004T Measures in at 1.72 inches, while the stock replacement Fel-Pro 95536 measures 1.61. Pictures are attached. It almost looks like they set all the tabs correctly for an "M" type engine, but used the measurements for a "J" type engine when setting the port size.