SBC Cylinderhead oiling issues
 

I've got a freshly rebuilt 350 with less that 1000 miles on it that is having oiling issues. The drivers side is oiling fine on all rockers but the passenger side is not at all. First off the Intake rocker/lifter on #6 cylinder is shooting oil over the fender. The #6 exhaust lifter is oiling normally as are most of the others but, #2 intake and #4 exhaust are barely getting any oil at all. After about 3-5 mins of running time they both will have oil starting to pool in the rockers but enough to flow over the roller tip or on to the valve. I changed the oil, adjusted the lifters, checked the dist to make sure its seated and in properly but none of that made any difference what so ever. The oil pressure sits at 60 until the thermostat opens then it will drop to 55-50 at idle. Any help would be gratefully appreciated.

James

Turn the idle speed up.

Oil only flow up the pushrod when the holes in the end of the pushrod are lined up with the hole in the rocker arm. The size of the hole in the pushrod, and whether it is chamfered or not can affect the flow as can the size and position of the hole in the rockers. Pushrods that are too long or too short will also change the oil hole timing.

New or used pushrods? If they are used, perhaps they are partially clogged. I have also found that some new pushrods with balls welded on the ends contain particles that are too big to fall out the oiling holes, but are big enough to restrict oil flow.

What kind of lifters?

tom

Ok I turned up the idle, no difference. I removed all the rockers and checked the pushrods. They were all clean and the openings were free of any burrs or debris. I then re adjusted them and still the same issues. They are a new hardend set and checked again that they are the correct length. I didn't reuse any interals other than the crank. I bought a lunita cam and lifter set. The machine shop just told me to bring it to them and they would look at it. I dropped it off with them this morning. Ill call them at lunchtime. I really don't want to pull this thing out. Thanks for the help.

Sounds like a plugged lifter. If the other lifters are getting oil then the galley must be clear. When you put it back together get a oil primer that goes where the dist is supposed to be and spin it with a drill. That way there will be no doubt that it is oiling.

I'd look toward restricting the oil coming from number 6 intake, it sounds essentially like this is a leak that is starving the rockers following it in oil feed order (back of engine to front). This is probably an issue with the lifter as it dictates the amount of oil entering the pushrod. In total there really isn't a lot of oil moving down the lifter galley so a lifter that isn't doing a good job metering oil to the rocker will starve everybody else on that circuit especially those after it.

We've seen a lot of lifter problems in recent years, having new ones is no assurance of a good part.

Bogie

Now that's just silly. It's more likely that that one has the least lifter-to bore clearance.

I'd say there's enough wear in the bores and the lifters are probably at the small limit size-wise. If there is enough oil flow at 1200 rpms, I'd not worry about it.

Oil flows around the belt relief of the lifter, the bore clearance is meaningless unless it's so loose as to create a leak back to the crankcase from the belt relief. Or the lifter is incorrectly machined and is missing the belt relief which would reduce if not terminate oil flow to the lifters of cylinders 4 and 2. But squirting so much oil out of the rocker feed hole that it lands on the fender sounds to me like a metering problem to the push rod from inside the lifter, more than the other pushrods are plugged up, or this is too tight in its bore. Kind of a logical conclusion because the problems seem to be after this lifter, so I'd start here and work backward.

But then I'm not there so I just have to take the clues and Sherlock my way backward.

I like to see all the push rods metering well and reasonable equally, I worry this to the point of fixing when they don't. Especially if the engine is running ball and socket rockers and sees high RPM (certain restricted classes) use as this is the only means lubricating the ball and socket and cooling the same and the valve springs. So unless this is some street junker rebuild, I rather think he has grounds to be concerned.

Bogie

Hey guys, sorry it's taken me a while to let everybody know what the issue was. I had broken the tip of the push rod off and the it welded itself into the rocker. I replaced the push rod and rocker. It slowed the oiling on #6 way down and the others started oiling better. Not even all the way across but much better. Thanks for the suggestion and advice.