I have seen people mix pump gas with 110 race fuel in the past and get by with it but I wanted to get some of your opinions before I tried it with my combination.

My motor is a 12:1 383 with TRW dome pistons and stock 906 heads.

Could I get by with mixing 50/50 or 60/40 race fuel to pump gas without damaging the engine? I know that it would be easier with aluminum heads but I was just curious if it was possible with stock iron heads.

Thanks guys!!

I do it constantly. Usually throw 5 gallons of 110 into the stock gas tank with the rest 93 pump.
10.5 compression iron head small block.

12:1 I would run the 110 straight.

Have you considered E-85? Might be worth looking into.

Agree. At 12 to 1 with iron heads I would run straight 110 to be safe

With those pistons and open chamber 906 heads, I'd run straight 110 in it.

Thanks for the input guys I was hoping to save a few bucks but if it's questionable at all I will continue to run straight 110. If I made the switch to aluminum heads someday would this be more favorable to a fuel mix?

I have thought about E85 but I am just now getting to where I can tune a gas carb a little I don't want to change now very bad lol. Plus the switch to E85 can be a bit expensive initially...

Thanks again!

The worst part is a pump gas 400 with the right cam would probably run as fast as this 12:1 383... Oh well it's what I got.

Within a year you will save enough to make the
switch to E-85... just have to understand that
you only buy E-85 during the summer months so if
you need to you fill a couple of 55 gal drums when
it tests fine(the tester is cheap).. I use to ask
the person ahead of me if I could get a small sample
then test it... never had anyone say no.. and they
would normally hang around to see the results

We run 100 low lead aviation gas in our 12:1 iron W2 408. $4.50 a gallon and available pretty much everywhere. Its amazing how many small airports there are. We've made in excess of 725hp with it. Check out https://www.airnav.com/fuel/local.html, enter your zip code and you'll find all the local locations and prices.

I agree, exactly what I do down under.

Good luck letting em pump av gas in a can or in your car out west where I`m at..........epa lol..........

any pinging is as you know extremely damaging. as said max out your octane right off the bat then proportion downward till it talks on your hottest/driest (most likely to ping) day then back up a bit cuz there is silent ping & you want a cushion to protect your baby

Yes you need to find a dodgy guy that has something to do with small planes and friend him

LOL. you guys can't even buy a NORMAL gas can.

I just take my 5 gallon cans to the airport near me and they fill them, pay the guy and leave.

Jonnyj00...100LL Avgas, if you can get, will work great in what you have and be a lot cheaper. My local airport lets me walk right in w/ my gas cans and get as much as I want. I think it's around $3 a gallon.
I didn't even think about using Avgas when I first replied.

x3

I've worked my way from 40% down to 25% LL mixed with 87 pump on all my iron-head 340's and 750 Aprilia. 10% on everything else.

Never a problem. Ever.

I can sure remember when people used to argue against avgas on here. Yep, "your car is not an airplane" .

Well, I don't know what's wrong with yours but mine sure grows wings when the Av hits the tank.

I've been asked to leave... because I was trying
to buy av gas... some places dont play that at all..
I went in there with my buddy who is a pilot there...
they said something to him also

I walked into the airport Saturday morning and bought 5 gallons. Think I paid $3.79 a gallon. I put 40 miles on the Lycoming powered airboat Sunday so Friday before I go home from work I'll pick up 10 more gallons. They wont let me bring the boat to the pump but will watch me carry all the gas cans I want. lol My coronet will be running it instead of race fuel this year