Exhaust manifold with NO gasket???

I am considering re-installing my exhaust manifold with NO gasket as was standard from the factory. My head and manifold both look pretty flat using a straight edge. I have been told the gasket helps with imperfections, I have had bad luck using them so far. But I failed to re-tighten it after 100 miles and I think that is super important.

My thinking is one good reason to use a gasket is it keeps the hot manifold from touching the head, as it creates a tiny space a lowing the coolant to keep the exhaust ports on the head cooler than the manifold, thereby extending life of the head and also slightly lowering the heat load on the cooling system.

1. Has anyone installed one with no gasket and what were the results?

2. What are the pros and cons of using a gasket?

i have never installed an exhaust manifold without a gasket. what you can do however is make your own gasket from copper. it needs to be about 1/16-1/8 inch thick, and use mr gasket copper coat sealer on both sides of the gasket.

a "gauge" or straight edge is just that, not a true and real test. It gives some idea about condition. There are better measures, but not available to many owners/drivers. The gasket has less to do with the temp (directly) than sealing the imperfections between surfaces. The idea being (I assume, I'm not an engineer) to better mate the 2 steel surfaces. Without a mate, the heat escapes thru the space/imperfection. Over time this deteriorates the surfaces, opening the hole more. You experienced this thru missing the "re-tq maintenance specs" on a new gasket, head, or ex. manifold install. Cycles of heating/cooling further change the mating abilities esp w/the changed area because it's experienced a different amount of heat than surrounding areas. "Difference" is not good - ever pour water on a hot cast iron skillet? I gets warped in the direction of that coolant.

the composite gasket will seal that better than the copper, it has 'more give'/is thicker something you may need since there has already been a 'blow out' or 2. I like your idea of following the "retq maintenance specs" the fellas who came up with that have more knowledge and experience than us.

I say go ahead and try it without.
Let us know the results!
Maybe we're all just wasting money on gaskets, like Ford figured out.

oh, that JackFish, he's just a 'contrarian' !


(or may be I just got found out "Booo000OOOgus!").
:roll:

Ahhh, those Canadians. Always with a different opinion.

He probably has a production engineer point of view. Not like normal people with an ease of repair ideation.

I like the gasket cause it keeps some exhaust heat away from the head.

Bill,

If you block your heater inlet, you won't miss it. No fumes in the cockpit.

chad":1gxk9eom said:

oh, that JackFish, he's just a 'contrarian' !


(or may be I just got found out "Booo000OOOgus!").
:roll:

Click to expand...

Contrarian eh? heheh I should start my own political party.

Ya know, I've never seen an exhaust manifold without a gasket, even on ones that have (from all accounts and evidence) never been off since the factory.

I have. Ford actually new what it was doing in typical Henry Ford fashion. You'all havent heard that the 200 cubic inch Model A carb was held on with just one bolt at Henry's request? That's a clue to how things used to be done for 81 years at Ford. By 1984, they stopped the minimum engineering schtick, and gasketed stuff. And its okay if you do to, only remeber, that if you do things acatly to the factory book, you sure don't need any.

No gasket, no intake manifold, two bolts holding the carb adaptor, its all good as long as someone hasn't been there before and over oiled the bolts or then tried to torque it up non uniform. When that's happened, then you get the carb and exhaust leaks, and suddenly it runs like a bag of sh!+.

Everyone of my log head engines (1966, 1972, 1981) had no exhaust gasket, and the 66 was on its third rebuild. The additonal problem was the crack prone early header, which was fixed with the primary light off cat 4-1/2 inch header on every 1980 on wards T, C, B and X code 3.3 or 4.1. The problem is that Ford shifted the engine mounts forward in the 250, and again in 1978 with the Fox so the later exhasut doesn't always fit. The aftermarket makes repro cast iron headers which work well. Or buy headers, and use aftermerket gaskets. Anytime you have tube headers, you need them.

i decided to go with the gasket, it did not lign up verry well the shape of the manifold and gasket holes are not well aligned but it seems to be working good

I think I noticed you say something about that earlier and wonder if the mani & head match. The gasket's gotta match one or the other and yet this might B the 2nd that didn't? Pic at some point would B great as it's hard to tell from verbage only...

Let C how this wrks w/ the 'retighten later' schedule.
Just a curiosity, you use lock washers this time?

I did not use lock washers. i went for a couple test dives, and i was able to re tighten it again already