I bought a 428 cj engine out of a 67 mustang that was rebuilt,ran for break in time and then sat in car for about 3 yrs,last week I put on a dyno.Engine started ran great 60lbs
oil press.all specs were set.The problem is it has a wobble to it like its out of balance.We swapped fly wheels just in case, thats not it.I tracked down the guy who rebuilt the engine,he said the crank and rod were balanced as assembly and should be fine.The strange thing is when you raise the rpm's,wobble seems to subside a bit.My dyno shop sez they knew the shop that balanced the set and said that their shops bal.machine was out of specs.for a long time,and thats the problem.Seems to me thats a little far fetched,I'm sure they would have gotten complaints from all over the place.I hate to pull this engine apart for no reason,but i'm stuck between the engine builder and the dyno shop.Anybody has any ideas...