2G Reusing OEM pistons

[Mando Vee]

So I am currently in the midst of having the engine rebuilt on my 95 gsx.

Timing belt got stuck while going 30mph and everything just went loose. Took the car over to my brother-in-law to assess the damage and saw that 6 of the intake valves were bent.

Other than that, everything looks good according to my brother-in-law which is the person helping me get this done. I have a background on collision repair but very limited to mechanics so my work will mainly consist of getting all the parts needed and help him clean/prep.

Our plan was to just do enough to get it back on the road and not mess with the long block other than cleaning since there wasn't any damage there.

My question is am I ok to do that?

I will list all the parts going in but will I be ok if I do all this and just come back to the block when I upgrade pistons which brings me to my next and main question, am I ok to reuse my oem pistons?

• OEM Timing mid belt cover
• OEM Timing lower belt cover
• OEM Cross member bolt
• OEM Crank trigger plate
• OEM Engine oil pan drain bolt washer
• OEM M16 Fill plug gasket (X3)
• GSC Zero tick lifter set
• ACL Balance shaft bearings
• Gates timing belt tensioner pulley
• Timing belt tensioner
• OEM Thermostat
• J2 6mm 4PLY Main radiator hoses (upper & lower)
• Engine camshaft position sensor upper standard PC45
• Oil pressure sensor
• Injen short ram cold air intake
• OEM Throttle body gasket
• Torque solutions Shifter base bushings
• OEM Engine oil cooler O-ring
• OEM Engine oil cooler seal
• OEM Oil filter housing gasket
• Gates water pump
• OEM Transfer case output shaft oil seal
• Exhaust pipe to manifold gaskets
• Catalytic converter gasket
• ARP m11 head stud kit (207-4203
• Front crankshaft seal
• Rear main seal
• Engine oil pan gasket
• 1qt redline mt-90 75w90 gl4 gear oil (X3)
• 1qt redline heavy shock proof (X2)
• Clutch kit (1105048)
• Head gasket kit (021059101)
• Timing belt
• Oil pump belt
• Timing idler pulley

I will also be resurfacing the head and flywheel.

I been told that I might as well replace the piston rings and bearings so I'm already thinking I should just go ahead and have the block resurfaced as well.

- piston rings
- bearings
- freeze plugs

I like the idea of reusing my pistons so I can save and get one of those kits that also come with the crank and rods in the future.

Tia

pictures of my progress are on my build thread, I appreciate any insight and recommendations on what else I should be getting for my rebuild.

 

[Canadian_CD9A]

I'm extremely weary about re-using pistons. A few things:

Replacement cast pistons are not expensive. Given the cost of rebuilding an engine, and the risk of having blowby, it's a very small price to pay. I assume you'll be checking them over very carefully to confirm there is no damage as a result of the timing belt failure. If the pistons or the skirts have any visual scoring, you'll need new pistons and an overbore. You won't know until you pull them out. If you take the chance that the longblock is okay upon visual inspection with the head off, that's your gamble to take. A compression or leakdown test would tell you what the general health is like, but that's clearly out of the question with bent valves.

I wouldn't throw new rings at a well-used block without honing the cylinders. If you run new rings on glazed cylinders, the rings won't break in properly and won't seat/seal. Dingle-ball hone tools on drills are dodgy, but they can get the job done if you know what you're doing. Go to a machine shop if you have any doubts.

You'll have to measure, measure, measure the bores. Even if they look okay visually, make sure they aren't ovalized/egg shaped anywhere in the bore. If they're out of round, you're inviting piston slap, and run the risk that the rings aren't going to seat and seal properly. After that, measure the pistons, and do the math to make sure your piston-to-wall clearance is within spec at every measurement point.