66 427/425 Fuel

[Joe Pearson]

Thanks everyone for your suggestions on fuel for the 11:1 engines. I have been buying the Cam 2 racing fuel online and delivered in 5 gallon containers. It's ridiculous at $10.00 a gallon but the motor runs perfectly on it. Perhaps I'll try a blend or the lead additives. Joe Pearson

[Clem Z.]

Re: 66 427/425 Fuel

20/25% race fuel should do it.

[Joe L.]

Re: 66 427/425 Fuel

Joe-----

Big bore engines are much more susceptible to pre-ignition and detonation problems than smaller bore engines. That's why, today, I'd NEVER build a 427 or 454 with anything like 11:1 compression ratio. All of GM's crate 454 and 502 engines with cast iron heads are built with 8.75:1 compression ratio and, even at that, REQUIRE the use of 92 or higher octane gasoline. Some GM crate big blocks with aluminum heads and designed for STREET operation are built with 9.6:1 compression ratio and require 92 octane, or higher, fuel.

You can be sure that if GM engineers thought that they could use higher compression ratios in these SERVICE-only engines and achieve knock-free operation with currently and GENERALLY available fuel, they'd be doing it. So, there's a lesson that can be inferred from this reality.

There's nothing more miserable than a "pinging", "knocking" engine. It's also VERY destructive to the engine, too. That's one of the primary reasons that, in 1969, I gave up on big blocks and went the small block route when I ordered my 1969 Corvette. My 1968 Chevelle SS 396 with L-78/M-22 was impossible to stop from "pinging", even though I used Chevron Custom Supreme in it (the highest octane generally available gasoline sold in California at that time). Timing and other adjustments achieved only minimal relief from the problem.

Having to use additives, aviation fuel, racing gas, etc. is a HUGE PIA, especially if one wants to take the car "on the road". Having to take these fuel measures is SO constraining, too.

You can be sure that I didn't forget these problems when I selected the components for my "ZL-1" project. I was VERY conservative regarding compression ratio----I want the car to be enjoyable to drive and easy to fuel. It's just not worth the risk for a relatively small amount of extra power that can be achieved by higher compression.

[Joe Pearson]

Re: 66 427/425 Fuel

Thanks for the info and advice. I'll try some blends. I only drive this one occasionally so it's not a huge PIA but thought I would see what people are doing. Joe.

[Michael H.]

Re: 66 427/425 Fuel

Joe,

Lucia is, as usual, right on the money. Other than using about 25% racing fuel, there's just no simple solution. These motors were designed and built when there was 100+ octane coming out of the nozzles at the local Sunoco station. If you're headed for the local drive-ins, just add the super juice but if your going on a long cruise, take your small block car instead.

The only thing I question is the use of aviation fuel as I was told many years ago that it contained many things that are undesirable for use in cars on the ground. One that stands out in memory was the huge amount of deicers necessary for high altitude use. I'm sure I'll remember a few more as soon as I submit this reply.

Michael

[Jon S.]

Re: 66 427/425 Fuel

If you have the room for it, I would check with your local speedshop about ordering racing fuel by the 55 gallon drum. This (Sunoco 110), along with an inexpensive hand pump is what I use to fuel my '69 L88. The cost of the fuel came out to about 4.50 or 5.00 per gallong last time I bought it.

[Clem Z.]

be CAREFUL doing this

i had a racing friend that was doing this with his garage door open,the wind was blowing into the garage and the gasoline fumes were blown under the door between the the garage and basement. his wife was ironing clothes next to the gas fired water heated in the basement and when the fumes hit the pilot light in the water heater the explosion burned his wife to where she never recovered.

[Jerry M.]

Re: 66 427/425 Fuel

Joe
One option to consider is going to a nice overlaping cam which gives you a dynamic c r. It will sound a little different than the 520/520 but it worked for me. Cheaper in the long run. Edlebrock makes a very good one it is their 6172. With that cam I can't make my engine ping or detonate no matter how I try. I am still running 10.5 pistons.

