Looks like I will have a 390 Holley too (started new post).

 

Well, you could.

The tube does not "drain" though.......

The tube is in a hole on top. So the oil comes in through the bottom and is pumped in until the tube fills up.

Gravity permits some of the oil to seep into each rocker. Excess oil overflows out through the drain (copper) "tube".

There's no reason to have a drain tube.

Pressurizing the hollow rocker shaft will only cause more oil to be pushed into the areas that you want lubricated anyway. ALL the oil that is sent to the rockers shaft, will leak out of the lubricated parts and drain out of the head......... there's only 1 drain at the end of each head where the tube is anyway.........


This is why most Y-block "experts" remove the drain pipe and "pressurize" the shaft.

You could just pinch off the drain tube if you weren't going to disassemble it but mine is already disassembled.

There's no reason to partially pinch the tube. Just use a pair of "vise-grips" and crush the end.

Since mine is already off, I'll put hex-plugs where the tubes were....



Cheers,


Rick

 

I don't want to butt in, but those so called drain tubes DO serve a purpuse and should never be completely pinched off or removed. The right front tube directs oil to a valley channel that feeds oil splash to lube the timming chain. The left rear tube does the same at the rear of the valley to lube the distributer/cam gears. Tom

 

Tom, this is my thinking on the subject. With or without the use of overflow tubes, no "flow" of oil will get to the timing chain. Lots of oil will get to distributor gear.

Oil to the chain from the valley can only pass through the two holes at the front of the block, which are well above the floor of the valley, meaning to me that it can only be in airborne droplet form, thrown about by the gears and valley hardware. I think most engines are mounted so that they point slightly downward in the back from horizontal, so most oil in the heads with plugged overflow tubes will exit rearward. With overflow tubes the one in front will drain into valley and migrate rearward also.

Airborne oil can also access the chain from beneath. So...I think I will be plugging my overflows.

Thanks for bringing this up. It made me get off my butt and really take a look at the block and heads, as I have heard this argument against pressurizing the shaft for quite a while. Mike

 

Mike,
Take a look at a bare block. The front of the valley has a dam to prevent the oil from draining back down the valley. It is high enough that the oil will drain out the holes at the front of the block.
That being said, if you've ever had the valve covers of, you can see that oil is everywhere, so it gets around one way or another. Same with the valley cover. I'm sure enough oil is flung to all the right places. Because of the incline of the engine, the distributor gear absolutely gets enough. For the timing chain, you got the oil from the front main being flung everywhere.
This seems to be supported by the number of people who pressurize the shafts without any issues.

 

Well what to you know. I was outside and took another look at a block, this time with better glasses and a light. There is a channel going to one of the front holes! I have never noticed that. Duh . When I looked at it earlier I looked at one of the holes with block standing up on trans end, and noted the hole higher than the valley floor, but didnt notice the other one is even with the floor, and didnt see the dam. Later turned over a block that is on a stand for another look, and, Man...

 

Hi Tom, You're not butting in at all!

I'll agree with you that Ford originally put them there for that purpose. The Y-block guy I asked about this told me that it isn't really necessary because the timing set is still well lubricated by splash oil. (the dist gears will still get oil from head run-off) Later SBF engines lube the timing set exclusively from splash.....

I even asked Mummert when I ordered the new rocker shafts and pushrods last week and he told me that it's a good idea to pressurize the rockers like I'm doing.......


I am thinking that it's really not going to be a problem.....