I am building a 327 and have a bit of a chicken and egg problem. The shop I was using went ahead and hung the new pistons on the stock rods before the rotating assembly was balanced. The shop that was going to balance the assembly indiacted that they did not want to risk damaging the pistons by removing the press in pins. So do I build it as is or risk damaging the pistons to get it balanced. If the pistons are damaged I assume if I buy the exact same set the tolerances would be good enough to prevent having to remachine the cylinder bores.
Ghack68
If they were a cleaver machine shop ... I don't see why they couldn't disassemble one Piston/Rod unit and get the Rotating and Reciprocating weights and then average them for the other assemblies 
Have them pick the lightest assembly to do their measurements and then match the other assemblies to the lightest one after it is reassembled.
This is a street engine isn't it ??? A gram or two (or three ...) difference is never going to matter :thumbsup:
If the machine shop you're working with is having a problem with the math, find another shop to do the work ...
I would imagine their are both just fussy because someone else worked on something - IMHO of course
Have them pick the lightest assembly to do their measurements and then match the other assemblies to the lightest one after it is reassembled.
This is a street engine isn't it ??? A gram or two (or three ...) difference is never going to matter :thumbsup:
If the machine shop you're working with is having a problem with the math, find another shop to do the work ...
I would imagine their are both just fussy because someone else worked on something - IMHO of course
This is the same crank and rods that were in the engine before. New pistons. All of the pistons should be the same weight so it should be fine - right?
If the pistons are damaged during disassembly replacing the piston with the exact brand, etc would be ok and would not require re-machining -correct?
If the pistons are damaged during disassembly replacing the piston with the exact brand, etc would be ok and would not require re-machining -correct?
many shop's and backyard mechanic's RUIN piston's pressing them on and off , the style rod and piston in a 327 has been around for ?? ??? let's see ???? about 50 YEAR'S !
look's like they would have figured it out by now but they have not ,
if your piston's were installed properly the first time and move freely on the pin's like if you hold the rod with the piston upside down you should be able to make the piston move just by the movement of the rod , THEN LEAVE THEM !
look's like they would have figured it out by now but they have not ,
if your piston's were installed properly the first time and move freely on the pin's like if you hold the rod with the piston upside down you should be able to make the piston move just by the movement of the rod , THEN LEAVE THEM !
Greg,
See if you can find a machine shop nerby that has the proper fixture to remove the pistons without hurting anything. Not many guys have it, it actually supports the rod from oinside the piston while you are pressing the pin out, that way there is no stress put on the piston.
As far as balancing goes, it really depends on how much heavier or lighter your new pistons are compared to the old ones. It has very little to do with the new pistons all being the same weight. If your new pistons were a stock replacement type, then they should be pretty close to the weight of the originals and you will probably be ok without balancing.
I have come up with a couple of imaginative ways to weigh the big end of the rod without removing the piston, then with the total weight you can get pretty close on a balance job, but it is not the right way to do it
See if you can find a machine shop nerby that has the proper fixture to remove the pistons without hurting anything. Not many guys have it, it actually supports the rod from oinside the piston while you are pressing the pin out, that way there is no stress put on the piston.
As far as balancing goes, it really depends on how much heavier or lighter your new pistons are compared to the old ones. It has very little to do with the new pistons all being the same weight. If your new pistons were a stock replacement type, then they should be pretty close to the weight of the originals and you will probably be ok without balancing.
I have come up with a couple of imaginative ways to weigh the big end of the rod without removing the piston, then with the total weight you can get pretty close on a balance job, but it is not the right way to do it
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