how loose is too loose ?
 

picked up a few of my piston and rod assemblys from the machine shop for my 330 gen IV freshen up, they seemed to be very tight although I could still move the pistons on the rods so I had the shop run a hone through them and press them back together. Now 2 of the three seem to be very loose with a very small amount on play between the piston pin and the piston ,and it only seems to be one one side ( Im guessing maybe .001 or .002 or so,but theres no way I can check it with out having them pressed back off) is this too much play ? will I hear it clicking ? a new set of pistons where not part of the budget on this one but, I just dont want to have to take this back apart in the near future

rf,
Normal clearance is about .0007 which is less than a thousanth. A little looser is ok but the only way to know like you said is to measure it. Try putting some oil on the pin and working it into the assembly, then see what it feels like. If it still feels real loose with the oil on it, there is a chance it will be noisy. If you have a .001" feeler gauge you could try to slide it in between the piston and the pin. If you can get it in, I would almost have to bet it is too loose.

By the way, your machine shop really should have measured it when they were honing it. The gauge is right on the rod hone and it is really the only way to know if you are honing it perfectly straight, or if it is too worn to salvage. Call them and ask them, they might know exactly what the clearance was.

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

I agree with Bill. I'm really suprized your machine shop would even let them out the door if they were not right. I typically do my own now however when I use to have this done by a machine shop they would always come back already lubricated. Before lubing I usually put them in the oven on 175 for about 15 minutes. The oil goes in much easier.

I would insist on getting an asnwer from your machine shop before assm.

thanks !
 

thanks for the replys gentleman i just got back from my shop where i shot some oil in the lube holes, the slop disappeared , after i thought about it i realized i had given the piston/rod ends a brake cleaner bath after rolling around on the floor of my truck and that must have rinsed the oil out of the pin bosses from the machine shop, hence the perceived slop anybody know ( for sure) the CC of the chambers on the peanut heads ? my casting number is 14092360 and yes ive seen the mortec website they dont list CC just thought somebody might have checked em with a burrette ( although i cant imagine why, they are pretty sad from what ive read.........)

I suggest you take them to another machine shop and have them inspect them for you. Just think of how much it sucked pulling the engine out. Do you want to pull it twice.

Why, were the pistons rolling around on the floor? The shop should have had them oiled and in a box to protect them, ready for installation, being a press fit they had tobe cleaned pre-assembly, was small end heated for pin install?if so they should have put oil on the piston pin bosses after cooling a bit to insure free play in boss. Make sure the pin is centered equally in piston, by sliding it from one side to the other looking at distance pin moves in boss.

I've got the same head casting. They are supposed to be 119-120cc depending on who you ask, per GM specs.
As luck would have it, (bad for me)(good for you) my heads are ready to be picked up from machine shop today. I tuliped some intake valves, requiring some head work. As part of calculating my final compression, these heads are being cc'd by the shop. I will let you know what they actually end up being...
As for being sad heads, not so fast . For a stock 330hp engine, they are perfect for your use. You can still run these heads all day up to 5Krpm, and they perform just fine. Beyond that, yes they start to run out of steam. But, below that, they are torque monsters. I have a mildly upgraded Gen IV package. With some bumped up compression, good fuel supply, and free flowing exhaust, that engine will run hard all day, and is very reliable.Thats worth alot these days. It's easy to feel you need to upgrade continually,especially after reading about some of the iron that folks are running, but..... $$$$$$$$
As they say, "Run what you brung" There will always be somebody faster.. Get past that thought, and now your having fun..

well they were on the seat in a box till i had to stop fast i figured the 5 seconds rule didnt apply to piston/rod assemblys so i just left em there till i got back to the shop lol

Rich, i would definatly be interested in having that info and i CAN get past that thought , i just hate when other boats get PAST me !!!!:eek:

PLEASE ANSWER THIS QUESTION FOR ME. When you brought the pistons back to the machine shop and told them to hone them out what was their reply ??