Hey guys I am brand new to the boards...well I was a user a couple years ago but since got married bought a house another Vette etc...
Well an interesting thing happened to me the other day, my car started eating starters and it turns out there is quite a lot of play in my crank, so it would push the flexplate into the starter. I am putting new main bearings in right now but my question is whether or not the rear mains are the only things keeping the crank from wandering since it has a taper at the ends. I cant think of anything else that could do this. The guy who built the motor (383) had put the original bearings back in! I dont see how this thing has lasted 50K without trouble. Any ideas???

My other question is about tuning my DFI. I dont have a WHOLE lot of knowledge of tuning the thing but whoever tried before has got it running, but very poorly. (he has an emmisions program and a run program) I am only running a cam not even as mild as a hotcam so I dont think there should have to be a program change to pass emissions. What do you think? Anyone out there willing to email me thier own tuning with a similar setup? Anyway thats a lot to cover on my first post but heck, thanks for anything guys. I will get pics posted ASAP.

:seeya

 

Didn't you know this was take your crank for a walk month. :crazy: Anyway, yes the rear main bearing on the small block chevy controls the end play for the crankshaft. There are bearing surfaces at the front and back that ride against a machined surface on the crank and block. Changing the thrust bearing(rear main) should correct the problem. I had a 440 mopar that lost the thrust bearing and ate a timing gear. When I finally tore the motor down, the crank counterweights had been riding against all the main webs and all the main saddles had a knife edge on the back side. Yup, blood was spilled, mine. Cause of all this mayhem, it was a 4-speed car and having the clutch trying to push the crank out of the front of the block. Good Luck with yours and check the timing gears.

:seeya

 

Well you know how these cranks need thier exercise :D Anyhow thanks for the tip about the timing gears I would have overlooked it. Yeah the wierd thing about this is that the bearings we replaced it with still left the same amount of play! So I dont know WHAT the last guy did but I am taking the crank out and having it mic checked, and ground to proper clearance to fit my new bearings. Thanks again! :seeya