360 LA Main Bearing Oil Holes Look Funny?

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dusterbuster5621

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Hi Everyone! I just picked up a LA 360 block for $400 (hopefully I didn't over pay too much). After getting it home I noticed that there are 2-3 holes drilled into some of the main bearing oil holes. Is this stock or did someone drill into it? If this is not stock how will it effect the blocks strength and oiling system?

Block is a 4179930 – 1975 – 1993, 360 la-series small-block.

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dusterbuster5621 said:
Hi Everyone! I just picked up a LA 360 block for $400 (hopefully I didn't over pay too much). After getting it home I noticed that there are 2-3 holes drilled into some of the main bearing oil holes. Is this stock or did someone drill into it? If this is not stock how will it effect the blocks strength and oiling system?

Block is a 4179930 – 1975 – 1993, 360 la-series small-block.

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That's factory... Those "extra" holes are for oiling the camshaft, lifter galleys, and rocker arms...
 
dusterbuster5621 said:
Hi Everyone! I just picked up a LA 360 block for $400 (hopefully I didn't over pay too much). After getting it home I noticed that there are 2-3 holes drilled into some of the main bearing oil holes. Is this stock or did someone drill into it? If this is not stock how will it effect the blocks strength and oiling system?

Block is a 4179930 – 1975 – 1993, 360 la-series small-block.

View attachment 1716111388

View attachment 1716111389

View attachment 1716111390
Click to expand...


Read through my how to article on block prep and inspection for rebuilding a small block, it is explained in the middle of the thread...

How to Rebuild a Small Block Part 4: Pre Flight Inspection After Machine Shop Before Assembly
 
So the oiling holes come in at an angle but they do not intersect close enough 'to the bearing oil hole' on a lot of blocks and so they put a counter bore so that they all feed into that little 'bathtub' is what I call it..and through the bearings oil hole un obstructed. There are a few runs of blocks out there they do not have these countersunk bathtubs joining the main and cam feeds , those engines have oiling problems because there is nothing lining up with the main bearing oil hole 'it lines up over the intersection of those holes partially blocking half of each' ..the remedy is to slot the hole on the bearing, dress it , clean it and install it.
1967- 1970 340 engines 'luck of the draw' are ones I've seen with this issue. Fwiw
 
Uncle Bob said:
I found that it seems to stop just before the engine is together. Am I missing parts of the series or is it incomplete? It's definitely helpful.
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I am doing them in sections... Been busy for a while with life's issues... I'm hoping to get back into it and continue the series soon...
 
krazykuda said:
I am doing them in sections... Been busy for a while with life's issues... I'm hoping to get back into it and continue the series soon...
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Too bad I will be finished with my engine long before then. Those how-to articles are at least partly to blame for me deciding to roll my own instead of buying a BP engine. :thumbsup:
 
Uncle Bob said:
Too bad I will be finished with my engine long before then. Those how-to articles are at least partly to blame for me deciding to roll my own instead of buying a BP engine. :thumbsup:
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I've been sorting some of my files and may have enough to start them back up very soon...

Stay posted... Keep looking...
 
krazykuda said:
I've been sorting some of my files and may have enough to start them back up very soon...
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I was just thinking yesterday it was probably a lot easier to put them together as you go. Then I thought, maybe he'll build another one and document the ending with that one :D

Also, kudos for the recommendation of the Irwin tap handle in How to Rebuild a Small Block Part 5: Crankshaft Install. I bought one at Lowe's and it made the tapping process a breeze.
 
Uncle Bob said:
I was just thinking yesterday it was probably a lot easier to put them together as you go. Then I thought, maybe he'll build another one and document the ending with that one :D

Also, kudos for the recommendation of the Irwin tap handle in How to Rebuild a Small Block Part 5: Crankshaft Install. I bought one at Lowe's and it made the tapping process a breeze.
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I was hoping to finish the engine that I started with my youngest son, but it's been a few years and he's getting busy with his life and hasn't had time to work on it...

However, I do have some other pictures from other builds that I have done that I think I can piece together most of what I need to continue... It not be as thorough as I want, but enough to continue and if/when I can work on the son's engine I can get more detailed pics that I don't have and update the threads then...
 
krazykuda said:
camshaft and timing gear next
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My engine didn't come with the gun-drilled bolt you describe here. How to Assemble the Front of a Small Block Now to find one.

Seriously, I get more out of your articles than the book I wasted $30 on. I checked it to see about that special bolt, and it skips from sticking the cam in the block to putting the timing gear on. Apparently the cam retainer just jumped on there when he wasn't looking or something.
 
Uncle Bob said:
My engine didn't come with the gun-drilled bolt you describe here. How to Assemble the Front of a Small Block Now to find one.

Seriously, I get more out of your articles than the book I wasted $30 on. I checked it to see about that special bolt, and it skips from sticking the cam in the block to putting the timing gear on. Apparently the cam retainer just jumped on there when he wasn't looking or something.
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You will have to buy one from someone that tore down an engine as they are not available aftermarket that I have seen...

I also did another article on installing the camshaft today...

How to Rebuild a Small Block Part 8: Install the Camshaft

My engine cc one also got approved with that one now let's see if the link shows up differently...

How to Rebuild a Small Block Part 7a (Optional): CC the Engine Cylinder to Find Compression


My next one will be on installing the camshaft thrust plate in the very near future... Keep your eyes open... That one should help you with your bolt issue as there is more than one way to get that done...
 
You can drill a hole in one of the cam thrust plate bolts, if you don't have one with a hole thru it. I just use a 1/8th drill on one. works good.

ole man Dave
 
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