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Imaginos 12-07-2009 05:48 PM

Good Sparkplugs for 350 Chevy
I was wonder what would be good sparkplugs for my 350 Chevy motor
here are some specs of it
Bored 40 over
512 Lift roller cam
462 Camel hump heads ported & polished from 67 corvet
600 holley
Eldebrok Perfromer intake

My motor always likes to flood and I have to change oil about every 800 to 1000 miles because I smell gas in it over time.
I have tried several different carbs including.
600 holley
750 edelbrock
750 Qudrajet
750 Holley Double Pumper
680 Quick Fuel

The 600 holley seems to be the best but my motor still dosent burn the fuel good someone told me I need spark plugs with hotter heat range.

Any Idea's guys ?


fast68 12-07-2009 05:55 PM

r45 or r46

holley are good for just dumping fuel

i dont like them

q jet way better

good luck

Imaginos 12-07-2009 06:03 PM

Thanks I will try those.Im also going to buy a rebuild kit for my quardrajet and put it back on I would have left it on but it has a bad dead spot and I dont know how to hook the choke up on it.I asked Advance Auto about it and they said that my Quardrajet takes a manifold with a heat riser what ever that is the man said that my Q-Jet was from 1969 or 70.Also gonna get some lower gears my car is 2.73 I wanna go 3.73 or 4.11.

Carlos Murphy 12-08-2009 01:50 AM

Fuel pressure?
What about fuel pressure?

Too much pressure can push fuel past the needle and seat, wash down cylinders and contaminate oil.

Imaginos 12-09-2009 11:41 PM

Thanks Carlos never thought of that.I'm gonna buy a gauge to check it with.What should normal psi be for a manual fuel pump ?

Carlos Murphy 12-10-2009 12:25 AM

Without looking it up, I would say 3 psi.

DoubleVision 12-10-2009 12:47 AM

With more compression and hot rodding mods you need a colder plug, not a hotter. By all means as you`ve already said, get a fuel pressure gauge. You can`t and won`t know what`s going on until you do. I`ve already learned, if the vent is blocked and there`s no other vent the fuel pressure can build and will go up to 14 PSI with a STOCK fuel pump just because the air pressure is pushing it. If every carb you`ve tried has had this problem chances are the rings are already shot from fuel wash down. But if the fuel pressure is in check then the problem is the fuel pump, when they bust internally fuel goes out and into the crank case causing massive wear very quickly and a very dangerous situation, one spark when the engines running with fuel in the oil and it`ll blow the valve covers off. A hole in a piston can cause this same thing. If the engine has already been exposed to this kind of condition you may as well rebuild it, as it won`t be long before the rings are gone so bad it smokes like a tar keel. Already seen it happen on a stock engine that got filled up with fuel once a week from a bad fuel pump. I told the owner what the problem was only he didn`t believe me. When we was rebuilding it a month later he learned rather well.

Imaginos 12-10-2009 12:58 AM

This motor has less than 4k miles on it.Fuel psi gauge will be installed next week when I get the time.I hope I havent ruined anyhthing.Mayby it just needs a new fuel pump.I bought this motor allready put together it was built about 4 years ago and i got it in 2009.
It was still sitting on an engine stand when I got it never even been started.
Can a fuel pump go bad just sitting on a engine over time even if it is not been cranked before ?

Carlos Murphy 12-10-2009 01:20 AM

Was the pump new when installed on the rebuilt engine or was the original pump re-installed?

Fuel sitting in the old pump could have turned to varnish and gummed it up.

Imaginos 12-10-2009 01:27 AM

It was new.

DoubleVision 12-10-2009 01:17 PM

Yes, it can go bad. Also what many don`t know about stock fuel pumps is the cavity has to be packed with lube before start up. If not it has no other lube other than a very light coat of oil it gets from the fuel pump push rod. If it`s dry, the spring overheats inside the pump causing damage. If your pump was new and sat all these years and wasn`t packed with lube chances are it`s shot.

luis12 04-08-2012 09:36 AM

first where is these engine what vehicle and i would recomend intank fuel pump and run it at 6-8 PSI chevy is know by running good on that fuel pressure

Catfish11 04-08-2012 01:10 PM

just a thought , are your heat crossovers blocked in the intake? It could be causing the carb to heat up and percolate fuel in the bowls pushing it out also.

DoubleVision 04-08-2012 04:44 PM

This thread is three years old. I hope he's got it fixed by now.

Catfish11 04-08-2012 10:52 PM

:thumbup: :thumbup: :thumbup:

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