You can not loose oil pressure by not having an oil pump pushrod. There is a ton of clearance between the pushrod and the bushing. You must absolutely have the bushing as it intersects with the main oil galley. Maybe the builder left it out thinking you would run an electric pump. Plugging the bushing will not increase oil pressure as there is no pressure on the inside of the bushing. My guesses are the plug under the cam gear, the oil pump bushing, the plug at the flywheel, a plug in the cross oil galley for full flow oil filter and then not installing one. You could start at the front and check the cam gear plug, pull the intake and check the main galley bushing. You can pull the plug on the back cross galley and check for an internal plug. You should have oil out the back of the engine if the hidden flywheel plug is out. Are you missing oil?
If the plug behind the flywheel is out he would have a big puddle under the cotter pin. And possibly a ruined clutch disc.
Put an air fitting in the gauge port with a regulator and slowly crank up the pressure. See if you can hear a large leak.
I put the engine in my car together a couple years ago probably has less than 6 miles on it as it’s race only. So it’s fresh (but abused haha). It cranks at 40 psi and runs at about 80. When I was starting it for the very first time it did start low but came up after about 3-4 seconds of cranking. But those seconds feel long when watching your oil pressure gauge haha My engine is an 8ba but depending on what oil pump you run it may be a relevant comparison
Yes this was a nail biter. I phoned two friends and they both said START IT. I ended up with 10psi priming the engine with the dist disconnected. with great fear of Nuclear mushroom clouds, I turned the key and it started on the first try and went to 45psi. And the gauge works now too. I don't know why it took so long to prime the engine and get pressure but it's all good now. I was sweating bullets and with all your help, I got through it without incurring 5 digit expenses.... this time! thank you all!!
It would be interesting to know what variety of oil pump has been installed in the engine. That oil pressure is fine with an old style pump with straight cut gears (and a "stretched" relief spring), but low for a later spur gear pump.
Tips for the future. First off. Cranking a motor over with plugs in its not going to spin too fast to build any real notable pressure. Secondly, electric gauges are finicky about voltage drop when cranking, so the gauge probably didn't want to read at the10 volts it was seeing when cranking. Glad you fired it up and got that hurdle out of the way.
It's a speedway standard flow pump. I have about 6 original pumps and just went with. New one instead of a rebuild.
That's the same one I referenced in post #22. It was new, I didn't know any better and installed it and also go only 45 psi. I was concerned and replaced it with a known good used Ford pump which brought the pressure back to 57 psi. You can live with 45 psi and it probably won't get worse. Replacing mine caused the new rear main seal to develop a slight leak which I haven't gotten back to yet (but I will). I would avoid Speedway oil pumps after our shared experience.
If you are talking PSI for oil pressure, I run no oil filter, fresh build running 20W-50 weight oil and I consistently get 70-75 lbs of oil pressure depending on the temp. outside. My motor is a 59L block.
Can you share your experience with Speedway pumps? My engine builder asked me to order the high flow Speedway pump for my Merc build. He said he's had good luck with them.
Pretty sure he mentioned should be 57 psi, and he and the OP shared the same experience with the Speedway pump
On a new engine, with a new (later 49-53 pump - which is what you have) and cold oil, it should easily pump over 60 PSI upon start-up at 2000 rpm. I stretch the front spring on my 39-48 engines (with this pump) and they will be pushing 80 lbs on start-up. Even when the oil is hot, I will have 60 lbs at higher RPMs. Also, I have increased bearing clearances and still see that type of pressure. The same is true on every flathead I've built with the 49-53 pumps. If it was my engine, I'd put a mechanical gauge on it and validate the initial cold-start pressure at higher RPMs. If it is NOT about 60 lbs or more, than I would suspect something is wrong. If you find that the pressure drops off once the engine/oil is hot/warm and the pressure at 1200 RPMs is now below 10 - 15 PSI, then the motor needs to come apart and be inspected. I've seen two instances where a cam was installed with .010 undersized journals - yet STD cam bearings. This causes it to initially show 45 - 60 lbs at higher RPMs, once hot the pressure drops at higher RPMs and gets below 10 PSI at high-idle. Many builders forget to check journal dimensions on the cam - as you don't see undersize journals on almost any other modern engine . . . yet they are fairly common on flathead cams (especially reground 32 billets). Don't just run it if you see any of the issues I mention up above. Lastly, who built the engine?
Read my post #22 again. Also, I would suggest you look for a new "engine builder". EDIT : Too much oil pressure is as much of a problem as to little, It adds strain to the system because of the extra effort required and also requires more power to run and causes everything to run hotter. The so-called "High-Pressure/High-Volume" oil pumps offered by the manufacturers are specifically designed to be use on racing engines with deliberately opened up clearances. They are specifically designed for racing and not street use. How do I know? I spend over $10K for "professionally built" engine for my restored '67 Corvette. The engine ran OK, but pegged the gauge at any stage of running. The long story short is that when I pulled it apart, I found the "engine builder" had installed a Mellings "M55HV/HP" oil pump (because it was $4 cheaper and an "upgrade"). Replacing it with a standard GM pump brought everything back to normal (after replacing all of the valve seals ruined by all of the oil pumped to the rocker chambers). Those old Ford and GM engineers knew what they were doing, so screw with their original designs at your peril.
X2 on Tubman's comments. I had exactly the same situ8ation with my 1965 337CI SBC, with the same Melling's as he did. The other issue I had was oil leaks, very annoying and too much oil. I had consistently 75PSI. Switching to a stock pump did the trick. For this case Tubman's sig shouldn't be followed "If some is good, more is better, and too much is just right! Carl Kohler" Regarding the need for a fuel pump push rod or blacking if using an electric pump, this is only necessary on 8BA engines. Not required, but I shortened my 59AB push rod. Good discussion here: https://www.jalopyjournal.com/forum/threads/eliminating-a-flathead-mechanical-fuel-pump.837989/
Also IMHO Id ditch the 3 2's and run her with a single carb for the first 2-300 miles. Easier to get her running right and no wash down on seating the rings. Been my recommendation on all engines I have built
I don't like the idea of cranking the engine to prime it especially if a fresh build with a new flat tappet cam. This could in my opinion wipe the cam break-in lube off before it get's it's chance to work. I always prime with a oil pump priming tool.
Unlike a SBC, it is very difficult to do with a flathead. The only way to do it on a practical basis is with a pressurized tank of oil and spinning the assembly manually.
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