Re: &%$*! exhaust manifold!
<font color="blue">...Could the engine block have been warped by the heat ... </font color>
Hi Pete,
How about using a "straight edge" to test for flatness on the block side prior to rebolting the manifold up...
(to test your theory) [img]/forums/images/icons/wink.gif[/img]
Re: &%$*! exhaust manifold!
Pete:
check out John"s idea. You may have to remove the head and have both taken in at the same time to get a proper mating surface.
Could gasket material be an issue ? What about the rest of the exhaust manifold, can it put strain on the one that keeps breaking
Egon
Re: &%$*! exhaust manifold!
John and Egon -- Thanks for the replies. I've wondered about the gasket material since these had to be cut out by hand from sheets. (Just try finding a gasket for an old poly head that was only made for a couple of years back in the 50's!) I'll do the straight edge thing if I ever take that manifold off again, but I'm hoping to avoid that step.
What a pain!
Pete
Re: &%$*! exhaust manifold!
Also look into a type of gasket material like asbestos, and very flexible that could basically "seal" the manifold without "torquing" to the breaking point...
Re: &%$*! exhaust manifold!
Pete:
Hope your solution works.
John's got a good idea.
Perhaps back off on the torque to help reduce stress.
Some usless trivia: Many a year ago I was told cast iron gets harder with age as carbon nodules will form over time at the grain boundaries. Now the fellow who said this had also had a bridge he designed fail in the construction phase due to spring runoff.
Egon
Re: &%$*! exhaust manifold!
Pete,
You might try double gasketing the manifold. That might give you the added float you need.
Steve
Re: &%$*! exhaust manifold!
Ahem, I did the high temp epoxy thing and ran into another speed bump. Since I couldn't find a replacement manifold for the 315 Poly in a truck, I used one for a car. The bottom end that connects with the exhaust pipe is about an inch shorter, so there's a gap between the manifold and the exhaust pipe! [img]/forums/images/icons/blush.gif[/img]
I'm so close!!! But I'll have to tow the beast to another shop to have them finish the job. Heck, might as well replace the entire rusted exhaust system while the old truck is there!
Pete
Re: &%$*! exhaust manifold!
Pete,
If you're going to tow the truck in, they might be able to deal with the mainfold problem too, or at least give you some ideas on what might be causing the problem.
Steve
Re: &%$*! exhaust manifold!
Pete,
Dig deeper and go with headers.