scmedic

Just wondering if anyone here has had any experience with an aftermarket exhaust manifold for a 22re?

I think the head mating flange on my exhaust manifold may be warped and rather than getting it resurfaced, I'm considering getting a new aftermarket manifold for just a few dollars more. Here are a couple of examples:

http://www.partsamerica.com/ProductD...e=1359&PTSet=A

http://www.partsamerica.com/ProductD...e=1359&PTSet=A

I'm wondering if I'm just asking for more problems by going this route? Any thoughts on these things good, bad, or otherwise?

Georgiadave

If your time isn't worth much, the problems are minor. Headers are notoriously prone to warpage and leaks. If you put one on, get locking fasterners. A header on these little engines is not going to do much for your performance either.

Sometines the factory exhaust manifold will crack, but warpage is pretty rare. What makes you think it is warped?

scmedic

Thanks for the input...

I actually haven't measured the mating surface for flatness yet so I don't know for sure it's warped. I have a tapping noise that sounds like exhaust leaks I have had in the past. The only way I can get it to go away is to keep the manfold/head mating bolts torqued right up to factory specs - if they loosen up by just a few foot-lbs the tap comes back. This is with a new OEM manifold gasket.

Georgiadave

You might try replacing the manifold studs and nuts with new ones. They should torque to spec and hold for quite a while. If money is tight, rough up the threads on the studs with vise grips or something similar, not too much, and that might work too.

scmedic

Thanks for the suggestion - I'll give the vise grips trick a try first...

Any thoughts on reusing the exhaust manifold gasket? I've only got about 500 miles on this one and at $50/ea I would hate to scrap it.

854x4

I have the same manifold on my 85 the original was cracked almost in half. When I ordered mine it came with the manifold, head and flange gaskets,3 studs, and 3 nuts. You have to reuse the head studs and nuts also you will need a o2 sensor gasket.I've had no problems after a few months.
Those two exhaust manifolds are the same,Dorman and Motormite the part numbers match 674272.

Georgiadave

You could give the old one a try. I have one from my engine replacement, as I used a Toyota gasket. I was not real impressed with the kit gasket, but it should work. If you want it, PM me and I will send it to you. I also have the exhaust flange gaskets, for the same reason.

You just need to rough up the area under where the nuts stop on the studs. Leave the end of the threads alone, so you can get the nuts started. There is no need to rough the stud end that screws into the manifold, methinks.

scmedic

I tried the vise grip trick and put the old gasket back in this weekend. So far everything seems to be working well. I think I 'll run it for a while and see how it holds up. Thanks for the offer of the extra gaskets - I'll let you know if I end up needing them.

854X4 thanks for the info on the motormite and dorman manifolds. It sounds like that might be a better way to go than resurfacing if that's what is necessary

Georgiadave

I hope it works for you. I will be out of town until Feb 22, if you PM me in that time I am not ignoring you.

RustBucket

iTrader: (1)

Here's another idea: I got a Remflex exhaust manifold gasket and it seems to be working great. It's a thick carbon gasket and squishes alot. Pretty cool idea and pretty cheap too. Just google them.

Georgiadave

You might also retighten the nuts in a day or so. I think the torque is faily low, around 15 lbs or so. Below is a short article on torque and gasket joints, if you are interested.

http://www.boltscience.com/pages/gasket.htm

Here is an excerpt that addresses your problem:

Creep or relaxation of the gasket material can be a practical problem. This is a particular consideration in joints subjected to temperatures greater than 100 °C. The amount of relaxation which can occur with gaskets is usually far greater than that which occurs in joints which do not contain such compliant materials. Because of the magnitude of bolt clamp force loss which can occur with gaskets, frequently a re-tightening schedule is specified 24 hours or more after initial tightening. The magnitude of the clamp force reduction due to gasket creep can be of such magnitude that is not feasible to design the bolts for this loss. To overcome this problem, re-tightening of the bolts can be specified after a period of time following initial tightening, frequently 24 hours. Such a schedule may involve re-tightening the fasteners on a regular basis to overcome the problems of relaxation.

dcg9381

I bought the same thing for my turbo truck recently - it's a beefy deal, not terriby cheap with shipping. My exhaust manifold can see pressures as high as 20psi.. I'll tell you how it works later.. :-)

shaeff

uh, that's really bad advice.

lets see:

steel studs, aluminum head. figure that one out. guess which will strip first? yeah, the head. then you'll have to helicoil all the holes that you screwed up.

scmedic

The Remflex gaskets look nice! How has yours worked out? I'd be interested to hear how they hold up with the turbo exhaust manifold also... Worst case the website says they offer a money-back guarantee so at least you can get your money back if you don't like it...

BTW, good point about crushing the threads. I hadn't thought about that. Luckily *every* single exhaust stud hole in my head has been steel inserted (because they've all stripped out at one time or another....) so direct contact between the studs and alum threads isn't an issue in my motor anymore. I think it's pretty pathetic that they've all pulled out though - I've never torqued any to over factory specs or overheated the motor.

Georgiadave

I think the best way to go is new studs and nuts. IF you can't afford that, roughing up the threads where the nut is is better than nothing.

I believe that is what I said. Did you read that?

ozziesironmanoffroad

most exhaust manifolds do it, lol.

scmedic

GeorgiaDave thanks for the bolt science webpage info - that definitely helps to shed some light on the problem!

I've been using 33 ft-lbs for the manifold torque which is what is listed in my FSM. Is anyone here using a different number? I definitely don't want to go higher since I've already had problems with the aluminum threads. I'd go lower if I could get away with it but am worried I'll get more gasket leaks....

dcg9381

I don't know yet, I'm waiting on my new manifold to get in from Canada (http://www.steedspeed.com). I also went to a smaller housing on the exhuast side of my turbo trying to get a little more spool... Should have it together within a day or two of the manifold getting here.