tuning question

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fishy68

fishy68

Tyr Fryr's Inc.
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We built a pretty health 418 (11.8 to 1 compression, fully ported Eddy's, Bullet solid flat tappet .625 lift and 268 @ .050 on a 106 center) for a buddy's car and he put a tunnel ram with 2 660 center squirters on it running it on E85. It runs great wide open but it runs pig rich at part throttle. The 660's don't have a provision for a power valve so he bought a couple metering blocks from a fellow that was supposed to know carbs and E85 real well. The guy put .076 power valve channel restrictors in the blocks and told Brian to run 86 jets in all corners if he used no power valve but didn't say what to run in the fronts if he did use a power valve. I did the math according to Holley's formula figuring jet area with those huge restrictors he'd need to drop the primary jets down to 67's which I can't imagine will run right on E85. I think it'll be way lean at part throttle with 67's. I think we need to put in smaller restrictors, something on the order of .060's and run 76 jets in the front (10 jet split front to back). My thinking is it doesn't matter what fuel you run you need it balanced between the front and back barrels but I thought I'd post this in hopes someone here has some E85 experience that might tell me if I'm right or wrong.
 
The majority of us tune on 86 octane pump gas and race on C12 or C16....I personally do not like biofuels...I just want the purest highest octane I can get....and even use Toluene on occasion.

(2) 660's? 86 jets? Sounds fishy. I would go back down into the high 70's.

Read the plugs and driveability till you get it dialed in unless you have a chassis dyno with A/F logging, local to you.
 
Sorry Fish, ya lost me when you said dual 4's on a tunnel ram and E85. Last time I ran one of those was on a 440 with dual carter carbs. Whole different ball game with the Holleys. I'm presuming that the dual 4 tunnel on E85 has got a few others running for cover also.
 
I agree that most run pump gas or race fuel but E85 has become popular so I was hoping someone here had experience. I wish we had access to a dyno. That'd make it so easy.
 
demon seed said:
Sorry Fish, ya lost me when you said dual 4's on a tunnel ram and E85. Last time I ran one of those was on a 440 with dual carter carbs. Whole different ball game with the Holleys. I'm presuming that the dual 4 tunnel on E85 has got a few others running for cover also.
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LOL... Know what you mean Terry. It's a whole new ball game for me too. It's a screamer, just gotta get the kinks worked out.
 
Call Quick Fuel or Holley and see what they have to say. Not a lot of us are running E85 yet. I've heard the fuel varies quite a bit yet in the gas to alcohol ratio so it is hard to tune for. Not saying I wouldn't but the closest is 30miles away from me.
 
fishy68 said:
We built a pretty health 418 (11.8 to 1 compression, fully ported Eddy's, Bullet solid flat tappet .625 lift and 268 @ .050 on a 106 center) for a buddy's car and he put a tunnel ram with 2 660 center squirters on it running it on E85. It runs great wide open but it runs pig rich at part throttle. The 660's don't have a provision for a power valve so he bought a couple metering blocks from a fellow that was supposed to know carbs and E85 real well. The guy put .076 power valve channel restrictors in the blocks and told Brian to run 86 jets in all corners if he used no power valve but didn't say what to run in the fronts if he did use a power valve. I did the math according to Holley's formula figuring jet area with those huge restrictors he'd need to drop the primary jets down to 67's which I can't imagine will run right on E85. I think it'll be way lean at part throttle with 67's. I think we need to put in smaller restrictors, something on the order of .060's and run 76 jets in the front (10 jet split front to back). My thinking is it doesn't matter what fuel you run you need it balanced between the front and back barrels but I thought I'd post this in hopes someone here has some E85 experience that might tell me if I'm right or wrong.
Click to expand...

Fish, I'm not familiar with E85, But i do think it requires more jet, but not as much as Alcohol, You could install small PVCRs & use the standard formula for gas as a base line, then just jet from there for best power, With those PVCRs being so large, it should still balance out useing the 67 jets from your calculations, Me personally would rather do like you said, run a smaller PVCR & larger jet, because the fuel will flow quicker into the main well through the jets then the PVChannels. I would installs .055"-.057" PVCR & start off with .080" jets & go from there.
 
jefflock said:
Call Quick Fuel or Holley and see what they have to say. Not a lot of us are running E85 yet. I've heard the fuel varies quite a bit yet in the gas to alcohol ratio so it is hard to tune for. Not saying I wouldn't but the closest is 30miles away from me.
Click to expand...

I may call Holley to verify it. E85 does vary quite a bit but Brian has a tester so we can take into consideration any variance.
 
JoeDust451 said:
Fish, I'm not familiar with E85, But i do think it requires more jet, but not as much as Alcohol, You could install small PVCRs & use the standard formula for gas as a base line, then just jet from there for best power, With those PVCRs being so large, it should still balance out useing the 67 jets from your calculations, Me personally would rather do like you said, run a smaller PVCR & larger jet, because the fuel will flow quicker into the main well through the jets then the PVChannels. I would installs .055"-.057" PVCR & start off with .080" jets & go from there.
Click to expand...

Your right, it does take more fuel. Thanks for confirming what I thought about the PVCR's.
 
member 340 8BBL knows his way around a tunnel ram and 2-4 barrels. He has done several different configurations with 2-4's. All are on Pump Fuel but the theory would be the same regardless of the fuel used no? You are just burning more fuel using e85.
 
Mad Dart said:
member 340 8BBL knows his way around a tunnel ram and 2-4 barrels. He has done several different configurations with 2-4's. All are on Pump Fuel but the theory would be the same regardless of the fuel used no? You are just burning more fuel using e85.
Click to expand...

Thanks for the info Louis. That's what I need is someone that especially knows dual 4's cause they seem to be a whole different ball of wax when tuning. I don't recognize his screen name but I'll look him up.
 
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