Car ran great last time it was run. I have it torn down right now, all accessories off the engine - valve cover off, front cover (camshaft gear) off and head off. The hogs head is off, so the car stays in gear. When you roll the car freely back and forth, there is a knock from somewhere in the crankcase, possible near the front. Any ideas - Im almost thinking its normal - because there was no knock last time we ran it. - no noise at all. Anyone every experience this?
Worn iron timing gear?
Loose belt pully?
The timing geat and belt pullys are gone - its completely stipped and the heads off. Like I said -it ran fine with no noise. now when you rool it over there is a knock - i was told that it is normal, but just wondered if anyone else had ever experienced it
The timing gears are gone? The pulley off the crankshaft is gone? How about the front bearing where the crankcase is fastened in the front of the car? These can get worn and move up and down or side to side. You could also have loose main bearings. If the pistons and rods are still in, crawl under while someone turns the engine over and watch the connecting rods. If they move front to back or back to front, that could be what you hear. They usually have end front to back play, but they shouldn't move back and forth with every turn of the crank. If they do, you might have a bent rod. When it is going up it will move one direction, and when going down move in the other direction.
Norm
I hate to tell you this but I had the same problem a couple of years ago on a newly rebuilt engine. It was rebuilt twice and on the second go around I had the crankshaft xrayed. it revealed an internal crack not vivisible to the naked eye. Onece in the car, the heat was cause expansion and the knock began after only a few minutes. Learned this technique from an old engine builder....
Could be backlash in the rear end or U-joint being transmitted through to the front. Also, there's some slack in the clutch pack, triple gears and drums if you rock it back and forth. If it wasn't knocking when you took it apart, it shouldn't be a problem.
Check for a dropped wrench or bolt stuck to the mag too. You never know.
Definetly was not knocking, and I havent done anything to change that. I too really believe it is backlash somewhere, but Im just really curious. No bolts or wrenches - That part is clear.
If it was running so fine,why did you tear it down?
Loose flywheel bolts?
Check the radius rod to oil pan connection.
Jack - Im restoring the car! Painting the block.
John,
If the hogshead is off, the fourth main is unsupported at the top, correct? If there is runout in the transmission or even if there isn't any, I'd think the fourth main could jump around under these conditions.
Could this be it?
Seth
Seth - might be - I'll check that out.