Piston removal

No.

Ron

Is it not needed to weight all the pistons ?

The correct way to balance an engine is to weigh all the pistons, pins, rings, bearings, small & big end of the rod. Then make all equal. bearings, rings & pins are pretty much no adjustment. These weights are then used to make a bob weight, which then is bolted onto the crankshaft and balanced from there.

quote:

Originally posted by r mccall:
Getting it out will not be a problem whatsoever. Getting it back in will be quite a chore from the bottom.


Ron

Maybe #2, but not other.

Yes, see air cooled V.W.

Thanks for the replies. I will report.

SIG

quote:

Getting it out will not be a problem whatsoever

I think that depends on the amount of wear in the cylinder, if there's a ridge where the rings bottom out, it could be difficult. Has anybody actually done this?

quote:

Originally posted by No Quarter:

quote:

Getting it out will not be a problem whatsoever

I think that depends on the amount of wear in the cylinder, if there's a ridge where the rings bottom out, it could be difficult. Has anybody actually done this?

The presence of the crankshaft bearings prevent the pistons from coming out from below, there is no place to pass them.

I did it! It is possible to remove piston 8 from below. It is only possible for piston 8 since the others are blocked by the crankshaft bearings. I had no significant ridge thus piston de- & re-installation was no problem. This saved me from removing the intake manifold and cylinder heads. I got the crankshaft balanced and they needed the piston, connection rod, etc to calculate the bobweight. They found 83 grams of imbalance. Engine spins way smoother now.
Brgds
Hartwig

83 grams is just about 3 oz.
So, for an stock externally balanced Cleveland crank, the factory damper completes/corrects the balance with an 28 oz off center weight, correct?

In your case would a damper with either a 25 or 31 oz offset weight have corrected the issue?

Or, the damper doesn't get touched and it's all done by drilling holes in the crank counterweights to compensate for the 3 oz imbalance?

I ask because I have a damper with a removable balance weight and it seems like modifying that might be easier than a bunch of drilling on the crank.

Well, in my case the previous owner got in the 80th a new engine installed by Hall Pantera. That engine had an early stroker kit installed (I measured 371 cubic inches). When I overhauled the engine I found the crank counterweights looking like a Swiss cheese (approx 25% of the crank counterweights drilled away). I'm suspecting that they took a crank that was internally balanced and tried matching it with the external balanced Cleveland configuration (Cleveland flywheel and damper) and obviously they were not very successful with that task since engine was vibrating so heavily that I got scared going above 4000 rpm. I found a shop in Germany that balanced the complete rotary assembly (crank, flywheel, clutch housing, damper, belt pulley). I brought them one piston and connecting rod to calculate the bob weights. The shop drilled additional holes in almost all crank counterweights. The improvement is very impressive. 83 grams imbalance make a big difference at high engine revs.
Brgds
Hartwig