Originally posted by BurritaSVT:
Why bored? quoted by Buckshot

"than that, I don't agree with the issue of not boring the motor out Tom. The main reason to do it is when using aftermarket pistons it's a lot easier to size the bore to the piston rather than vice versa. With 6 stock grade sizes of pistons ADC ran into that very issue when they ordered a "stock" bore size piston set for a customer. They're now sitting on a set of 3L pistons that are sized for a grade 1 bore block. I just found a high performance coating they can use to build up the piston size enough to be used in other blocks so they can at least salvage something out of the pistons. In all the engines I've done, I've never had a full grade 1 block and the vast majority are grade 2 piston size blocks."

my .02 cents any block no matter how many miles or knocks it can be used. I saw a long block with a knock for $75 and slap a clean bored on it and what you have $200 new motor. High milage blocks will only be found as years go by. I have over 30,000 in my car it will stay with me till I hate it.

I will be ordering my pistons this week except now i will go dished making my CR drop to 8.5:1 so I can put some monster boost to it and keep the cylinder temps down.





I'm not saying to have a professional hone done to match the pistons and even out the bores. The point is, aftermarket shyte usually isn't close to matching the bores exactly so you will HAVE to match your pistons. However, selecting pistons isn't as easy as buying joe schmucks forged jobs. Forged pistons can be a variety of metal compositions. What is rate of expansion on the piston versus the stock piston? Stock pistons have extremely tight piston-bore clearances because they have limited thermal expoansion. Not so on forged jobs. Ring tension, type of hone, all play a role.

Slapping in aftermarket forged pistons with a cheap hone and hoping they will work is as bad as any other option out there.

Former owner of '99 CSVT - Silver #222/2760 356/334 wHP/TQ at 10psi on pump gas! See My Mods '05 Volvo S40 Turbo 5 AWD with 6spd, Passion Red '06 Mazda5 Touring, 5spd,MTX, Black