Header crossover fabrication

[gnpoweredrail]

I am getting ready to build a new header crossover for my HYE Tech headers...
Has anyone ever used a bellow in the crossover for expansion and contraction....
also anyone with a solid one piece crossover....can you use different header gaskets like copper or Remflexes or just the ones used when it they were built..Im wondering if the different thickness of the gaskets would be a problem.

 

[gnpoweredrail]

anyone??

 

[Paul Lohr]

The bellows might cost you a little in exhaust gas velocity. Additional heat loss through additional surface area is probably minimal.

I am assuming you will be building the crossover from stainless. According to the chart on the page linked below, 304 stainless expands with heating at a rate 24% higher than mild steel. Look for "steel" and "stainless steel austenitic (304)". Concern about additional expansion over mild steel is right on, best I can tell.

http://www.engineeringtoolbox.com/linear-expansion-coefficients-d_95.html

You could use a slip joint halfway between two pipes that compose the left and right sides of your crossover system. I think that would allow the pipes to expand and contract without transferring a majority of the movement to the headers. Although now that I think about it, a horizontal and vertical slip joint may be needed to allow for contraction/expansion in both directions.

Is this the system you have now?
http://www.hyetechperformance.com/image45.html

Others may have better ideas...I am open to hearing them.

 

[Chuck Leeper]

If you use a bellows, be sure it's OK for turbo use. Some are not, and may have the inner liner collapse.
There's a couple different ways to do this.
1. A good s/s bellows, woven outer and spiral inner. Several vendors with these. Race Parts Solutions has them, as does Vibrant. [Got 1 from Summit]
2. A inconel inner slip tube liner, and an accordian type s/s exterior. SPD sells them for about $180.
3. Use a double slip connector. Spd and Columbia River Bending have them. [High end exh system builders use these.]

 

[gnpoweredrail]

The bellows might cost you a little in exhaust gas velocity. Additional heat loss through additional surface area is probably minimal.

I am assuming you will be building the crossover from stainless. According to the chart on the page linked below, 304 stainless expands with heating at a rate 24% higher than mild steel. Look for "steel" and "stainless steel austenitic (304)". Concern about additional expansion over mild steel is right on, best I can tell.

http://www.engineeringtoolbox.com/linear-expansion-coefficients-d_95.html

You could use a slip joint halfway between two pipes that compose the left and right sides of your crossover system. I think that would allow the pipes to expand and contract without transferring a majority of the movement to the headers. Although now that I think about it, a horizontal and vertical slip joint may be needed to allow for contraction/expansion in both directions.

Is this the system you have now?
http://www.hyetechperformance.com/image45.html

Others may have better ideas...I am open to hearing them.

Yes those are what I have and had..I kept blowing the center apart untill I welded it.I bought a new pair without a crossover with the intention of a custom crossover.
I do not want to run the HYE Tech crossover as it swings out wide for starter clearance...I do not need starter clearance as its a different setup..
I was mainly wondering about the reliabilty of a bellow.
If I start with copper header gaskets could I use a thicker one like Remflexes if I needed to later if I dont use a bellow??

 

[Chuck Leeper]

"If I start with copper header gaskets could I use a thicker one like Remflexes if I needed to later if I dont use a bellow?? "
If you don't use the gaskets you intend running, when you make the pipe, [such as the Remflex], the v bands may not want to fit w/o a flex bellows, or a double slip joint.

 

[gnpoweredrail]

thats kinda what i was thinking