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I just went out last night to the one local service station in my area on Long Island that carries Cam Two (110 octane; purple color)to fill up two five gallon containers and boy, has this stuff got expensive at $7.99 per gallon (guess it should come as no surprise) For years I have been mixing 5 gallons of Cam Two with 93 or 94 pump gas for my 66' L72 coupe (11:0 to 1:0 compression ratio) and the car ran very well. Now, given the price of Cam Two, I am thinking about cutting the Cam Two input to 2.5 gallons and see how the car performs. Is anyone on the DB running an engine with 11:0 to 1:0 compression ratio on 2.5 gallons of racing fuel with the balance being pump gas? If so, what has been your experience? Thanks
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Re: Cam Two Fuel
I have an L72 - 11:1. I typically run a 50/50 mix of 110 leaded and 93. I have also run 5 gallons 110 leaded to 7 gallons 93 and it ran fine. I just bourth 15 gallons here in NJ and paid $7.00 per gallon. The owner told me it was oging up to $7.50 with the next order he places. -
check on the price of 100LL av gas
this stuff is about 106 octane the way the rate car gasoline. i know the stuff about av gas it built for high altitude and will not run well in auto engines. we used it for years in race cars with no problems. back in the days before race gas was on the market most all race engine builders used av gas for dyno testing because it is govt speced and all batches are the same so you knew your results could be accurately compared to each other. JMHOComment
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Re: check on the price of 100LL av gas
Is there a "secret" to purchasing AV gas? I've looked into it and as I understand it - they are not suppose to sell it unless it is going directly into an airplane. Maybe you can get away with a gas can if they think you are a pilot but not directly into an auto.Comment
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Re: check on the price of 100LL av gas
It's about $4.00/gallon. Sold at your local airport. But I don't think they're supposed to pump it into street going cars. Believe it's supposed to be for airplanes only. Not sure, though.
(Usually not a problem. Who'd want to pay more and go out of your way to buy gas for your car?)
BTW, the "LL" in 100LL stands for "low lead." But I'm informed that the lead content is still quite high. Good for mixing with no lead gas. Bad for spark plugs, oxygen sensors, and catalytic converters.Comment
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Re: check on the price of 100LL av gas
it has 2 cc of TEL per gallon,race gas has about 4 cc per gallon. mixing it 50/50 with unleaded will not cause any plug problems.they will not put it in your car you need a container. we used a 250 gallon tank in the truck when bought it for racing so there was no problem,they were glad to get the moneyComment
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try it and see
My 1969 L89 runs a 4.25 stroker crank for 489" and has an honest 10.3:1 compression. With 4 degrees initial advance and a total of 34 degrees at 3000 RPM, it will run OK on 93 octane CITGO gas for the street, but runs on a little when I shut it off. If I add a gallon or two of leaded high octane, it doesn't run on either. You may be pleasantly surprised especially if you're running the stock cam and ignition curve.
MarkComment
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Re: check on the price of 100LL av gas
My 70 L-46, 11to1, runs the best on the 100LL. I used to pull right across the runway to the fuel truck, and get filled no problem. Small local airport.Comment
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Re: check on the price of 100LL av gas
I have a 69 L-46 all stock and it run's fine on 93 pump gas. Never a pinging problem or run.I have had it 3 years and never a problem. TomComment
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Re: try it and see
Octane requirement has many variables. Driving environment is a big input - higher temperatures and lower altitude increase the octane requirement.
For as build OE engines with typical OE machined deck clearance, the actual CR is typically lower than specified by half a point and if they are rebuilt with a thicker composition gasket they will be nearly another half point lower than OE with single shim gaskets.
Also, the later the inlet valve closes the lower the DCR, so SHP engines can handle more compression because they have relatively late closing inlet valves relative to medium performance engine cams.
So everyone should experiment to determine what their engine's octane requirement is. Start with the highest octane unleaded premium available in your market. Slight detonation can often be eliminated by retarding the initial timing 2-4 degrees, and you can file the slot out in the dist. cam assembly to gain back the total WOT timing at high revs.
If ignition map adjustments won't eliminate detonation, add a small amount of leaded race gas or 100LL avgas and find the minimum blend that will keep the engine out of detonation. In most cases it will be no more than about 25 percent.
Anecdotal evidence indicates that most SBs can be tuned to run detonation free on 93 POM pump gas, but some BBs may require a little more.
DukeComment
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