What are most of you using for fuel in a primer system? Higher octane pump gas, regular pump gas, racing gas or a combination or additives?

I always used just regular pump gas.....

quote:

Originally posted by "The Bender":
I always used just regular pump gas.....

Me too. Very little cylinder pressure at idle or light throttle. Never had an issue using it.

I used premium gas when I ran injection with the primer plus.

Ran that for a few years and it worked very well.

On my old car with injection I had the std primer and used pretty much any gas....worked fine as well....

If we run straight 87 octane our engines will sometimes “diesel” for a second or two when shutting them off when they’re hot. When using 91 octane they don’t diesel. I either get the ethanol free 91 from the local station or mix a gallon of the lowest octane race fuel the track has with 4 gallons of 87.

When I ran a Rons system with primer I would mix reg unleaded 50/50 with 110 race gas. Not that it was necessary I just wanted the extra octane and lead. I would warm the engine on the primer first fire up of the day and run it on the primer at the end of the day to remove the alky from the cylinders. Other than that I never used it during the day. I didnt like how it mucked up the plugs. JMO of course, your results may vary

87 octane or 93. Never an issue 582 CI 14:1 compression

I’m on primer plus with 93 octane anytime the sbc is not on racing surface. If I loose 2nd rd I’ll have gone through more 93 than methanol.

I don’t worry about what the spark plugs look like. They’ll be black from running PP system. When I switch over to methanol the engine comes to full power.

I recently pulled the plugs out of my present engine checking to see if any were wet from oil. 288 runs and they all looked perfect…… dry and black as the bottom of my race shoes. You’ve seen the pics.

What’s interesting is that the plugs go in gapped at 30 thou. They measured 39 thou now. The ones in my other engine with 500 runs on them measure 41 thou gap. The bottom of the spark plug strap is wearing away.

I’m not changing plugs in the present engine or re-gapping. I have Grid 7720 that outputs very high spark. Runs the exact same having a 9 thou larger gap now.

I mix 91 octane with 110 race gas. I’m not particular about the ratio, but didn’t like the dieseling so always want some good stuff in there.

On my primer system I could not get it right with gas or E-85 so ended up using alcohol which still makes it hard to start in cold weather.
With the way my system is now I will squirt a little gas if it is really cold on first start. Then after that I hit the primer for about 15 seconds and then hit ignition and leave the primer pump going until mechanical pump comes in and then shut off primer.

93 octane pump gas in the primer plus with a Ron's Terminator system. We run it on gas until the burnout with no problems. Our R-M 540 is easy to start in any conditions.

Personally I prefer a general race gas or 50/50 mix over straight pump. Maybe the pump gas around here is crappy. But on race gas I can run the primer leaner so the quart lasts longer. Also isn't as tempermental on the race gas. On pump gas mine will diesel like mentioned above, vary more rpm, and wants to kickback or ping on a restart

Scott

quote:

Originally posted by markemark:
I’m on primer plus with 93 octane anytime the sbc is not on racing surface. If I loose 2nd rd I’ll have gone through more 93 than methanol.

I don’t worry about what the spark plugs look like. They’ll be black from running PP system. When I switch over to methanol the engine comes to full power.

I recently pulled the plugs out of my present engine checking to see if any were wet from oil. 288 runs and they all looked perfect…… dry and black as the bottom of my race shoes. You’ve seen the pics.

What’s interesting is that the plugs go in gapped at 30 thou. They measured 39 thou now. The ones in my other engine with 500 runs on them measure 41 thou gap. The bottom of the spark plug strap is wearing away.

I’m not changing plugs in the present engine or re-gapping. I have Grid 7720 that outputs very high spark. Runs the exact same having a 9 thou larger gap now.

Autolite Racing eh?

quote:

Originally posted by Mike Rietow: Autolite Racing eh?

quote:

Originally posted by markemark:

quote:

Originally posted by Mike Rietow: Autolite Racing eh?

Hmmm, Autolite Racing lose their gap same.

I use 91 octane mixed w Xylene, usually 1/2 pint to 2 1/2 gal of gas. I pull my race plugs and put in some old sooty plugs. I do this in and out of my trailer, shop and during warm up. My system is home made, I'm able to warm up to about 2500 rpm

Always the cheapest race gas i can buy at the track. Only used generator gas once, didn't like it.

I use Av Gas. Low lead 100 in my primer system. I run a terminator and use the gas to put heat in the motor and drive around pits

My 15:1 582 was never happy with 100% pump gas. I always used race gas cut with 93 pump gas. I was unbelievable how it acted the few time I tried pump gas.