I dropped the oil pan on my ”˜30 2 door coupe yesterday. Everything looked pretty good except the screen on the oil pump. The main screen looks intact, but there appears to be a secondary screen over it that has broken apart. (see photo).
I need to understand more about this, and what to do to get things working.
What you see is the complete screen. That is the first design oil pump and it used what we call a "half moon" screen. The wires that hold the actual screen in place are broken. I suggest that you get a new vane oil pump of the second design which uses the "flat bottom" type of oil screen. You can also go with the later replacement gear type of oil pump as well.
Also thanks for the picture... I can see the little clip with the square nut in the upper tight of your crankcase... my oil line clip and nut were laying in the bottom of the oil pan and I wasn't sure where they went 100%. Some previous owner took out the screw from outside and released the parts into the pan... oops!
I have a few NORS gear and vane pumps if you decide to go that route send me a pm.
Dave I purchased a gear pump from Dave for a great price and it works better than any vane pump I’ve had but in all honesty, I never had a new vane pump either. When the car is cold and I first get on the road, oil pressure will be 22-25lbs under rpm. Once hot it will run around 13-15lbs under rpm. With a newly rebuilt engine I really like the higher pressure. I figure it has to be delivering more oil to the top/valve train and to the center main. Of course all parts of the motor too but the troughs can just flow right over and the dippers will only pick up what they’re capable of. More flow into the center main and up to the rockers is more dependent on the oil pumps efficiency. I’m no expert on the 194 so I could be wrong.
The only part on a 1929 that is getting the full pressure is the center main bearing. On a 1930-1931 the front main also. The oil trouhs and rocker arms get low pressure.That being said the oil flow to all parts is more constant than with a vane pump......if this is a good thng? and some may disagree with me.
Any pump that results in oil flowing to the end rockers is okay. These engines do not rely on the oil to do any cooling and have open ended tubes in the lubrication system. As long as you have positive pressure at idle all should be good. Besides the only "benefit" of higher pressure is "peace of mind". The down side is that it takes some horsepower to produce the higher flow and pressure. A '30 engine doesn't have a lot of horsepower to lose.
It is possible to obtain a small piece of hardware cloth similar to the material you are missing. Form it around a ball to replace your damaged screen. It is a bit of a challenge but doable and gives a sense of accomplishment when the oil screen is restored.
Besides the only "benefit" of higher pressure is "peace of mind". The down side is that it takes some horsepower to produce the higher flow and pressure. A '30 engine doesn't have a lot of horsepower to lose.
I agree with the above statement and I prefer the flat bottom vane pump over the later gear pump on the 1929-32 engines.
Actually from Bruce listed below, he is local to me here in VA, actually visited him a few weeks ago :)
Options: *Gary Wallace at Early Chevrolet Parts (314) 293-1991 Missouri *Lonny Ekstrand at Stanleys Parts (817) 478-7265 Texas *Bruce Bugay at bwbugay@aol.com (Posts on here as chevy b) Virginia *eBay Hunt Down and Watch for one[/quote]
AACA - VCCA - Stovebolt - ChevyTalk Love the Antique Chevrolet's from 1928-1932 The Beauty, Simplicity, History, and the Stories they Tell
I have a few but never installed a replacement gear pump. I have probably (have records but too lazy to check them) driven vane oil pumped Chevrolets over 30,000 miles in the last nearly 50 years. I average over 1000 miles each year on VCCA tours. Yes, I often drive my '51 when I want to get lazy or drive over 50 mph. So far I have not had an oil pump problem with the vane pumps. So exactly why should I want to change them?
BTW, the boss sent in the passport miles for the '28 Coupe and got back three little plaques to display. The Louis Chevrolet VCCA Touring plaque that is centered and a "Veteran" that displays below and "5000 miles" that shows above it. The total was 5460 miles and we didn't always get its passport stamped. This is for information only and not to derail the discussion on oil pumps. So please just consider going on a VCCA tour with out a posted comment.
There are many possible ways to duplicate the half ball shape.
Best is find a rigid, solid ball (croquet anyone) that is about the right diameter. With good gloves and a small hammer, push, tap the hardware cloth into the desired shape. It will wrinkle and bunch up places so you may have to either bend individual wires or clip them so they conform to the desired shape. Once in the general shape you will need to trim the open edge to fit the solid screen base. Then crimp, solder or tack weld the half ball in place. If the inner screen is damaged you might have to replace it as well. It should be a little easier to shape but you will end up with creases as the wire is forced into smaller shape. That is okay as long as the screen remains intact without holes. A few overlaps will not reduce oil flow enough to be a problem. Sealing to the base can be a bit tricky but careful soldering or crimping can minimize places where crud can bypass the screen.
A little more complicated method is to push the flat screen into a pipe with the correct (or nearly correct, smaller is better than larger) ID. Just remember that you will be expanding the screen openings so you have to start with screen with smaller original opening.
The best is to find or make two molds or dies (male & female). Then using a press squeeze the wire between the two to get the desired shape.
The outer screen was supposed to help keep the "ball" from collapsing. As the screen plugs up with junk and sediment it will start being sucked in. If enough junk forms in the pan it will get to a point it will restrict the oil flow. When I was cleaning out the bottom of the 29 conv sedan the outer "hardware cloth" type helper was gone and the screen was squished into a very small glob by the suction. I took it off and carefully inserted some mechanics wire down in it to help it keep its shape. I agree with JYD the vane type pumps are just fine. Make sure it is the 30 to 32 with the bigger impeller depth and also drill out the connection in the block to upgrade the fitting from 1/8" pipe to at least 1/4" pipe and use 3/8" copper pipe from the pump to the block. Car now has 12 to 14 psi at idle and 20 to 22 psi at speed - had 0 psi before. Deb just had eye surgery so Rosalie and I took it out on a tour with the Skagit HCCA last Saturday. She knows a lot of those people and they were in our area for a tour.
My question is: do I need to remove the oil pump from the engine block? My fear is that I’ll take something apart and a gazzilion springs and parts will come flying out. It looks like maybe 2 or 3 bolts hold it on? Thanks!
