what fuel can i run

[wagonman]

On a recent 1000 mile trip with a 11.5 SBC I used VP additive. In a 19 gallon tank with 91-93 premium added half a quart can and really felt a good difference. Got it at a local race fuel supplier, $18 a can. Supposed to raise octane 5 points and I belive it. On the first tank used some 108 octane boost and the car started surging BAD. Live and learn. The VP also smells like race fuel from the exhaust when running. I also use Lucas boost with good results on my 440 but it is way lower compression, like 9.8-1.

 

[383coronet]

hi guys putting my big block mopar together and before I buy a carb I was wondering what fuel im going to have to run here are the specs on the motor 500 ci with wiseco pistons for a 4.150 stroke and 6.760rod flat top pistons book says 11.5 to 1 compression with 78 cc heads I have the trick flow 240 power port heads with a 40 thousands head gasket and a 15 thousands deck clearance wondering what my actual compression will be in the end and what fuel im going to run 93 octane e85 or if I can run 91 octane thanks cj

If this is mainly street car i would get different pistons.You wont loose much power going down 1 point compression.

 

[Ironbuilt]

called them today looks like im at 11.45 to 1 comp thanks for the help do you guys know what a drum of 110 is going for

Here is a 2018 price chart that will give you a general idea.
https://us131msp.com/racing-fuel-prices/

I did a little search and it seems that Sunoco Race fuel is available in quite a few places in Wisconsin. Be happy that you don't live in Commiefornia.

https://www.sunocoracefuels.com/fuel-finder?city=&state=Wisconsin&zip=&fid=&range=300

 

[Bicylindrico]

Maybe you should run your known engine specs through a calculator to determine your static & dynamic compression and see where the numbers come in. I kept seeing to keep your dynamic compression under 8.5:1. I came in at 8.6 and have no problems running 93 octane with a can of octane boost

 

[69 GTX]

Are your pistons flat tops or do they have a D dish? Quench can play a big part in detonation. I told my engine builder I wanted to run 91 octane fuel. We ended up with 9.9:1 compression with a D dish flat top piston and a 236/242 cam with the trick flow 240s. He also said I might be able to get away with 89 octane. There are many variables to consider. Even the humidity can make a difference one day to the next. Everything must be planned to work together. My 2 cents is your flirting with too high of compression for the street.