283 Oil Flow Issue

[Joseph L.]

I have a motor issue that I am attempting to identify.
It is a stock 270HP and the motor judged correctly for the May assembly date. I have driven it for 2000 miles during the three years I have had it. I have no information on what is inside the motor and have not had it apart, except for removing the intake manifold. The cam sounds like an 097, and it adjusts like one. Oil pressure continues to run at 30 psi idle to just below 60 psi at freeway speed. The pressure has not changed with the new issue.

The motor had been very good sounding at idle, and at cruise. No noises. I took it out last Saturday for about 20 miles. When I got off the freeway, I had a lifter noise. I took it home, checked the valves on the side that sounded noisy, and they measured well. I then started the engine with the valve cover removed, and had no oil flow from the pushrods. The adjusting screw areas were dry. I took off the other valve cover, started the engine, and that side was also ran dry. There was one short term flow of less than 1/2 ounce to the rear pushrods/rockers. Oil pressure was about 45 psi at 2000 RMP. Oil level is correct.

Removed the stock 891 dual point distributor, got an old 891 I have, removed the distributor gear, installed it and connected a drill. I got a continuous 45 psi oil pressure. Both of my distributors have the correct distributor body configuration above the gear for this block. While running the drill for one minute, there was no oil flow from the pushrods. The rear two on one side squirted once when I initially started the drill, but there is no flow otherwise. I checked a pushrod and it was not clogged nor was the end peened closed.

It may be time to pull the motor. I am also concerned since I do not know what other parts of the motor may not have been receiving oil and the condition of those components. The issue may be in just the lifter oil passages? It does not seem to make sense to remove the pan for access to the oil pump since I am getting pressure and the drill is straining to create that pressure.

If you have seen this before and have some idea of the cause or where to look next, please let me know.

Joe

[Richard M.]

Re: 283 Oil Flow Issue

Joe, I rarely find that using a drill is enough speed and torque to get oil flow to the top end, emulating what a running engine does.

I would check the oil filter. Remove it and cut the filter open for any signs of foreign matter.

A possibility is that the plugs at the front of the block at the forward ends of the lifter galleys may have been compromised, ie pushed out. I think originals used Welch plugs there. Most engine rebuilders tap for threaded plugs. The oil would then drop back down to the oil pan. They're accessible, but you must pull the water pump and timing chain cover and cam gears to check. I don't think the rear plugs are the problem as the oil would be dripping down behind the flywheel all over the floor.


Rear


Front


The other possibility is a improperly positioned galley plug in the block in the area above the oil pump. A friend experienced this on s 327, but on a new build. Engine had great oil pressure on the gauge using the normal tap at the rear of the block, but no oil to the top end. This can be measured using a long thin rod down into the port where the oil gauge line sits.

[Frank D.]

Re: 283 Oil Flow Issue

I'd follow Rich's advice carefully and not run the motor any more than you have.
When I adjust the valves on my original 270hp car (hot) I have to use oil deflectors or the oil will shoot out the pushrods and soak the inner fender.

[Dan D.]

Re: 283 Oil Flow Issue

Joe, it sounds like you know this, but let me throw it out just in case. The early distributors (I think 55 and 56) did not have a full circle recess on the distributor housing. One side had a flat area. If you do not install the distributor in its correct orientation you will not get oil to the lifters. Oil has to go around this area in order to feed the lifter oil galleys. You said you had the intake off, so I that makes me wonder if you installed it correctly.

I bottom end is obviously getting oil or you would not have made it back home, so I don't think you have damaged the bottom any. But I know from the old days that you will not get top end oil if the distributor is in wrong.

-Dan-

[Joe R.]

Re: 283 Oil Flow Issue

Joe,

The above suggestions are great and you should follow them to the letter! Hope that this is a oil filter problem with the bypass valve right above the filter as it is accessible.
Don't think you specified how many miles were on this motor and probably don't know. If it's a lot of miles you may be looking at cam bearing failure as that is what exhibits your symptoms.
Like I said try all the other suggestions cause cam bearing failure will need you to pull the engine and find you a great machine shop to fix the problem.

JR

[Joseph L.]

Re: 283 Oil Flow Issue

Thanks all.
My 3 amp drill struggled to turn the oil pump, but an 8 amp drill was strong for the minutes I ran it.
The oil filter paper did not have a large amount of particulate matter. The bypass valve appeared intact and there was no crud stuck in it.
The galley plug measured 8 1/4" from the top of the block. I have seen the earlier distributors and I have a full circle recess on the housings of the ones I have. Everything looks good at this time.
It looks like I am going to be removing the motor for a better inspection. This was not in my current restoration plans.

Joe