Connecting rod bleed holes

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cash said:
I wonder if some of this squirt Gets on to the cam?
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I wonder that too.

But they don’t point towards the cam, so I can’t see how the holes will deliver any more oil to the cam than if it’s dispersed as general ‘splash’ without holes ?
 
Triton Thrasher said:
I have to wonder where a timed squirt of oil aimed at the piston actually ends up, at 6,000 rpm
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Since there are two holes in each crank journal, there are two big squirts plus a continuous squirt from each conrod hole on each revolution of the crank. Due to the orientation of the journal holes, those big squirts happen around 90 degrees before and after TDC so both the front and back of the piston/cylinder wall get a big squirt.
 
Not disagreeing but as anyone actually seen that it's a big squirt or is it a constant bleed then flicked off big end ? Test rig ? , like 50psi and 5000rpm . Not much time for lubrication to exit the orifice.
 
Shelby-Right said:
Not disagreeing but as anyone actually seen that it's a big squirt or is it a constant bleed then flicked off big end ? Test rig ? , like 50psi and 5000rpm . Not much time for lubrication to exit the orifice.
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I haven't but it is clear that oil is escaping from those holes all the time and that there are two times per crank revolution where that has to increase since the journal and conrod holes align.
 
If the service manual says to orient the OEM rods in a specific way, orient them that way. If they are aftermarket rods that have alternate instructions, do it that way! If they were installed contrary to instructions, bite the bullet, disassemble and install them correctly. ;)
 
Shelby-Right said:
I was taught , on car engines that the oil hole or short side of piston pin " some pistons are offset by like 1.5 mm for quietness i think ,etc goes to the major thrust side . depending on bearing clearance oil ,comes out of the sides of the conrod .
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Wrist pins (gudgeon) are offset front to rear in the direction of crank rotation.

I don't think the orientation of the rod holes left/right would coincide with this variable.
 
FWIW,
I followed the advice of (the very missed) Jim Comstock. At least I’m pretty sure it was from him. Somewhere on this forum he said that he did not believe those holes served much use. I flipped the big end bearings and blocked them off. Now approaching 15k on my motor (or is it engine?) and have not seen any adverse affects. I did how ever see an increase in overall oil pressure. Could possibly be from the rebuild, but my original big end bearings were in good shape, so it’s hard to say for sure.
 
Here's a pic of my 385 ci windsor crank at 3000 rpm 3.750 stroke with Bob weights ,can't imagine the oil hole alignment turning into a squirt .good discussion though.
 

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If everything is symmetrical, why wouldn’t the holes work the same way when turn opposite?
 
1973x75 said:
If everything is symmetrical, why wouldn’t the holes work the same way when turn opposite?
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They would but the oil would be directed inwards rather than outwards, the question is would it make any difference. I fit 4 bottom shells so the holes are blocked and also machine a slight depression on the rod so the oil coming out the sides goes more upwards.

Connecting rod bleed holes
 
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I know what the books says, but with the hurricane of oil mist inside the crankcase when operating the only area that might be starved for oil would be the rear of cylinder barrel. If holes align at 90 degrees as Greg said it would eliminate this problem. But which side shouldn't matter. 20-50 Pennsoil with added Zinc
 
One thing is certain - with the holes oriented as designed/specified in factory shop manual no harm will be done .
What seems to be a matter of conjecture is whether or not harm will be done with the holes oriented contrary to spec.
I can’t say with any certainty if harm will or will not be done with the holes in the other position. I can say that no harm will be done with them installed to spec . Why choose the uncertain path ? To save a couple of hours work and the cost of four con rod bolts/ nuts ?
Physician‘s creed - “ First do no harm “
Stepping out of this now - good luck with whatever you choose.
 
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