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Hey guys well I was doing the pre assembly and a piston accidentally dropped out with no rings in, hit my engine stand :CRY: . Now its got a slight dent in the side of the piston, not deep at all. Is this gonna be a problem?
Any input is appreciated.
Thanks
I'd replace it. I'd probably pull all the other pistons and rebalance them at least.
Ill post a pic up later of the piston. I dont see how it would be much of a problem, since you have the rings sealing.
Why would I re balance? Everythings already balanced, and if i purchase a new piston, its not going to be any weight difference.
Its gong into my 85 chevy 1/2 ton shortbox pickup. The combo should produce 425 hp and 523 lb ft of torque at the flywheel. Probably wont ever see the strip, will only be my summer vehicle. my buddies also have hotrods, and we run em here and there. Wont see too much abuse, only when runnin my other friends.
its my 400 bored to a 413 that wre talking about. Right now im at work still, but tomorrow (saturday) around noon, I will post a very high resolution picture. Thanks
Well, as Dirty Harry said "do you feel lucky?" Sounds like you have some money in the engine and it would be a shame to have a problem once you put it all together.
But, as Denny said, without a picture we are guessing.
Don
if the rings turn free in the ring lands and the skirts are not bad size etc file off the hi spot run it . new pistons can and do have a weight dif that is why you bal the mass so all the pistons /rods are the same to 1 gram or less new pistons can be off more then 3 grams to a set of new pistons if this is a forged pistons they take take alot when made . if cast look for cracks by the oil ring land this would be the back side webbing that holds the piston skirts to the piston the oil ring on a cast is wide open and this makes them weak
Alright guys, I have the pics. Click on the links
small hint . . . resize the photos.
There, they are resized... . .Quote:
Originally Posted by Henry Rifle
The ring groove looks deformed a bit to me............
yes i know this... I need advice whether I should be running this, or replace it.
How much for one piston??
30 dollars
I just wouldn't use it. If it came like that you sure as heck wouldn't take it, right? Get another and match the balance.
Kitz
Replace the piston. A gouge that close to the ring groove is going to cause problems. If not instantly, then eventually... No reason to wipe out a new engine for the price of one piston....
do you think by buying just one new piston, that I would have to re balance it? If so, how would they balance it? because i just got my rotating assembly balanced for $175Quote:
Originally Posted by kitz
thanks
you will need to weight match it with old one like i saidQuote:
Originally Posted by facemelter
Thanks Pat, I did notice that. Thanks for the advice, I will just have to purchase a new one.
Thanks
well, i now ordered a new piston. What im wondering, is whether it is really necessary to balance it being its only 1 piston? Would it really make much of a difference?
Thanks
Alright, thats understandable. What I want to know next, is when I bring the piston to the shop. Do they just compare one to the other, then add weight, or subtract, etc. or do i need to bring my crank, all my pistons, bearings, back down to the shop so they can re weigh it all out. I would rather not have to pay $175 for a full balance if not necessary.Quote:
Originally Posted by DennyW
Thanks
i would just match the new one to the old one..... i'm sure they can weigh each one for you and tell you how close they are for free...... if they're the same then no balance required...... if not then they can probably just balance the new one to the old ones weight
if the new one is heaver they will mill some grams off the piston if lighter them you can use a heaver pin if close with a gram or so it will be ok but it should be check you just need the one rod /piston not the hole mass . the piston s new should be match in weight but now you have a broken set. it need to be check to old piston this stuff i know i balance engines
Thanks pat, thats exactly what I needed to know. Its appreciated.Quote:
Originally Posted by pat mccarthy
That is more than runnable.........Jeweler's file, go easy, don't disturb the skirt coating, use the ring you plan to run for fit (remember, even the factory has ring clearance specs found in shop manuals and ring manufacturors for such a situation). The areas you displayed do not "see" the cylinder wall unless you raised the material to astronomical height. It was designed to place the ring for control, not hold the engine together. If all else fails, mic it again and again to be sure then get anal and replace (better safe than sorry). If you cracked a skirt or severely gouged the ring lands, I'd be replacing it. You don't have anything to worry about if handled properly. You should see what a fuel motor goes thru in one run and they re-use and re-use....etc.
by the way......you should have the old card from balancing......grams per piece....they can do it whith out having the assembly in their possesion. Food for thought, if a small block chevy has 1/4 gram off of the balance placed at 6 inches from the centerline of the crank, It's like swinging a 6 lb weight at 4000 rpms which robs about 18 hp.