i just put a rebuilt 318 in my "79 Aspen n all i wanted to do with the exhaust is turn it it ooff the header collectors 90 degrees n run it out behind the front tires, i had a buddy tell me that i would lose my exhaust valves that way...any truth behind this and/or other problems i would run into down thee road in doin so?

 

I dont know the answer but Im sure someone will chime in. I have always heard this as well except that it will burn the valves with no exhaust manifold or header. I rebuilt a 383 when I was a kid and ran if for a long time with just open headers. I also dove it that way about 30 miles to an exhaust shop. I never had a problem with the valves.

 

You won't burn the valves with headers properly installed (no leaks). You will burn them up if you ran no exhaust though.

By having it dump out behind the front times, you will have very little back pressure and will need to run at a higher than normal RPM, fine for drag racing only applications.

If you run the exhaust so that it dumps out behind the rear tires and install a muffler, you will have more back pressure and in turn it will allow you to run at a lower RPM, great for on road driving.

 

Yeah, They are called tickets for no mufflers.

 

If your headers are properly sealed and your header extensions are reasonably tuned, you won't burn your exhaust valves.
This is just a myth perpetuated by so-called bar-room experts.

I have a similar set up to allow me to drive my racecar on the street without getting tickets and I have installed a fabricated "supertrapp" style set of disks in the end of my collectors which exit behind the front wheels.
I was too cheap to buy a set of Supertrapp disks but mine seem to work pretty well both noise wise and power wise.
This will also silence the bench racers who told you about losing your valves.

If you want to look at (and listen to) my exhausts go to YouTube and search "Raindance Cortina"