110 Octane at the pump

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Hey Clint, looks like ya don't have to base ball bat the wheel wells anymore, now you need a bigger tire ha ha!!
 
Have you guys heard about the new Race Gas additive. I have seen it advertised on some car shows. Haven't tried it yet, but with a 10.5 to one moderately built 340, I think I'll give it a try.
http://race-gas.com/
 
Should be no reason (or gain) at all running straight 110 octane with just 10.5 to 1 compression unless your running such a small cam that the DCR is real high or your engine is just not very efficient. My 408 is 9.98 to 1 compression with iron heads and the DCR is 8.22 and it runs at max with 89 octane. Higher octane burns slower. You want your cylinder pressure to peak at 12-15 degrees ATDC. If your using higher octane than you need the peak pressure will fall later which results in less power output
 
fishy68 said:
Should be no reason (or gain) at all running straight 110 octane with just 10.5 to 1 compression unless your running such a small cam that the DCR is real high or your engine is just not very efficient. My 408 is 9.98 to 1 compression with iron heads and the DCR is 8.22 and it runs at max with 89 octane. Higher octane burns slower. You want your cylinder pressure to peak at 12-15 degrees ATDC. If your using higher octane than you need the peak pressure will fall later which results in less power output
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X2

I'd try a more docile timing curve if it really needs this fuel before I'd spend that kind of coin on gasoline.

I run 17/35 all in by 3500. 10.5:1, 160CPSI. 91-94 octane. It does prefer ethanol free.
 
roccodart440 said:
X2

I'd try a more docile timing curve if it really needs this fuel before I'd spend that kind of coin on gasoline.

I run 17/35 all in by 3500. 10.5:1, 160CPSI. 91-94 octane. It does prefer ethanol free.
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I run 14 / 32 all in @ 3200 11.4:1 , 190 cyl pressure , runs better with a mix of 1 gal 118 /3 of 94 , of course the 94 has ethanol , cannot find ethanol free 94 . And have a small cam . it runs on 94 , but does ping at times , not often , never with the mix of 118 .
 
jerry6 said:
I run 14 / 32 all in @ 3200 11.4:1 , 190 cyl pressure , runs better with a mix of 1 gal 118 /3 of 94 , of course the 94 has ethanol , cannot find ethanol free 94 . And have a small cam . it runs on 94 , but does ping at times , not often , never with the mix of 118 .
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Your lucky with that small cam and 190CPSI. Damn that's high. But it goes to show what a conservative tune can do.
 
Tracy you are right

Mine wants maybe 2 gallon per tank to keep it quite. The only reason I filled it up is my plan was to go south and this way I can put gas in a couple of times and still have some 110, or it will be stored for the winter and then don't have to worry about fuel separation.

It really should run on pump gas, have changed the tune, taken timing out and nothing helps.

Probably next year the engine will come back out, cam change, head change and hell might make it a stroker. Or do something completely different

It is a pain in the *** not being able to run on pump gas without fear of damage.

I did check into some octane booster, but the cost per quart is about equal to buying the race gas. The only good thing is being to drive where ever with a bottle of juice to keep going.
 
WildCat said:
Tracy you are right

Mine wants maybe 2 gallon per tank to keep it quite. The only reason I filled it up is my plan was to go south and this way I can put gas in a couple of times and still have some 110, or it will be stored for the winter and then don't have to worry about fuel separation.

It really should run on pump gas, have changed the tune, taken timing out and nothing helps.

Probably next year the engine will come back out, cam change, head change and hell might make it a stroker. Or do something completely different

It is a pain in the *** not being able to run on pump gas without fear of damage.

I did check into some octane booster, but the cost per quart is about equal to buying the race gas. The only good thing is being to drive where ever with a bottle of juice to keep going.
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I got ya Larry. I've ran into a few like that which are just stubborn and require something better than pump gas to keep them quiet even though the compression isn't all that high. If you do a stroker you'll love it. Mine is real mild and even with the 3.23 gears I have in it now if I could get it to hook up I think it'd break into the 11's. I've gotten 17 mpg cruising down the hwy too.
 
I'm wondering if I end up needing more octane if there is any available out of the pump in my area, which is in the middle of nowhere. I'm going to do everything I can to keep CR down but could be a challenge with 69 (340) block and desire to run EQ Magnum heads. Have learned on this site a cam with late duration cycle can help, much to learn for me.
 
It's the late closing intake valve(ICA) that can make or break your combo. The static C/R is of importance,to be sure, but only insomuch as it is used to achieve a working Dynamic cr.
If you know the exact measured static C/R, and the exact ICA , the exact boreNstroke, and exact rod length, then it's possible to calculate the operating Dcr of the engine. From success stories, we know that an aluminum headed engine can successfully burn 87E10 on a Dcr of 8.5 to 8.8. And 93 octane will support a Dcr of 9.2. Iron heads need to reduce the Dcr about .5 to .8.All figures are corrected to sealevel. If you observe these parameters you will have success.
I like to push the limit, cuz I'm willing and able to put the tuning time into it.Plus I don't race my car, and so it spends very little time running on the edge where detonation lives.Plus I have a 360, which is a more than adequate street performer. If I was stuck with a smaller engine, it would have to work a lot harder, and then pushing the envelope could get expensive.If you need help with the Dcr calculation, you will need to obtain the exact figures, as noted above. Keep in mind that if your 340 has pop-up pistons in it, you will need compatible heads.
 
Back in the day (late 60's), Sunoco 260 premium was 110 Octane. the catch phrase for it was: "Power to be used, not abused".

btw, it was 39¢ a gallon.

My 68 HEMI RoadRunner loved it.
 
AJ/FormS said:
It's the late closing intake valve(ICA) that can make or break your combo. The static C/R is of importance,to be sure, but only insomuch as it is used to achieve a working Dynamic cr.
If you know the exact measured static C/R, and the exact ICA , the exact boreNstroke, and exact rod length, then it's possible to calculate the operating Dcr of the engine. From success stories, we know that an aluminum headed engine can successfully burn 87E10 on a Dcr of 8.5 to 8.8. And 93 octane will support a Dcr of 9.2. Iron heads need to reduce the Dcr about .5 to .8.All figures are corrected to sealevel. If you observe these parameters you will have success.
I like to push the limit, cuz I'm willing and able to put the tuning time into it.Plus I don't race my car, and so it spends very little time running on the edge where detonation lives.Plus I have a 360, which is a more than adequate street performer. If I was stuck with a smaller engine, it would have to work a lot harder, and then pushing the envelope could get expensive.If you need help with the Dcr calculation, you will need to obtain the exact figures, as noted above. Keep in mind that if your 340 has pop-up pistons in it, you will need compatible heads.
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Thanks, I'm hoping that with the correct head gaskets and machine work either stage 1 or stage 2 can accomplish the clearance I need. Really should have checked into that as already have Magnum valve covers and Edelbrock 7576 intake (LA). All I know about fuel around here is that we have Pacific Pride which doesn't have ethanol, I believe.
 
Not going to berate your choice of fuel, but as others have said, highly likely you don't need that much.
I used to have a bike that ridden hard in hot weather would ping. Local station had CAM2, don't remember the octane rating. A quart of that to two gallons of 93 or 94 worked wonders. Performance? No noticed difference, just controlled the pinging.
A friend ran it for years in his Eddie headed, 10 to 1 440, at some point he had put pump 93 in and ended up at the track... Ended up running it's best time ever, guess what he runs now?
Frankie mentioned Sunoco 260, I'd think those 110 numbers back then were Research numbers, not R+M/2. That said, I would still guess that would come out in the high 90s to 100.
 
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