This warp in my 1F manifold is causing a pretty big exhaust leak. Is there a cheap way to fix it or am I better off looking for another manifold?
warp in 1F manifold
- Thread starter Vinca1
- Start date
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It is a pretty easy fix if you have a machine shop handy. They will put it on what looks like a really big belt sander and true up the sealing surfaces. Even if you were going to replace them I would true up any set of manifolds just because of how cheap it is to do and it makes for so much better sealing.
X2.
I had one warped that bad. The machine shop did as much as they could but a Remflex gasket took care of the rest.
landcruiserrich
Bench Wheeler
The manifold pretty much needs to be machined every time you remove it. If they had made them so the intake and exhaust mounted separately instead of being bolted together it wouldnt be as bad, like if you replace the stock exhaust manifold with a header. I wish I had known about those remflex gaxskets when I did mine!
- Thread starter
- #6
good advice... went to a machine shop this morning at 10... had it running by 12. Took the guy less than 5 minutes to sand it. He didn't even charge me.
Some info for others, in the future, who read this thread (since you already took care of the problem)----
The first thing that needs to be done in this situation is to separate the intake and exhaust manifolds. Then clean up the mating surfaces, install a new gasket, and bolt the manifolds back together. Once this is done THEN you are ready to have the manifolds surfaced.
Don
The first thing that needs to be done in this situation is to separate the intake and exhaust manifolds. Then clean up the mating surfaces, install a new gasket, and bolt the manifolds back together. Once this is done THEN you are ready to have the manifolds surfaced.
Don
Handcannon's advice is correct....UNLESS you live in a hot State (Texas) and don't want your exhaust manifold superheating the intake. I always separate the intake from the exhaust manifold and mill off almost 1/2" from the bottom of the aluminum intake. I then make a blockoff plate out of 1/4" steel and bolt it and a gasket onto the exhaust manifold to seal off the gasses from the intake. I also remove the exhaust flapper valve and weld up the pivot holes. If you do that, your fuel is much cooler as it enters the cylinders, and your intake and exhaust mounting bolts/nuts just need to have a large washer under them to even the load across both manifolds. On my own engines I either weld some aluminum to the intake, or braze the exhaust to get both manifolds at the same height, so I can still use the original round washers when mounting to the head. You definitely still need to have a nice flat surface on both if you want a tight seal to the head.
Dougs advice about the block-off plate, and flapper, is good for just about every place, although 1/4" is thicker than I've ever heard before. Removing the flapper may be a bit extreme for those areas that do receive a lot of cold winter weather though.
Don
- Thread starter
- #10
I separated my manifolds and welded the flapper open, and then I made a tight fitting piece of metal to block the exhaust. I "welded" the plate to the inside of the cast iron manifold using silicon bronze wire. Not sure how well that will hold, but for now there seems to be no exhaust leak. I put the manifold back together without a gasket which raised the exhaust about a 16th of an inch in relation to the intake, so I enlarged the bolt holes a little to match the aluminum intake.
