snowri

Hi Everyone,

I have a 75 Olds Delta 88 with a '69 455, C heads, Performer intake, 4L80e, 3.42 posi, TBI & CC distributor with about 20k miles since the engine was rebuilt. I replaced a bad lifter last year and since then I have been consuming a quart of oil every 500 miles or so.

Dry compression test on all cylinders range from 175 to 182 but seem to have some discoloration variation on the spark plugs... especially #3 & #5 which has a lot of build-up. No issues with coolant especially in this hot Texas heat and have no visible external oil leaks. The baffles are still intact on the valve covers and PVC looks shiny...

I think I am sucking in oil through the turkey tray and probably exhaust gases since PVC is shiny. I purchased Mr. Gasket 404 and plan to replace this weekend. My approach was to use the Mr Gasket 404 using permatex high tack spray on head side with ultra gray around the water ports, reuse the turnkey tray by cutting out the water/intake ports (using only as an oil shield) and silicone bead along the front and back edge.

I know there's been a number of posts regarding aluminum intake leaks but I haven't found one where oil consumption was the issue vs coolant leaks... Before I spend all day on this, would like to make sure I'm heading in the right direction.

Thanks for your advice and help,
Scott

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foo

Edelbrock recommends you not to use steel intake gasket due to it not being able to seal correctly

joe_padavano

I've never had a problem sealing an E-brock intake with the stock metal gasket. I don't see how an aluminum aftermarket intake would seal any differently that an aluminum factory intake (and all of those used the metal gasket). This is more a case of E-brock trying to sell a set of their gaskets in addition to an intake.

foo

I was just going off the sheet they send with the intake for install

joe_padavano

And every header manufacturer says their headers don't fit Supremes....

foo

Im taking my 2 cents back

matt69olds

Joe blasted me a few years ago for my suggestion of using the Mr Gasket 404 with an aluminum manifold. My opinion? In a perfect world, I agree with Joe. The factory used the steel shim gasket with their factory aluminum manifold with zero issues. However, 30 years later, things probably aren't as prefect. How many engines with aftermarket manifolds are in factory condition? If the heads have been killed, the block decked, etc thing probably don't fit exactly the way they would in a perfect world. The fiber gasket is much more forgiving of slight machining tolerance

joe_padavano

Well, all I can tell you is that none of the motors I've ever built were pristine originals. All had some amount of machine work done. All of the intakes I've ever installed (especially the E-brocks) have been beat-to-hell used parts that have been bead blasted, welded and repaired, etc. None have ever had the mating faces remachined.

The raised bead around each port on the metal gasket is taller than the thickness of the aftermarket gaskets and thus able to accommodate MORE tolerance. Of course, most of the problem people seem to have with these is because they don't take the time to actually read the CSM and follow the installation procedure. And also of course, you can't reuse the metal gasket once you crush the sealing beads.

I'll also put in a plug for Permatex Ultra Black RTV. I've used this stuff the last few times I've installed intakes. Wow! This is the best RTV I've ever used.

snowri

Thanks for all the comments. I'll consider both the metal gasket only OR 404 (w/trimmed old metal gasket) once I've taken everything apart and dry fit each. Perhaps there are head-block-intake machining tolerance issues or me not reassembling properly. In any case, this weekend is a no-go for me.. I'll report back next weekend on how it went. Thanks again. Scott

oldcutlass

If you block off the exhaust crossover, then there is no need for you to use the metal part of the turkey tray.

RROLDSX

I used the Edelbrock gaskets and still had oil being sucked into the intake ports. Looks like I’ll need to have the intake manifold machined. I think the surface angle on my 2151 is bad right out of the box?????

RetroRanger

Make sure to follow the torque sequence and spec as called out in the CSM, I have read the olds sequence differs from other popular makes.

RROLDSX

I did follow the correct sequence and torque specs. The face angle is not correct for my engine. The heads may have been planed slightly. I did not think it was enough to change the angle to the intake but I guess I was wrong.

joe_padavano

Unlike a Chevy engine, the intake mating surface on an Olds head is exactly 90 degrees to the deck surface. Milling the heads doesn't change the intake angle. If the heads are milled a LOT, the intake mating surfaces can become too close together for a stock intake to seal properly, which is why it is occasionally necessary to mill an Olds intake (but not normally).

RROLDSX

That’s what I thought, so I guess we have to be cautious of our Performer intake fitments.
I wonder if anyone else has come across this issue.

olds 307 and 403

I heard more issues of oil being sucked in with the composite intake gaskets. Yes, many of the Edelbrock intakes are not straight out of box. Good luck getting those thick composite gaskets in there if the heads have been milled at all or even on a stock 350 with factory shim gaskets, no way the Ultraseals would go on with the Performer intake. I use aviation sealant around the fuel ports and use Ultra Black or Copper around the water ports on both sides of the steel gaskets. As Joe said the Ultra Black is very good, only use it or the Copper for higher temp like the exhaust. I have reused the turkey tray without issue but it should be a one use item.