E85 Ethanol turbo 300

[DuckRyder]

O.K. I will bite...

An e-85 turbo 300 sounds like a lot of fun, but I have to ask, why destroke it to a 240 (wouldn't that make it a turbo e-85 240?)?

[averagef250]

Hypereutectic pistons run less clearance, overheat them and they come apart. Hyper pistons are nowhere's close to a good forged one. They have the benefit of tighter clearance in stock applications for better cold ring seal and piston life over cast. They have the same RPM capability as cast and they're more dangerous than cast in a forced induction or high compression application since the tighter run clearance gives less fudge room for detonation.

I used KB pistons once. The $200 I saved over forged cost me $1800 in redoing machinework when they came apart at 7500. They worked for awhile, I got 10K hard miles from them, but there was no warning when they let loose. I learned two lessons with that motor: Don't run hyper in a hot engine and don't think because you can't hear the engine ping it isn't. I never heard it ping once, but lines in the rod bearings from the shock loads of pinging were clear evidence it was.

How does the stroke of the engine have an effect on static compression?

[DuckRyder]

E85 has a very high octane rating, I am not sure what the compression ratio is on a 300 but I would expect you could run reasonable boost on E85 and stock compression.

Hyper rpistons are very brittle as well, they will not tolerate tuning problems well, and it is likely you'll have some teeting issues with a one off set up like this.

[sideoilerfe]

I was destroking it to get lower compression. And it would not be a turbo 240 it would be like a turbo 270.

240 and 300 use the same bore but different stroke. You get one or the other.

[tybob81]

If you could find a set of forged pistons for the 300 and have a good machine shop balance the rotating assemby and use arp fasteners on evrything in the block it could work. With a custom set of pistons made you can choose your compresion ratio to work well with boost. There is plenty of room on our truck to route the piping and turbo. You even have plenty of room to mount an intercooler. The ez to do it would be use a holley blow thu carb set-up. The only problem would posibly be timing but that should be an ez fix.