Re: Steel Crank Turned .040 ?
 

Oil temp gauge should be standard equip. in all high perf. boats. It could tell a lot of things related to your bearing failure. My guess is high oil temp due to improper clearences or wrong or missing oil bypass. A car guy might not know about the marine oil bypass. A oil temp gauge would have alerted you to the problem. Oil temp can be too high even with normal water temps.

Re: Steel Crank Turned .040 ?
 

Do You Have A Picture Of This Oil Bypass?
Thanks For You Help

Re: Steel Crank Turned .040 ?
 

No I don't, sorry. Do a search. Oil bypass is something that has been talked about here a number of times. It has led to many engine failures.

Re: Steel Crank Turned .040 ?
 

The inconsistent wear in bearings from journal to journal may or may not be from machining differences in the crank or rod big ends.
It may be because of rifleing ( the way the oil travels in line through the passages to the block) with the rear bearings getting the best supply of oil and toward the front of the block it may suffer due to leakage from a variety of reasons.
Overheating and loss of hydrodynamic wedge (oil film) will do this. The crank wants to twist out of shape.
Learning from other builders, teaches me to take the oil pressure from the front of the block if at all possible.
Also drilling the main feeds will allow for more flow.

Re: Steel Crank Turned .040 ?
 

Also , I agree on the oil temp gauge, a boat I'm working on with thermostatically controlled oil coolers tends to run hot on one motor so it gives us a heads up to back off after it starts to climb too high. We changed everything except cooler which is one season old. Same problem. BBB