My second pump gas damage mistake

[Domenic T.]

The first was trying our CA 91 octane when I ran out of my mix of 91 and avgas. I only let the engine warm up and moved the car with low power loads to keep it from pinging. When I turned the ignition off the engine dieseled so I turned the ignition back on and the engine ran again. The car has a automatic trans in it so after trying 3 more times I turned the air on, lights, and put it in reverse and it shut down. That one cost me a piston skirt so I stored the car until I could pull the engine that had less than 2 K on it.
Put avgas in it and the engine ran great except for the piston knock. Went to move the car and it was out of gas so I suckered into the second mistake. I poured pump gas in it to get it back in the shop and: With the starter turning the flywheel in the correct direction, the engine fired backwards because of the flame rate and took out the starter drive.
It's a 425 BB automatic that I tuned to factory specs. I did de-tune it once to see how it would run on pump gas but was dissapointed in the lack of performance, the reason I had the 425/427.
No 3rd time for me.

Dom

[Joe L.]

Re: My second pump gas damage mistake

The first was trying our CA 91 octane when I ran out of my mix of 91 and avgas. I only let the engine warm up and moved the car with low power loads to keep it from pinging. When I turned the ignition off the engine dieseled so I turned the ignition back on and the engine ran again. The car has a automatic trans in it so after trying 3 more times I turned the air on, lights, and put it in reverse and it shut down. That one cost me a piston skirt so I stored the car until I could pull the engine that had less than 2 K on it.
Put avgas in it and the engine ran great except for the piston knock. Went to move the car and it was out of gas so I suckered into the second mistake. I poured pump gas in it to get it back in the shop and: With the starter turning the flywheel in the correct direction, the engine fired backwards because of the flame rate and took out the starter drive.
It's a 425 BB automatic that I tuned to factory specs. I did de-tune it once to see how it would run on pump gas but was dissapointed in the lack of performance, the reason I had the 425/427.
No 3rd time for me.

Dom

Dom-----


This car must be some sort of conversion as GM never made any 425/427 Corvette with an automatic transmission.

Big blocks are very susceptible to detonation. That's why, for satisfactory street operation, I do not recommend going higher than 9.0:1 for a big block. As far as being "tethered" to a source of aviation gasoline, forget it as far as I'm concerned. I want to be able to fill up anywhere my travels might take me. I don't want to be a "prisoner" to a source of aviation fuel.

[Domenic T.]

Re: My second pump gas damage mistake

Joe,
The 425/427 is what I put in mt 74 chevelle that was automatic. The CA smog laws allowed me to do that when it became smog exempt. Behind the engine is a 400 turbo trans. I respect the view Joe but if I took away the power by lowering the compression then I guess I would have been happy with a station wagon with a small engine.
I built the car to run hard, not for vacations or normal driving. Something to have fun with!

Dom

Dom

[Joe L.]

Re: My second pump gas damage mistake

Joe,
The 425/427 is what I put in mt 74 chevelle that was automatic. The CA smog laws allowed me to do that when it became smog exempt. Behind the engine is a 400 turbo trans. I respect the view Joe but if I took away the power by lowering the compression then I guess I would have been happy with a station wagon with a small engine.
I built the car to run hard, not for vacations or normal driving. Something to have fun with!

Dom

Dom

Dom-----


1971 Corvette with LS-6 had 9.0:1 compression and 425 HP. It's easy to build a 427 with 9.0:1 compression and 425 (or more) horsepower. Or, convert it to 454 by simply changing the crank and pistons.

[Domenic T.]

Re: My second pump gas damage mistake

Joe,
I converted a 454 to a 427/425 so I could have fun at the stop light!! The original 425 HP was over 425 HP. Reason was insurance!
Joe with ALL respect joy the HIGH compression. Those that can't afford gas to perform need to have GARAGE QUEENS!!
On another note I need to pick your brain on compressor back plate ##

Thanks Dom

[Michael J.]

Re: My second pump gas damage mistake

I struggle to keep proper fuel in my FI tankers, the combination of the fiberglass tanks, high compression, and FI is tough. I am mixing 91 octane ethanol free with 101 octane racing fuel. At my altitude, 7000 ft., this works great. I am just afraid of the day both those fuels are not easily available nearby.

[Dick W.]

Re: My second pump gas damage mistake

Dom-----


1971 Corvette with LS-6 had 9.0:1 compression and 425 HP. It's easy to build a 427 with 9.0:1 compression and 425 (or more) horsepower. Or, convert it to 454 by simply changing the crank and pistons.

Not that easy to convert some of the 427 blocks. Only the mid to late '69 512 blocks had clearance for the increased stroke. Been there, done that. Of course you can spend some time with a die grinder to get clearance in the block.

[Mike E.]

