Exhaust Manifold Gaskets

[kishy]

As a quick aside from the exhaust work in my Lincoln thread:

When I removed my existing manifolds, there were no gaskets present, which I understand to be normal for the factory original manifolds.

If I reinstall the original manifolds, can I just bolt them right back on with no gaskets and making no changes to the mating surfaces?

I have gaskets on hand if needed, and expect I will need to use them for the 90 TC manifolds if I go that route, but I'm unsure if I need to use any when reusing the original ones.

[EaOutlaw1969]

Take a straight edge to the manifold and heads after cleaning the mating surfaces if neither are warped your best to run it without gaskets.

[VicCrownVic]

I had no issues putting my stock manifolds back on without any gasket since they came off the same engine without gaskets.
Checking things like EaO said can put your mind at ease.

[sly]

As long as surface contamination has not been allowed to occur, ie: rust, you shouldn't have any issues if everything remains straight. Of course, if there ends up being a leak, you'll get to add gaskets later... so you might just do it anyhow so you don't have to later.

[kishy]

I took a good look at them...no straight edge or anything scientific, just my eyes.

There was no pitting (not on the mating surfaces anyway).
There was no pattern indicating a prior exhaust leak, except on #5 which looks like it may have. However, the bolts on the 5-8 manifold were just barely past finger tight so that may have something to do with it.

I took a gamble on it and just bolted it right back together. It isn't going to be the end of the world if I need to adjust this after the fact such as adding gaskets.

Time will tell if I will regret this choice lol.

[EaOutlaw1969]

You are normally better off doing like you did by not installing aftermarket gaskets on a stock engine that did not come with them orginally.

Gaskets just add another part that will be effected by expansion and contraction.

When i turned wrenches for a living, I would use a straight edge to check a vehciles exhaust manifold and head normally if it had a leak i was attempting to repair, I normally would not do this on a regular service when a leak wasnt present.

I would focus more on making sure I had clean surfaces and good bolts, if the bolts were at all rusted, pitted, or had rounded heads i would replace them. then if possible I would tourque them to according to the manual then recheck them after a thermal cycle.

All of this was dependant on the type of engine and if it had known common problems with exhaust leaks. Like a old Ford inline 6 cylinder.