ty_ty13

iTrader: (42)

after putting about 10k on a motor and deciding to swap pistons (only because of performance purposes) how much would i have to bore/hone the motor to ensure a clean entrance for new pistons?

TIA

Steve Bryant

iTrader: (1)

What kind of piston change do you want to make? If the cylinder walls are not scored, you may can leave the block in the vehicle, pull the heads and run a carbide brush in the cylinders to clean and give the cylinders some tooth to seat the new rings.

Steve

ty_ty13

iTrader: (42)

just a swap from a -8cc to a -32cc dish... this will be next winter though so i can turn up the boost.

hals73rs

iTrader: (4)

How about a rebalance??

Steve Bryant

iTrader: (1)

hals73rs is right, the rotating assembly will need to be rebalanced. The reciprocating mass of the -32 cc pistons will be different from the -8 cc pistons. The bobweight will have to change according to half of the difference in reciprocating mass for each piston assembly. You'll need to plan on pulling the engine and disassembling the engine.

Steve

Beast96Z

iTrader: (21)

If all is well in the walls, a light hone will be sufficent. I wouldn't think any more than .001-.002" would be removed at most.

ty_ty13

iTrader: (42)

so could i replace the pistons with another 4.030 piston without honing, just balancing?

hals73rs

iTrader: (4)

It's gonna need honing to get the rings to seat......

ty_ty13

iTrader: (42)

what about if i did the swap before the motor was ever ran? could i just use another 4.030 piston as long as the motor had never been installed/ran?

Beast96Z

iTrader: (21)

If the motor hasn't been run, then the hone shouldn't be broken. In that case, you'll just need a re-balance and assembally.