tuning an alky motor

Old 01-24-2011, 05:29 PM
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fast75vega
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Default tuning an alky motor

ok... one of our vega's has 434ci sbc running on alky. we think its running rich cause it never gets over 160 deg. and the oil gets real milky after just one weekend of running. we want to install the sensor in the exhausts but not sure how to got about it or what to look for while tuning it.


any help as to what you think as far as the engine temp/ milky oil problem or how to do the sensors would be great :wink:
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Old 01-24-2011, 06:23 PM
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maxpower671
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how about a complete rundown of your car and application..
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Old 01-24-2011, 06:36 PM
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fast75vega
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its a 1/4 mile drag car

434ci sbc pro top heads...it has a 4/7 swap 675 lift cam.......950 holly carb (i think it has 151 jets all the way around)

the engine temp just doesnt get hot....the highest it gets is just under 160 on a hot day

what is the best way to go about tuning it?
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Old 01-24-2011, 08:40 PM
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hammertime
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Does it gain any temp going down the track ?

any idea where the idle mixture screws are at ?
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Old 01-24-2011, 09:48 PM
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fast75vega
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Originally Posted by hammertime
Does it gain any temp going down the track ?

any idea where the idle mixture screws are at ?
it never goes over 160 even after a run
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Old 01-25-2011, 05:45 AM
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fast75vega
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car runs 9.50's and very consistent....... the car runs cold and seems really rich.......plus doing alot of oil changes cause how milky it gets. i know it will run cooler and use more fuel but i dont know if the milky oil is normal or if not getting up near the 200 deg temp is hurting anything?
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Old 01-25-2011, 07:07 AM
  #7  
maxpower671
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Default Build some Heat!

Originally Posted by fast75vega
car runs 9.50's and very consistent....... the car runs cold and seems really rich.......plus doing alot of oil changes cause how milky it gets. i know it will run cooler and use more fuel but i dont know if the milky oil is normal or if not getting up near the 200 deg temp is hurting anything?
try leaning it a little at a time...when your consistency goes away you're too lean...you may build a little heat during the pass..

your oil is getting milky because you are too rich, and/or you are not getting enough heat in the engine... do you have header evacuation or a vacuum pump?

with mechanical injection, fuel can be bypassed to lean engine out and build heat, with a carb not sure what would be the best way? :?:
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Old 01-25-2011, 08:35 AM
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fast75vega
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no vac. system. we even turn the fan and water pump of trying to build heat and the damn temp stays put(we tried different temp gages too to rule out a bad reading) i heard that you can tune by exhaust temp ... is this true and how is it done? what temp should the exhaust be at then ?
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Old 01-25-2011, 12:25 PM
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hammertime
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Originally Posted by fast75vega
Originally Posted by hammertime
Does it gain any temp going down the track ?

any idea where the idle mixture screws are at ?
it never goes over 160 even after a run
so if you hit the starting line @ 160 it stays at 160 when your back at the trailer ?

How about the idle mixture screws in the metering block, they will have a lot to do with it at idle building temp.

How big of a radiator do you run ?
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Old 01-25-2011, 12:51 PM
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fast75vega
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Originally Posted by hammertime
Originally Posted by fast75vega
Originally Posted by hammertime
Does it gain any temp going down the track ?

any idea where the idle mixture screws are at ?
it never goes over 160 even after a run
so if you hit the starting line @ 160 it stays at 160 when your back at the trailer ?

How about the idle mixture screws in the metering block, they will have a lot to do with it at idle building temp. the radiator is like 2ft x 2ft x 3"

How big of a radiator do you run ?
yeah.... it will be around 160 after a run and as we get back too the trailer. it will be around 145 at the line as far as the screws go... im not sure off the top of my head
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