LT's leaking
 

I cannot get my pacesetter lt's to stop leaking...
i even installed percy dead soft alum. gaskets and they still leak..

i was curios to know if i can get away with cutting the header flange in three sections?
has anyone tried to do that and been successful with it?
or is it a bad idea?

I've never tried it but I have heard that it will help if you have a bent flange. Are you sure the bolts are staying tight? I used the copper gaskets that came with my Pacesetter's and haven't had any leaks. I also retightened the bolts everytime I drove the car for the first couple of weeks. I tried to tighten them while they were still as hot as I could stand it. I did get a couple of minor burns, but no header leaks.

I went through 3 sets of gaskets (soft metallic and otherwise).
I even tried different bolts and nuts ...
torqued those suckers down with the impact wrench and they still vibrated loose.

Eventually I just cut the flanges off and went with a slip-fit + 3" wide band clamps.
No problems since. (and I gained 3/8" of clearance :D)

LT1's have an inherent issue with the exhaust primaries not being spaced evenly, most often the middle 2 leak due to being put right next to each other, the rear (#8) leaks due to being a hard to reach area. I used paper, copper, and 2 different dead soft, multi layer aluminum the Flowtech worked the best but still had leaks. This was on a set of Jet hot LT's

I had pace setter shortys, OMG what a junky ass header, i am sure the LT's are no different, they are cheap to buy and you get what you pay for.

Put a straight edge on the flange to see if its warped.

no probs with my pacesetters..love them..good quality for the price

same here

I can virtually guarentee if you take your gasket off, there are black spots on some of the primaries (that indicates a leak, even though you dont hear it), LT1's dont have the best bolt holding pattern and that is a big reason why, also alot of people dont take the time prep the surface and dont start from the middle and work their way outward.

I agree with everything you stated... i did clean the surfaces off really well...
i even installed them with the engine out of the car... so i was able to get to every bolt very well...

i originally had the copper gaskets and i couldn't hear them leak. however when i removed the headers you could see the carbon deposits and tell that they were leaking...

maybe i should pull them off and get a machine shop to true them up...
i will also cut them into sections and try that... if that doesn't work then i'll just live with it...

you could use some copper seal rtv with the gaskets.

The best you can do is have the header trued up, and take a straight edge with feeler guage and see if the head is off. From there the Flowtech multi layer aluminum worked the best, I had the least leaks of all header gaskets prepping surface is key, start from the inside bolts and work out. Now mind you, use anti seeze and do them tight, dont strip the threads but be very tight. Re-torquing bolts will be required after the first few drive cycles. You need to stay on top of them, once they leak, they can blow, when they leak, they will not improve.

My Pace Setters are a piece of junk as well. After a year, I still cant get them sealed up. I have tried copper and the metal/paper gaskets and I didn't work. Everything is straight and true as far as I could tell with a straight edge. I found that the ports on teh headers are way bigger than the ports on the heads. So i filed out the gaskets and it worked well on the driver's side but not much luck on the passenger side. Keep us posted if you get them sealed. I am curious if it will help if you cut the flanges into 3 sections. Good luck!

If it was a LS1, you could try that but with the #4 and 6, or 3 and 5 primaries use that flange to help seal, you cant put anything between the middle primaires.

Any update on your leak?

my gasket hung over the primary ports a little. not much you can do about that.

haven't had time and i will be out for the next 2 wks...
just not ready to rip off the headers yet either... PITA

i'll repost here when and if i get it solved...