Bad main housing bore=low oil pressure

EP · Jan 3, 2018

I remember a few months ago someone was having oil pressure problems that they couldn't find the source. I think in a 1030. Anyway I have an engine that was brought to me with the same problem. It's not a Case but could be relevant to any engine. I was suspicious of bad housing bores and sure enough that is the problem. Caps have shrunk and or block has shifted. In the pics the dial bore gauge should be on zero.
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<image src="http://forums.yesterdaystractors.com/photos/mvphoto8578.jpg"/>

<image src="http://forums.yesterdaystractors.com/photos/mvphoto8579.jpg"/>

<image src="http://forums.yesterdaystractors.com/photos/mvphoto8580.jpg"/>

<image src="http://forums.yesterdaystractors.com/photos/mvphoto8581.jpg"/>

C. Amick · Jan 3, 2018

Has someone filed down the main bearing caps in order to tighten up the bearings? I've seen that done when they don't want to buy or can't find new bearings.

ScottNC · Jan 4, 2018

Is the cap a snug fit in the block? By snug fit I am referring to the register the cap fits into on the block. It could be tight enough to require a hammer or loose enough to wiggle in and out by hand.

EP · Jan 4, 2018

There are 3 loose caps. Barely any
register, they should have to be
lightly tapped in with a hammer, after
lubing the sides. The cap can be tig
welded on one side then surface ground
to get it centered back up and get the
proper amount of register. Then mating
surface is ground also, then line honed
or bored to correct the whole mess.
Housing bores in the block and
connecting rods are often overlooked
during a rebuild but can come back to
bite you.

Bad main housing bore=low oil pressure

EP

Member

C. Amick

Well-known Member

ScottNC

Member

EP

Member

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