Re: My second pump gas damage mistake

I struggle to keep proper fuel in my FI tankers, the combination of the fiberglass tanks, high compression, and FI is tough. I am mixing 91 octane ethanol free with 101 octane racing fuel. At my altitude, 7000 ft., this works great. I am just afraid of the day both those fuels are not easily available nearby.

I am curious as to how the fiberglass tank figures in. My 62 Gulf racer had all of the above except altitude, and I had no problems with fuel.

[Michael J.]

Re: My second pump gas damage mistake

I am curious as to how the fiberglass tank figures in. My 62 Gulf racer had all of the above except altitude, and I had no problems with fuel.

Damage to fiberglass fuel tanks by ethanol laced fuel has been known and documented for more than a decade, boats are the most common examples. Here is an article about that: http://articles.latimes.com/2008/apr...ness/fi-boat15

And, when I acquired some of my tankers, the PO admitted to using ethanol fuel, and the results were easy to see as many bits and pieces of resin, gunk, and goo were in the fuel pumps and fuel filters. A used fuel tank was recently for sale, it was cut in half, and the ethanol damage was apparent.

How long have you been using ethanol fuel in your big tank '62?

[Joe L.]

Re: My second pump gas damage mistake

Damage to fiberglass fuel tanks by ethanol laced fuel has been known and documented for more than a decade, boats are the most common examples. Here is an article about that: http://articles.latimes.com/2008/apr...ness/fi-boat15

And, when I acquired some of my tankers, the PO admitted to using ethanol fuel, and the results were easy to see as many bits and pieces of resin, gunk, and goo were in the fuel pumps and fuel filters. A used fuel tank was recently for sale, it was cut in half, and the ethanol damage was apparent.

How long have you been using ethanol fuel in your big tank '62?

Michael------


I don't think that pure gasoline is too easy on fiberglass tanks, either. Actually, there is no such thing as a fiberglass fuel tank (nor is there any such thing as a fiberglass Corvette, either). The correct terminology is fiberglass REINFORCED PLASTIC (FRP). Plastic is an organic material; gasoline is an organic solvent. The type of plastic used in these FRP fuel tanks was not particularly resistant to an organic solvent.

Many modern-day fuel tanks are made of plastic (although not fiberglass reinforced). However, these are a type of plastic which is highly resistant to gasoline (and, ethanol, too). But, they're still not 100% resistant (as steel is to gasoline).

[Michael J.]

Re: My second pump gas damage mistake

You're right Joe, I was being sloppy with my technical language, but the tankers had tanks very much like what boats have, and it has been shown that ethanol laced fuels are more damaging to them than fuel without ethanol. Here is a picture of a tanker's tank cut in half that shows the damage of ethanol fuel after years of sitting around.

[Terry D.]

Re: My second pump gas damage mistake

I am just curious, is 91 octane the highest you can get in your state? I have a friend here in Ohio with a Chevelle, we built a 454 that dynoed at 683 horsepower, runs on 93 octane Sunoco with no problems! There were lots of really high horsepower cars on the Hot Rod Power Tour that ran on whatever high test was available and did not have the problems you have.

[Joe L.]

Re: My second pump gas damage mistake

I am just curious, is 91 octane the highest you can get in your state? I have a friend here in Ohio with a Chevelle, we built a 454 that dynoed at 683 horsepower, runs on 93 octane Sunoco with no problems! There were lots of really high horsepower cars on the Hot Rod Power Tour that ran on whatever high test was available and did not have the problems you have.

Terry-----


On the east coast and central USA, 93 octane is the typical octane rating for premium fuel. On the west coast, 91 octane is the typical octane rating for premium fuel. I've never seen 91 octane when I've been on the east coast and I've never seen 93 octane anywhere on the west coast.

It is possible to obtain higher octane fuel on the west coast but stations offering it are few and far between and, where available, it comes at a great cost. Ethanol-free fuel is also extremely difficult to find on the west coast.

[Justin S.]

Re: My second pump gas damage mistake

Joe,
Ditto. I'm visiting the Portland area and have seen some ethanol free stations at $4.50/gal.
I can remember some 76 stations in the Phoenix area during the mid to late 90's offered 100 octane. Those pumps had a checkered flag on them. I can't remember the price however.

[Joe L.]

Re: My second pump gas damage mistake

Joe,
Ditto. I'm visiting the Portland area and have seen some ethanol free stations at $4.50/gal.
I can remember some 76 stations in the Phoenix area during the mid to late 90's offered 100 octane. Those pumps had a checkered flag on them. I can't remember the price however.

Justin-----


Union 76 (now part of Phillips) used to have a division that manufactured and sold high octane fuels at some locations at a rather high price. That division was later "spun off" and is known today as Rockett Racing Fuels. This is available at a few, select locations in several high octane ratings. It comes at a dear price, though, and "tethers" one needing such fuel to those outlets where it's available. Not for me.