Poorsche

I read somewhere in my research that the stainless and the cast iron have different coefficients of expansion (expand/contract at different rates) which cause a variety of problems--none are good from what I read.

I just told you more than I really know.

Dave_N

I have heard similar things, thats why I would say not to use stainless.

That explains all the trouble Hope it all works out.

Dave

ThirdBird

Galvanic corrosion. Dissimilar metals corrode quickly when in contact, even stainless. Plus, it's hard to know what grade of stainless bolt you're getting. There's stainless and then there's STAINLESS!!

ThirdBird

Why would you bother slotting a stud and then remove it and replace it with a bolt? Just use the stud and put a washer/nut on it. That's the way I always do manifolds,,,,,,, the end bolts where the gaskets hang get replaced with studs/nuts,,,,,, forever. The only thing you need to make sure of is that the studs are fully engaged. Double nut 'em and thread 'em in.

Liberator21

Poorsche,
Did you go there directly to pick them up, or did you order them through the web? I did a search on the site, but didn't find much. Also, if you don't mind me asking, how much did he get for a pair?

Poorsche

I've been to the yard a number of times. Billy had shown me the parts the last time I was there. I just called him and verified stock status and he shipped UPS with a VISA>

He's a great guy (Billy) and like his Dad, he knows where everything in the place is and what they will sell it for.

They are tough negotiators but gentle persuasion can be useful--and they have the goods. The website is really just a telephone number listing--there isn't any real detail info there.

ROTAX454

Understand. Not using a cast iron (merc style) exhaust. Using the KE cast Aluminum. Now, is it OK to use the stainless (real stainless) bolts in this application?

Poorsche

We're finally installing the GLM exhaust manifolds. First problem is several of the bolts thru the manifolds into the block don't want to come out. We had a wrench and long extension and still can't get them to trun out.

Any "special sauce" or trick to use? Of course the problem bolts are on the monifolds on the insed of both engines.

Thanks--

txriverrat2001

If the risers have been leaking externally and the heads of the bolts are rusted away - it's easier to cut them off with the engine out. Though I've done many with the engines installed - it was a real pain. Once all the junk is knocked off with a punch or air hammer - I grind the remaining bolt head off with a die grinder and lots of stones. I shy away from taking a torch to them inside anyones boat. I've done them hanging in the air - but only as a last resort. On almost all of them - once the bolt head is gone and you can remove the manifold - the remaining studs will generally come out failrly easy. They're hardly ever stuck in the head - but stuck in the manifold itself.

Do not use stainless to attach the manifold to the head. You can't maintain the proper torque. If the risers don't leak - the factory bolts work just fine.

If a manifold is leaking on the outside - it's time to replace.
Period.

Poorsche

Thanks for the feedback--we douched the bolt overnite with some CorrosionX and this morning they came out (with some sweat, blood and extreme profanity).

Got two of the new ones on and two to go--

The other day someone with a project boat wanted some used manifolds. The OSCO's we took off my boat really didn't need replaced--they were Fresh water cooled. I saved them in case someone still needs them.

Also a two pair of Mercruiser stainless 4" elbow's we decuded not to use if anyone is interested.

Again Thanks for advice.