[Arkangel]

Hi

I'm rebuilding my car's engine,and i want to replace the pistons along with the piston ring and pins, so i was wondering,do i need to balance the pistons (mounted to the rods) and all that,or there is no need of that because i'm changing all of the pistons?
And is there a way i can change the pistons my self,because the pistons have semi floating pins,so i know that i need to use a press to get them out,and then an oven to heat them and place them on the rods (if i'm not mistaken) can i do that my self or i need some big *** press?

thanks

[richard stewart 3rd]

Hi,
Welcome to Hotrodders .com Glad to have you with us.

You do not need a re balance if all 8 pistons weigh the same. Get a digital scale w/grams and weigh them all, then make them all the same weight as the lightest one, If they are all within 3-4 grams of each other, then you should be fine.
Rich

[CNC BLOCKS NE]

Originally Posted by Arkangel

Hi

I'm rebuilding my car's engine,and i want to replace the pistons along with the piston ring and pins, so i was wondering,do i need to balance the pistons (mounted to the rods) and all that,or there is no need of that because i'm changing all of the pistons?
And is there a way i can change the pistons my self,because the pistons have semi floating pins,so i know that i need to use a press to get them out,and then an oven to heat them and place them on the rods (if i'm not mistaken) can i do that my self or i need some big *** press?

thanks

You may want to have a shop remove your pistons and hang the new ones and have the pin bores in the pistons checked as we see alot of pistons where the pin bores only have .0004 to .0006 clearance which is not enough.

If your new pistons weigh the same as the old ones you should be good to go,

[Arkangel]

thanks for the replays.
you confirmed what i suspected it look like that i'll need to let the shop remove the old pistons and place the new ones, but i have no idea if thay will charge me extra for the balancing/wighting the pistons and rods.
so i'm thinking about leaving the old pistons and just changing the piston rings.
what will i gain with new pistons,or loose with old pistons with new piston rings?
will it make a big difference in performance???

[GS 455]

What did the engine run like? How many miles were on it? Do the cylinder bores have any scrapes down the walls that wont clean up with some honing with a stone hone that you can get from a parts store? PS use lube when honing. Measure the bore and see if it is within specs. Measure taper in the bore as the top and the bottom comparison. They have specs for all that and if it is to much you need to bore the cylinder out and put oversize pistons in it and you should have the crank and line bore checked too. Dont forget to check the rods. When you get down to the bottom of the engine and you want to make it run forever always do it right so you dont have to do it again. I always want .002 bearing clearance in my main and rod bearings in my Buick 455 and I run 10.78 on good weather days in the 1/4 mile without hurting any parts in the engine.

[Arkangel]

Originally Posted by GS 455

What did the engine run like? How many miles were on it? Do the cylinder bores have any scrapes down the walls that wont clean up with some honing with a stone hone that you can get from a parts store? PS use lube when honing. Measure the bore and see if it is within specs. Measure taper in the bore as the top and the bottom comparison. They have specs for all that and if it is to much you need to bore the cylinder out and put oversize pistons in it and you should have the crank and line bore checked too. Dont forget to check the rods. When you get down to the bottom of the engine and you want to make it run forever always do it right so you dont have to do it again. I always want .002 bearing clearance in my main and rod bearings in my Buick 455 and I run 10.78 on good weather days in the 1/4 mile without hurting any parts in the engine.

well it ran OK,it has lost a little bit of it's power but it was still OK,the cylinder bores a really clean/smooth no markings/scratches on them.
i definitely agree with you, to bore the cylinders and have some new pistons,check the crank,and rods, thats the best thing to do.
but the thing is that i already have the new pistons,they were bought a long time ago .so now i just want to refresh the engine a little bit, so the thing is that if i change the pistons i'll need to balance them to make them all wight the same,so my headache now is what will i gain with the new pistons,or i won't gain much with changing them so i can leave the old ones on and just change the piston rings???

how does the piston wears out,or just the piston rings wear out ???

[Greg T]

It's not enough to make all the new pistons the same weight. They have to be the same weight as the old pistons. Otherwise you need to balanace the entire rotating assembly.

[Arkangel]

Originally Posted by Greg T

It's not enough to make all the new pistons the same weight. They have to be the same weight as the old pistons. Otherwise you need to balanace the entire rotating assembly.

yeah that's what i'm thinking. one more thing why i should just leave the old pistons and replace the piston rings only (also clean the carb deposits from the old pistons) let's wait and see if somebody can tell me the up/down side of new/old pistons

[CNC BLOCKS NE]

On your old pistons if the ring lands are worn you may as well get new ones while the rods are out its a good idea th check for size and roundness and bend and twist.

[Arkangel]

Originally Posted by CNC BLOCKS NE

On your old pistons if the ring lands are worn you may as well get new ones while the rods are out its a good idea th check for size and roundness and bend and twist.

how can i check that,only visually inspection or some measurement or special tool is required?

because they look like they are in good condition (no scratches or any thing like that)