[Steve Antonucci]

Re: 66 427/425 Fuel

Jerry,
I recently restored my 69 L/89 ( 396-375hp ) and I went back to 11:1 pistons.
I conversed with Joe Lucia too late in the decision making process. My bad
luck. I went with an original spec. cam from Comp Cams because I was stuck in
the resotration frame of mind on my 69 Camaro. I have not yet fired the engine
up. I'm just wondering if I should consider another camshaft before I put
the engine back in this summer. Since I'm using factory aluminum heads
( 3919842's ), what cam specs. do you think I should consider? I too want to
run on pump gas, if possible. Lastly, one final question for the group. I was
considering having my L/89 dyno'd and set up for the best performance using
pump gas. Knowing that I have restored it to 1969 specifications (4346 Holley,
points distributor, etc. ), am I wasting my money in the dyno?
Steve

[Joe L.]

Re: be CAREFUL doing this

clem-----

That's another good reason to do everything possible to AVOID the need for purchasing and STORING fuel to accomodate octane-hungry engines. Fueling vehicles is best and safest when performed at a fuel retailer. Even then, it's NOT risk-free. I wouldn't even consider keeping stores of fuel around the house (i.e. garage, storage sheds) to accomodate such needs. Plus, it's a violation of the fire and building codes to keep more than a minimal amount of fuel around. Cars are designed to be fueled at commercial filling stations; other, more-or-less improvised fueling methods are risky business.

If one can achieve one's octane needs by adding cans of additive, that's ok. Storing significant quantities of special gasoline is another matter, entirely.

[Jack H.]

Definately NOT wasting your money....

on the dyno run with a few proviso's.....

(1) Is the dyno shop a u-run only service? Some shops have race qualified mechanics on hand to provide services and hand hold--WELL worth the expense!

(2) Some shops only fixture and report HP vs. RPM. Others monitor tail pipe emissions at the same time for a more comprehensive service. The ultimate have drop-on hoods to measure air intake CFM flow, RPM, HP and tail pipe emissions to 'box' the whole input/output equation model. What are you getting for what you pay?

(3) What fuel is in your tank, plumbed through your carb(s) at dyno run time can make a diffence in measured performance (pump gas, race fuel, aviation gas, Etc.).

(4) Does the dyno shop have experience doing Corvette? While this sounds 'funky' (one car vs. another) it can make a BIG difference in test results. You see, Shark cars are 'bottom' breathers. Air flows under the nose, makes a right angle turn based on turbulance created by the 'spook' air deflector, fills the nose of the car, then makes another right angle turn through the radiator.

Most cars are 'nose suckers' and barrel dynos are static, so they have to supply car-in-motion air flow via fans to properly emulate on-track dynamic conditions. If the dyno is 'tuned' for a nose sucker (through the grille air flow) and you mount/run a bottom breather (Shark era Corvette), well, garbage in = garbage out times a multiplier is ye olde computer saying; you get what you paid for....often a non-realistic evaluation.

[Dick W.]

Re: be CAREFUL doing this

One other point on using buying a drum of racing gas. From my experience it has a short "shelf life". It will go dead, stale in a fairly short period of time. Surely there is someone in a reasonable driving distance that is using racing fuel that would sell five gallons at a time. There are so many short tracks and drag strips around the country, I would have to think that it would be obtainable.

Check out the link, it might assist in finding a supplier.

http://www.tracksideguide.com/racingfuel.htm

[Chris H.]

Detroit area ho octane gas

Turbo Blue sells 110 octane leaded and 100 octane unleaded gas for about $3.60 right out of a pump at about 30 gas stations in Detroit area. (Sunoco, Citgo, Marathon, etc.) Unleaded octane is sold at 3 of the 30 stations and the 110 leaded is at 27 stations.

I called up Turbo Blue and they sent me the list.

Chris

[Steve Pettit]

Re: Detroit area ho octane gas

Are there any stations in the N. California area that sell high octane gas?

Regards, Steve Pettit

[Warren F.]

Re: Northern California High Octane fuel

Steve:

There is a Unocal station at the Infineon Raceway park (the old Sears Point track) that sells 6 different grades at the pumps. They have 96,100 & 104 on one side of the island, and 110, 114 & 118 on the other side. They take all the major credit cards too.