Fox T-Bird/Cougar Forums

Technical => Engine Tech => Topic started by: 20thanniver-ls on November 04, 2008, 06:36:19 PM

Title: general exhaust ????
Post by: 20thanniver-ls on November 04, 2008, 06:36:19 PM
this may be a dumb question, but is it harmful to a motor to run it (just at idle) without any exhaust manifolds or exhaust connected?:mullet:
Title: general exhaust ????
Post by: 32VFoxBird on November 04, 2008, 07:33:03 PM
not a good idea. you could warp the valves, with having absolutely no back pressure.
Title: general exhaust ????
Post by: 20thanniver-ls on November 04, 2008, 08:42:44 PM
what about with just the headers? would that make any difference?
Title: general exhaust ????
Post by: ZondaC12 on November 04, 2008, 08:44:32 PM
Here's a question. Exactly how long do you need to run this for like this...?
Title: general exhaust ????
Post by: 20thanniver-ls on November 04, 2008, 08:46:17 PM
just long enough to see if the exhaust was the problem i was having maybe about 3 or 4 minutes
Title: general exhaust ????
Post by: 32VFoxBird on November 04, 2008, 08:57:42 PM
and why would removing exhaust solve a problem?
Title: general exhaust ????
Post by: 20thanniver-ls on November 04, 2008, 09:15:47 PM
cats were smoking, believe they were clogged and not releasing pressure from the engine
Title: general exhaust ????
Post by: V8Demon on November 05, 2008, 07:15:46 AM
Quote
you could warp the valves


Depends....With open headers in place I'd say no as I've done it.

Excellent discussion on the topic here:
http://www.eng-tips.com/viewthread.cfm?qid=225069&page=1

Quote
with having absolutely no back pressure.


NO.  It's the possible lean condition that causes the POTENTIAL problem. 

http://www.foxtbirdcougarforums.com/showthread.php?t=19019

http://www.popularhotrodding.com/enginemasters/articles/hardcore/0505em_exh/index.html

FWIW anybody who states backpressure is needed in an exhaust should shove a banana up the pipe(s) on their vehicle and take it for a drive.  Let us know what happens ;)
Title: general exhaust ????
Post by: ZondaC12 on November 05, 2008, 11:13:00 AM
:rollin: :laughing: Yea that is thrown around SO much. Only time it might actually be relevant is with 2-stroke engines, but even then I don't know a whole lot about it.
Title: general exhaust ????
Post by: 20thanniver-ls on November 05, 2008, 04:15:50 PM
did you drive it with open headers or just let it idle?
Title: general exhaust ????
Post by: V8Demon on November 05, 2008, 04:17:20 PM
Drove it 30 miles....non stop to where the welding machine was ;)

That was about 10 years ago.
Title: general exhaust ????
Post by: 20thanniver-ls on November 05, 2008, 06:44:00 PM
backpressure......:mullet: just makin sure i wont screw anything up