I have searched for at least an hour - can't find the final verdict on header install (1 Viewer)

[spotcruiser]

For the life of me, I could not seal the old 6-1 header following an engine rebuild. I tried 1 gasket, 2 gaskets, OEM gaskets, Fel-Pro gaskets, with sealer, without sealer, in just about every configuration possible. I worked on the headers to get the flanges in line. I ground the intake bolt contact areas to get the thicknesses just right. It was just that the freaking header had warped to where it would no longer sit flat against the head all the way around. Never before have I had that much trouble getting something to seal.

A new header solved the problem, with 1 Fel-Pro gasket and no sealer. I had to build a new exhaust headpipe to meet the new header, but it was worth it.

 

[1973Guppie]

For the life of me, I could not seal the old 6-1 header following an engine rebuild. I tried 1 gasket, 2 gaskets, OEM gaskets, Fel-Pro gaskets, with sealer, without sealer, in just about every configuration possible. I worked on the headers to get the flanges in line. I ground the intake bolt contact areas to get the thicknesses just right. It was just that the freaking header had warped to where it would no longer sit flat against the head all the way around. Never before have I had that much trouble getting something to seal.

A new header solved the problem, with 1 Fel-Pro gasket and no sealer. I had to build a new exhaust headpipe to meet the new header, but it was worth it.

this is exactly why it pays to get even a brand new header remilled by a machine shop, I have seen several of the flanges warped, my experience has only been with the one piece cheapo header....

 

[Tools R Us]

o.k. here is the report:

all bolts came out without issue, as did the two nuts

the intake manifold was already ground due to the fact that there was a header there in the first place

the new header was indeed a total bolt-on replacement

except for the collector being ever so slightly shorter, which had us missing about a half inch at the flange to the exhaust pipe - relocating the exhaust further frontward solved that problem

I have to say, this went amazingly smooth not even any need to take pics

and: the cracked header was cracked worth than visible from the outside when still in the truck

A couple of pix of the cracks, they are at the collector welds. We made a simple bracket to go from a collector bolt to the bell housing. Hopefully it will help support the collector, delaying/reducing future cracking.

 

[2thdoc]

IIRC, pardion started with extra thick washers and just ground down one half of the washer so that it could be used to balance out a low intake OR exhaust. I'd never seen this done until I had the opportunity to work on his daughter's rig at Rubicon Springs two years ago.

Though I have not had the need to try this yet, I think this is an interesting option and thought I would share it, along with the source.

Best

Mark A.

P.S. As far as the gasket question: single, quality gasket with copper coat on the exhaust ports ONLY! NEVER had an issue with this arrangement.

Pulling this thread back from the past a bit.

Why copper coat on exhaust ports only? I've seen other suggestions of no copper coat, copper coat on all surfaces and re-apply after sitting a bit.

What's the best way to go here? I've just received a header from Mark a week or two ago and am quite inclined to follow his recommendation, but just checking to see if opinions have changed in the past five years (since the quoted recommendation).

 

[Pighead]

Why copper coat on exhaust ports only?

I do not know why.
But, my last manifold gasket is a Remflex...no coppercoat and no regrets.

 

[DSRTRDR]

my then-new header is still fine at the block - it's got an exhaust leak somewhere downpipe, again

 

[Midwestcruiser]

i am doing the MAF header install as well. To re-ask 2thdoc's question in hopes of a reply, why coppercoat on exhaust ports only?

 

[65swb45]

i am doing the MAF header install as well. To re-ask 2thdoc's question in hopes of a reply, why coppercoat on exhaust ports only?

Intake ports are exposed to gasoline, which will eat thru the silicone-based copper coat in a short while.

Best

Mark A.

 

[2thdoc]

Thanks everyone, and thank you Mark for the explanation.