Highest Possible Compression 5.9 EQ heads

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macdrew77

macdrew77

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Just brainstorming about an E85 5.9 build. Wondering what the most possible static compression would be with off the shelf pistons. The highest compression height piston is could find is KB107 or ICON 741 at 1.675. At zero deck, 63cc head, .028 gasket that yields 10.99:1. Is it possible or feasible to get much higher?
 
Easy.... IC743 domed is an alternate. Note in the Icon catalog says: " Will Fit Edelbrock Cylinder Head" so I would expect it to fit an EQ head's closed chamber too. Another 2.5 to 3 points in SCR, so you might have to massage them a bit or open the EQ chambers if you want something like 12.5 SCR.
 
I'm no expert by any means. I just want to watch this thread and clear something up for me.
When you say "feasible" are you referring to the compression ratio or money? Ya you can shave heads, relieve piston valve clearance, deck the block etc...
 
at least a half point
stroker would be one way to get more compression but with the additional cu in you do not have to go to max to get same torque
usually max compression is going to mean a big cam and a narrow torque curve way up high rpm- or at least more toward that than to a broad fat Engine Masters style
what's your rpm drop when shifting- and go from there- work it backwards
 
11:1 on e85 is not a big deal. You could run more, but why? Especially if it's a streeter on e85.

You'll get marginal gains with more compression and exponential potential headaches with the tuning window.
 
macdrew77 said:
Just brainstorming about an E85 5.9 build. Wondering what the most possible static compression would be with off the shelf pistons. The highest compression height piston is could find is KB107 or ICON 741 at 1.675. At zero deck, 63cc head, .028 gasket that yields 10.99:1. Is it possible or feasible to get much higher?
Click to expand...

It is possible to get higher according to Icons on line catalog using IC 743 pistons..........14 to one with 60 cc chamber, 13 to one w/65 cc, 12 to one w/70 cc....let us know what gasket will keep it in there
 
crackedback said:
11:1 on e85 is not a big deal. You could run more, but why? Especially if it's a streeter on e85.

You'll get marginal gains with more compression and exponential potential headaches with the tuning window.
Click to expand...
Not sure I understand... 11.1 on e85 looks to be about like 7:1 on gas.... lower than /6 territory LOL. The gains from high CR would be all down in the low RPM's.... definitely what I would want in a street engine.
 
Icon will make what ever you want, given the specs And the money!
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