[spmdpm]

I put the sump back together today and was wondering - what function does the diaphragm part no 106.00.01.204.00 (see attachment) perform? I'd be interested if anyone knows.

 

[tubut]

I would guess that, since it is a wet sump engine, the diaphragm prevents oil from splattering back up into the block and thus keeps more oil in the baffled area where it gets collected by the pickup tube.

 

[Gordon Raymond]

um, where's the attachment?

 

[tubut]

Here's the page from the parts manual showing the diaphragm at the top:

 

[DPeterson3]

I would guess that, since it is a dry sump engine, the diaphragm prevents oil from splattering back up into the block and thus keeps more oil in the baffled area where it gets collected by the pickup tube.

The 2600 is a dry sump engine? I must have missed something.

 

[tubut]

The 2600 is a dry sump engine? I must have missed something.

Actually I missed something. It is a wet sump and I had started the sentence with something too wordy that initially read "not a dry sump engine." Thanks for pointing this out -- I corrected my post above.

 

[twoliterlover]

Not a dry sump, but good idea!

Don, you can see that the 2600 pump "sucker" goes into the oil in the pan, and it in no way has a "dry sump". However, wouldn't such an arrangement to limit the oil push up into the block be a great idea on a 102/2000 engine! :clap::clap: On extended and hard cornering the oil in those engines is pushed by tangential force entirely to one side and it piles up into the block so the sump end of the pump ends up sucking air instead of oil. I have NEVER been able to run laps at the Seattle track (Formerly Seattle International Raceways; now Pacific International Raceways) without starving bearings for lack of oil because of the pump drawing air, and because of that have had to rebuild a lot of engines.:cursing: I have always hoped to find a dry sump like there is on the Sportiva. I know the 1900 Matta (i.e. Alfa jeep) had a dry sump too, but the crankcase was weird. Anyway, the next time I rebuild a 102/2000 cast iron two liter engine I will fabricate just exactly such a sheet metal piece between the pan and the block. Might be just what I have been searching for during the last 40 frustrating years. I have never worked on the bottom end of a 2600 engine, so I never realized how Alfa found an easy way to solve that drawback of the 1900 and two liter engines. :clap::clap::clap:

 

[AlfistiSA]

I know it as a windage tray, I have them in my 750 and 101 engines. Easy to make, installs on 2 brackets held under main bearing cap nuts on opposite ends of the block.

Stops oil surge out of the pan, helps to de-aerate the oil returning to the sump and cuts down on the parasitic drag of the strings of oil hanging off the spinning crank.

Gordon Raymond has made some fancy GTA ones on other threads.

Ciao
Greig

 

[spmdpm]

Don't know what happened to the attachment. I tried to convert it from a PDF attachment to a JPEG inserted image and it seems to have disappeared - sorry.

But thanks for the answers - it's always nice to know what something does!

 

[twoliterlover]

Even an old dog can find a new bone!

I feel "so soon old, and so late smart" when I suddenly come across something as simple as a "windage tray" to solve such a long nagging problem. I have some vague memory of having heard that word, but never realized what it was or why it would have been so wonderful all these years. Maybe Myron Cottrell of the High Performance farm (I guess that is what HP means to him?) who finally perfected the spin on oil filter for 1900 and 102/2000 engines to include the filter saving pressure relief spring on the intake side might want to construct some of these for us. Let's all ask him. If he does one, it will be perfect. Myron Cottrell = [email protected] in Chaska MN.

 

[PSk]

I feel "so soon old, and so late smart" when I suddenly come across something as simple as a "windage tray" to solve such a long nagging problem. I have some vague memory of having heard that word, but never realized what it was or why it would have been so wonderful all these years. Maybe Myron Cottrell of the High Performance farm (I guess that is what HP means to him?) who finally perfected the spin on oil filter for 1900 and 102/2000 engines to include the filter saving pressure relief spring on the intake side might want to construct some of these for us. Let's all ask him. If he does one, it will be perfect. Myron Cottrell = [email protected] in Chaska MN.

I must say I'm a little confused. Everybody I know knows that baffling your sump is required to track/race your car ... I guess not all cars require this but surely after the first engine failure this was considered, especially as you appear to know the cause.

All that is required is that you enclose the oil pump pickup with sheet metal. To allow oil access you drill holes in that sheet metal. The number of holes will control how fast the oil can flow away from the oil pump pickup, so not too many.

Problem solved and your car can pull big cornering G's and the oil cannot flow away fast enough not to supply the oil pump.

You will need tin snips, possibly welding gear, drill and a free weekend to do this and then problem permanently solved. Designing this addition so the sump can still be removed can be one of the challenges.
Pete