Homebuilt drysump pump for radial engine

thought some of you might find this interesting....the guy is building a 9 cylinder radial aircraft engine that uses VW Type I pistons and cylinders....I'm guessing the plans came with the plans for the pump as well...hmmm wonder if they sell them seperately ???

Badass mike. always thinking....always thinking

FINALLY you posted something useful!




Unlike me, I have yet to post anything useful.

They would have to cheaper than the Autocraft ones like I used in my stroker four and work better too. That pump could draw a 10 inch vacuum in the crankcase at 6K RPM and that equals free HP!!!

One guy, Jappe, here in Finland have already done them.

QUOTE (914Timo @ Nov 2 2005, 11:16 PM)

One guy, Jappe, here in Finland have already done them.

Cool, I am still looking for a good DS type 4 pump.
Unfortunately I now only have the choice between a $99,-- Schadeck CB pump with tiny 21/26 gears and unsupported by bearings or the € 800,-- ($ 1000,--) remmele pump with nice 30/36 bearing supported gears (besides the ultimate : a $1.500,-- Autocraft pump)
There is just nothing in between...

What are the costs of this one (if it is available for sale)?

Thanks,
Walter

QUOTE

What are the costs of this one (if it is available for sale)?

Sorry. I have no idea

But, Jappe is very nice guy and I think you should ask him. Send him e-mail to jpr_vws@hotmail.com

If you like to see more of his works, CLICK HERE

He has/had 914 and have been here too. Not for a long time. I am not sure if he have sold his 914.

Very interesting find, Mike.

I'm still trying to figure out what this guy did. A few questions for you or anyone else :

1) What supports the driving shaft : just the bores that go through the sections ?

2) How do you think this shaft is sealed ? Something similar to crankshaft end seals, perhaps ? Seems like there has to be some oil sqeezed into the bore that supports the shaft (to reduce friction) but not too much (or oil would leak out.) I gather that for the stock oil pump this isn't really an issue, since it's inside the engine.

Sounds like a very cool idea to re-use common oil pump parts.

I just had a strange idea about a cheap DIY dry sump setup. Please tell me a) why it's crazy and wouldn't work and/or how many people have already thought of it...

The idea would be to use the oil pump in the engine as the pressure (oiling) pump, and merely adapt a fitting to the pickup tube that could pass through the oil pan to an external oil tank. The oil tank would be higher than the pump, and so keep it primed by gravity. For getting the oil out of the pan and up into the tank, a simple electric pump could be used; there's really no pressure demand on this pump, it just needs to keep the pan sucked clean. For disaster prevention, I suppose a level sensor in the tank and/or the oil pan could shut off the engine if the oil isn't being delivered properly.

OTOH, all that shiny metal in the other guys DIY pump looks pretty awesome...

QUOTE (jsteele22 @ Nov 3 2005, 02:27 PM)

I just had a strange idea about a cheap DIY dry sump setup. Please tell me a) why it's crazy and wouldn't work and/or how many people have already thought of it...

I was thinking about the same thing. It should work just great as long as the scavange pump is bigger/faster than the pressure pump. That will be the challenge.

-Ben M.

QUOTE (jsteele22 @ Nov 3 2005, 03:16 PM)

Very interesting find, Mike. I'm still trying to figure out what this guy did. A few questions for you or anyone else : 1) What supports the driving shaft : just the bores that go through the sections ? 2) How do you think this shaft is sealed ? Something similar to crankshaft end seals, perhaps ? Seems like there has to be some oil sqeezed into the bore that supports the shaft (to reduce friction) but not too much (or oil would leak out.) I gather that for the stock oil pump this isn't really an issue, since it's inside the engine. Sounds like a very cool idea to re-use common oil pump parts.

the "drive" shaft goes thru all of the gears, if you look closely at one gear for each section, it has a slot in it (broached)....

for sealing, there are O-rings as well as seals similar to lets say the output shafts on your transmission...

an electric pump could work, but I'd think you'd want it to vary in RPM along with the engine......

What's the flow rate on the stock pump? I think the 911 pumps are typically sized so the scavenge pump has 120% of the flow rate of the pressure pump. You don't need to have the scavenge pump change speed with the engine. One can make an argument the pressure pump should be engine driven, since you want oil pressure to go up with load, and load is (roughly) going to go up with RPM (better to actually have the pressure pump be load sensitive). However, the scavenge pump is just trying to move oil out of the pan as quickly as possible to the tank.

Note that the scavenge pump will routinely run dry, so it has to be self-priming and shouldn't overheat if run dry.

QUOTE (lapuwali @ Nov 3 2005, 03:45 PM)

You don't need to have the scavenge pump change speed with the engine. .... However, the scavenge pump is just trying to move oil out of the pan as quickly as possible to the tank.

The scavenge pump has however a noticeble side-effect that benefits power, especially, or better: only, at higher revs: it creates a vacuumpressure in the case. That doesn't happen if the scavenge pump has a steady, low-ish rev...

It's true that the scavenge pump can't run behind the supply (feeder ?) pump. But one big advantage is that it only has to pump at a very small pressure differential : just overcome the viscosity of oil in a fat tube and raise it a foot or two, as compared to the supply pump that has to force oil through a network of tiny passages. So, CASOB that I am, I figure there has to be a simple inexpensive option out there for a scavenge-only single-section pump. The kilo-$ stuff for racers seems way, way over-designed for this humble task. Maybe a diaphragm pump ? They are self-priming, run dry, and are reliable. Don't have a clue what kind of flow rate we're talking about, though. Anybody know ?

Hi everybody!

Timo mailed to me and asked if I could make more those pumps in reasonable price. I don't have exactly that model anymore, bub I can offer 2 piece of stage 3 pumps for vw engines.
-It will fit straight in its place in block and needs no modifying at all
-Aluminium parts are AL6082, gears and axles are CrMo. Gasgets are NBR O-seals
-Gears are 38mm long, 3-stage model need one extra suction tube in to the block f.e.x. in that usual T-2 and T-3 oilfillerhole.
-Fittings are G3/4" in suction and G1/2" in pressure side
-If you use Porsche 993 Turbo pistonsquirters, the pressure are about 2bar without accelerating and about 5 bar in highwayspeed with warm oil
-Generates underpressure to 0.3 bar if block are properly sealed and breather uses backpressurevalve

Here few pics about pump.







Here is that second scavening plate in "Oxyboxer" block




If somebody are interested of these pumps, please mail to me at jani@aircooled.fi

I like that set-up. How much?

-Britain

840€ (euro) + shipping from Finland

Still mucking around at the cheap end of the spectrum, I came across something interesting. The mid/late 1980's Honda Accord has an oil pump that is a removeable unit : pulley, shaft, seal, bearings, and gerotor style pump in a bolt-on housing which inserts into the engine block. Looks like all it would take to use is to machine out a block of aluminum with intake/outlet ports and make a bracket -- much, much easier than machining the actual working parts of the pump.

Anybody know if there are other makes of car with this kind of oil pump ? (Most seem to be driven directly by the crankshaft.)

My thinking is to use this as a scavenge pump, and keep the stock oil pump as the supply pump. I have no idea what the rate of the Honda pump is, but that can be tweaked by changing pulley ratios.

Here's a pic :

I just came across some specs for the Accord pump. At 5500 RPM, it pumps 40.3 L/min. I don't know what a T-IV engine pumps, but for a Suby EJ25, the figure is 47 L/min at 5000 RPM. So the Accord pump would have to be driven a little faster. It would be nice to find a pump similar to the Accord's, but w/ a little higher pump rate.