I know. I was just wondering about your 59A comment. The 59A does not have a hole drilled in the bushing and removing the rod likewise makes no difference.
I don't like the idea of packing the pickup tube with Vaseline. Seems like you'd be creating a blockage more than priming a pump. Unless your pump is defective, it should pull oil right away. Think about this--- every time you shut off an engine the oil drains down from the pump. It never needs to be reprimed. The only time a pump needs to be primed (if at all) is when the pump is dry, like a new pump or an old one that was washed clean. As for the fuel push rod, without the rod you may lose some oil pressure, you will not lose ALL oil pressure. You still haven't found the problem.
The fuel pump rides in a bushing with a small orfice to let oil in,what if the bushing was left out? Would that affect oil pressure? Pete
Did a rebuild many years ago in my commercial shop. After warmup, the low oil pressure fell to practically zero, but no knocking noise. The short of the story is that when we finally pulled the engine and miked everything, we had .020" under main journals running in the machine shop supplied .010" under mains. My mechanic assembled without checking. Worse, when we plastigaged the rods and the mains before engine removal, the weight of the crankshaft had spread the plastigage in the main caps and bearing shells to create a false OK clearance indication. With the engine upside down on the bench, the crank barely spread the plastigage. This was a three day advanced course, "Oil Pressure 104".
Man,,,I am so glad Ryan created this site. Flatheads are an addiction !!! This is the first thread that I have read all the way through in a long time. Keep it coming,,it never ceases to amaze me how much some guys on here know about old engines. Tommy
The 8ba that is in my roadster was an interesting build. We bought the complete driveline out of a 48 ford that the owner was doing a 350/350 MII front end etc on... pulled a plug on the motor and it had shiny exhaust valves. Score! Never fired rebuilt motor. Decided to check it before firing it. Turns out it had a rat nest in the oil pan.... complete disassemble clean and reassemble. Thank god we didn't fire it up. Upon reassembly we found that the brand new oil pump had sheered the pins. So you never know what could be wrong Posted using the Full Custom H.A.M.B. App!
Not trying to be smart ass. In your first post you say the engine started right up? Why would you start a fresh engine without knowing you had oil pressure? Any fresh or long time setting engine gets turned over without spark until I am satisfied there is oil pressure before I start it.
Right now waiting for new gaskets to validate issue but I not only left out the rod but the bushing as well for the fuel pump rod. Just left a big hole so right now assuming that will be the issue. Probably won't use the vasoline as I didn't like the sound of it but will prime it by pumping some oil through the hole for pressure gauge. Hopefully will post results this Saturday or Sunday. There were a few other good suggestions I'll check as well though before button back up.
This is a little off topic; but some Chevrolet small blocks were assembled at the factory with a cam bushing 'outer' slightly over-sized to match the difference in the cam bearing bore, as factory sizes varied, ever so slightly. I know, there is a progression as it goes from front to rear. This little known fact is often overlooked in rebuilds and results in reduced oil pressure because off-the-shelf cam bearings are not the several hundreds thousandths over-sized, as per the factory fix. The slight difference lets oil under pressure bleed out where the bearing surface mates with the cam bore in the block, resulting in lowered oil pressure after a build --- a real head-scratcher for those expecting more oil pressure, not less. That said, however, my first thought was that the cam bearings holes might be misaligned. Blockage from trash is also a possibility, as has been mentioned. Or, the dreaded 'something is missing' scenario. Many builders use white grease (lithium) on the pumps to lube the gears before oil reaches it. Specialty manufacturers blend and sell lubes for cams and lifters that could be used with a more efficient end result: Isky-Lube comes to mind. I walked away from Flatheads when the parts pipeline dried up the first time (tells how old I am). Even so, I'm still in awe of what can be done with backyard engineering. Good luck with yours. Carl
Don't be afraid to use Vaseline to pack your oil pump. I have used Vaseline on oil pumps, rings and bearings on all my rebuilds since I was a kid and have never had a issue. It stays in place until it gets hot enough to melt out. It is what my auto mechanics instructor taught us to use in the late 60's and he was a old flathead guy
I have packet it with cam lube figuring that the extra zinc is always good on a fresh rebuild and there is usually some left over from dropping the cam in anyhow.
If the bushing was omitted then I think you have found your problem. Keep in mind that for what ever time this engine ran you likely only had pressure to the rear main and 4-8 rod bearing. Depending on how long you ran it it may warrant further investigation. Your call on that, good luck.
If it was me, before wasting new gaskets and a lot of work, I would stick the pan up with a couple of bolts and put some oil in it. Pull the coil wire and the plugs and spin the motor over with the starter to see if it has oil pressure. That way the only thing you have to pull back off is the pan and you will be able to see the fuel pump push rod port and inside the valley (if the manifold is off). Dave.
great thread and i'm glad you solved your problem. I had an 8BA recently that had very low oil pressure at crusing speed <10psi and i could not identify the issue. I replaced the oil pump with a new unit, removed the mechanical fuel pump push rod and installed a plug, checked on pick up height but still had very low pressure. I have since replaced the engine with another flathead but i will remove the timing cover tonight and check for the plug above cam. Thanks guy's!!
Here's what I did and results. Plugged the fuel pump passageway altogether as suggested by someone, packed the pump with vasoline and temporarily installed what was needed to test. Cranked a few times and almost immediately got 20lbs. so seems problem is solved. Now have to put it back together permanently. I'm a hobbyist and not technician so expect to miss occasionally as I did here. Read everything on the rebuild but never caught the fuel pump change impact and just didn't tie it together. Off course a big hole there is a problem. Regarding the concern about running it. Basically got impatient and knew the risk. Had been cranking it and not getting pressure and found little on line about what levels to expect or similar. Also started with the gauge extended out from port 3 inches using brass pipe and there was sure to be some drop there. Removed that almost immediately. Was just hoping a quick spin of the pump was what was needed. I had been adding oil in cylinders and down intake in between and used plenty of assembly lube in the build process so I am going to cross my fingers on this one. It sure sounded cool for those few short seconds though so can't wait to give it another try. I'll amend this if it turns out I screwed up and caused bigger problem. Thanks for all the input and I really enjoy the learning process even though it can be painfull.
First time starting a fresh engine is definitely not for the faint of heart! Here's hoping everything continues to work out for you.
Vaseline is a petroleum jelly and is not grease by definition. To my limited understanding of lubricants, grease contains additives designed to prevent metal to metal contact under shear. I know Vaseline is cheap and readily available, and I only mention the difference because it was never intended as a lubricant for machines. Perhaps no harm will come from using it, but grease is a better choice when you are concerned about damaging expensive, or hard to find parts.
I have heard of vaseline being used to help the rover (nee Buick) v8 oil pumps to prime. I also know the OE transmission manufacturer ZF use it when rebuilding valve bodies to ensure the check balls stay in place during reassembly. I would have no concerns whatsoever in using it for either of these purposes. A nice quick prime on the pump is a big advantage and outweighs any perceived worries. Glad you are on the way to getting it running properly. Mart.
Did you put the bushing in then plug the bushing? I think you need to do it that way. The oil goes around the outside grove on the bushing to the oil tube then to the front of the engine. I'm not sure,can someone confirm that?Pete
The Jalopy Journal
