Exhaust cutout

Rat Rods Rule

Help Support Rat Rods Rule:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Willowbilly3

A *real* tin magnet
Joined
Dec 10, 2007
Messages
7,847
Location
Black Hills South Dakota
This isn't really a tech tip, more of an idea. I had a couple GM EFE flappers, you know, the thing right on the manifold dump that closes to force the exhaust through the crossover for warm up. I know they wouldn't totally seal but I was thinking they would make a cool cheap cutout. If you had them plumbed right they would just open everytime you went wfo and the vacuum signal dropped.
 
Whit,
Those things used to come on just about all the "Smogdog" GM cars and trucks in the 80's...You know, when the whole world went "Pollition Crazy":eek:
 
My Y-block 292 had a heat spring flapper on it originally. Forced exhaust through the intake crossover to warm the carb.

That would really work pretty good for me since I leave for work at 5AM and have to be real gentle on the throttle till I get out of the neighborhood. By the time the flaps warmed up and opened, I'd be gone.
 
I made cable operated butterfly type flaps and built them into the collectors on the headers on my Black Rat 55 project. When closed, the exhaust was diverted to the pipes and mufflers underneath. Even though I had a pretty good fit into the pipe they did leak, kinda like a leaky collector gasket sound you'd get with regular headers.
I guess it depends on your noise level tolerance, it wasn't so great when in city traffic, (not to mention scaring old ladies and making babies cry:eek:) but with a yank of the knob, it was full open and there is no sweeter music to my ears :cool: (when does the ringing stop ??)
 
But wouldn't it be quiet enough to get you away from the cop that's in the other lane? ;) Or like cruising through a hospital zone or the like. Or in my case, leaving for work at 5AM. An exhuast leak sound isn't cool, but sometimes loud ain't cool either.
 

Latest posts

Back
Top