.060 Over 351?

[Nosfed92GT]

Just wondering if going .060 over on a 351 late model block (83) a bad idea? The machine shop I talked to said that they do not like going over .040 due to cooling issues and block strength. This would be used on a 83 block, 3.85" stroke crank, .60 over forged 302 pistons, Victor Jr. heads (ported) and a Comp 282 camshaft. Thanks

 

[hllon4whls]

Why not stick with .030 or .040? What is the reason to go so big?

 

[Nosfed92GT]

Why not stick with .030 or .040? What is the reason to go so big?

They would not clean up even with a .040 over bore. I got the motor out of a running coupe but when I pulled the heads I noticed that it needed a rebuild. I already had .030 forged pistons so this block is either going .060 over and I have to buy new pistons or take a chance on another block. Thanks

 

[macx]

From what I know, I'd agree with the machine shop. Especially when going a longer stroke which puts more side load on the pistons, and more compression also. At 060 that thinwall casting will get pretty flexy, causing excessive pressure loss past the rings.

 

[Vipersix]

I would never recommend anyone going above a .030 on a 302 but the 351 is a whole other animal. Depending on how hard you push a motor that's been .060 over you could get all kinds of life from it. If you don't plan on pushing more than 500 hp or above a 11:1 compression I don't see any problem running .060 over on a 351. The Windsors have a significantly thicker casting and can easily accept that large a bore.

You might also consider seeing if a .050 bore would do the job if you're going to punish your block or even get sleeves put in. That would solve any strength questions you might come up with.

 

[Nosfed92GT]

Hey Viper, I'm at Ft Campbell also and MOHR performance near Bowling Green told me that. Have you dealt with any other shops locally? Thanks.

 

[Vipersix]

Delk down in Lebanon is a real good place. They've done most of the work on all my friends vehicles though I can't say I've ever taken anything there. The only thing I've ever farmed out was for my rearend and I took it to L & R in Madison and they did a ****ty job. Not real sure if they're around still.

Here's the contacts I have for each:

Delk (615)453-2300
L & R 1236 Northgate Business Pkwy. Madison, TN