[hyde888]

As I stated in my previous post, the #5 piston on my 71 has melted, seems to be caused by timing advanced too far. Since I need to replace one of the pistons, I'd like to replace them all at the same time. Now, I need help from the beginning. I have no experience with engine block. Which pistons should I use?? I have a P90 head which had been modified to be used with dished pistons. Oh, it's a n42/l28 block by the way. Can I get used set of pistons, or do I HAVE to get a new set?? I know new set is always better, but I am on a tight budget. Any tips or advice on removing/installing pistons on a motor still in the car?? I don't have equipment nor space to remove the engine from the car. Any input will be greatly appreciated. Thanks in advance!!

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PS. Please let me know if you have a set of L28 dished pistons/rings, or whatever I seem to need, that you're willing to part with. Thanks!!

 

[aren77z]

If you have dished pistons in it right now the easiest would be just to replace with new/used. If you want to spend a bit more time you could get flatop pistons and check the valve clearance and CR to be sure everything would work. However, doing this could be more time consuming/tough especially for a first timer at it.

You don't need new pistions but you need to make sure that the ring gap is not excessive in the used pistons. I did exactly what you are proposing and spent approx $30/ea. for pistons new from Nissan. I bought new Nissan rings too. I replaced the pistons with the block in the car. The process was something like this.

MAKE SURE YOU PUT THE CAR AT "TDC" BEFORE THE FOLLOWING:

1. pull the head w/ manifolds. (Get someone to help ya!) Don't forget to block the timing chain so it doesn't fall off(replace it while your there if it needs it.)
2. pull the oil pan
3. pull the pistons (make sure to keep the caps matched with the pistons
4. take the pistons w/ con. rods to mach. shop have pins pressed out and new pistons pressed in
5. Hone the cylinder walls as long as there is no damage.
6. Take new pistons w/ con. rods home and install new rod bearings with engine assy lube(DO NOT FORGET THE LUBE)
7. Make sure you torque the rod bolts to spec.(You dont want those falling off)
8. Install new gasket, and oil pan.
9. Install new head gasket, and head.

Follow up, reconnect everything you took off.

This is all covered in the Haynes, Chiltons, and FSM.

Disclaimer: This is a consolidated plan of attack, always refer to a service manual for a more complete step-by-step process.

Good luck,

Aren

77 280z Mod.
Bend Area Datsun Association
www.bendareadatsuns.com

 

[jeffp]

Hi Hyde, I have a set of stock L28 dished pistons and rod assemblies I will sell you. I took them out of my car when I rebuilt them. All of the assemblies are in very good condition. Mail me if you would like them. I will take 75.00 plus shipping for them.
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