Hi I've just purchased a 1951 flathead 8ba. I've connected a mechanical pressure gauge to the rear of the engine and turning over on starter I get about 5psi oil pressure. On startup and revving it doesn't get anymore. I'm running 30 grade oil. ---- It has the original filter - This didn't seem to have a restrictor so I have blocked the feed on the block - no difference. I've removed the inlet manifold hoping to find a pressure relief valve (see attached picture) but don't know what i'm looking for? Also I've taken off the front cover to see if the I can see if the top feed has the plug in, but can't see behind the sprocket - When I turn it over like this I don't see any spraying of oil at the front - I would expect to if the problem was the blank plug missing? Now when I turn it over as it currently is - I only see a little bit of oil coming up the fuel pump post and a little but dribbling out of the end of the camshaft. Where should I be looking for flow of oil? I'm assuming my next point of investigation is take the sump of and see if the oil pump is okay and the play in the crank/bearings? Any suggestions ? many thanks (I'm in the UK)
The relief spring in the later (8BA series) flatheads is in the pump itself, not in the valley like the earlier models. It looks like you're in for a teardown.
If I remove the Gauge so the hole is open at the back of the block should the oil squirt out?- It just sort of runs out at the moment
If a second gauge reads low, you might consider removing the cam gear to look at that front plug. Otherwise, sounds like you may need to take a look at the oil pump drive gear behind the flywheel to see if it's installed correctly (not backward) and then pull the pan for a look at the oil pump.
So my brand new mechanical gauge seems to be the problem - Hooked up a another gauge and it goes up to 40psi just using the starter (serves me right for buying a £15 cheap gauge) . Thanks everyone for their help
Just for added info—-I was informed many years ago that 10 pounds of pressure for every 1,000 rpm was adequate for a Flathead ford v8. I have not used a filter on any flatheads I have built for my own use or those motors I have built for others because the flathead has what is referred to as a partial flow oiling system that is not very efficient—-was led to believe only 20%of the oil gets filtered and if bypassed or removed from the engine MAY actually show a small increase in actual pressure. I use the old mantra—-oil is cheap; motors are not. I generally changed my oil every thousand miles; maybe overkill but I have never blown up a flatmotor and I have run many very hard. Had a 32 cabriolet highboy that was drag raced and using a lower gear in the 9 in rear ran 80 mph in the 1/8 and next day replace the pumpkin to a 2:75 and continued to run many many street miles. Flatheads Forever!!
I personally believe that the stock "bypass" oil filter system used on these engines is the best choice for these engines because of the way they are used and maintained these days. A member on "The Ford Barn" did a controlled study and found that all of the oil in the engine passes through the filter every eleven minutes. Because of the way the system works, the filter can remove smaller particles from the oil than a full flow system. In effect, you are trading quantity of oil filtered to quality of oil filtered. The way these cars are pampered these days, operated under ideal conditions, and maintained to a standard unimagined when they were new, makes the stock filter the best choice for everyday use.
I think i'm going to run without the filter because it looks a lot cleaner. Nice car - you all seem to have a lot more fun over in the US!
Not to muddy up the waters, but is there a reliable way to externally check the oil volume on a flathead? I'm thinking like checking the fuel volume of a mechanical fuel pump. Could you check it at the same port on the engine that's used for the oil pressure reading? Would the engine's cranking speed be enough to give a dependable measurement?
60 years ago a friend had a similar problem on a flathead Ford found out screen on oil pickup completely covered with sludge.
Ford flathead lubrication is always an interesting topic. Back in '32 the engine developed 65hp, and with regular upgrade the figure nearly doubled for a stock engine at the end of production. Along the way Ford upgraded the oil system several times, the later pumps usually show 50-60 psi on the road. Filters were rare on cars in1932, but Ford went with the industry trend and offered an optional by pass set up. This filter became standard equipment on most models. Some commercial and military models came with a full flow set up., with the extra tapped hole on the rear of the block. In the early 50s the industry had moved on, with full flow becoming the norm. As Ford's new engines appeared, all had full flow. The spin on filer came later. Over the years I have converted three engines to full flow, along with the late model oil pump etc. For me, it just made sense to help the motor live longer
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