Don Terrill’s Speed-Talk

I'd agree that you're probably over driving the pump. A good place to start is 50% of crankshaft speed. My pulleys are 17/34. However it will probably make your 15 psi of idle pressure worse, but try it before increasing to the 1.450 higher volume pump body/gears so you have a base line. What weight...

OP, have you monitored the oil temps at the track?? If yes what they were? I did not. Oil temp never got above 230-ish because I never really got the chance to push this thing. And did you searched what viscosity that oil is at 230-ish degrees? Might be scary low working with those clearances.. :sh...

BrazilianZ28Camaro wrote:OP, have you monitored the oil temps at the track?? If yes what they were?

I did not. Oil temp never got above 230-ish because I never really got the chance to push this thing.

Sorry I meant the internal pump gear width to get an idea of the pump volume. As well as the external pulley teeth count to get an idea of pump speed. I'm using this pump which comes with either a 1.200, 1.450, or 1.700 width gear which is low, med, high volume respectively. The light grey portion o...

Thanks guys for the feedback, it has been helpful. It is clear that the OP is highly intelligent and an experienced engine builder and that he presented this situation to SpeedTalk because he felt that it was something unusual. Detritus in the oil causing wear is not that unusual. Well....I did have...

I'm very curious what pump you're using and how wide the gears are. Also what tooth count on each pulley. I ask because I also run an external pump on a SBF but for a road racing application. I check my pressure at the rear of the block with a -3 line to a mechanical gauge.

So...based on what I see and the feedback you guys have provided, here's where I'm at: 1) Trash got into the bearings. Had to be a fair amount through out the oil to get all journals and be small enough to only effect thrust side of journals. Fine silica most likely. I should add that the drain plug...

Ok this is the best I can do. Same journal, clean, dry, and in my lighting near impossible to not get some kind of reflection on this polished surface. You're gonna have to trust me that I'm not color blind and I know what discoloration from heat looks like. These journals all look the same across t...

Guys...I'll try to get a better crank picture later today, clean, dry, and better lighting. Not sure I get the dental pic reference?? ...and yes the crank came directly from Callies. It was a shelf 6.200 rod crank that Callies cam cut the counter weights for 6.125 rod per my request. Someone mention...

We have piston scuffs, only upper shells/thrust side showing signs... Not sure if you mentioned all eight shows exactly the same, still wondering how you/everyone ruled out the tune a bit off. With all the possibilities mentioned, a bit missed tune can easily put more heat on the pistons and cause ...

All great input guys, thanks a bunch. The thing that was, or I guess still is troubling me is the wear only being on half the circumference of the journal, that just seems odd to me. And the crank being torn up more than the bearings. Anyway I'm going to do the following... - Check the crank for pro...

Here's the pan I'm using. Its listed as a 6qt pan and honestly I don't recall if I had 6, 7, or 8 qts in the filled and primed system. I'm guessing it was 6 in the pan and 1-2qts in the system. Under the baffle is a diamond shaped box with trap doors on all four sides pretty typical for a road race ...

So my first reaction when I saw the crank was trash in the bearings as well. But I would think if it was trash the scoring would be 360 deg around the journal, not just 180 deg, And all the journals look the same, which would have meant a fair amount of trash versus a couple pieces that got circulat...

That motor wouldn't have lasted much longer with that much bluing on one side of the journal. How did you prime it? Is there a permanent gauge measuring oil pressure at all times? Where are the pics of the bearings? How are you measuring journal to rods bore clearances? You better be sure and fix t...

-how much rod side clearance is there? -when you take a rod cap with a new (and an old) bearing and slide it up against the thrust to where you can see the bearing and the crank radius---how close is the bearing edge to that radius? -Have the bearings ever been chamfered for more clearance? -have y...