E85Forum.com

Walkinshaw · Joined: 26 Sep 2010 Posts: 5

I currently have a Holley 750HP carb (list 80528-1) that I am to convert for E85 on my 408ci alloy Cleveland (12.2:1, 249/257@50, 4000rpm stall). I have done a reasonable amount of research on what appears to ”work” with regards to setting up a Holley for E85 on a motor similar to mine. Can anyone see any huge flaws or areas for improvement in what I’m proposing below.

Gas calibration

PMJ 73
SMJ 73
Front PV 6.5
Front PVCR unknown
Rear PV 6.5
Rear PVCR unknown
IFR unknown
IAB 0.075
HSB 0.036
Booster 0.159
Anti-syphon unknown
Eholes 3 off factory drilled metering plate
Front Accel Pump 30cc
Front Pump cam pink
Rear Accel Pump 30cc
Rear Pump Cam pink
Squirters (pri) 0.031
Squirters (sec) 0.031
Needle/Seat factory (0.130?)

Proposed E85 calibration

Using a QuickFuel E85 Metering plate
PMJ 85
SMJ 93
Front PV 4.5
Front PVCR 0.080
Rear PV BLOCKED
IFR 0.033
IAB 0.065
HSB 0.026
Booster 0.170 (what will be the impact if I retain the stock 0.159 down legs?)
Anti-syphon 0.028
Eholes (metering plate has 4 holes from top to bottom) blank 0.028 blank 0.028
Front Accel Pump 30cc
Front Pump cam pink
Rear Accel Pump 30cc
Rear Pump Cam pink
Squirters (pri) 0.042
Squirters (sec) 0.042
Needle/Seat 0.130 (is there a need for a 0.150)?

Am I on the right track?

Drag Chevette · Joined: 18 Sep 2007 Posts: 458

ron · Joined: 27 Feb 2009 Posts: 16 Location: NY

Walkinshaw, That's a nice carb to convert to e85. If the boosters are a 0.159, they would be to small for that size motor and carb combo. I think the 0.170 is a better choice and if hp is over 525, a 0.178 booster. Jetting to be safe about 92's for a start. It's usually about 10 jet sizes over a known gas setup. In this case 10 over 73 jets would be to lean. If you use a PV on the SMJ, about a 84 jet for a start, on a new setup it's sometimes easier to square your jets to get a better handle on jetting and then latter ad a PV and reduce jetting. A IFR of 0.033 is more for gas, start with a 0.043 and your HSB is a good start, a IAB in the 0.055 to 0.060 range start at 0.055 first. The needle/seat's are fine at 0.130. Your squirters and pumps are also a good start, just about every motor/carb combo is different, at this point it's trial and error depending on how the car is used, race/street or both and also a footbrake or transbrake car. Hope this is of some help. Ron
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ron

ron · Joined: 27 Feb 2009 Posts: 16 Location: NY

Walkinshaw, I meant PMJ 84 with a PV. But I think the jetting you chose is right on.
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ron