IMCO manifolds discoloring
 

Just had my engine builder complete my engines and he also suggested installing some Imco manifolds (4 hrs total) on both of the 502 mag n/a. They Don't look as trick as my CMI'S on my old ride, but they do look clean and have heard perform resonably well under 550hp and my builder recommends them.
Well, took the boat out for a good blast at sunset at our lake and noticed some discoloring on one of the risers at the connection to the manifold assy. The black area is starting to bubble up. It all happened within a 15 minute blast. And now the engine runs rough. So i shut it down and limped in on one engine.
Thoughts?

Re: IMCO manifolds discoloring
 

From looks you've got a leak around the gasket. How did you prep the mating surfaces?

I lost two engines because the "mechanic" used an air-driven wire brush to remove the paint from those surfaces. Needless to say they leaked like a sieve and I got water in all the cylinders and hydrolock--on one test run.

Of course the shop said the manifolds were defective and since I provided parts they had no liability.

Re: IMCO manifolds discoloring
 

I am not sure how the shop prepped the surfaces. He said he installs many of these and assume he is qualified to follow product procedures.
He sold me the manifolds and installed, turn key at the same time he rebuilt my other engine. Very reputable shop, message is on their answering machine waiting for a response.

Re: IMCO manifolds discoloring
 

Start keeping a "blog" of all conversations and start organizing reciepts. Hopefully they have some sort of errors/ommission insurance but you'll have to sue to get and resolution.

Re: IMCO manifolds discoloring
 

Can you post a full view of the engine. It looks like they installled dry joint elbows with old stlye manifolds that don't have a provision for a jumper hose. The damage shown in that picture is from heat not a leak. soemthing is wrong with the water flow and that manifold got smokin hot.

Re: IMCO manifolds discoloring
 

Hillbilly,
Here is another shot. Hope this helps
Thanks

Re: IMCO manifolds discoloring
 

From what I can see in the picture I don't see a water outlet for the manifolds, he water somes in the botom but has no way to get out. Those elbows have no water ports they get their water through the hoses that hook to them. Like I said it looks like they used dry joint elbows with wet joint manifolds and no jumper. It got hot and puked the gasket and from what you described it sounds like you have water in the clyinders now. I'd see what the builder wants to do from here.

Re: IMCO manifolds discoloring
 

Mine are hooked up exactly like you have shown. My water exits thru the tail pipes. After three years the chrome looks like new. It definetly looks like it got hot, at least that one. How come the others are not discolored?

Re: IMCO manifolds discoloring
 

yes, it looks like only one is discolors...you would think that if they are hooked up wrong all would discolor ....looks like maybe a sealing issue as discribed...

gociggie
...I guess you will see how reputable your engine guy really is. :eek: ..best of luck and keep us posted.

If it turns out good let us know who he is ....and also if it is bad, I would like to know who to stay away from when I dump my money in another gofast later this fall.

again, best of luck

Re: IMCO manifolds discoloring
 

It looks to me like the hoses are hooked up wrong. The hoses that feed the manifolds should come off the aft hose connections (closest to the intake manifold) and the hoses that feed the risers should come off the forward hose connections (they have the checkballs). The one manifold may have overheated due to the checkball sticking.

Dave