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chris78 05-21-2013 11:40 PM

spark plug choice
 
I have a 40 over 350sbc in my drag car with flat tops and phase two bowtie heads with 64cc chambers.this heads had 184 runners i believe but have been professional port out to about 194 and have 2.02 valves.I've been running auto light racing 134 spark plugs but have to replace them often and been told need a hotter plug by guys at track.wondering if anyone had a recommendation on what would be a good plug to use.i run a 750 holley and i putting quite a bit of fuel to the motor.any advice would be gratefully appreciated .

F-BIRD'88 05-22-2013 01:05 AM

Swap in a set of Champion RV8C plugs. The carb probabily nned work and the ignition timing curve probabily needs work. a matter of setup.
More details on the engine. Camshaft/ carb jetting/power valve// spark timing curve fuel used.

chris78 05-22-2013 03:22 PM

The carb is borrowed so unsure of the jets probably factory its a holley 750 vacuum secondary.the cam us a comp extreme energy. 12-677-4 advertised duration 274/280 with .501/510 lift and i have 1.6 roller rockers.i know carb had a kit in it last fall.my main concern is i have been told the ar134 plugs are not a hot enough plug for the compression i have now.on new plugs car runs good 8.15 in the 1/8 at 86mph but after 20 to 30 passes plugs are dead .wondering if a different plug would help this.i would like to stick with autolite if i could.

oldbogie 05-22-2013 03:29 PM

Quote:

Originally Posted by chris78 (Post 1677673)
I have a 40 over 350sbc in my drag car with flat tops and phase two bowtie heads with 64cc chambers.this heads had 184 runners i believe but have been professional port out to about 194 and have 2.02 valves.I've been running auto light racing 134 spark plugs but have to replace them often and been told need a hotter plug by guys at track.wondering if anyone had a recommendation on what would be a good plug to use.i run a 750 holley and i putting quite a bit of fuel to the motor.any advice would be gratefully appreciated .

Are they fouling with fuel or oil, or busting up? The former would need a higher heat range to get'em and keep'em clean. It they are busting up it would mean detonation or preignition in which case a hotter plug would be the wrong direction to go.

Bogie

chris78 05-22-2013 03:52 PM

They are fouling.pulled them othet day and they were extremely wet with fuel.i believe they need to be hotter just don't no how much and what to use

F-BIRD'88 05-22-2013 04:49 PM

You need to expand your horizons a bit. Champion RV8C is the right spark plug.
There is no exact Autolite cross ref for this plug.

Plugs are WET.. you have a carb fuel control issue...flooding,fuel pressure.needle seats fuel filter etc.,

there is a big difference between WET plugs and plugs that are a little on the cold side.

and or a ignition system fault. Cap coil wires etc..
But the RV8C plugs are the right plug for the job.
any auto parts store will have them.

chris78 05-22-2013 08:45 PM

Are the RV8C's a short plug or long.I'm used the ar134's because there short to work with my headers because the bowtie heads are angle plugged so the don't leave much room with my headers .

oldbogie 05-23-2013 12:11 PM

Quote:

Originally Posted by chris78 (Post 1677855)
They are fouling.pulled them othet day and they were extremely wet with fuel.i believe they need to be hotter just don't no how much and what to use

The AR134 is only one heat range below the hottest range for that plug. A heat range typically changes the tip temp about 100 degress F. So if these are soaking wet, I'd be inclined to look at the mixture ratio more-so than the plug heat range at this point.

Bogie


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