Bearing clearance spec question...
 

Getting ready to do the initial assembly of the bottom end of my 525SC...

Will be checking all clearances, & I was looking at the Mercruiser specs...

http://www.perfprotech.com/store/art...fications.aspx

I see that this must be for non HP motors...Should I run the clearances on the upper end of these specs?

.0030 rods & mains (#'s1-4, & .0035 #5)...

The crank was polished & left standard. Block was line honed, not bored. I'm thinking that should not effect clearances much...

Engine will be in the 600HP range, 5600 wot, bearings will be Clevite 77 H series, melling 10778c oil pump, running 20/50w oil.

Thanks for any input on this...

Yes you would want to be on the higher end for clearences. .003 is a little loose on the rods. .0027-.0028 would be good. .003 #1-4 and .0035 #5 are good numbers.

I just finished assembling 540's for my boat with H bearings. 0.0028" - 0.0030" on the rods, 0.003" on mains with a little extra clearance in the # 5 main.

That is the clearance I use in my darg motors, and they look good for a couple seasons.

Thank you for the input...
I'll be doing some measuring this weekend :drink: