threw another #3 rod, how to prevent this from happening again. Options

[crash914]

So blew up my #3 rod. wondering what caused this. lack of oil, due to rpm? poor return? oil pump sucking air?

last time it was #2 rod. I really don't want to live with this again.

Motor specs,
Dual oil coolers with full flow plumbing
102 bore by 80mm stroke
long rods,
ham heads and valve train.
Running to 6800 rpm
g loads to 1.5
windage tray modified at pushrod tubes for oil flow
tuna can with 1/2 extra oil

Pics of horror below. First are this failure, then old failure.

[HAM Inc]

Herb are you running an accusump?

I'm of the opinion that an AX car doesn't need a dry sump system. A good tuna can and some mods to the windage tray are a big help.

Blocking the head vents will help keep oil from accumulating in the valve covers. That's a quart and half or more right there.

There are a bunch of little mods that can be done to improve the wet-sump function.

Properly engineering a dry-sump system is more complicated than just adding a dry sump tank and the plumbing. This is especially true if you are using a two stage pump, like the CB, which is a simple plug and play pump and adequate if proper prep is made, but not if you don't as the scavenge stage is not substantially larger than the pressure stage.

The mistake a lot of people make (I made it too) is to think that by adding the tank you can give short thrift to the scavenge aspect of the case prep. The reality is, you still have to prep the scavenge capabilities the same as if you were running a wet-sump system.

If you don't, when you corner and oil moves away from the pick-up you stop pumping oil out of the engine, but you don't stop pumping oil into the engine. This extra oil wraps around the crank and sloshes around in the case. With every significant corner you end up transferring oil from the tank into the crankcase.

At best this condition just robs power, but at worst it foams the oil so badly that even baffles in the tank can't de-aerate the oil fast enough. And if you vent the crankcase directly into a breather can and bypass the tank the oil that transfers from the tank to the crankcase will transfer out to the breather can.

The case mods I made to our dry-sump engines radically reduced the case-sump capacity with expoxied in place panels. The panels were arranged to direct oil to the pick-up which was down in my home made tuna can.

I also removed the goofy stud that runs through the pick up and cut off the restriction where the o-ring fits into the case. I welded a bung to the pick-up and sealed it to the case with a bead of silicon. The pick-up was secured to the bottom of the case with a bolt that went through from the bottom.

The stock by-pass circuit was sealed off with epoxy and an external regulator put in line.