On my motor from the 9C1 I noticed the 3 oil galley plugs had .040 holes drilled thru them,maybe to help lube the chain?Now I'm finally getting ready to put my new short block together and was woundering if I should drill these hole in the new plugs or leave them out.(And yes I can drill them at the shop)What is the purpuse of them?Thanks

 

If I remember correctly, it IS for providing a positive source of lube for the timing/water pump gears. I would guess that if you've converted to a double roller chain and electric pump, you probably don't need the additional oiling. Hope this helps!

 

Drill the holes in the two lifter galleys and make them .030. The chain will love it.

 

I agree. The chain only gets oil from splash at the front of the pan. Since most of the oil sits in the bottom of the pan and any oil that drains down out of the block will flow backwards, the chain will only get oil during hard braking. Drilling out some holes in the gallery plugs just makes sure the chain is constantly being oiled.

Dart recommends drilling the gallery plugs on all their blocks for this same reason.

 

I used them on my motor and many others. It does lube the chain and between the gear and wear plate well. Really doesn't effect oil press...

 

Sorry to bring this one back to the top, I didn't see a need to start a new one.

I noticed my shortblock doesn't have these oil holes and I guess even if I'm running the double roller I should go ahead and drill these huh? It might be a little late though I think b/c everything is pretty much assembled... is there any way of doing this without getting metal shavings in oil passages? Or is this something that needs to be done prior to final block cleanup before assembly?

 

I wonder if you could use this Moroso A&B epoxy.

http://www.jegs.com/webapp/wcs/store...tegoryId=17221

You could fill in the 8 holes in the lifter valley and force the oil to the front or back of the engine that would at least divert the oil in two directions and create more oiling.

I have a pic that Bret sent me when I was working with my lifter valley screens. I'll send it to you if you like.
Side note: (I scraped the kit I bought because they were pre shaped and didn't want to work correctly.)

 

Ah, I don't really want more oil.. I just want to know if with a double roller (no waterpump gear) if I should be worrying about the .030" holes up front.

And if so, can it be done w/ the engine pretty much assembled.

Lastly, wtf does one buy a .030" drill bit locally...

 

Maybe I'm just being thick but wouldn't both give you the same result.
Drilling the three oil plugs out will provide more lube for the chain; as would forcing more oil to pass through the front drain holes in the block.
I would imagine that the holes directly behind the gear would cause more direct lubing so that would be a benefit.

Either way...I don't think it is advisable to drill on a block, even just freeze plugs, that has already been assembled. Just to much of an opportunity for debri to cause a problem in my opinion.

 

Ah I got whatcha meant now.. but I don't think I'd want to plug the holes in the lifter valley...

 

I'm with you on that...hopefully one of the more knowledgable guys will chime in and give you better info. I'm still kicking around whether I want to do it or not.

 

Yah, I'd really like to know what to do. This is yet another one of those debated topics with no real answer.. most of what I see when I searched talked about the LT4 ED chan, not a double roller.

 

Drill the holes with the bit packed in grease. Let the bit cut and don't force it. The shavings will stick to the grease and if ya handle it easy they will stay stuck.
Ya could remove them,drill the holes in new ones and put them in.Or get the ones from GM that have the holes and install them.Or go with no holes.Choice's!!!!
The holes were put there to lube the water pump gear in a stock set up but the chain will love it.

 

"o" just drill the two side galleys and not the top one. Ya can get a .030 bit at Grainger any good hardware store it is a 1/32" or a number or letter drill.

 

Little too late for me, she's in and running Hopefully all will hold up based on everyone else's engine who is running w/o them (considering how many have golen and vre engines w/ no issues)