I was wondering how much Hp you think a motor would lose by lowering the compression by a couple of points. I currently have a 13.5 - 1 512 with cnc ported max wedge Indy SRs. The motor made 800 Hp and 710 torque. I live in Canada and our wonderful government is making purchasing race fuel a difficult proposition. Plus the cost is to buy it is sky rocketing. A buddy just bought a barrel and it was almost 900.00. This is crazy!!! I am thinking that pump gas is the way to go! I have raced a lot of Super Street in the past and the car with the current set up will run 10.90 at 135 - 137. It is plenty fast but wondering what you think it would do with 11.5 rather than 13.5

Honestly it could be as much as 10% of overall power, maybe more, maybe less. Figure at least 50-80HP.

Does Canada offer E85 fuel yet If so convert to that instead of lowering the comression Or maybe convert to straight Ethanol fuel if it is cheaper than race gas like here in the states

Thanks Guys - So far no E-85. Not sure the Oil tycoons in this neck of the woods are all that fond of veggie power. I had considered the alcohol route but was unsure of all that was involved and have heard lots of "horror stories" about milk shake oil, draining carbs at night, water in the fuel etc. Pump Gas just seems simpler.

13.5:1 at your elevation I would not hesitate to run 100LL AvGas. You will hear many opinions on this, however, I can state having no issues with 100LL at that compression ratio running in Alberta.
I certainly do not want to start another AvGas thread but thought you should take it into consideration before lowering CR of the motor.

Edge - That's a thought! Had not considered Av Gas. I may have to consider that.

Have you got your motor done yet??

B1 Motor is finished, looks nice but headers not finished yet so we have not made any noise yet, car is currently getting a full moly 25.5 chassis with four link and strut front end, decided the ladder bar back half would be to much of a handful on some of our tracks so will have to wait till next season

Looking good. When its is all done you will have to bring it to Castrol. I think there were 50 A body mopars at the track on Sunday and only 2 early generation Camaros. Never thought I would see the day. I remember when my Demon was different! Not any more. Build Looks really good! Looking forward to seeing it in person. Good luck with the build.

Probably about 30 hp max and with aluminum heads.Ypu might loose .1 in the quarter at full power and you will be able to run 94 with 255 ish @ .050 cam. Cylinder pressure is the key keep cranking below 200 and 94 should be fine. That is all I have ran for 9 years since I got Indy heads. My old motor ran for 5 years with 195 low and 204 high cranking on 94. 263 @ .050 flat tappet 11.7 to 1 compression.
This one is 11.5 to one with 272 roller thinking of going to 91 once I get rings broke in I'll check my cranking but can't see it going past 170.

Old 540 RIP had a 274 @ .050 roller and 11.6 to one and was fine on 94 only about 165 cranking and it never blinked on 94 even in 40 F sea level air (5 C in french) too bad the balancer failed and gutted the engine (my fault long story )

My cam is 272 Intake and 280 Exhaust at 50. Wondering if you think this would work?

Heck yes mine is 272/ 282 @ .050 roller 11.5 to 1 452 inch and runs great on 94. I have aluminum rods that may actually give me more compression hot with growth.

What is your cranking compression now???

Bet you only have to drop to 12 to one to be cool on 94. (maybe only 12.5) what is your stall speed

Here you go..


http://www.wallaceracing.com/hp-cr-chg.php


Chris..

800 HP at 13.5 to 1 compression = 762.73 at 11 to 1. You coul use toleuno at 25 percent and mix it with pump gas. You can buy it at any paint store.

Thanks guys for your replys. It would appear that the power loss would not be significant. As I had said I am already way faster than I need to be to run my class. Jim the alcohol thing is interesting. I was checking out Rons Web site and they make it look easy. I guess I will see. Has anyone had any experience with the snow performance system that injects ethanol into the engine?

Thank you. I don't know that I will do this but I just added you to my watched users list and If I go forward I'm sure I will be asking you lots of stupid questions.

check the prices of avgas, its a good option but not always cheap...airports set their own prices usually and if they have a monopoly the price is typically 15-25% higher so shop around. Tim

On your deal lowering the compression to under 11.0 to 1 would be what I would do
My old 518 C.I. low deck stroker motor(10.78 to 1 comp ratio) with a set of Indy SR M.W heads pump gas Duster that weighed 3450Lbs with me in it ran 9.993 at 134.+ MPH in the 1/4 through the full 3.0 inch exhaust system on the car with the 16x3 inch tall air cleaner on using the local 91 octane pump fuel
That motor made 727 HP at 6500 RPM with a single 1050 CFM Dominator carb on the stock early cast Indy 400-3 intake manifold in Klamath Falls, OR at 4300 Ft altitude on a stingy DTS engine dyno, no all out trick race parts at all
I run pump E85 on my current bracket car, I love it and so does the engine

Where are you in Alberta? There is a gas station on 17th ave sw in Calgary that sells E-85 now.
https://gbfuels.biz/home/e85/

8.5 years later lol