A. G. Olphart Posted October 13, 2002 Share Posted October 13, 2002 My Vortec 350 needs a new crank (ruined thrust bearing surface), and I'd like to source a good/cheap fully balanced crank. Stock is external balance for powdered steel type rods and fairly light looking pistons. Are these cranks balanced to the same bob weights as the earlier (2 piece seal) cranks? If so, an adapter would mate my engine to an old crank. The rods, pistons & cylinder bores look decent, so I'd like to reuse the stock rods and pistons. Quote Link to comment Share on other sites More sharing options...
Mike C Posted October 13, 2002 Share Posted October 13, 2002 Regardless of what you do for a crank, you should balance the complete rotating assembly with the new crank. If it is just a "stock" motor, I guess it wouldn't have to be done, but if that is the case, just get another one piece rear seal crank and just put it back together. I would assume that the part of the crank inside the block is balanced approximately same as the older cranks, but the end where the flywheel bolts on is different and requires a counter balanced flywheel, which means in addition to the seal conversion you will have to buy one of those if you don't have it. How did the thrust surface get damaged? Pounding on a balancer or a ballooned converter? Quote Link to comment Share on other sites More sharing options...
A. G. Olphart Posted October 13, 2002 Author Share Posted October 13, 2002 I don't know the history of the engine... I got it as a core. It has the standard transmission clutch boss (tapped hole), so my guess would be dirty oil, heavy clutch, and starting many times with the clutch depressed. I start all my vehicles in neutral with the clutch out, but the safety police seem to have eliminated that option in newer rigs. Since I got only a dead long block, I need to buy a small harmonic balancer, flex plate, pulleys etc. If the old & new cranks are balanced the same, I know I can get the pieces for the old style crank. I don't know if the crank snout is the same on the one piece seal engines (all balancers would physically fit) or not. I will be using the smaller points type distibutor, so I don't need the special (big/expensive?) crank trigger damper that comes on a Vortec engine. These are probably questions for Grumpyvette. I'd like to build it stock (no balancing involved) as I'm on a fixed income like all retired folks. With the lift limition of the Vortecs and the rpm limitation of the new sintered/powdered rods, I'm hoping stock balance is good enough. My guess is that these new rods have a closer balance out of the factory than the old ones. Quote Link to comment Share on other sites More sharing options...
DavyZ Posted October 13, 2002 Share Posted October 13, 2002 Northern Auto Parts These guys have Scat Cranks (better than stock) for pretty cheap. Also they have reconditioned OEM canks for under $100 I believe. Davy Quote Link to comment Share on other sites More sharing options...
A. G. Olphart Posted October 13, 2002 Author Share Posted October 13, 2002 Oops- my typo was kind of left out for God & everybody to see, wasn't it? No spell checker (and a few other excuses which I won't list at this time). Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.