Even my luck is good somtimes. Cracked bedplate and mainweb

[art leong]

Originally Posted by Mike Taylor 3601

I was told the same thing years ago,about no counterweights causing problems.They were running chevettes here on dirt track, some of them were cutting counterweights off,I balanced several of them ,they never did run long.
I do know 4.750 stroke BBC will run faster w/ crank w/extra center counterweights,even though it's heavier, than crank w/o extra counterweight. All I can guess is that extra center counterweight must smooth out some of the harmonics and in doing so eliminates some twist/flex in crank,and picks up some power.
Some signs of harmonics are balancer and flywheel mounting areas will show signs walking,galded surfaces, also where main caps meet block,or in your case main bed, will show signs of walking ,main bed may crack like yours before it walks,because of it being held in line w/alignment dowels.
Something else come to mind is a engine that is lugged will break mains/main webbing,Art you have'nt been lugging down the neon so you don't go too quick have you?LOL

Mike Taylor 3601

Mike you might have something here. I've cracked 2 trigger wheels And had trouble with the bolts holding them to the balancer breaking. The first time it happened I blamed the balancer (actually myself for using a hammer to help install it). I put a plain aluminum pulley on it (no balancer) and it happened again. I found someone that wanted to buy the custom balancer so I sent it back to the manufacturer to see if it was repairable. Other than the bolt holes it was fine. So it didn't have anything to do with the previous problem.
The number 5 (last ) main bearing was badly beat up on the front half. And that was the one web with no cracks. One other thing that was not normal was the rod bearings (1 run)were showing some wear at the ends. I remember with the hemi's we had to cut the rod bearings when we used a full radius fillet crank. The neon cranks are not full radius but undercut. So it should not be needed to trim the bearings.
I don't have a clean neutral so when I lift it lugs down. But I don't think thats the problem.
A lot of these neon's are making more power than me and don't seem to have these problems.