Can i reuse these Wiseco pistons? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Garage Skidz · 01-14-2018, 05:40 PM

I bought a 240 for cheap with a built sr20 but previous owner said it had a bad bottom end noise. So as i disassembled the engine i found that it ran without the oil pump drive gear attached, so no oil at all (however the engine only idled for 5 or so minutes). 3 of the rods were fine so i figure i can reuse them without a problem. Three of pistons are not worn too bad and was wondering if i could reuse them or not. i got one new 87mm piston and measured the skirts with a caliper and they are close but slightly worn down from the lack of oil. they are supposed to be 87mm at the base of the skirt as i measured with the new one but they are 86.95mm on the other 3.

this is a budget build so i would like to replace the least that i have to and pistons are expensive.

So my question is, will .05mm be a big difference? Will that cause piston slap or will i be ok? Can i just lightly sand these smooth and be ok? Has anyone done this and it work?

new vs #2 piston

#2 up close

#3

#4

ANDY black s13 · 01-14-2018, 10:01 PM

It's not the best way to do it it,but it will work as long as the bores are not tapered
or scored from the lack off oil flow,
if the bores are in spec a good hone new wiseco rings gaped for increased boost
it should be ok,I would leave the piston as is

Garage Skidz · 01-14-2018, 10:07 PM

I have a new block and getting it bored out to 87 and honed. i know the skirt guides the piston i just dont want this to become an issue at higher power. shooting for 350whp.

ANDY black s13 · 01-15-2018, 12:04 PM

Quote:

Originally Posted by Garage Skidz

I have a new block and getting it bored out to 87 and honed. i know the skirt guides the piston i just dont want this to become an issue at higher power. shooting for 350whp.

with another block it will be fine as long as the boring and honing work is spot on to spec,measure and check everything before building it up
you will probably have more issues with the top end like rockers and lifters

KAT-PWR · 01-19-2018, 09:02 PM

ask machinist, but should be usable if not gouged or scored

thegr8one013 · 01-20-2018, 06:32 AM

with no oil pressure and the car idling i would really check the head out good.

those pistons look okay but check the cylinder walls for scores, the rods for discoloration, and the crankshaft for contact from the bearing.

01-14-2018, 05:40 PM	#1
Garage Skidz Join Date: Nov 2017 Location: Charleston SC Posts: 15 Trader Rating: (0) Feedback Score: 0 reviews	Can i reuse these Wiseco pistons? I bought a 240 for cheap with a built sr20 but previous owner said it had a bad bottom end noise. So as i disassembled the engine i found that it ran without the oil pump drive gear attached, so no oil at all (however the engine only idled for 5 or so minutes). 3 of the rods were fine so i figure i can reuse them without a problem. Three of pistons are not worn too bad and was wondering if i could reuse them or not. i got one new 87mm piston and measured the skirts with a caliper and they are close but slightly worn down from the lack of oil. they are supposed to be 87mm at the base of the skirt as i measured with the new one but they are 86.95mm on the other 3. this is a budget build so i would like to replace the least that i have to and pistons are expensive. So my question is, will .05mm be a big difference? Will that cause piston slap or will i be ok? Can i just lightly sand these smooth and be ok? Has anyone done this and it work? new vs #2 piston #2 up close #3 #4

01-19-2018, 09:02 PM	#5
KAT-PWR Nissanaholic! Join Date: Dec 2011 Location: US Posts: 2,040 Trader Rating: (11) Rides Gallery: KAT-PWR Feedback Score: 11 reviews	ask machinist, but should be usable if not gouged or scored __________________ MRP Manufacturing

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01-14-2018, 10:01 PM	#2
ANDY black s13 Zilvia Member Join Date: Mar 2012 Location: erith kent england Age: 53 Posts: 153 Trader Rating: (0) Feedback Score: 0 reviews	It's not the best way to do it it,but it will work as long as the bores are not tapered or scored from the lack off oil flow, if the bores are in spec a good hone new wiseco rings gaped for increased boost it should be ok,I would leave the piston as is

01-14-2018, 10:07 PM	#3
Garage Skidz Join Date: Nov 2017 Location: Charleston SC Posts: 15 Trader Rating: (0) Feedback Score: 0 reviews	I have a new block and getting it bored out to 87 and honed. i know the skirt guides the piston i just dont want this to become an issue at higher power. shooting for 350whp.

01-20-2018, 06:32 AM	#6
thegr8one013 Zilvia Junkie Join Date: Jun 2006 Location: nassau, ny Posts: 479 Trader Rating: (1) Feedback Score: 1 reviews	with no oil pressure and the car idling i would really check the head out good. those pistons look okay but check the cylinder walls for scores, the rods for discoloration, and the crankshaft for contact from the bearing.