vibration issue

[john-dickjr]

had a vibration issue..so i took the motor apart..so far only thing i found was the the timing cam gear is broke in 3 places but still together..im wondering if that gear is vibration and sending it down threw the crank ..its bad enough that the flywheel bolts are backing out...yes it does have the correct damper and flex-plate on it..

 

[bubba22349]

I doubt that cam or it's gear could cause that type of vibration turning only half the RPM of the crankshaft. I would check weight all the rod and piston assemblies and check or have the everything in the rotating assembly rebalanced including the torque converter. Also have the drive shaft balance checked

 

[john-dickjr]

motor is torn down..probaly just going to sit it in the corner and put a 302 in it and be done with it

 

[xctasy]

Hang in there, its not a lost cause!

Check the camshaft for run out. I'm 100% certain that The Frenchtown Flyer said that sometimes reciprication parts (camshaft in particular) get bent because they are long, spindly items. Normally, its not a problem, but I've learned that there are guys here who have forgotten more stuff about these engines then we mear mortals will ever know. When really gunned, the cam can bend.

The problem should be a simple balancing issue. By all means shove in an interim 302, but know that a balancing problem with an I6 is simple, and you just need to bump this post up untill you get a satisfactory answer...thats why we have on line communities like this, so you won't get peed off, but get the help you need.

 

[john-dickjr]

taking the rotating assembly down to machine shop today, another thing i found was it has the wrong pistons in it..it has 240 pistons in it..so they are .230 in the hole, sounded good for a motor with 7.5-1 compression ..ill get some 351w pistons and out in there, bumped the compression up to around 10.5--11 to 1 range