Scored Main Cap Bearing - Ouch

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A press-in plug goes into this oil passage at the rear of the block. The plug is about 21⁄8 to 25⁄16 inches up from the bottom of the block (without the cap) and 71⁄2 to 711⁄16 inches down from the china wall. The plug forces oil from the oil pump to the oil fi lter and then to the main oil galley.

(2 and one eighth to 2 and 5 sixteenths from the cap mounting surface)



What the HELL kind of measurements are those???
 
pittsburghracer said:
A press-in plug goes into this oil passage at the rear of the block. The plug is about 21⁄8 to 25⁄16 inches up from the bottom of the block (without the cap) and 71⁄2 to 711⁄16 inches down from the china wall. The plug forces oil from the oil pump to the oil fi lter and then to the main oil galley.

(2 and one eighth to 2 and 5 sixteenths from the cap mounting surface)



What the HELL kind of measurements are those???
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The way I wrote it, or they did?
It's sure not 71 halves of an inch to seven hundred and eleven/16 of an inch.:D
 
The rear passage for oil to the filter plug is installed up from the bottom, in until it hits a stop. If it is not in deep enough oil flow in from pump could be reduced. If left out oil will bypass filter
 
Marcohotrod said:
The rear passage for oil to the filter plug is installed up from the bottom, in until it hits a stop. If it is not in deep enough oil flow in from pump could be reduced. If left out oil will bypass filter
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Apparently some were hard to tell when you hit the stop also, so the measurements are nice to know.
 
I think I have a photo of the oiling system of a small block if anyone is interested. It’s probably in most of the popular small block books and well worth taking the time to understand it.
 
pittsburghracer said:
Mine never did hit a stop. I drove it the measurement given from the top and called it job complete.
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So now you are making me wonder if the ones that don't hit the stop were all driven from the top, and from the bottom it's a bigger diameter.
If the bottom bore is larger and the top bore smaller to make a ledge as the stop.
That could mean the plug ends up getting resized by the smaller bore through the top and ends up loose in a slightly larger bore.

Hmmm
Now I have something to add to the "Gotta find out the details on that some day" list.
 
TrailBeast said:
So now you are making me wonder if the ones that don't hit the stop were all driven from the top, and from the bottom it's a bigger diameter.
If the bottom bore is larger and the top bore smaller to make a ledge as the stop.
That could mean the plug ends up getting resized by the smaller bore through the top and ends up loose in a slightly larger bore.

Hmmm
Now I have something to add to the "Gotta find out the details on that some day" list.
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Top hole is tapped for 1/8 pipe thread. You would never get a 9/16 plug in there. Driven out from top, in from bottom.
 
If the plug depth is correct... new bearings, LUCAS GREEN ASSEMBLY LUBE, and prime it while hand rotating the crank this time.
 
Just something I like to do but I have an old oil gauge from a past project that has a flex line on it. I screw it into the 1/8 oil pressure fitting so I can check out oil pressure while priming it with my 1/2 inch drill. Makes me sleep better at night.
 
pittsburghracer said:
You made me run down to my shop to see something. In that I think its the fifth picture down where you can see that 9/16 oil plug. Its hard to tell from pictures but man it doesn't look like that plug is installed deep enough. Please double check that because if it isn't seated past the oil filter outflow hole that's a major issue. I'm not sure what the measurement is from the bottom but its approximately 7 9/16 from the top deck surface.
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Good eye, I missed that!
 
I have 1 13/16 to edge of plug and 2 1/8 to center of plug. Sounds OK right? You guys think its OK if I do what Mopar Official suggests #135 I have an extra oil pressure gauge to measure while priming. John and group thank you for helping me.
 
TrailBeast said:
View attachment 1715484921

Got this from Moparts.

A press-in plug goes into this oil passage at the rear of the block. The plug is about 21⁄8 to 25⁄16 inches up from the bottom of the block (without the cap) and 71⁄2 to 711⁄16 inches down from the china wall. The plug forces oil from the oil pump to the oil fi lter and then to the main oil galley.

(2 and one eighth to 2 and 5 sixteenths from the cap mounting surface)
Click to expand...

The picture is wrong where he's sticking the tool to measure ! that is the oil pump drive shaft. I don't think you can measure it with the cap on, I have to go out and look.

4-7.jpg


KIMG2888.JPG
 
blewbyoutobad said:
I have 1 13/16 to edge of plug and 2 1/8 to center of plug. Sounds OK right? You guys think its OK if I do what Mopar Official suggests #135 I have an extra oil pressure gauge to measure while priming. John and group thank you for helping me.
Click to expand...

Mic what you can but it looks like a dry start just as much as it does trash in the oil.
So I'm thinking if you just get it oiled this time... the trash is out, in the old filter.
 
the aftermarket sketch in how to hotrod sbm of rear of block is drawn with the plug too high-looks like it is blocking oil in! the chrysler sketch is much better
 
Hey give your son a call out. Post a picture of his business card. Always looking for good machinist's.
 
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