pontiacfreak142 Posted October 18, 2012 Report Share Posted October 18, 2012 This is my dads car, it has a flat tappet 302 in it with heads, cam, flat top pistons, intake and quick fuel 750 carb. The car has 2 issues that we are pretty sure are seperate. First one started a couple weeks ago with the car just randomly getting extremely rich to tje point it will miss/ backfire when you get into it. He has checked all the jets and everything seems good. His guess was possibly a power valve?. Second issue is the one we are really worried about. It just started this past weekend, but at about 3000 rpm, it gets a nasty vibration to the point that i tightend down his air cleaner, even just reving it in neutral would cause it to vibrate loose and start spinning around lol. Any ideads on what to check? Quote Link to comment Share on other sites More sharing options...
DKilbourne Posted October 18, 2012 Report Share Posted October 18, 2012 Check and see if the balancer is coming apart. Quote Link to comment Share on other sites More sharing options...
Green Bastard Posted October 18, 2012 Report Share Posted October 18, 2012 ^^ I was thinking the same thing, but also, are you having any spark issues? If spark is blowing out (i know its not as likely on a n/a motor), it could cause vibration and it to run rich. Quote Link to comment Share on other sites More sharing options...
nurkvinny Posted October 18, 2012 Report Share Posted October 18, 2012 Check and see if the balancer is coming apart. Yep. Quote Link to comment Share on other sites More sharing options...
schmuckingham Posted October 18, 2012 Report Share Posted October 18, 2012 Balancer, if it is an auto car something my have ballooned in the converter too Quote Link to comment Share on other sites More sharing options...
pontiacfreak142 Posted October 18, 2012 Author Report Share Posted October 18, 2012 Check and see if the balancer is coming apart. That was one of our first thoughts, but havent had a chance to check it yet, but will do. We have checked the entire electrical system and everything seems to be fine there. Quote Link to comment Share on other sites More sharing options...
DKilbourne Posted October 18, 2012 Report Share Posted October 18, 2012 That was one of our first thoughts, but havent had a chance to check it yet, but will do. We have checked the entire electrical system and everything seems to be fine there. I've seen a few of these come apart. Not hard to pull either. Quote Link to comment Share on other sites More sharing options...
gbracing81 Posted October 18, 2012 Report Share Posted October 18, 2012 Maybe the oval is coming loose, better put a bowtie around it before it falls off Has he had a chance to isolate the converter yet? Quote Link to comment Share on other sites More sharing options...
NTHER91 Posted October 18, 2012 Report Share Posted October 18, 2012 750 cfm is way to big a carb for that unless its got something you didn't list. Even at 100% volumetric efficiency it wouldn't use a 750 Quote Link to comment Share on other sites More sharing options...
Cordell Posted October 18, 2012 Report Share Posted October 18, 2012 750 cfm is way to big a carb for that unless its got something you didn't list. Even at 100% volumetric efficiency it wouldn't use a 750 I tried telling his dad that 2 years ago when you could see the fuel vapor behind the car going down the track. Quote Link to comment Share on other sites More sharing options...
Buckeye1647545503 Posted October 18, 2012 Report Share Posted October 18, 2012 I'm on running a 750 on my 393 Quote Link to comment Share on other sites More sharing options...
pontiacfreak142 Posted October 19, 2012 Author Report Share Posted October 19, 2012 Maybe the oval is coming loose, better put a bowtie around it before it falls off Has he had a chance to isolate the converter yet? Nope not yet, hes gonna take the balancer off first, but hes leaving for tennesee this weekend so thats not gonna happen till he gets back. The awesome thing is, when the vibration got bad, his first words were " time to put an LS in it" lol Quote Link to comment Share on other sites More sharing options...
pontiacfreak142 Posted October 19, 2012 Author Report Share Posted October 19, 2012 750 cfm is way to big a carb for that unless its got something you didn't list. Even at 100% volumetric efficiency it wouldn't use a 750 Yea we know. Hes planning on building something bigger for it in the future (pending on whats wrong, maybe the near future), so he planned ahead on went bigger. I guess he called quickfuel and asked them if he could it to work ok with his setup and they told him the main body was the same size as the 650 and told him to change a few things out and would be ok. Its always been rich, but doesny seem to be to bad usually. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.