Hi - Exhaust manifold question from a newbie...

[Anonymous]

Hi all, (hope this is in the correct forum - please move if not - thanks!)

One of my friends has a very cool 1968 Mustang 200 I6 Coupe and we have been investigating a blow in the exhaust...
He got a new gasket put on, but when we took the manifold off yesterday we noticed that the gasket had been partially burnt away on all bar 2 of the ports. Lacking a spare gasket, we sealed it up again DIY style with some firegum and the old gasket i Haha! result! it sounded sweet! - needless to say it didn't last more than a day

Does this happen a lot? Are we right thinking that we need to start skimming things? :roll: ### :roll:

The other thing that reeeeealy annoyed us, is that it seemed to be near impossible to get one of the nuts done up tightly enough: there is one underneath near the middle left that we couldn't squeeze the ratchet between it and the manifold - do you guys have the same problem?
(In the end, we undid the whole thing again, and did this one first - gave us -just- enough clearance but it was darn tricky. Was it designed with maybe some torx bolts or similar originally?)

Thanks for any responses (I have been searching the forums and net all afternoon)

Mark
:mrgreen:

Oh - and this is a pic of his car:

 

[addo]

A burnt exhaust gasket is about all the "ashes" you blokes will see. Yes, you usually do need to start machining stuff.

The head has to be milled if eroded - no sealant will endure - and if the motor is virginal, the head gasket face needs milling also, to compensate for the extra thickness of newer gaskets. Ignore this and your grunt goes out the window.

Manifold itself might benefit from a skim, too (if really rogered, consider some headers). Can you use a stud on the hard-to reach bolt?

Exhaust manifold bolts are typically torqued between 15 and 20 foot-pounds. Overtorquing risks damage to the head. You need to retorque several times after replacing the gasket, to make up for settling.

There are locking manifold bolts on the market; while these assist, retorquing is still advised.

Cheers, Adam.

 

[Anonymous]

Ashes? Well, at least I've prooved they are here in England safe and sound where they should be

If he gets it skimmed, is there any cost benefit in not doing so and getting a new head, as I think he will be wanting too.
He says there is a new aluminium head coming on the market soon. I've looked around here but can't see any dates. Are any expected? - If it's soon then maybe getting a new one now isn't a good idea if it's going to be a good part.

The hard to reach bolt, is a stud, and it's the nut end we are trying to put on. I think I have seen a good product here:http://cquesttechnologies.com/fspp/proddetail.asp?prod=BSL%2D200%2DEHB
Are these suitable for the exhaust manifold as well?

I'm so jealous of how easy the I6 is to understand - my Saab 9-5 has more electronics than a small japanise city

Mark
:mrgreen:

 

[Anonymous]

the aluminum head is coming from no other than HERE...
check this same forum of details...

 

[Funky Cricket]

i think his issue was the exaust gasket not head, but same theroies apply. most likely something not straight..

 

[addo]

GP, you're right. It is a simple motor and responds well to educated "mishandling".

As the exact release date and rough price of the new head are unknown at present, I would advocate working with what you've got. Quicker, and much cheaper. It may even bump performance from the present level.

Note well: These motors do not respond in the manner of, say, a 350 in terms of bolt-ons. You will NOT get a massive HP gain from a set of headers (although some economy). It's more a cumulative thing - while the head is a great power restrictor, the 200's block needs a few things finessing on it, and a decent cam, more than it needs a fancy head.

Some people always want the high-visibility items, so the potential market for stuff like alloy heads is not challenged there, but you can find 5% gain here, 6% there all around and still run the existing head...

Cheers, Adam.