New rebuilt 283 chev engine?
I have just started a new 283 chev engine and run in the cam.The engine has a mild cam and ported heads etc and runs a 650 holley carb.I have been playing with the jets in the carb and they seem to be ok at first on idle and then after the engine comes up to temp 170 f the right exhaust starts to puff a bit of black smoke. ( the left exhaust pipe is fine ). Can anybody shed some light and could you also let me know what the timing and plugs should be.I'm prity sure the plugs and timing is ok but I thought i'd check.
Unfortunately the hotrod ( 32 Ford ) is not licenced yet so driving it on the road is out of the question for now.
- Anonymous1 decade agoFavorite Answer
the right bank is getting too much gas.try turning in the right jet a little more.
- 1 decade ago
Assuming you have correct jets, First, the holly... make it gone. (a little secret here, an old quadrajet,mid-to-late 60's can be made to flow up to 750c.f.m. simply be changing both the front,AND rear jets, later models did not have replaceable rear jets) Second, a 650 is too much for your poor 283(I love 283;s, done many of them), a 500, maybe even a 600, with a little extra porting, and slightly more than 'mild' cam, but not a 650. A good set of headers will help scavenging the waste output mix, do not forget a crossover pipe here. Back in the day, it was common to use larger exhaust pipes(progressively), but the progressive use of smaller pipes is growing in popularity( the belIEf is that this speeds up the exhaust flow due to more restriction, ie: same amount of exhaust- smaller pipe= exhaust has to travel faster, I am not sure of this myself, being old-school). Kinda got off the beaten path there for a moment, sorry. You may want to recheck your heads, I assume you had them magna-fluxed, if not your valve seats/valves may have issues. hope this helps, and I am not clouding the issue for you. OH, you may want to recheck your valve seals also.Source(s): Dunn-Wright Transmission Service and Auto Repair. owner-(burts chevy)
- Anonymous1 decade ago
Hmm.... playing with the jets.... I would go back to the stock jets and reset the carbs rich/lean mixture screws. A 650 should be fine on a 283, you could go a little bit bigger, like 700cfm.... but your carb is just right for your engine. For plugs I have used (for 25 years now) Champion and never have had any problems. Every plug manufacturer has platinum plugs now. I would stay away from Bosch and NGK, I've had bad experiences from them.
- 1 decade ago
Put a quadrojet on it.
Thing a small cubic inch engine and a large carb over 650 cfm is theirs a chance to over fuel the engine especially at idle.
If you have platnimum plugs in it throw them away.
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- 1 decade ago
trash the holley -283 needs a 600 max is intake ported and polished ?--plugs arent bosch are they? alot of open avenues here-huh?Source(s): ase master tech gm tech -and so on -