need help BBC donovan

BBC donovan block, AJ billit heads, burning up front 4 push rods on both sides of the heads,and rocker arms ,tryed 3 differnt length push rods, no change, not much oil in top of heads ,after warm up, burns them on the warm up, 125lbs of oil pressure. this is getting old, any ideas,please help.

 

Change the oil galley restrictor.
Are all the plug in the block. Sounds like they might be missing. Chevy valve train is last to see oil.

 

donovan oiling

no restrictors, all plugs in.

 

I have notched he lifters on standard bbc motors to improve oil flow to the top. Just a little brush on the grinder that sort of chamfers the oil hole. I'm guessing my bores were too tight, but didn't have the tools to measure back then.

 

if it matters they are 1" lifters, pulled the intake off, there is oil in every lifter.

 

Has the block been repaired at all. Can you pull the lifter plugs out and see all the way from front to back with a light. No blocking or metal hanging into the holes. Just sounds like your not getting oil all the way to the front of the engine. Do the cam bearing feed oil to lifters in Chevy? Can't remember.

 

grind the lifters

We went through this with our century block, Checked everything no success . We were told to notch the lifters but didn't believe it. Finally gave in, made tiny notches between the 2 holes in the lifter and problem solved immediately. We put a drill on our oil pump and we got oil right away. Do it you will save a bunch of push rods.

 

If everything thing else up to the lifters is clear then the lifter itself & the clearance of the lifter in the lifter bore is the next possible restriction for the oil on the path to the pushrods and the rest of the top end. As others have mentioned, opening up the restriction to the oil feed hole on the side of the lifter via a groove or a flat spot could be required. You should be able to verify good top end lubrication by priming the engine with a drill instead of burning things up while running.

Good Luck!
Joad

 

there is only one small hole in the lifters, isky brand,

 

when you say notch the lifters, are talking to grind off on the hole side?

 

NO! I just used a small cuttoff wheel on a die grinder. My oil holes are ~3/16" above the oil band on the lifter. I just "brushed" the lifter from the hole down to the band to create a little extra clearance for the oil to get into the hole.

 

My NO! comment may have been misunderstanding what you were asking. I read "should I grind off the Whole side".

 

i think i found the problem, hope so, the dunn mag drive oil slot does not line up with the oil galley hole in the back of the block. guess i will have to modifiy the mag drive. anybody have this problem before?

 

yes..
that will generally only starve one bank of lifters.
Pull the galley plugs out of the back and you can visually see the alignment of the groove. It can restrict or make a huge internal leak. I had spacers on all my Chevy mag drives.
We ran Isky lifters with no restrictors mostly. A little goes a long way on the lifter mods. A groove can pump a huge amount of oil.
Our last set we used a fine jewelers file and made a .050 flat spot.
We ran a wetsump and did not want excess oil pumping to the top.

 

did everything you guys said, still no oil to front 4 pushrods. maybe wrong lifters, no band on them just a small hole and the groove i put on them. WTF.

 

Can you post pics of your lifters? I'm only familiar with Chevy style blocks, but I can't figure out how you could get any oil flow without bands in your lifters that line up with the holes in the lifter bores?