De-stroker kits for 351W?

[jyrki sulka]

I have done mainly Ford euro 4-bangers & V6`s, so i have "few" black points doing good old 289-351W Ford V8`s. Time to learn more.

Main question is; is that true you can do high revving "small-block" doing de-stroke for 351W with reasonable/cheap costs?
If it is, what parts you guys recommend to use, and +`s and -`s, if compare to 289/302?

Thanks for your advises,
Jyrki

 

[Mike Pass]

Hi Jyrki,
There are essentially two types of small block fords. The 289/302 (4.7/5.0 litre) and the 351 (5.7 litre). The bores are the same on both but the 351 has a "taller" block to allow a longer stroke. It also has much bigger main bearings. So if you want a high revving motor there is little point in destroking a 351 as you are going back to a 302 in effect.
If you want high revs you need a strong block with strong main caps suc as one of the Ford Racing race blocks with very solid castings and 4 bolt main caps. Use good H section rods, quality forged pistons and a steel crank. Use top notch stuff eg good race spec bearings and ARP studs and bolts. Use a top quality harmonic damper. Get a really good balance job - possibly an internal balance. Small block Fords are usually externally balanced - the out balance crank is balanced by an out of balance flywheel and crank damper. The revs it will go to will then depend on the cam, heads and inlet setup. You need to plan all this out bearing in mind what you want to use it for and how drivable it needs to be. On the road a full race motor is real pain. A good torquey motor is usually far better than a screamer unless you are on a track with the engine a high revs all the time. A good guide to performance is to look at the area under the torque curve rather the max power. Power tells you the max speed. Torque tells you how quickly you will get there!
Cheers
Mike

 

[Gordon Levy]

I've designed and engine like this. One of these days I'll build it. Basically using a 9.5 deck 351 and a 302 billet crank, Custom I beam rods because H beams won't take the change in momentum as the revs go up and down. It will also need a good solid roller cam and absolutely bullit proof valve train.
I figured it would be around 750hp at 10,000 revs and about 485 lbft of torque.
The issue I see it this engine would want to rev to around 12,000 revs but the block won't take the harmonics past 10,000 revs and the valve train just won't keep up.

 

[Dave Wood]

There is an aftermarket( and may also be an FRRP one) 351W block available that uses the smaller 289/302 journal, so you can effectively build you a short stroke 351W, without the expense of machining spacers. I believe it's a World block ( and possibly an FRRP one). I had initially planned on building a 289 for the Coupe, but all the hardware was for a 351W based engine,plus the ports on the shorter engine would have probably exited right into the upper frame rail. I have a fresh crank waiting and when I saw the block I began doing some math to determine which rods/pistons I would need for the build. I know it's been available at least 6 months and maybe longer, so there is that possibilty.

 

[Chas]

Woodz is correct. (Thank you woodz)
We make both 8.2 and 9.5 blocks in 2.248 main size.
They can be found here:BILL MITCHELL HARDCORE - Man O'War Blocks
We even have 7- 9.2 decks in inventory with the small main. We have discontinued casting those.