Piston size

[fiat218]

What is better
0.4mm Iap sells
0.60 mm. I have already
84.4 mm . Vicks auto

[So Cal Mark]

I'd steer clear of the Vicks' pistons. I had a customer that bought 1608 pistons from them and was supplied retainers that weren't compatible with the pistons. One came out and ruined the cylinder wall.

[fiat218]

I was just wondering what could I do to make the engine better in torqu and horsepower

[narfire]

Hey Jim. I've had stock motor, motor with IAP .4 oversized pistons and stock head, then stock 1800 head then went through the gamut of various heads with varying degrees of head work and oversized valves and finally settled with a decently massaged head with Mark's cams and adjustable cam wheels. In my opinion the most benefit was realized with head work, cams and adjustable cam wheels and degreed in properly. I have a FI engine so air and fuel delivery is still stock.. In your case dual downdrafts will help as well.
headers helped as well.

[So Cal Mark]

size matters! Make it as big as possible

[narfire]

size matters! Make it as big as possible

Yes, that too... If or when I build another engine, I'll be sourcing the 85mm pistons for the block..

[fiat218]

Ok thanks, 85mm, where do I find that

[fiat218]

http://www.midwest-bayless.com/storefro ... =252478096


This one works?

[narfire]

Jim, the 85mm were for the 1800 or 2L. Were you doing a 1608? those are 80mm stock I believe and have no idea as to what oversize you could get for those.

[manoa matt]

Bigger isn't necessarily always better. I think I'd start with the next size up from what the cylinder wall diameter is currently. The power/torque increase from a 0.4 to 0.6 oversize might not be noticeable, or could be compensated for with other work to extract more power/torque. With the quantity of blocks and pistons available you would not want to bore the block to the largest size, as something as trivial as a broken piston ring scoring the cylinder wall would render the block useless. Step up in increments and allow yourself wiggle room if something goes wrong to use the block for the next piston size up.

[BEEK]

jim 81mm is the largest for the 1608

[BEEK]

Bigger isn't necessarily always better. I think I'd start with the next size up from what the cylinder wall diameter is currently. The power/torque increase from a 0.4 to 0.6 oversize might not be noticeable, or could be compensated for with other work to extract more power/torque. With the quantity of blocks and pistons available you would not want to bore the block to the largest size, as something as trivial as a broken piston ring scoring the cylinder wall would render the block useless. Step up in increments and allow yourself wiggle room if something goes wrong to use the block for the next piston size up.

not to argue, but more displacement is better. i do understand your point about available blocks,but one can sleeve a block to repair cylinder wall issues once maximum oversize has been achieved. in my race motors i sleeved all of them, the metalurgy is better in the sleeves that i could buy than in the block itself

[manoa matt]

What is the typical cost of re-sleeving a block, for a customer?

[BEEK]

last one i had done was 200.00 including sleeves, that one had to be standard, the racing rules would not allow any overbore

[manoa matt]

Not trying to argue, just want to understand and learn. So $50 per cylinder includes: The new sleeve itself, the labor to press out the old sleeve, the labor to press in the new sleeve, and honing of the new sleeve? Why is it so cheap? Most machine shops will charge a least $50 per cylinder just for a hone of the original sleeve.