When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Happy New Year everyone! Got a question for you experts. I am in the process of building my exhaust system for my flathead V8. I have reds headers, the long style and smittys mufflers. I am at the point of .welding my pipes up and my question is should I install a crossover pipe?
I see most dual exhaust setups have a crossover. What is the purpose and are they necessary?
I want to do this right.
I don't think a crossover will do much on a flatty. The exhaust path is so long before it gets to the trans area that any attempt at tuning isn't going to be successful. I've never seen a flatmotor with a crossover, and you can bet if it offered an advantage you'd see them.
That sounds reasonable Ross. I think I will forget about the crossover my Reds headers are about 3 or 4 feet long.
Tinman, my pipes are 2" diameter as are my smittys mufflers.
Just a side note; the stock intake manifold provides a crossover between #2, 3, 6, and 7. You can plug it to help keep the carb cool, it's an old hot rodder trick. The difference in exhaust note is amazing, considering it is only 5/8" diameter. I have been running with plugs in the passage, drilled out to 1/4" to provide some heat, and got a distinctive "rap" at about 2000 RPM or so, very pleasing actually. This summer I discovered my carb was ice-cold after running at full temp in 90 deg. weather, so I took the plugs out. It is much quieter, and the rap is gone. It also runs better under almost all conditions.