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Discussion Starter #1
All headers have a raise portion around the header tube that is a weld that was made between the tube and flange. This portion is raised to bit into the header gasket and the area on the outside of this flange is lower so it doesn't really contact and hold the gasket.

My heads have very large ports and the gaskets need to clear the ports are about 2.2 inch diameter while the headers are 2 inch. This causes the raised portion of the header seal to fall inside the gasket. I really should be 2 1/4 inch headers but getting that size tubing to fit would be a nightmare on the steering box side. I could do it on the passengers side.

I took the mig and added another raise portion outside the existing flange around the tubing

Some carefull work with a grinder, being careful not to grind below the existing raised lip around the tube and then working with a file, a hand file to blend the new welded section to the height of the old machined raise section and then I finally just made a light pass with a blending wheel on the grinder to make it look goo

This shows all 4 done with the increased wider raise section that hopefully will clamp the gasket between the flat surface of the head adn this wider lip seal on the header.

Only time will tell if it works as hoped and maybe I can make a set of 2 1/4 headers as a winter project.
 

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Discussion Starter #2
Notice that I also cut between each tube. Not totally through the flange but very close. This allows each tube to be clamped to the head, giving if some freedom to flatten out agianst the head.
 

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Thats a pretty cool fix. I'll have to look at mine, but I think they came with the head face machined flat.
 

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Not that you need more power, but you should never run smaller pipes than the head ports. You have caused instant turbulence. You would be better off running 2 1/4 primaries at least 6-8 inches down and then stepping them to 2 inch.

i know that your exhaust system is stainless are your headers also stainless? I had and the word is "had" Headman headers on my Vette. Well I decided to buy that thermotec header wrap. I did a great job. Actually too great. I had header primary pipe melt down.
 

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Discussion Starter #5
Not that you need more power, but you should never run smaller pipes than the head ports. You have caused instant turbulence. You would be better off running 2 1/4 primaries at least 6-8 inches down and then stepping them to 2 inch.

i know that your exhaust system is stainless are your headers also stainless? I had and the word is "had" Headman headers on my Vette. Well I decided to buy that thermotec header wrap. I did a great job. Actually too great. I had header primary pipe melt down.
George I would love to run 2 1/4 inch tubing but how do I get it to turn before runnin into the steering box. 2 tubes #'s 1 and 3 would be the problem.
Between the plugs and the steering box it would be extremely tight.
If I could get past the first 6-8 inches the rest would be no problem.
I am also running Hedman headers and thought alot of them BEFORE I had to modify a set of Hooker supercomps. After working on them my hedmans are nothing in comparison.
The hookers are alot heavier 16 gage VS 18 for hedman along with the heavier 3/8th flange vs our what? 1/4 inch.
The 2 headers don't compare.
If I could buy a set of 2 1/4 I would, if I could find a kit but in 16 gage I probably would and custom made my own but agian cylinders #1 and #3 scare me.
The wrap works but I too feel in time it changes the structure of the tube because the headers run alot hotter then thermo coated or open
 

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All headers have a raise portion around the header tube that is a weld that was made between the tube and flange. This portion is raised to bit into the header gasket and the area on the outside of this flange is lower so it doesn't really contact and hold the gasket.

My heads have very large ports and the gaskets need to clear the ports are about 2.2 inch diameter while the headers are 2 inch. This causes the raised portion of the header seal to fall inside the gasket. I really should be 2 1/4 inch headers but getting that size tubing to fit would be a nightmare on the steering box side. I could do it on the passengers side.

I took the mig and added another raise portion outside the existing flange around the tubing
Some carefull work with a grinder, being careful not to grind below the existing raised lip around the tube and then working with a file, a hand file to blend the new welded section to the height of the old machined raise section and then I finally just made a light pass with a blending wheel on the grinder to make it look goo

This shows all 4 done with the increased wider raise section that hopefully will clamp the gasket between the flat surface of the head adn this wider lip seal on the header.

