[gtobob67]

Broke down my engine today. It's a .030 455, stump puller, SD 6X-4 ported heads. Compression 9.7. I've put 2500 miles on a total rebuild. I used JE forged pistons, eagle H beams. Had the rods sized and the rotating assy balanced. The list goes on and on. This is a street motor and not too heavily beat on. Haven't taken it over 5500 RPM. Not a hint of detonation that I can hear. 20 psi idle oil pressure heat soaked. Using 10w-40 Brad Penn Oil. Rod bearing clearance .002, mains .025. Using King rod bearings, FM mains. All my upper bearings are showing copper. The copper on most of them is only on the outboard side of the bearing. Number 8 rod bearing is the worst. Here are pictures of #8 and #4 upper bearings and #8 lower bearing. Crank looks perfect. All rod bearings are smooth. Can't feel anything with my fingernail. Where do I go from here?

[tom s]

Usually copper on the rod end is a sign of some detonation.Off to the side I guess could be a few diff reasons.See what the others think.tom

[tom s]

Factory crank or aftermarket?Tom

["QUICK-SILVER"]

What was the reason for tearing it down?

Clay

[gtobob67]

Factory crank. Tear down to modify lifter bore like Paul Carter does for noisy hydraulic roller lifters. Fully heat soaked the lifters were a bit too noisy.

[lust4speed]

I don't see any corresponding wear on the bottom bearing shell that would indicate a bent rod or improperly finished big end. Copper showing with so few miles sure seems to point to detonation.

[shaker455]

That's not the best oil pressure for a new build and I was never a fan 10w-40 no matter the brand.
I run Valvoline VR-1 racing 20-50.
Are you running a melling MS-54 pump?
How was you engine timed and what carb & jetting?

[tom s]

JMO,with those tight clearance I would not run over 10-30.Tom

[tom s]

What lifters are you running?Tom

[tom s]

Also,do you have a record of the side clearance on all the rods?Make and type of rods?Pontiac J or BBC J?Tom

[gtobob67]

Oil pump is a Melling 10540. Carb is a 72 Buick 800 CFM 7042240 spec'd out by Cliff using his parts. AFR at idle is 13.0, cruise is around 13.6, full throttle is 12.0. Initial timing is set at 15 BTDC, 20 degrees mechanical all in by 3000 RPM. Dizzy done by Sun Tuned.
Lifters are Comp Cam 857S. Noisy at start up, which I expect, then quiets down. Car sits for long periods. A bit noisy when fully warm. Almost went hybrid with solids but decided last minute to try these. Seeing it's winter and I have plenty of free time I figured I'd try that mod to the lifter bore Paul Carter does. Insures the lifter sees oil when on the cam base circle.
Rods are Eagle 6.625 bushed 4340 H beams. Had them sized before installing them. Side clearance was .015 to .017 on all rods.
Detonation was my first impression when seeing the copper, but I never heard a hint of it. You can count on one hand the number of times I've run through the gears full throttle since the rebuild so needless to say I was shocked when I saw these bearings.

[azbirds]

With all the work that was done to the engine can I guess that you tapped the front 1/2" oil plug holes? If those are too deep and the plug is screwed it all the way I have seen where they can restrict oil flow. one of mine was previously done and the plugs went in enough to close off almost half the hole. I machined off some of the back of those plugs and used a flashlight to see if they protruded into the holes that lead down to the mains.

[gtobob67]

I did tap those holes for the plugs but I made sure they were shallow enough so they wouldn't reach those oil holes.

[JSPONT]

Did you check every rod clearance? How do the main bearings look? That is a little tight on the rod clearance, but upper bearing is detonation.
When heat soaked, does it ever diesel after you shut the key??

[gtobob67]

I did not check every rod clearance. I know I checked more than one though. Every upper rod bearing is showing some copper. I haven't removed the crank yet. Had to walk away after seeing the rod bearings. I'll pull it in the AM. It has never dieseled after shut down. Temps runs 180-190 at all times.

[hurryinhoosier62]

Originally Posted by JSPONT

Did you check every rod clearance? How do the main bearings look? That is a little tight on the rod clearance, but upper bearing is detonation.
When heat soaked, does it ever diesel after you shut the key??

For a street engine .002 is perfectly fine. That’s the clearance Ken Crocie has recommended for years. I’m leaning toward detonation as the cause of the wear.

[chiphead]

Originally Posted by gtobob67

Oil pump is a Melling 10540. Carb is a 72 Buick 800 CFM 7042240 spec'd out by Cliff using his parts. AFR at idle is 13.0, cruise is around 13.6, full throttle is 12.0. Initial timing is set at 15 BTDC, 20 degrees mechanical all in by 3000 RPM. Dizzy done by Sun Tuned.
Lifters are Comp Cam 857S. Noisy at start up, which I expect, then quiets down. Car sits for long periods. A bit noisy when fully warm. Almost went hybrid with solids but decided last minute to try these. Seeing it's winter and I have plenty of free time I figured I'd try that mod to the lifter bore Paul Carter does. Insures the lifter sees oil when on the cam base circle.
Rods are Eagle 6.625 bushed 4340 H beams. Had them sized before installing them. Side clearance was .015 to .017 on all rods.
Detonation was my first impression when seeing the copper, but I never heard a hint of it. You can count on one hand the number of times I've run through the gears full throttle since the rebuild so needless to say I was shocked when I saw these bearings.

My .02:

Rod oil clearance slightly too tight or rod journal had eccentricity. Wear on lower halves is a clue. I had moderate detonation on my motor, and the bottom halves didn't look like that. Top halves looked worse. Your uppers are suspect for some silent detonation.
Rod side clearance on Eagles should be a bit wider, .020-.025"
At 9.7 CR with irons, I'm thinking timing should be 31-34* total mechanical timing in by 2800-3000 RPM.
Cruise AFR might be a scotch lean. How do plug look?
Any signs of oil control/oil burning issues? OIl control issues will increase risk of detonation. Detonation can happen during any moderate throttle, don't need WOT. Ever watched a datalog from a LS? Scary stuff.

What cam grind, what rear gear, what fuel, how heavy is car?

[hurryinhoosier62]

Originally Posted by gtobob67

I did not check every rod clearance. I know I checked more than one though. Every upper rod bearing is showing some copper. I haven't removed the crank yet. Had to walk away after seeing the rod bearings. I'll pull it in the AM. It has never dieseled after shut down. Temps runs 180-190 at all times.

Detonation can occur with little to no outward indication. It doesn’t show until another problem develops.

[johnta1]

To me it looks like a lack of oil problem?
Especially with the noisy lifters?


Detonation usually has some kind of damage like pieces coming off, or pock mark look sometimes.


What was the oil pressure readings usually?

[Mike Davis]

I say oil problem. What type of filter are you running? Oil pressure doesn't mean a whole lot without volume. Oil pressure at idle doesn't mean much either. What was the pressure at 3K, 4k?
I like around .020 on side clearance.
Any dark spots or discoloration on the rods themselves?