bck

I may have missed it. Have you verified what pressure bypass is in it or if it's been plugged?

ctuck0659

They had the std 10 lb differential plugs

dunnitagain

What Oil Pans are on these Engines? Your sure your not whipping the oil into a foam , with to much oil in the pan . Over full oil , and the crank is trying to beat it out of the way . It will Aerate the **** out of the oil in 2 minutes . Oil with entrained air will compress ( low oil pressure ) , will not transfer heat worth damn , and won't maintain the oil wedge on a bearing surface either . The air in that foamy oil , will kill a set of bearings .
We did several very expensive tests on how to run very low oil levels to save weight , gained alot of knowledge , and blew up alot of High Dollar **** . We called it Test Till Destruction !!!! Clean up was a ***** though.....

ctuck0659

These eng's started out as stock Merc 502's. Kept the same pan- can't remember if it's 8 or 10 qt. Using same Merc dipstick setup that plumbs into the pan at at the drainhole on the bottom.

ctuck0659

There's been a lot of discussion in this string about ideal bearing clearances.. I'm just a hobbyist so my opinion doesn't mattter but I think this article makes a lot of sense:
http://www.superchevy.com/how-to/eng...learance-info/

Here's a summary:
Clearance to Run Checking Main Bearing Clearances –
Chevy High Performance Magazine
How Much Bearing Clearance Is Enough?

Mike Petralia Jan 17, 2000
.An increase of only 0.001 inch from 0.0025 to 0.0035 will increase the oil flow rate around the bearing by 150 percent, or 1.5 gallons per minute. This excess oil is thrown off the crank and creates windage, which robs power and creates oil control problems for the piston rings.

Temperature rise is minimal as long as the clearance stays above 0.0020 inch. Reduce the clearance to 0.0015 and the chart shows well over a 50-percent increase in temperature.

How load capacity is affected by bearing clearance: The highest load capacity is at 0.002 inch; however, a wider clearance of 0.0025 inch is desirable since it provides more oil for cooling while sacrificing very little in terms of load capacity. A higher load capacity is always preferable.

One or two thousandths of an inch extra doesn't sound like much, but it can mean the difference between life and death for your engine bearings. We're talking about the effect bearing clearance has on engine life and power. Too much bearing clearance creates problems because all the oil that's pumping in to fill the gap between the bearings lowers engine oil pressure. This excess oil is then thrown off the crank, creating windage, which robs power and generally decreases engine performance. Years of research have been devoted to improving bearing technology, but there are still some inexperienced engine builders who run very loose bearing clearances thinking it will make power.
0.0025 IS THE KEY
Callies Performance has studied the effects bearing clearance has on oil temperature, flow, and load capacity with an emphasis on how reductions in clearance affect the life and performance of the bearings. Callies research has shown that a bearing clearance between 0.0020 and 0.0025 inch is ideal in almost all street and race applications. Although the difference between these two dimensions is small, there is much to be gained or lost if bearing clearance deviates far from it. Bearing clearance between 0.0020 and 0.0025 inch is the best compromise between high bearing load capacities and low bearing temperatures.

Callies Performance Products
Fostoria, OH 44830
419-435-2711
www.callies.com