MD spun rod bearing

Anonymous-0 · May 18, 2014

Please forgive long post. MD spun a rod bearing on no. 1 rod. NO warning. 75 lb oil pressure. Happened when running in barn. Tractor was worked on a few months ago to try to correct the infamous oil leak in the right corner of head and block. The oil passage holes in block and head are right there and are not aligned. Oil is held in check solely by the head gasket. To take pressure off the gasket, oil hole in head was remachined to line up directly with hole in block and connected with a hollow dowel. Just wondering of this "operation" would have somehow caused oil starvation to no. 1 crank journal. Based on what I found in the oil pan, I think Ill be looking for a new crankshaft, rod and main bearings, possibly new (reconditioned) rods. Don't know if its worth the fix, but need MD experts' opinions as to why it happened. Thanks for your time.

Duane Rushlo · May 18, 2014

dont know just what happend. oil goes from pump to mains threw crank to rods. dont know where you are. but do have a short block in barn. was in parts buness. now retired . Thank you Duame.

rustred · May 18, 2014

you are saying you had 75 psi oil pressure. it may be possible a brg. turned and this caused no oil to that brg. also is there oil starvation on the rest of brgs? if you were lacking oil pressure it would show on the other brgs. also. once brg. clearances are maxed out anything is possible.
as for that hole in head it maybe just a drain hole? hard to tell unless a person does a visual on the components.

Anonymous-0 · May 18, 2014

Im in NY, but might be interested. As i understand, a short block has crankshaft, rods, pistons, right? Where are you located?

DanMD · May 18, 2014

How much do the oil holes line up in stock form on the head and block?

Dan

Anonymous-0 · May 18, 2014

They do not line up at all. Thats the reason for the oval hole in the head gasket (to surround both holes). OIl passes from block to head thru width of head gasket. Oil containment depends entirely on head gasket.

Janicholson · May 18, 2014

I was the one that indicated issues with the leak and possible solutions. The metering of oil to the head does not depend on the gasket, as that would be such a variable that IH would not engineer that into the system. (water flow control with gasket hole size yes, oil no)
I do not believe they were connected in causality.
With a 75psi pressure, the bearing should not have had issues. The bearings in lower ends are not floated by oil pressure, they are just supplied with oil and the oil's lubricity and laminar flow characteristics separate the metal. Down stream pressure loss, or even low oil pressure does not ruin engine bearings.
You would be appalled at the low pressure found at hot idle in today's cars that have 0w-30 oil in them. If they had pressure gauges, oldsters would panic. Jim

DanMD · May 18, 2014

Is it a pressure or return port?

Thanks,
Dam

Anonymous-0 · May 18, 2014

Pressure port to valves. Thanks.

pete 23 · May 18, 2014

The oil to head is metered so your modification would not effect the flow to rods. One thing caught my eye though, the four cyl, gas start diesel IH engines oil pressure is normally about 45 psi and gas engines can run close to 75 psi. Lot of wrong gauges have been swapped over the years giving peculiar readings to operators.

MD spun rod bearing

Anonymous-0

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Duane Rushlo

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rustred

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Anonymous-0

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DanMD

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Anonymous-0

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Janicholson

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DanMD

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pete 23

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