Only time will tell if it works as hoped and maybe I can make a set of 2 1/4 headers as a winter project.

There are a few custom companies that make headers with a thicker flange and is Blanchard ground after welding to make a full flat mounting surface. They claim this prevents many mounting and sealing problems. Sound like a very good way, but have never tried them. Will have to look up who they are. :D
 

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Discussion Starter #7
There are a few custom companies that make headers with a thicker flange and is Blanchard ground after welding to make a full flat mounting surface. They claim this prevents many mounting and sealing problems. Sound like a very good way, but have never tried them. Will have to look up who they are. :D
I would like a flat ground flange also and believe it would help. This is sort of what I was trying to do. Increase the clamping area so my gasket isn't blown out.
As for custom headers I would be very leary with my heads. The raised exhuast port with standard plugs puts that plug right in the middle of 3 tubes on a standard set of headers. I had to cut and reweld after moving 3 tubes out of the way.
Mine is not the only headers that needed cutting, moving and welding. I did 2 sets a few winters go for myself and Brian. Brian my friend with the hot all aluminum 427.
 

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Why not get some headers that fit? the misalignment, especially on the long side radius really hurts performance. If any, the header should be larger than the head port. If you want to stick with the headers, why not cut (or have cut) some new flanges w/ the proper size and use starter cones to reduce to the 2" primary size.
 

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Discussion Starter #9
Why not get some headers that fit? the misalignment, especially on the long side radius really hurts performance. If any, the header should be larger than the head port. If you want to stick with the headers, why not cut (or have cut) some new flanges w/ the proper size and use starter cones to reduce to the 2" primary size.
I agree Marck the headers are junk, at least not right for me. I really would jump at a chance for say 2 1/4 inch tubes but they have to fit. Around cylinders 1 and 3 would be a real problem. Between the steering box and I have more clearance then stock and the spark plugs and agian I run into plug clearance problems because my ports are raised .600 and it puts the plug right into the header where under normal conditions it would be above the bend in the tube.
I agree I need to address the headers but it is one of the worst jobs you can do. building your own headers.
 

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Increase the clamping area so my gasket isn't blown out.
.
Norval,

those look like composite gaskets. I've gave up on those a long time ago and use copper. They also make a new dead soft aluminum gasket.

Metal gaskets can leak a little but they won't blow out.
 

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Discussion Starter #12
Norval,

those look like composite gaskets. I've gave up on those a long time ago and use copper. They also make a new dead soft aluminum gasket.

Metal gaskets can leak a little but they won't blow out.
They are a composit gasket from Fel pro. It has a wire mesh in it and if this doesn't work I will go to the copper ones.
I modified the flange last night, installed new gaskets and I used high temp silicon at the same time.
If this doesn't work I will stop dinking around and go with a solid metal gasket
 

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Discussion Starter #13
Very nice write-up Strider.

Sometimes working with what ya got is the only option, you certainly took a sound approach with running an extra bead for a better seal. Looks good too.
Yes sometimes you have to make due. It is summer, time for driving and I don't want the car laid up.
It takes me about 5 minutes to weld up all the ports and another 5 minutes per tube for grinding and hand filing but the headers were put back in last night and I am ready to go driving.
Any real project must wait for winter. Maybe this winter it will be handmade large tube headers. Maybe:laughing:
 

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Discussion Starter #14
This is the fit with 2 inch headers. I have to be able to fit a plug of coarse and still bend a 2 1/4 inch pipe around to clear the steering box.
Not much room
 

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This is the fit with 2 inch headers. I have to be able to fit a plug of coarse and still bend a 2 1/4 inch pipe around to clear the steering box.
Not much room
:devil: :devil: You MAY wanna consider a RACK install, that way alls it is is a rack shaft, not a whole damn box stuck up there in the way.....:smack :smack :cheers: :spanked:
 
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