Conventional head 15:1 BBC, 34* timing on alcohol.
-9 NGK plug gapped at .025
Switching to 112 race gas.
Should timing stay the same?
Should plug stay the same?

I would use 116. You will most likely see less swings in DA. I'd stay the same on plug and timing.

I'd say 114 at a min, might call your favorite fuel company and ask them.

Under 7500 RPM's and staging under 150 degrees I'd have no worries using 112 fuel.
Leave the timing until you read a plug and adjust from there.
I run -8 plugs at near 15:1 on 110 gas.

Why switch? Agree on the fuel, I'd go 116. Although my stuff was 12*, it wanted 4* more timing on alky than on gas...But for a conventional headed BBC, that seems like a reasonable number, but I'd start at about 30-32 and see what the plugs tell you...

I would go down to Killeen, Texas at Cen-Tex Dyno and dyno the motor. Joe will get you dialed in quick and then you will have good tune up and know exactly torque and horsepower to get perfect converter. He can tell you if it needs more octane, get timing perfect and will save you a ton of money over weeks of testing.

not to argue. Why switch to gas?

Because I can

quote:

Originally posted by Big Steve:
Conventional head 15:1 BBC, 34* timing on alcohol.
-9 NGK plug gapped at .025
Switching to 112 race gas.
Should timing stay the same?
Should plug stay the same?

What CID? VP C14 fuel or X16 or C15, do not run C16! Alky timing sounds close. Depending on the piston dome, it may like 36 to 38.
Same plug for sure! I'd open the gap to .035

quote:

Originally posted by wideopen231:
not to argue. Why switch to gas?

Quicker warmups, cleaner oil, near zero maintenance required, and don't have to carry 55 gallons for a race weekend.

I've had some guy tell me he couldn't afford to race if he had to pay $8.00 a gallon for race gas......same guy who has used up 3 fire extinguishers last season trying to get his P.O.S. alky carb engine started cold.

quote:

I've had some guy tell me he couldn't afford to race if he had to pay $8.00 a gallon for race gas

What race gas can be had for that $8 price? Have to believe race gas is more than that.

quote:

Originally posted by Goob:

quote:

Originally posted by wideopen231:
not to argue. Why switch to gas?

Quicker warmups, cleaner oil, near zero maintenance required, and don't have to carry 55 gallons for a race weekend.

I've had some guy tell me he couldn't afford to race if he had to pay $8.00 a gallon for race gas......same guy who has used up 3 fire extinguishers last season trying to get his P.O.S. alky carb engine started cold.

Goob

I have run both gas and alky (carb and injection). Properly setup alky will not milk the oil, if fact is stays cleaner longer. From a cost factor, it's a bit cheaper or was when I ran it but as you stated you will use twice as much. Over time alky will rot out AL fittings, even with top end lube added. They both have their place in bracket racing.

These days, I don't see any consistency advantages with alky over gas. In fact there are times where I know gas is more predictable than alky. Same with Q16 vs race gas!

After doing some research and comparing specs on VP, Sunoco and the new Fuel factory race gases and on a very good recommendation I ordered a 55 gal drum of Sunoco Maximal from my local distributor. $780 for drum delivered to the house. Should last me all season.
Just for a little comparison, I would bring 70 gallons of alcohol with me when I ran a NHRA event with the Blown TD
https://www.sunocoracefuels.com/fuels/fuel/maximal

quote:

Originally posted by markemark:

quote:

I've had some guy tell me he couldn't afford to race if he had to pay $8.00 a gallon for race gas

What race gas can be had for that $8 price? Have to believe race gas is more than that.

I'm running Finish Line 110, direct from a bulk distributor, picked up local in the drum for $400. ($7.27 per gallon)
Don't know if there will be a bump this year yet, I still have 50 gallons left over from last season.
I usually buy 2 drums in the spring. We run it in various mix ratios in the grandkids motorcycles and go carts too.

quote:

Originally posted by Big Steve:
After doing some research and comparing specs on VP, Sunoco and the new Fuel factory race gases and on a very good recommendation I ordered a 55 gal drum of Sunoco Maximal from my local distributor. $780 for drum delivered to the house. Should last me all season.
Just for a little comparison, I would bring 70 gallons of alcohol with me when I ran a NHRA event with the Blown TD
https://www.sunocoracefuels.com/fuels/fuel/maximal

Big

I have run Supreme at 16 to 1 with no issues. Max is a good fuel too. I friend has a 9 degree motor with 17 to 1 and sprays a 150 shot with Max.

Steve, Top38 is correct. 38* on Sonoco blue 112. Depending on the conditions, don"t be surprised if it likes 40*. JMO

P.S. Yes open the gap to .035.

Thoughts about methanol Vs gasoline.
The original question from Steve is related specifically to his engine. The intake port and combustion chamber of Steve's engine present certain air and mixture patterns. Another engine will have different results. Example, the SBC 23* intake and chamber present different mixture patterns and because of that, in almost all cases the SBC is faster and more consistent on methanol. Thus, when talking about pros and cons of fuel, the specific engine must be a part of the discussion.

quote:

Originally posted by Big Steve:
After doing some research and comparing specs on VP, Sunoco and the new Fuel factory race gases and on a very good recommendation I ordered a 55 gal drum of Sunoco Maximal from my local distributor. $780 for drum delivered to the house. Should last me all season.
Just for a little comparison, I would bring 70 gallons of alcohol with me when I ran a NHRA event with the Blown TD
https://www.sunocoracefuels.com/fuels/fuel/maximal

70? wow

agree on 70 gal. thing / Never used more than 40 with the funny car or TA/d. Plus price difference at time just made buying at the track easier and hauling leftover home for later.