Dry Sump.

[1 more spyder]

Has anyone seen an external ( belt driven ) oil pump arrangement on the 2 L engine? Arrangement used for a dry sump system is kinda' what I'm thinkin'.

Regards, Darrell

[spiderserie4]

alfa actually offered a dry sump conversion for formula cars.
A thread here might be of interest
http://www.alfabb.com/bb/forums/engi...-dry-sump.html

[Gordon Raymond]

Darrell,
We experimented with these at Ausca years ago. First to avoid failing oil volume at very high 8,000 + rpm. In that we were successful. With the gears and pumps of the period, the system drained off too much power, so we used the system instead to lower the engine in the chassis. Regulations caught up with this first time out, as "engine relocation" and that use was also shelved. The next use was oil cooling pistons with squirters from below on the GTA jr. 1300 engine that suffered from inadequate piston quench area with high compression and high rpm. This also worked, but power loss driving the system was not recoverable with this engine. Ausca built 2 or 2.5 of these systems, I believe the last intact system was sold by Karen McGowan some years ago.
For formula car use, to lower the engine height, and center of gravity, this is a useful idea.
With more modern pumps with lobed rotors replacing geared pumps, this might be useful for some applications, but it is a VERY expensive experiment, and not worth the effort or money unless you have an engine that is still building power and torque past 7500 rpm. The NORD head design and valve angles work against this possibility.
Just my opinion from my experience. I built a custom pump for a customer in Norway that runs his 2L past 8000 rpm often. His solution is use an Accusump system to provide oil volume beyond the pumps capacity for the brief instances when his engine lives in that operating range. A much less costly solution. Below (I hope) is a link to a video of some qualification runs.

1okt rudskogen Qualify.mp4 - YouTube

[1 more spyder]

Thanks for the reference to the thread. Seems like a kinda' interesting mod but as G. Raymond indicated seemingly took considerable engine HP to operate the pump. Kind of defeats the purpose but my question has certainly been answered. When it's time for the next build I'll just search out the best pump available ( Think Gordon supplies these as well ).

Thanks, See ya next time I have an arcane question.

Darrell

[genericwood]

There is plenty of modern experience with dry-sumped Alfas, and not only on formula cars. Lots of SCCA race cars built in the last 25 years used dry sump systems. The modern pumps don't require an inordinate amount of power. A portion of the power loss can be regained by pulling a vacuum on the sump and reduced windage. And don't forget, the stock pump takes power to run also!

The cost of a complete system is prohibitive for most applications. But you can still buy a new sump for an Alfa block. If you wanted to just run an external pump, but not as a dry sump, it should be possible. I have considered using a single-stage from a dry sump pump to replace the stock Alfa pump, but retaining a wet sump.

If the vintage rules I race under didn't prohibit a dry sump, I would run one!

[PSk]

If the oil is still contained in the sump does it matter how the oil is used or pumped to break a wet sump rule?

My point is as the Alfa 105 series sump is so large, could you not seal off above it and make a dry sump system that sucks the oil out of this area and puts it in the sump below (after going through an oil cooler). The sump is already well baffled. Oil pump could sit above one of the sumps wings ... in fact you could weld mounting brackets on to the sump.

Thus you would get your vacuum and have the oil stored in a nice and lower place. Only negative is it is still located at the front of the race car.

A very expensive modification though ...
Pete

[genericwood]

Pete, that's an interesting idea to use the original sump as the dry sump tank. But somehow I think that the presence of a scavenge pump would cause the tech inspectors to rule this an illegal dry sump system.

[Tifosi]

Query:
If running one off the crank pulley is too much of a power draw, would it be more benificial to run it off the differential input flange?

I know certain series of racers use that configuration by preference or design, though they are making gobs more power than the hottest Alfa I4 could.

Thought process being (as I understand it anyway) it utilizes the gearbox just the way the differential does: variable selectable ratios to ensure greater ease of rotation.
In 1st the propeller shaft, and thus the ring, pinion and pump are easily turned with progressively greater resistance as gears go up.

