Connecting rod failure

richter69 wrote:my guess is if he puts a billet Oliver I beam deal in it and nothing else the result will be the same.

I'd wager if he had a top shelf Oliver rod in there it would NOT have broken. I recall an endurance engine had a bearing spin coming out of a turn, lost oil at about 7,600 RPM. That thing melted the bearing out. That rod was black, but it did not break. Yes it was an I beam, but I'd say it did not break because of the material it was made out of, how it was processed, and finished. If it had a rod made like an Eagle or Scat I am sure it would have broke regardles of I or H beam.

Although there is a technical advantage to an I beam over an H beam I'd say it is of minor importance. What matters is the material, processing, and finishing of the rod.

Guess this is why you see Oliver rods and Bryant cranks in endurance engines when the customer is serious about winning.

466cj wrote:

Dave De wrote:Just put it back together and went back to the track after a short break-in.

Ran three 1/8th miles and on the third 1/4 at the end of the track right at the trap #2 rod broke about 2 inches from the wrist pin.
Ive been having trouble keeping oil pressure at shutdown and last Sunday was no different. The bearings show lack of oil again and I think the rod failure was not related.
The only thing thats left useable is the the heads complete with 14 bent valves, 6 rods and pistons and the usual non moving items.
Dave

I'd say the oil issues and the rod breaking are separate issues. Did you just lift off the gas pedal? Hardest thing on a rod is a closed throttle at 6k - 7k RPM. My though is you just may have gotten a bad rod.

Your oiling issue, well something as others have said is not right. Making a right turn crusing down the street should not result in the oil pressure taking a dive. I'd inspect the oil pickup and pump real close for cracks.

The other thing that stands out to me is how did you end up with 14 bent valves? Did the timing chain or cam pin break? Was the piston to valve clearance checked?

Steve

Yes the chain broke and the pin and the 7/16 grade 8 cam end bolt. P to V clearance was checked.

I hear more about Olivers breaking than I do H beams.

Even if the rod didnt break in this case it dont change the fact there are issues.

Again the rod type used is not the root of the problem in this sisuation.

richter69 wrote:I hear more about Olivers breaking than I do H beams.

Even if the rod didnt break in this case it dont change the fact there are issues.

Again the rod type used is not the root of the problem in this sisuation.

i agree but, I have never broke an oliver rod....or saw one broke.

Kasse oil pump
Moroso 20625 oil pan http://www.summitracing.com/parts/mor-20625/media/images/make/ford
Eagle H-beam rods
Moroso 1.5 qt accumulator
Ford A460 block
Run 9.5 quarts of Brad Penn 20-50 oil
924 engine hp.

No problems so far. Oil accumulator was put on after 2nd time at the track, as I noticed oil pressure would drop during breaking after a pass. Accumulator fixed the problem.