I have a chance to pickup a spare set of E5TE heads off of a F250HD w/ 351W (same as my truck).

Are the E5TE heads worth porting and gasket matching? I've heard people have had some good luck with porting down the AIR bump....

Also, my motor has a stock bottom end bored 20 over (I believe). What kind of compression ratio can I run with the stock bottom end? I eventually what to run propane (105 octane) + 11.5:1 compression + ported factory heads for more power (hope picking up 75HP?)

 

not sure about bottom end but am up on propane and compresion. Cam selection will be everything re propane and cr- You have to know your dynamic compression and 9:1 would be tops for reliability- higher if its a shorter lived hi-po motor. So a mild/moderate rv cam would dictate static compression of 10.5:1-11:1. Cams bleed off compression based on duration/valve lift so it's an important consideration. A DCR over 9:1 will make much heat and large SCR- say 13:1- is a lot of enginered pressure.

I'm searching, trying to figure out heads myself- other engine forums have a lot more info regarding specific builds- but doesn't help much with specific W parts.

 

aluminum heads allow for higher compression because they disapate the heat better. i would not exceed 9.1. whats this motor going into and whats its use?

 

propane and some aluminum heads don't get along- enough that i'd skip using aluminum unless it got figured out. I'd exceed 9:1 SCR for propane every time but not DCR- in fact I'm settling on about 8.1 DCR which is able to use 87 pump (400- with awesome quench) - don't know if I can do that with the windsor- I like my stroked clevelands. detonation won't be a problem with propane due to the 105-110+ octane. I'm having hardened seats and top of the line valves put in to take the heat as is-intake as well.
BTW the cam I'm putting in my 400 is a 212/218 @050 which is a midline rv grind- mild for a roller and it's draining about 1.5 pts off static compression SCR. Now a motor under 7.5 DCR is about worthless and if you went with 9:1 you would end up at 7.5- not a bad build but not great for propane which needs compression to make up for it's lack of btu per mass. A DCR of 7.9-8.3 or so would be a significant propane engine and might burn some form of pump gas depending on quench etc. 8.5-9.0 would be a very strong build but propane or race fuel only and over 9.0 is a race type app.

Anyway...thats what the reseach has led me to believe based on the 400. FE motors will take more compression and not sure about where the w stands.