Bushing under rear main cap?

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JDMopar

JDMopar

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Is there a proper name for the bushing under the rear main cap, that the oil pump drive comes down into? Steel bushing that protrudes out of the block, and fits into the main cap. I've searched every site I can think of for block hardware kits, and it isn't included in any of the kits. I was prepping my 273 block to go be baked and blasted, and noticed that bushing is cracked. I need to get one before putting the motor together after machine work. Just to be clear, it's NOT the bronze bushing up in the lifter galley area. Thanks.
 
It sounds like it should be part of the oil pump. If I am understanding you correctly.
Pictures tell the story.
 
Never seen one, maybe part of an old dist bushing ?
 
8FBE041C-8971-4818-BEED-06F85653B03E.jpeg
FA88C465-BD27-4B27-8C3C-91DF208B4390.jpeg
 
Thanks. I figured it must serve that purpose, and also locates the oil pump so it lines up with the drive from the cam. It being cracked at the top worried me. I'll do some more searching to see if I can locate one.
 
JDMopar said:
Thanks. I figured it must serve that purpose, and also locates the oil pump so it lines up with the drive from the cam. It being cracked at the top worried me. I'll do some more searching to see if I can locate one.
Click to expand...


Are you sure the crack is a crack and not a seam?? Almost all dowels like that have a seam.
 
yellow rose said:
Are you sure the crack is a crack and not a seam?? Almost all dowels like that have a seam.
Click to expand...

I'll look at it closer and see. It's captured inside and out, so it would probably be ok to use like it is. I found a replacement though. Early Hemis have the same dowel under the rear main cap. It is definitely factory installed, and I have seen them in other small blocks including 340's and 360's.

Early Chrysler Hemi, Main Cap Rear Hollow Dowel Pin, Hemi Main Dowel Pin (hothemiheads.com)
 
When I first started building engines my first was a 273, I think in 1972 so I might have lost that thought.
In 1975 I stated collecting 340 parts for my next build.
 
That's a split locating dowel... it's that way so it expands when hammered into place. One of the extra bits Mopar put into their engines back in the day. Helps to keep the cap from fretting. I see where most high HP truck and tractor engine have the those dowels installed to let the bearing live longer.
 
I showed it to my machinist the other day, and he said the same thing. I told him about the new one I found at Hotheads, and he stopped short of horse laughing me! He said "Yeah, theirs are $9 each.....I can get a box of them for that!" He said mine was fine as is since it's captured inside and outside, so I took the block on to the place that bakes and shot blasts them. I pick it up Tuesday.
 
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