PDA

View Full Version : Exhaust system flathead; crossover ?



32vertex
30-11-07, 06:15 PM
I am about to buy the parts for my exhaust system in my flatty powered 32 roadster. It will be completely one-off from headers to tips, with dumptubes right behind the front wishbone mounting point, Smithy silencers, done in stainless 2".
Should I incorporate a crossover pipe, between the left and right tubes, somewhere between headers and silencers ? What is the actual use for this ?

Any answers gladly welcomed !
erwin

Vinnie
30-11-07, 06:35 PM
Have a look here:

http://www.nsra.org.uk/forum/topic.asp?TOPIC_ID=42898

rem
30-11-07, 06:47 PM
Is a dual 2" system a bit big for a Flathead? I can't remember if there was a thread on this on the old forum, but I seem to remember one on Fordbarn where they recommended dual 1-3/4" for a street engine. Of course, if the Flattie is not the wildest of motors it probably won't matter - in which case maybe it isn't worth worrying about cross-over pipes?

32vertex
30-11-07, 07:05 PM
Vinnie, mille grazie for your reply; all clear now.
Rem; I'd like to keep the system bigfrom the start, having blowers on my mind...(i'll rip it off Jim Turnpike's ride, hehehehehe)

cheers
erwin

crusty
30-11-07, 08:19 PM
Erwin, a cross overpipe increases torque, but you have to place it in the correct place.
Correct me if Im wrong but to position the cross over correctly (someone told me this years ago) try and get it as close to the headers as possible.

Brizey
30-11-07, 08:29 PM
Vinnie, mille grazie for your reply; all clear now.
Rem; I'd like to keep the system bigfrom the start, having blowers on my mind...(i'll rip it off Jim Turnpike's ride, hehehehehe)
cheers
erwin

Don`t worry about a crossover pipe Erwin, they`re not worth it for the gains recieved.
I run 1-3/4" header pipes into a 2" system with `Thrush` turbo mufflers which give good performance and a nice mellow tone when you tromp on the throttle...

rem
30-11-07, 08:44 PM
Rem; I'd like to keep the system bigfrom the start, having blowers on my mind...(i'll rip it off Jim Turnpike's ride, hehehehehe)

cheers
erwin

Ha! Good luck with that - he'll be a hard man to beat!