racing fuel

[thebig450es]

Who here uses racing fuel for their built engine? I never used it, but with the high compression stroker build almost done i need to run a min of 110. I found some sunoco 112 leaded for only 7.99 a gal.

[2001400exrida]

what compression is it?

if it's 11:1 you can run 100 octane. lots of airports sell it for like 4.50 a gal.

[NacsMXer]

I used to run straight 110 in my GTT stroker. But FYI, just last summer I started using a 50:50 mix of 110 leaded and pump premium 93 with no problems at all, even on the hottest days. There's a way to calculate the mixed octane, but roughly it becomes somewhere around 100 octane.

I have 2 local gas stations that sell the 110 leaded at the pump, so if you can get that Sunoco 112 the same way it's always convenient. The race fuel is expensive, but the 400EX only has a 2.6 gallon tank so it really isn't too terrible. And if you do a 50:50 mix with 93 you will offset the cost even more.

One thing I like about the race fuel is it's self-stabilizing. It will not break down, varnish, or gum up your carb like the ethanol pump fuel will if you do not treat it with Stabil/Seafoam. It will keep for months and months without issue.

[thebig450es]

Well its the same compression as nacs engine but i was talking to laz about keeping the +6 key which would need the extra octane. And since race fuel has a good shelf life i'll buy 10 gallons and have it. Also this station has 100 unleaded for 5.99 a gallon.

[2001400exrida]

depending on your compression....the mix is a good money saver too. 2 gal of each at a time is what i used to do.

Now i go to the airport for the low leaded 100 avgas. it's cheaper at $4.49

[NacsMXer]

Originally posted by thebig450es
Well its the same compression as nacs engine but i was talking to laz about keeping the +6 key which would need the extra octane. And since race fuel has a good shelf life i'll buy 10 gallons and have it. Also this station has 100 unleaded for 5.99 a gallon.

I agree with Laz, I would run the straight 110 if you add a +6 key. I run stock timing on mine. You might be ok with 100 octane but there's no good way to say, and isn't worth chancing it. Leaded fuel is more desirable anyway.

That thing's gonna be a runner if you add a +6 key lol :eek2: You would be the first person i've ever heard of to run one of those with that stroker kit.

[thebig450es]

How much advancment is worth while? Can you have too much advancment to where power goes down. It will have the +6 and the GTT CDI, which create heat so i'll be running the 112 leaded and a spal fan and air scoops. The 112 is rated by sunoco for 15:1 compression but idk the conditions of the engine...air or liq cooled. Thanks Nacs for all the great pms and posts.