The Stovebolt Site Forums The Shop Area Engine Shop High volume oil pump 235???

I'm curious if anyone knows the part number and price of Melling's hi-volume oil pump for the 235 (the block is a '57) or any other make/model. Also, who makes the best aftermarket water pump (besides GM, of course) for same engine. Thanks in advance

-GLC-

Usually high output pumps are unneeded for the 216/235/261 straight 6s because the RPMs and power levels don't warrant it. Proper bearing clearances and a good stock pump will keep the pressure between 20 to 45 PSI. I'm doing a lot of research now into distributors and oil pumps for 235s because of a problem I'm having. Check out my 'lost oil pressure' thread for worst-case scenarios.

From what I've heard in the past few days, high-output pumps may cause the gear to shear off the distributor shaft, or other similar problems. Supposedly the distributor shaft and drive gear aren't designed to transmit the higher torque required to turn a high-output oil pump.

good luck

chip

Chip, I'm going the modified 235 route...
You know, Mallory elec. ignition, Clifford 4bbl intake and headers, mild performance cam. I'm not sure if the cam gear shearing would be a problem...I was just curious if there were high volume pumps available and what the pros and cons would be. Same goes for the water pump...I'm running an electric fan so stock fan speed isn't a problem...Thanks for writing back!!

-Geff-

One thing that I have learned is that the stock pump in a 235 will pump more oil into the valve train than will drain back to the pan at speeds over 4,000 rpm.

I built a similar 59 235 last year with the 848 head, stainless back cut exhaust valves, seats, shaved, decked, v8 seals, 60 over, moly rings, balanced, Howard m4f cam, full pressure system with remote filter. The stock pump delivers 45 true lbs of pressure hot with 30 wt and runs 170 degrees. I would like to assure you once again that your engine does not need a special high volume pump.

iketheband, High volume pumps for 235s are only used for racing. When racing you want greater clearances for less friction therefore you will need a higher volume pump to keep the oil pressure up. A Mellings pump is built stronger then a stock but works the same as stock. From what you said that you are building, I don't think you will be running it for the track. If you install a high volume pump it could give you problems in the future if you don't increase the clearances, it will continually be blow out the bypass which can cause air to build up in the oil. High volume does not mean high pressure. Your bearing clearances are what dictate your oil pressure, that and what the relief bypass is set at. To high of oil pressure can lead to problems also.

Oh, by the way. Great Question. Now if I could only figure out what went wrong for Chiphead and how one gets water in their tranny.

I'm no expert on fluid dynamics, but if the pressure is ok then the volume must be fine or the pressure would drop off. Ok, lets hear from the board engineers on this Some Chevy builders have used GMC pumps , which have longer gears and more volume.I have used Mellings and Sealed Power pumps, they had the same size gears as whatever pump was already in the engine.
Running oil psi higher than necessary for proper engine lubrication only serves to waste power, heat up the oil and stress out the pump drive.Of course the trick is to know the minimum pressure your engine needs.
Small block Chevy guys like to install a high volume pump, like Chip says they beat up on the pump drive gears.Back 20 years ago, before drysump oiling became common on circle track engines,350 Chevy engines devoloping 600 hp at 7500 rpm back then could survive a 300 mile race with as little 60 psi, using a stock Z-28 oil pump.Generally, engines requiring high oil pressure for survival, have a poorly designed oiling system.
And to make Chiphead more nervous, certain types of cams cast iron or billet each require distributer gears of the proper metal for long life.

Mind telling me what HEI gear I need with the M4F cam, Oh great one?

Like was said before, the high volume pumps maintain the 30-60 PSI with more volume and looser clearances. The high pressure pumps have the relief spring set higher for 40-90 PSI (pontiac), but with 'standard' volume for normal bearing clearances. Exact pressures and volumes needed vary widely depending on engine family, and any modifications done to a particular engine.

The oiling on a 235 is adequate at best. Strange oil return passages, oil pans with almost no baffles, inefficient pickups, fat, wide bearings with large diameters, goofy valvetrain oiling passages, etc. I suppose its possible to pump a 235 pan dry in some situations.

Chip, oh Mister Pontiac man, back when I dragged raced,some called Pontiacs "track oilers" cause when they blew up ,a Pontiac carried an extaquart of oil to mess the track more than a Chevy or Mopar.
I read Chevy switched to cast cams around 1954 so most all 235/261 distributers are ok for cast cams. Is the M4F a cast cam? i have no idea.I suspect it may be something that really doesn't make much differene

Yup, 326-455 Ponchos usually carry 6 quarts of oil. Don't know why that is, though. And in all fairness, JoeH is the pontiac man, I'm just the acolyte. Although with all this upthrust and downthrust distributor mumbo-jumbo, now I know why the dist shot out of my Pontiac Lemans when the clamp came loose. Must be an upthrust.

Anyway, we're stepping on Ike's thread. Ike, what setup you going with, and what vehicle?

chip

Chip, I have a '54 3100 Deluxe Cab (5 window)...it's stock as far as body and interior goes (if you don't count the stainless tilt column and Dakota Digital guages). Underneath is a different matter all together...the front end is a Mustang II with coil-overs and tube A-arms with a Wilwood disc brake setup and Flaming river rack and pinion with Thrust D Torquer wheels covered in BFG's. The rearend is a 1990 Camero with 3.42 Richmond gears and a Torsen posi unit (drum brakes back there for now). The trans is a Saginaw 4spd with the 3.11 low (so I've been told, does anyone know where these "grooves" are that determine what type of Saginaw one has?) and the engine is a 1957 235ci with Clifford Performance 4bbl intake and exhaust headers with Edelbrock 500cfm carb. The engine's been bored .060 over with forged TRW pistons, the cam's a mild performance hydraulic from Howard's, the head has been rebuilt with no-lead valves and seats, and on the electronics end, I'm running a Mallory Unilite mech. adv. with Pertronix Ignitor elec. unit to replace the points. The cooling is taken care of with an electric pusher fan on the front of the rad. so there is no concern with the '57's water pump hitting the radiator. That's all, nothing too exciting