Sidepipe Gasket

[zachman]

Removed sidepipes and noticed the gaskets that are between the header and the sidepipes have the center of the gaskets removed. Is there a reason for this? Motor is a Roush 427.

[RedBarchetta]

The factory header/sidepipe does not meet flush in the center. Some have taken some welding rod and filled in the gap. The gasket isn't removed...it's just been burnt/blown out.

-Dean #747

[RonNichols]

How important is it to fill in the gap? I noticed this on my sidepipes also. I didn't observe the headers though.

R

[RedBarchetta]

I suppose that with the small gap there is the possibility of exhaust gas reversion occuring, and arguably at lower rpms. The power loss would be negligible (though I'm no flow scientist). I believe if it were a bigger issue there would have been more talked about it here at CC.

There is actually more power robbing occurring further downstream, mainly the 2" ID factory mufflers and the 4-1 collector (which from a flow standpoint is a mess). Many here (including myself) have performed upgrades on the ID of the mufflers with good results, but few (Buckshot Fabrication comes to mind) have tackled the 4-1 problem. The factory SB header is also restrictive and the factory now offers an improved design for those running the big inch Roush motors. Check with your dealer.

-Dean

[RonNichols]

Thanks Dean,

I've read some of your past posts on the muffler upgrade. I'm pondering that and the merge collector upgrade now. I ordered louvered core glass packs and when I get it in will order the merge collectors. The wheels are in motion at least. Right now, my maintenance guy is getting a welding jig ready to do it. Keep your fingers crossed for me.

R

[greg schroeder]

My original headers and side pipes had high spots of weld near the center.. The original assembly ended up having the gaskets blow out quite easily as the torque of the bolts around the outside corners simply pulled the metal to bend and leak around assorted areas. The gaskets burned out pretty quick to get noisy. The center burned out pretty good too. At the time I pulled the parts and ground them flat with a belt sander so they were flat to a metal straight edge. That worked pretty good with new gaskets and changing to good solid high grade bolts with lock nuts. Just plan on a new set of bolts and gaskets each time you pull the side pipes. It's a better job that way.

When I switched to new headers which didn't cover 1/3 of an inch width of each exhaust port like the original Superformance headers the new had a low spot of maybe 1/8 inch in the center were they attach to the side pipes. I cut the center of the gasket out knowing that all four pipes would have a cross over point at that location. I'm not sure of the science or theory that might be behind having the pipes with a slight internal leak between all four pipes, but it seems to work. All of the lengths of pipe before the collector are different anyway. For whatever reason it seems to work well.

When I got the Buckshot Racefab side pipes the surface which mates to the headers was perfect with clean welds and a perfect flat surface. I've not had an outside gasket leak yet, but still do have a low spot in the center of the header side of the connection. Here is a link from my gallery of a dyno pull. The pull has zero smoothing for display and would be corrected values.
http://www.clubcobra.com/photopost/d...3_wheel_HP.JPG
Torque and Power is pretty good, maybe better with the little space, who knows? I'm not going to worry about the center. Exhaust is weird at times.

I've ordered new gaskets from the Olthoffs and the place out of California for a good value. I keep a little stack of them around the garage.

[scootter]

I bought new gaskets from Superformance. They were cheap and they shipped right away. I cut the centers out before putting them in. I also used stainless steel bolts to connect the pipes. A while back I lost one or two bolts and replaced them with regular bolts. I snapped off all of the none stainless bolts when I removed the pipes. The stainless come right off. I did have to retorque them a few times after installing the new gaskets.
Scott

[dblvenom]

Planning to change my SPF factory headers with 2" customer headers...Can anyone recommend a reliable source for the headers?

[emberglo66]

Contact Olthoff Racing in North Carolina. They make a header I believe. found the image below on CC galleries .... Greg Schroeder's gallery I think

The top header in the image is the Olthoff and the bottom is the older Superformance.

I was told that Superformance has changed or upgraded their headers but have not received an answer from my dealer yet.

[emberglo66]

oops guess i should have read the whole thread.

[dblvenom]

I am aware of the new SPF headers "402's" offered through Olthoff. However, they only have larger ports and are not 2" all the way through...