11 to 1 - too much on CA 91 pump gas?

[ERA Chas]

I'll say this once more-not sure if the OP is even watching anymore. This is solvable without going into the engine or running 20 degrees total.
I say this because every day I used to document engines' performance on DTS dynos. The bulk of those had these parameters: 91 Octane Shell pump gas, 10.75 to 11.3 CRs, 427 to 632 C/I, AFRs from 12 to 14, aluminum heads, smallest carbs were 850's, biggest were 1050 Dominators. HP ranged from 560 to 825. All cams had 108 to 114 LSAs, were SFTs or juice rollers and had advance from 28 to 36 degrees. All were tested under load and none pinged or ran hot. NONE used octane boost. The drag engines had 12.5 to 14.0 CRs and ran on C-14.
Doesn't it just make sense to try the simplest, least costly, proven suggestion???????

[greg schroeder]

You'll destroy the pistons with 91 octane in time. It's funny how many people do it and then sell the car with the "never been raced" sales pitch.

If you get 116 octane fuel to set in the garage just dump in 3 gallons to be mixed with 10 of the 91 octane pump and it will be around 97 octane. Done.

I most often used 100 octane unleaded from the pump here in Scottsdale, AZ.

[patrickt]

If the OP is still watching, he should try what Chas has recommended. If it doesn't work, then have Barry spec out a new cam for you. Maybe you can change it out without pulling the engine. I wouldn't keep a 55 gallon drum of race gas in the garage.

[ERA Chas]

Originally Posted by greg schroeder

You'll destroy the pistons with 91 octane in time.

Greg,
I respect that you're smart enough to run 10's but how do you account for this statement - nitrous? I didn't encourage the OP to run with detonation.

All those engines I wrote about were warrantied for 2 years and they only came back for broke pistons (and not covered) if they were sprayed by a dummy.

[greg schroeder]

Originally Posted by ERA Chas

Greg,
I respect that you're smart enough to run 10's but how do you account for this statement - nitrous? I didn't encourage the OP to run with detonation.

All those engines I wrote about were warrantied for 2 years and they only came back for broke pistons (and not covered) if they were sprayed by a dummy.

Sorry man. I didn't mean any disrespect to anyone and I didn't think of anyone in particular other than making a general joke because I've watched guys pick up cars from the dealer and thrash on them right off the lot with new engines and also put them right on the dyno with minimal warm up time. Seriously just a generic statement. The fuel thing is because I don't know too many people that take the time to buy the proper fuel for high performance cars. It's just too inconvenient for most.

My car ran some casual 10 passes because I corrected some of the original install power robbing issues and stuff. Basically it was set up better than how it was delivered.
Fuel delivery with 8AN tank pick up to carb
Aeromotive fuel filter
Properly tuned carb from Pro-Systems
Larger surface air cleaner
Different headers that don't cover 1/3 of an inch width of each exhaust port
Side pipes with a bit more flow
Drag radials to start from idle and have 1.7 or 1.8 60ft time
Different half shafts
Detroit TruTrack rear end with 3.73 gears
Light weight flywheel
1/4 tank of gas for less weight
Lower density altitude
100 octane unleaded fuel on Roush original timing

If anyone can let out a clutch from idle, press the gas and shift through gears they'll run a high 10 on a well prepped track with drag radials, 2450 race weight and 475 wheel HP.

Something that's a common misconception is that a casual start drag pass is hard on the car when in fact a few seconds threw the gears. It's not a big deal on a proper air fuel ratio. Its a few seconds not much different than a romp through the gears entering the freeway. Alternately more damage can occur from things like sustained hard load to store heat and particularly on a lean air fuel along with pinging. Throw in a cold new engine to start and wow. It happens not because people want to cause damage. Generically speaking many just don't know.

[ERA Chas]

Originally Posted by greg schroeder

The fuel thing is because I don't know too many people that take the time to buy the proper fuel for high performance cars. It's just too inconvenient for most.

No harm Greg. This is a true statement. I just can not condone encouraging a guy to make major and expensive changes to his engine because of 91 octane fuel.

My car is a second off your pace on 93 octane with 465 WHP, 200 more pounds and terrible for drag racing Hoosier T/Ds. Just couldn't put it down -1.9 60 ft. It took half as long to go the last 1/8 mile than the first. 121 MPH was a great top end charge though.

You made smart changes to your car and know how to feed it.

[Bernica]

I am running just under 11:1 comp in a Shelby aluminum block with Shelby aluminum heads and Stage II porting, 482ci. I'm here in CA, and the 76 station near my house still sells 100 octane pump race gas (unleaded). It's not cheap. Currently around $8.75/gal. But once I filled my Cobra with that stuff, all was good. Running around 35 deg timing. No knocks, no pings. Just an empty wallet after a 42 gal fillup!!

[RodKnock]

Originally Posted by Bernica

I am running just under 11:1 comp in a Shelby aluminum block with Shelby aluminum heads and Stage II porting, 482ci. I'm here in CA, and the 76 station near my house still sells 100 octane pump race gas (unleaded). It's not cheap. Currently around $8.75/gal. But once I filled my Cobra with that stuff, all was good. Running around 35 deg timing. No knocks, no pings. Just an empty wallet after a 42 gal fillup!!

So you're telling us that your CSX runs great with 11:1 compression and race gas. Cool.

[SP01715]

Originally Posted by Bernica

I am running just under 11:1 comp in a Shelby aluminum block with Shelby aluminum heads and Stage II porting, 482ci. I'm here in CA, and the 76 station near my house still sells 100 octane pump race gas (unleaded). It's not cheap. Currently around $8.75/gal. But once I filled my Cobra with that stuff, all was good. Running around 35 deg timing. No knocks, no pings. Just an empty wallet after a 42 gal fillup!!

I wonder if this is CARB legal gas? The places down here in the San Diego area have been cracked down on, and alot of them wont even sell race gas anymore.