The Stovebolt Site Forums The Shop Area Engine Shop No oil coming out of rocker assembly: 1955 235

I replaced the original bhive filter assembly with a remote oil filter mount from Moroso. I chose the one with the in and the out for the oil and the additional out for an external oil pressure guage. This is a newly rebuilt motor and I just got it started for the first time last weekend. Here is my question:

There is no oil coming out of the rocker arm assembly at idle or increased rpm. The oil pressure guage is reading about 15lbs at idle and about 25 to 30 at increased rpm. Is this enough pressure? Do i need a restrictor placed on the out to the block line to increase pressure? If i add a restrictor, will it fix the issue with no oil coming out of the rocker assembly? Do i need to prime the block by spinning the oil pump with that device racers use to prime blocks (essentially a flat head screwdriver attached to a drill)? Any and all answers greatly appreciated.

Jackson

Excellent discussion on this very topic about 1 month ago.

http://www.stovebolt.com/bboard/cgi-bin//ultimatebb.cgi?ubb=get_topic;f=2;t=009450

That sounds like the pressure is a little low. Try plugging the line to the filter & see if it increases. You co not need to prime the oil system now since you already have run it. Make shure the passages to the rocker arm are clear. If you havent run it very long it may take awhile for the oil to get to the rockers. Put some oil on them while you are testing. You don,t want to run them dry.

Based on the picture in the link provided above, can someone confirm that hole #1 is the pressurerized out to filter hole and hole #2 is the non pressureized oil return to block. If this is correct then i have my remote filter plumbed incorrectly and this would probalby be where the problem is. I have the hole closest to the firewall as the out from block - in to filter and the hole closest to the radiator as the out from filter - return to block. Just to clarify, I am deffinitely using the holes marked #1 and #2 from the picture in the link provided above.
Again, thanks for any and all help with this.

Jackson

If you mean a remote filter with a throwaway filter,and your engine has not been converted to full filter flow,you need a small restriction in the hose feeding the filter,something like the stock hoses had,around .110. If none of the above applies,you have two problem,no oil to the rockers and a fresh engine with low oil pressure.A 235 will do ok with 25 psi in light duty use,but 40-45 psi is more like it when running down the road.
There should be a oil tube under the side cover to supply the rockers on your engine,pull the cover and check it out.

I have also heard of having the head gasket on backward which some have speculated will block off the oil passage to the rockers. I suspect that this happened to my motor so I ground a grove through the threads on the center passenger head bolt and problem solved. I had plenty of oil pressure to the rockers after doing this. It creates a new flow passage for the oil to travel, bypassing the old passage altogether. Worked for me. I have 3000 miles on it now. All is well. I also have no restrictor on my oil line to the filter. I run about 10 psi at Idle and 30 at RPM. I'm gonna try the restrictor soon to see if the PSI will come up a bit.

On a 235/261 engine,there is an small oil drillway next to that center right headbolt.The head gasket has an oval shaped cut out where the head bolt passes through so the oil can make it's way past the bolt and to another drillway to the rocker shaft.The bolt hole in the head is larger than the shank of the bolt or the slight area of threads that stick pround of the block once the bolt is torqued.The area around the bolt can become blocked with crud.
Remove the head bolt and rocker assembly center oiling tube,spray some stuff like carb cleaner down the head bolt hole and rocker feed hole,use a oil galley brush or even a rifle bore brush to loosen the crap.Then pull the distributer,spin the oil pump with a drill motor to see if oil comes out and to flush out the gunk.While you're at it,clean out the rocker shafts.

I learn something new everyday. Thanks Tony. Wish I had that advice when I had the problem. I was thinking there was some special head bolt for that hole to allow the oil to pass. I remember now, I had the head redone but not the block. This is a fairly common problem for most of us rookie builders so I think this should be added to the tech section.

There's another way to clear the passageway at the center head bolt hole. Remove the head bolt, and whittle/shave a piece of broomstick until it's a very close slip fit in the hole. Fill the hole with motor oil, insert the dowel, and smack it with a BFH! The hydraulic pressure will clear the gunk out of the passageway. Sometimes it will take more than one swat.
Jerry

I think everyone is missing my question. Before I unbolt anything, i want to make sure that my remote filter is installed correctly. Can someone please tell me the direction of the flow of oil on a 1955 235? It was fitted with the factory oil filter system that bolted to the intake manifold. Which hole is the pressurized hole and which hole is the oil return hole in this picture? http://www.stovebolt.com/bboard/cgi-bin//ultimatebb.cgi?ubb=get_topic;f=2;t=009450

OK, in the picture, the hole at the rear, where you've got the oil pressure sensor, is the pressurized port. It's in the oil gallery. The hole just above the pan rail is the return, which just dumps back into the pan. If you don't have a restrictor orfice installed somewhere in the return line, your oil pressure is going to be very low because most of the flow is going through the filter and back to the pan, bypassing the bearings. Unless you're using a filter designed for a bypass-type filter system, you're killing the pressure to the engine. To test that theory, disconnect the filter plumbing, and install a direct-reading pressure gauge to the upper port, dead-heading that port into the gauge. I'll bet the pressure rises noticeably.
Jerry

Hotrod Lincoln,

Thanks for the information. From what you have said, my filter is plumbed correctly. I will try a restrictor of some kind on the line back to the block and hopefully with increased oil pressure, i will get some oil to the top of the motor. Thanks again for your help. If that doesn't work, i might replace the whole thing with a Ford......just kidding.

Jackson

Try this little trick:
The copper tube that's on the return side, clamp a Vise Grip on it, and squeeze it about 3/4 of the way flat. If you get a rise in oil pressure, you'll know that's where the pressure drop is coming from. Once you've established that, try threading the inside of one of the return fittings to take a Holley carburetor main jet, and replace the piece of flattened-out tubing. It's easy to drill the jet a few thousandths at a time to get a good compromise betwen flow through the filter, and oil pressure.
Jerry

Jackson - as asked a few times, have you tried just eliminating the filter temporarily to see if the situation changes? doesn't sound like you know for sure that the filter is the problem ......

Bill

No I have not tried bypassing the filter altogether. At lunch, I did go and and verify that what i had assumed was the pressure hole and return hole are correct. My next step is to remove the center head bolt and possibly the rocker arm assembly and check everything out. I guess my other option is plumbing a line directly to the hole at the top center of the head and that will ultimately fix my problem.

Another question: In this 235 motor, are their channels that run throughout the block to supply oil to all the necessary places like on a v8?

but if you try eliminating the filter until you have good oiling, you might find the problem isn't the motor, but the filter - seems to me folks are saying the filter needs restriction so it doesn't drop the pressure too much - try it, you might find things are easier than you think, or maybe you'll confirm there was something done wrong in the rebuild, non-OEM modifications should not be necessary to get satisfactory oiling on a fresh engine!

Bill

Problem Solved. After removing the side cover I discovered that the pipe that moves the oil from the rear of the block (up from the rear cam bearing) to the middle of the block was missing. This motor was rebuilt and partially assembled several years ago. My pressure is still very low so i am going to try an inline restrictor that is made for turbo applications. Thanks for all the advice though.

Jackson