Max Compression Ratio for E-85 for a Coyote?

[SStang]

Since I have access to E-85 where I live, Ohio. I would like to take advantage of it or is there no advantage to running a higher compression ratio then 11:1.

Thanks.

 

[s8v4o]

E85 should be able to handle around 14.0:1.

 

[SStang]

What would the ball park gains in hp/tq and fuel mileage?
I was thinking 13:1.

Thanks.

 

[s8v4o]

What would the ball park gains in hp/tq and fuel mileage?
I was thinking 13:1.

Thanks.

Well I believe it was Bruce that noted you would get a mileage break-even point around 14.5:1. At that compression you'll get the same mileage as a gas engine at stock compression. As for the compression affecting HP check out the webpage below. It has LOTS of calculators.

http://www.wallaceracing.com/hp-cr-chg.php

Based on a stock compression ratio of 11.0:1 and a base horsepower of 420 you get the following results if increased to 14.0:1.

"Your old Compression Ratio of 11 and HP of 420 is now calculated
as a Compression Ratio of 14 and 444.00 Horsepower.

Not bad for a stock engine with nothing more than just compression.

 

[rcm90]

12.5:1 and a shit load of boost will wake it up a little.

 

[W3bb3r04]

I saw an NA 12:1 compression coyote on e85 made ~640/480 on an engine dyno.

 

[jodadejss06gt]

^ I saw that too RJ!

 

[W3bb3r04]

I was a little off on the numbers but here it is

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[SSPSTANGBANGER]

15:1 comp has been done and it makes a lot of power with supporting mods like ported heads, cams, etc.
I am debating between 12.5:1(pump gas/torco mix) or 15:1(E85) on my new engine I am building for big nitrous(400-600hp)
I know of a 15:1 comp Coyote engine that made 600+RWHP. I cant say who it is or what is in it because its a competition engine that they don't want to give info out on.
I can say I will likely have a copy of those custom cams in my new engine.

 

[BruceH]

If I was to build a motor for e85 only it would be 14:1. The reason being that e85 is going to vary some depending on where you get it from.

I was able to make pretty good power with 12:1 and e85. I don't think the total benefits of the fuel really start to show until that level. My example would be the 11:1 4.6 motor I had built. It gained about 10/10 with e85 over 92 pump gas. Once that motor was supercharged the e85 gains were huge. This has been the case with every supercharged motor I've had and every type of supercharging I've used. The increased cylinder pressure gets more out of e85.

A compression ratio of 14:1 will give the same cylinder pressure as an 11:1 motor with 4psi of boost. However, power isn't being used to drive a supercharger.

I'd guess that with the excellent head flow of the coyote motor along with e85 and 14:1 compression that you would be making significant power. As much as a coyote with 5-6psi from a supercharger with e85.

Looking forward to your build and results. That's how we verify the guesses we make.

Since I have access to E-85 where I live, Ohio. I would like to take advantage of it or is there no advantage to running a higher compression ratio then 11:1.

Thanks.

 

[Dillon Dollar]

Sub

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[CPRsm]

Something you need to watch out for on these small engines is raising the compression so much, the dome dicks up the flame front.

 

[Department Of Boost]

I was a little off on the numbers but here it is

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That looks impressive, and it is. But it isn't amazing. A motor on a dyno, with no CAI, no accessories, duno headers and no mufflers. It probably makes 515 at the wheels. With a lot of RPM.

 

[SSPSTANGBANGER]

That looks impressive, and it is. But it isn't amazing. A motor on a dyno, with no CAI, no accessories, duno headers and no mufflers. It probably makes 515 at the wheels. With a lot of RPM.

yea @ 15% typical loss its 530RWHP. that's still good considering its only 12:1 and not much of a bump over stock compression. If it was closer to 15:1 it would be around 600RWHP given proper cams/etc.

Those dyno headers are a production old 4V header with a adapter. My SW 1 7/8" longtubes flow more I am sure.

The only accessory on a Coyote in the car is W/P and alt so maybe 5hp difference there. (Under full throttle a/c cuts off so that doesn't matter either)

Given the Hemi chamber of the Coyote flame travel is not a issue N/A(boost is another story)