Intake/Exhaust Manifold Gasket

My exhaust manifold gasket just blew out. I was wondering if i could could remove the intake and exhaust manifold together with the two sill bolted together and the carb still attached. Also any recommendations to were to get the best gasket because i don't want to do it again.

 

You can remove them together, no problem. But you have to have them loosend to get them to line up properly when you reinstall them. So if you have to loosen them you may as well replace the gasket between them. That would be the gasket for the heat riser chamber. They can be somewhat difficult to get apart some times.

 

A leaky exhaust manifold gasket is a very common problem for a 232/258. IIRC they won't come off any other way. You have to remove the manifolds as a unit, then separate them. The Jeep flat rate mechanics would leave the carb attached to the mainfolds, as you suggest. For an amateur (like me) it's probably less work to take the carb off first. The assembly is pretty heavy - be careful and don't bump the radiator (BTDT).

I like the Felpro gaskets - make sure that the head and manifold surface is perfectly flat and clean. If the manifold is eroded around the leak, you can have it surfaced to make it true again.

<edit> Use the steel donut gasket.

 

I pulled the manifolds off today and noticed two small cracks on the back side. Should i leave them, Get them Welded or find a new manifold?


Sorry about the fuzzy pics my camera is not so good up close. Thanks

 

Well, I'd fix it one way or another. You can buy a new manifold http://www.actionsalvage.com/detail.asp?product_id=101002 or find a used one. I'd expect that welding would not be a lot cheaper than replacing.

I replaced my intake and exhaust manifold on my truck with a pair of manifolds from an '85 CJ. After 1980, the intake is aluminum and has 2 barrels. The exhaust manifold is also lighter and smoother. These bolted up to my 258 with minor changes. I had to notch the PS bracket slightly to clear the new exhaust manifold. You've already got the MC2100, so I'd think this would be a good plan. I paid $50 for both manifolds, and had to spend another $15 for the throttle bellcrank. Pics are available if you want to see 'em.

 

Can you please post the pics, thanks.

 

Ok ...



These are the ones I can find easily. The aluminum intake stands out clearly. You'll have to reroute your heater hoses to preheat the manifold. The exhaust flap between the manifolds is replaced by an electric heater underneath the carburetor. I chose not to connect it, which leads to somewhat longer warmup times. If you want to use it, you'll need to rig some kind of temperature dependent relay. The EGR gets exhaust gases through a tube that can almost be seen under the EGR valve.

The PS bracket interferes with the exhaust manifold at the right-angle stiffener that you can see on the bracket, right behind the obvious bolt that goes into the intake manifold. The exhaust manifold comes out from the head straighter, so that right angle part has to be notched. AFAIK all these exhaust manifolds have AIR injection ports, so you'll have to plug them. 1/8" pipe plugs work, as do oil pan plugs (or so I've heard).



hth!

 

Thanks for you help, i end up putting the old manifold back on because i need the Jeep next week. But i plan on upgrading later down the road. Thanks for your help.