Compression and E85?

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Feb 1, 2016 | 10:12 PM

#21

EX1

Melting Slicks

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From: Lubbock TX

I ordered some -18cc Wisecos today. They should put me at around 10.1:1 with 70cc chambers. This is about 1/2 a point compression bump from my previous build. I was going to go higher but I am adding flex fuel this time around instead of E85 exclusively.

Feb 2, 2016 | 01:50 AM

#22

usmcpony

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Quote:

Originally Posted by EX1

That's the exact combination ERL told me to go with for 9.7:1.

Last edited by usmcpony; Feb 2, 2016 at 04:21 AM.

Feb 2, 2016 | 10:38 AM

#23

EX1

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From: Lubbock TX

Quote:

Originally Posted by usmcpony

That's the exact combination ERL told me to go with for 9.7:1.

Do you happen to know your piston deck clearance? Looks like you are running a .051 thick head gasket too, correct?

Feb 2, 2016 | 12:05 PM

#24

usmcpony

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Quote:

Originally Posted by EX1

Do you happen to know your piston deck clearance? Looks like you are running a .051 thick head gasket too, correct?

It's circled on the right I believe

Feb 2, 2016 | 12:11 PM

#25

EX1

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From: Lubbock TX

Quote:

Originally Posted by usmcpony

It's circled on the right I believe

That is piston to head, I was hoping you knew how much, if any, they kept the piston in the cylinder at the top of the stroke. Was your block decked?

Here are the specs from Wiseco regarding those -18cc pistons with a standard 70cc chamber and a 0 deck.

Last edited by EX1; Feb 2, 2016 at 12:12 PM.

Feb 2, 2016 | 04:29 PM

#26

usmcpony

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Gotcha. It should be zero deck once finished. I don't think they're that far yet.

Feb 3, 2016 | 07:38 PM

#27

C5 Pete

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If the quench is .056 and the gasket is .051, wouldn't it make sense that likely the piston is about .005 in the hole?

My friend is making 920 to the tires on E85 at 11:1 CR.

Feb 3, 2016 | 08:55 PM

#28

EX1

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From: Lubbock TX

Quote:

Originally Posted by Capthuff

If the quench is .056 and the gasket is .051, wouldn't it make sense that likely the piston is about .005 in the hole?

My friend is making 920 to the tires on E85 at 11:1 CR.

That is what I get. Which according to my noob math skills should put him right around 9.7:1 like ERL told him.

I know we are using .040 gaskets on mine which puts it 10.0:1. I think my engine builder said 10.05:1 is around where it would be.

Anyway, I don't see any issues running 10.0+ on a E85 boosted LS. I chose not to go much higher because of my flex fuel setup.