Hi Guys, I need some help/advice. My 390 has been ticking for awhile (not real bad,just an aggravation) so I thought i'd play with it awhile today. Its a 390 w/adj rockers, and a mild hyd cam. I had the heads redone about 95-96, cam+lifters,pushrods, and the adj r/a's added at the same time. Anyways, using the 'ol stick routine I found the one that was ticking and started backing off on the adjustment to see if it would get worse. Something didn't look right so I shut it off. The top of the valve stem was wore down to just a hair above the keeper, with a dished kinda look about it. Some p/rods spun like crazy while I had it idleing, and some where barely turning. On this particular valve it didn't appear to turn at all, but started some when I backed it off on the adjustment. This is on an intake valve. When the heads were redone all the ex valves were replaced allong with hardened seats, and new valve springs added due to the cam. I was told the intakes were ok with just a regrind. So now I'm looking at pulling the top end apart, and at the very least 1 new valve and probly an adj rocker. While I had the valve cover off I noticed there was plenty of oil coming from the rocker stand that has the oil passage ( 3rd one back pass side ) but there didn't seem to be alot toward the front of the shaft ( I was mainly looking because of all the oil mods talk here ). In actual miles this thing probly has 50-60,000 on the rebuild ( not counting the heads being redone ). My Dad had it rebuilt back in the mid 80's, and I got it in '92 when he passed away. He mainly drove it when he went fishing ( L.A. to Colorado River and back) and me just puttin around town on weekends here with some firewood hauling in the fall. Any help/advice on what might of caused this, and what I need to look for when it goes back together agin. Also reguarding some push rods spinning good and others not, could that be a symptom of a bad cam/lifter combo? Thanks in advance, Al

 

Is the bad valve at the end of the shaft where you did not see oil?
If the shaft is dirty on the inside, it can starve the ends of the shaft for oil. Also check the rockers for oil passages blocked.
It sounds like an oiling issue in only some places which is prolly a plugged passage. HTH

Putt

 

Thanks Putt, no the rocker/valve that is wore is between the 2nd and 3rd hold down bolts. It all oiled, you just had to rev it up some to get full shaft oiling. Where the oil passage/bolt is theres PLENTY of oil. When I first got the rocker assemblys I disassembled them and cleaned everything up real good. The shafts only had oiling holes on the bottom part of the shaft. The casting #'s are late '50's on the stands, probly from a solid lifter motor. Al

 

Have you checked your oil press? If you must rev it up to get oil, it sounds like lo oil press./volume. It could be worn brgs, oil pump, etc. I have seen a couple oil pass in the block that sprung a leak(passage to the rockers), but that would put oil in the coolant. Reread and saw lots of oil at the bolt...
What about the wrong bolt in the oil passage loc? It should be necked down.

Putt

 

Hi Putt, well to be honest, I did this almost 10yrs ago, I guess I'm fixin to find out ( about the bolt ). So every thing points to an oiling problem you think? It makes sense in a way, but how come only 1 valve out of 8 I wonder.Thanks for responding, this thing has got me pissed in a way since doing the heads there ain't any milage on them to speak of. Thanks, Al ps- this thing has exellent oil pressure, hot or cold. I doubt there's 50-60,000 on the overhual. the 'ol boy how did it used to be a circle track racer back in the 50's, and knows these 'ol motors. He had a good reputation for his work.

 

Well I'm about out of ideas. Sometimes it's just the luck of the draw. It is poss the intake valve had been surfaced on the tip before and 2nd time cut thru the hardened part of the stem. It sounds like tear down time and check valve stem length.


Putt

 

If you have a lot of oil around the rocker stand that supplies oil to the shaft but not much anywhere else on the shaft, the rockers themselves are probably worn and allowing too much oil to escape around the shaft. Or, you have a gap or opening between the oil feed stand and the head. Where is the oil coming from? Around the rockers, or from the top/bottom of the stand itself?

Did you restrict the oil feed to the rockers?

A push-rod not turning is NOT a good sign, that usually means the lifter is not rotating and is wiping out the cam... if you wiped out the valve stem already, it sounds like not enough oil getting to the rocker tip - these rockers have oil feeds in them to the tips, right?

If so, clean everything up, replace that valve, and make sure you check the cam to see if it's OK - pull the lifter and if it's really concave (worn) you'll need a new cam too

Then, check the rockers-to-shaft clearance, it's possible the shafts are worn enough to allow to much oil to escape and starve the rest of the rocker assembly.

 

Well as best as I remember, it looked to me it was mainly coming from around the stand/drip rail area. The rockers and shafts I think are rebuilts from PSE. I say that because the rockers are bushed, probly to compensate for a turned down shaft? The stands and rockers are marked with a B8 or 9 casting #, and the shafts only have oiling holes on the bottom ( would this accomplish the same as restricting the feed hole to some degree?). So much to learn...... Thanks, Al Oh yea, everything was taken apart and cleaned before install

 

The shafts only have holes on the bottom since that is where the pressure is at from the rockers. The shafts can't be turned down because then they would not fit the stands. The rockers wear tho and could have been bushed to restore the proper id.
If the oil is coming from the bottom of the stand then something is plugged or restricted in the shaft IMO or the wrong stand bolt.
As Krewat stated the non turning pushrod is a very bad sign, I would say you will need a new cam unless you are verrrry lucky and new lifters too.
Good time to upgrade to a more modern, efficient cam!

Putt