[Lancair IV]

I have a chance to purchase a 1978 351W out of an Econoline van. (cheap) Hasn't run in 3 to 4 years and has 70k miles on it. He claims the van is a heavy duty version, and that the motor might have 4 bolt mains. I don't know!

Questions:

Is this block a good starting point for a stroked motor (someday)?

If I rebuild this motor 30 over with aluminum heads, aluminum intake, stock crank, and aftermarket cam, can I get between 400hp and 450hp?

Thanks and Happy Holidays

 

[Joe R]

I would disreguard his statement about 4 bolt mains. Does the motor have antifreeze in it? Is it a stock 4.00 bore? The block (if good) is a 150.00 core. I built a stroker with a 74 351W. You won't use much besides the block, main caps, pan, oil pick up, timing chain cover, balancer, flywheel, pulleys and brackets.

 

[tom1195]

'74 and earlier 351W blocks have beefier main-webbing than the '75 and newer blocks. The '78 will not have 4-bolt mains, and the main webbing will not be beefy enough to support a 4-bolt conversion. However, it will support a stroker up to 500-550 hp, assuming you won't be spinning the motor too hard, and you use a main stud girdle. If you rebuild this motor as a 351W, .030" over, with a good set of aluminum heads and a healthy cam (& aluminum intake, etc...), you should definitely be able to get 450hp. The stock crank should be fine, assuming you don't spin the motor much past 6000 rpm. At the very least, you'll want to upgrade your rod bolts, although it would be better yet to get a good set of H-beam rods. Aw hell, ya may as well go ahead and stroke it with a nice forged crank, H-beam rods, and forged pistons. (This is much the same rationale that led to my 408W.) The Sportsman and SVO blocks are more costly, but more reliable, options. Sportsman blocks have nice, beefy main webbing that will support a 4-bolt conversion. SVO blocks have beefy main webbing + 4-bolt mains. I haven't checked the cost of either of these lately.

Good Luck & Happy Holidays,
Tom

 

[MikeD]

Rob,

I bought a 1978 Econoline Van 351W engine last September for $250. (probably too much)

It was the 2bbl version (140hp!), so I'm not using the intake or carb. In fact, the only parts I'm using are the crank and rods (and the block of course).

I've read (here and other places) that the 351W block should easily make 350 - 450HP given the correct parts. Mine will have Keith Black 151 flattop pistons, solid lifter cam (TBD), aluminum heads (TBD), Edlebrock Performer intake, carb (TBD), Gordon Levy Road Race Pan.

Pictures here: Mikes Cobra Build