Been a while since I posted around here... I made a turbo kit for a 2008 Si a couple of months back. When I welded the head flange I bolted it to a ~3/4" thick piece of aluminium using all the bolt holes, then checked flatness by going over it quickly with my belt sander. At first install it doesn't leak, then after some tuning/aggressive driving when it heats up, the manifold starts to leak from the area near the top two bolts that hold it to the head. When I go to tighten the bolts they are a bit looser than they were installed. I haven't removed the manifold again to check for leaks, but I assume it's still flat. I am hesitant to put loctite on the bolts because I'm afraid they could break or something. I've also thought about replacing the three bolts with studs like the other two are, but I don't want to go to all the work to change them if it's not going to work. Any ideas to keep this thing from leaking?

 

we use a 3" aluminum heat sink - you can easily warp 3/4". using loctite is not a good idea or solution. take the manifold off & see if the surface is warped

 

3", damn! Time to make a new plate... thanks!

 

Manifolds will warp really easy. I would recomend that you take it off and check flatness again. What intake manifold gasket are you using. If you are still using the stock, maybe go to a hondata (or simillar) gasket and it might seal better.

Stefan

 

I'm talking about the exhaust manifold, not the intake manifold, I'm sure a spacer wouldn't last a minute on the exhaust side.

 

so loctite some studs in the head and use flange head nuts instead of bolts on those 2 holes.

mike

 

 

Bring it to your machinist and spend the $45 to get it resurfaced.

 

45.00 will get me a belt sander resurface, if u want a real resurface pay the ~100.00 or so and have a machinist mount it in a vertical mill and resurface llike cylinder heads get resurfaced.


mike

 

If you're paying that much your getting ripped off.

My machinist has charged me $40 in the past. The extra $5 was for RI inflation

Not many shops will charge more than $75 to have a head surfaced on a mill.

 

i said manifold on a vertical mill (like a Bridgeport) not a head on one. i get my heads resurfaced for 35.00 sir. but a manifold, something thats awkward to mock up on a mill and harder to level i get charged for machine setup time also. but ive only done that once hense the reason all my stuff is resurfaced on a belt sander.


mike

 

Yep, well maybe he should give his machine shop a call and see what they have to say. Nothing wrong with a belt sander re-grind on this piece either.

 

$100 is reasonable for machining it. the setup is a pain in the ***.

there is often a small amount of warp in any manifold. i tell all my customers to re-tighten the studs after the first couple heat cycles and to do it while it is still hot. that often flattens everything out.

 

That is actually what I did already. I will take it to my machine shop and get it surfaced if it comes off warped, but like I said it wasn't warped when I installed it. I have thought about the studs/loctite but I'm worried something might just pull out instead of coming loose, and the repair will be a lot more time consuming given the placement of the kit and how much of a pain it is to remove the turbo, downpipe and manifold from the back of the engine bay. I guess for now I will re-tighten it and see how it goes, if it continues to get worse I'll try studding it, and if I have to take it out anyway to do that I'll get it surfaced at the machine shop (it's about $60, done it before).