Author Topic: Ceramic coating pistons, how does it effect balance? (Read 3422 times)

subsonic · « **on:** January 08, 2008, 03:49:35 pm »

I will be having mine done. I am wondering about weight of the coating and how consistent it is? If I am going to be spending money to have all my components balanced, I dont want to be getting these things back with the weights all over the place. It will just cost more to have them matched up and balanced.
Anyone check weights before and after?

jimfoo · « **Reply #1 on:** January 08, 2008, 04:24:42 pm »

I asked at the machine shop when I dropped my stuff off and he said it is not to worry about it as I am getting mine balanced before coating.

Kudagra · « **Reply #2 on:** January 08, 2008, 05:15:58 pm »

Quote from: "jimfoo"

I asked at the machine shop when I dropped my stuff off and he said it is not to worry about it as I am getting mine balanced before coating.

That doesnt make alot of sense to me. I had mine coated and am now having my assembly balanced. They take off of the bottom side of the pistons to balance them. Yaknow...the place they dont coat.

jimfoo · « **Reply #3 on:** January 08, 2008, 05:23:12 pm »

I think because the coating weighs so little.

subsonic · « **Reply #4 on:** January 08, 2008, 07:51:49 pm »

Well to what weight range do they balance to? Are we talking 1gram, 0.500grams, .250grams etc..?
If I have the tops done and the poly moly applied to the sides, it must add weight.

jtanguay · « **Reply #5 on:** January 09, 2008, 05:13:34 am »

a gram difference from a piston to another one shouldn't affect it enough on our diesels??? maybe to a high revving formula one car but i doubt to a 5k max engine... the benefits of the coating far outweighs the loss in being fully balanced (if there is any)

CoolAirVw · « **Reply #6 on:** January 09, 2008, 07:30:18 pm »

Piston balance should be within 1 gram, but I agree that on our low revving 4 cylinders that balance isn't nearly as critical.

Right out of the box my new kolbenschmidt pistons were...
519.9 grams
520.4
519.7
520.6

But.... if you engine is needing piston coatings for hard use (ie increased boost) it certainly could benefit from full balance work (rods, pistons, flywheel & crank)

The smoothness of a balanced engine isn't just for driver comfort. Its for longevity of parts and balance of power amonst the cylinders. Balance of power contributes to the overall performance of an engine.

Note: They dont put weights on to balance they remove weight by removing material in non-critical areas.

DonGTI · « **Reply #7 on:** January 09, 2008, 10:15:28 pm »

Quote from: "CoolAirVw"

Right out of the box my new kolbenschmidt pistons were...
519.9 grams
520.4
519.7
520.6

Of the 4 pistons in the 1.6d i am running now, not a pair of them came out from the same engine... The guy who was helping me assemble the engine used a precision scale (to .00 of a gram) to balance the pistons to within .5 of a gram

Quote from: "CoolAirVw"

The smoothness of a balanced engine isn't just for driver comfort. Its for longevity of parts and balance of power amonst the cylinders. Balance of power contributes to the overall performance of an engine.

Note: They dont put weights on to balance they remove weight by removing material in non-critical areas.

The piston's weight was shaved off by removing as you said metal from the skirts, i didn't see connecting rod balancing but he said they shave off from the bottom/thickest part of the rod as well as from the top.

The last stage was balancing the lot together and not sure how that was done but he said he took weight off (drilled into) the crank counterweights... On a friend's engine which was built from bits running around as was mine there was no balancing done and its hard to see any difference between the two, both in driving and idling although at high revs his engine definitely does not run as smooth as mine, as are high speed stretches of road.