E85 and supercharged or turbo'd?

[it's all dodge]

All this talk about E 85 and the compression it'll support, makes you wonder, can you run maybe 7 pounds of boost on a 8-8.5 to 1 engine, in a towing rig? or more? Something like a 318 stroked to 4", since small bore engines are better about less detonation? With regular or prem. gas, it usually aint adviced, atleast in a towing rig. I aint got the money for it, just wonder how it would work, see what opinions are

[TrashedCharger]

I think you can go to 8psi safely in a relatively stock v8. Any higher than that and you should start looking into custom head gaskets. The reason that the inline six motors can handle more boost without a metal head gasket is because they have more head bolts.

When you start stroking an engine, you increase compression. I think you would be better off with a 360. Those are a 4" stroke from the start and most have an advertised compression ratio of no more than 8.5:1 The actual compression is less than that. Usually down in the high 7's to 8:1 flat, unless you have an early '72 or late '71 dated 360. Those were higher compression. Something around 9:1 - 9.25:1.

I think the reason that smaller bores do well with detonation is because they usually get their cubic displacement from stroke, rather than bore size. Simply put, because of that, the engine has more leverage and it's easier for the combustion to move that crankshaft in the direction that it should.

For whatever it's worth, I'm going to run E85 in my Charger and it's getting boosted, via a ProCharger.

[kick_the_reverb]

Originally Posted by TrashedCharger

I think you would be better off with a 360. Those are a 4" stroke from the start and most have an advertised compression ratio of no more than 8.5:1 The actual compression is less than that. Usually down in the high 7's to 8:1 flat, unless you have an early '72 or late '71 dated 360. Those were higher compression. Something around 9:1 - 9.25:1.

Some magical 360 you have there. Every Mopar 360 came from the factory with a 3.58" stroke (as opposed to 273/318/340 which had 3.31").
I also doubt the statement about the high compression in the early years, but I don't have the time to look that up now. Anyway, it's not good to assume anything about compression ratio, always measure and calculate what you have.

Ran

[rumblefish360]

The super charger store advertisement has a kit for this.
In theroy, it should make some excellent power.
I so no reason why it wouldn't. Same rules apply. More fuel, more spark, under more squeezzzzee. LOL = Zooooooooooooom!

[it's all dodge]

thought this thread was dead! Actually, since I'm talking a TRUCK engine, (low speed power!) say for hauling a trailer, I would take the more stroke than bore approach, worked for 2.2s and 2.5s, Course, the common block 2.5s were limited to a rod stroke ratio about as low as a 400 Chevy, either 318 or, a 273 with a 4 inch stroke! Since a person would need custom pistons anyway. I'm not very Cummins 6 cyl knowledgeable, seems they are also less bore than stroke?

[JVMopar]

We had a E-85 supercharged 5.3 silverado when I was in college. 480 hp at the wheels (clayton dyno). I don't remember much (almost 10 years ago and it was a GM) except they milled the heads and had to add an extra fuel pump and 4 injectors for when the boost got high. I would guess 6 - 8 psi of boost and I'm sure the stock 5.3 was a 9:1 motor to start with. Hmmm time to buy a turbo car and some common blocks and do some testing.