Downside is working out the pulley drive ratio to allow adiquate flow at low input revs yet not go stupidly overboard at higher revs so at to not present more mechanical drag via the pump than neccisary. (perhaps a centerfuge clutch drive arrangement on the pump proper)

Well that and actually moving oil when the car is sitting static. (an electric auxillary pump motor could likely help with that)

Flip side is that it would continue to move oil regardless of engine even running or the transmission even being in gear as long as the car was physically moving.

Might be an interesting way to prime the system pre~startup, and in endurance races may save a bit of fuel by giving safer conditions in which to shut down and coast on even very subtle downhill grades.

The plumbing would offer a bit more volume too.

Again, just asking.
It kinda makes more sense (to me) than direct driving off the crank proper.

[Gordon Raymond]

The way at least one builder I know did this (illegally) within Erik's requirements, was to use the existing pump to fill a remote 1/2 gallon header tank, with an electric driven remote hydraulic pump that actually oiled the engine. This worked, much like the Accusump system, but was always "on".
Ferrari transaxles have contained oil pumps since the '50's, for the sole purpose of transaxle lubrication. These do increase transaxle power draw.
From my experience.

[genericwood]

I can't think of any reason driving the pump off the diff would have any advantage. And the disadvantages are numerous. The engines oil pressure/volume requirements vary with engine speed, not vehicle speed.de

Gordon, using the stock pump to fill a reservoir which then feeds an external pump is interesting. And I don't see how it would constitute an illegal dry sump. The sump is still very much wet! But if the stock Alfa pump is adequate to keep the reservoir filled, I wonder why the need for an external pump? On average, the external pump would be limited to providing the same volume of oil delivered by the stock pump, otherwise the reservoir would drain and the sump would overfill. Was this regulated somehow in the application you saw?

[Gordon Raymond]

Erik,
This technique is used by John Hajduk at Motorkraft Ltd for vintage racing Ferrari's.
The idea is to provide oil volume beyond the sump pumps ability, or in situations where it might suck air. There are check valves in the system. A return shut off AE valve avoids the system overfilling the sump on shut down, and (as used to happen with my Ferrari 500TRC), filling the cylinders, and locking the engine!
System works well. It has many applications.

[Alfar7]

Using an internal oil pump to scavenge the sump and keep the reservoir full isn`t a new idea, even for stock Alfas. The pump feeding the reservoir tank has no resistance in the feeder lines to reduce flow volumn like a pressure pump has to overcome, so the reservoir level exceeds the pressure pump`s demand.
The two chain driven internal oil pumps in the Montreal engine do that very thing. One pump scavenges the sump (which is a fairly shallow dry sump design), and the other pump provides pressure to the engine drawing from the reservoir..

With the well designed windage trays available and the excess capacity of the 4 cyl oil sump, using an external dry sump system only increases complexity and adds another failure point to a race motor.
The factory oil pump`s capacity to flow can be increased with a little port work on the oil exit from the gear chamber.

I have seen too many belts slung off due to rubber lumps being slung up from the race course and finding the belt.

I`ll take the wetsump with accusump design over drysump systems every time. Both less weight and complexity.

[1 more spyder]

So much great information available every time I have a query. The thought of a dry sump derived system has now flown from my mind. When the next need to open up the engine arrives I will have the right answer for improved oiling and reliability. Thanks to all and thanks for this forum in general. I recently purchased a 1980 FI Fiat 2000 and as a result of searching the Fiat counterpart to this forum, I've found no comparison. About 8000 members and a level of knowledge, where very helpful nevertheless, does fall far short of the knowledge and general expertise of this site.

Much appreciation and regards, Darrell

[Gordon Raymond]

Well said RJ. I could not agree more! The more complex ANY system becomes, the more important redundant back-up systems become, which just makes everything worse. Failure of a simple system requires simple diagnostics, and usually a simple resolution. In racing, or with vintage mechanicals, there are plenty of problems right there with no need to add complexity.