quote:Originally posted by Art Stephens:
...Would it be safe to run the engine in the driveway up to 6200-6300 rpm(that is as high as Russ wants me to rev it)? I do have a 6500 chip in it as Russ recommended. I was thinking it would be nice to do it in the dark to see if any sparks were jumping...
As a first step I would like to see you identify what's causing the abnormal sound you hear coming from one side of your exhaust & repair that before going any further.
Yes its safe to rev the motor unloaded in the driveway, although the neighbors might not understand. Best way to deal with that is to invite the neighbor over to assist. If the engine is running poorly, bucking, misfiring, don't hold it there let it idle back down. Holding an engine running like that risks damaging the reciprocating assembly. Don't blip the throttle, just slowly depress the throttle and ramp the motor up. Keep your eye on the temp gage too. If there are arcs jumping around, you should see them at idle. After the exhaust is eliminated I'm suspecting low voltage causing the ignition system to loose steam as rpm increases. If that's the case, the motor should drop off, even unloaded. It won't misfire, just get weaker and reach a point where it can't rev any further. If you wired the ignition into the oem harness, feeding the MSD through the ignition switch, there is a very real possibility you have a big voltage drop that gets worse with rpm. If you have a voltmeter you can monitor voltage applied to the ignition while somebody revs the motor. As an alternative run the ignition directly from the battery with a jumper & see if the motor improves.
Troublehsooting over the internet is pretty frustrating. To do any good a person needs to be there, to listen to the motor, to put your hand on it & feel it run. The best way for you to resolve this problem would be on a dyno, with an exhaust analyzer stuffed up the tailpipe and an engine analyzer on the motor. A good dyno operator could pin point the trouble within 15 to 20 minutes.
However, you never mentioned wether or not Russ was informed of this trouble. If I were your mechanic, if that was MY motor, I would want the car into my shop pronto so I could diagnose it. I wouldn't want you listening to the advice of some cyber jockey on the internet to troubleshoot MY motor. Russ may feel the same way.
Like PTA mentioned, lets get your motor healthy before we start buying intake manifolds & carbs. Your power goal may be reached simply by getting the motor healthy.
Your friend on the DTBB