Do any of you have this valve cover screen installed in your stock valve cover? All of the 500 parts manuals show it. Neither my 499cc engine or the two Polish 650cc engines have one in the valve cover.
Ordering parts and wondering if I should order one.
John

I have one fitted John. Its always been there, so I always put it back. I don't think the valve on the filler cap would function correctly without it and you could end up with excessive oil vapour being drawn into the air filter without it and that would ultimately end up in the carb.

Tony

Thanks Tony. If you can, take a quick picture of it installed if it is easy to see with the oil cap removed.
John

jjacob said:

Thanks Tony. If you can, take a quick picture of it installed if it is easy to see with the oil cap removed.
John

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Hi John here are a couple of pictures as requested. Excuse my thumb but I was trying to show you what I meant about the filler cap valve. This is on my 650 engine sitting on a pallet in the garage, so it's easy access.

Tony

jjacob said:

Do any of you have this valve cover screen installed in your stock valve cover? All of the 500 parts manuals show it. Neither my 499cc engine or the two Polish 650cc engines have one in the valve cover.
Ordering parts and wondering if I should order one.
John

Click to expand...

I would avoid using one of these as most that I have encountered have either started to break up or jettison some of the steel wool filling which is not a good thing to have washing down into the engine. It was superseded by the thing that looks a bit like a pipe cleaner and fits inside the rocker box breather outlet.

Toshi I think you are correct. My 1965 parts book shows both the screen in the filler neck, and the brass filter in the hose. The 1975 parts book shows only the brass filter in the hose.

Thanks,
John

Notwithstanding the fact that Toshi's suggestion makes sense and is evidence-based, my current and every other 500 I have owned, came equipped with both items.
I will check but despite having one with a stainless thing that cracked at a weld, I'm not sure they have any wire-wool filling.

I would agree Peter. The pictures on the supplier web sites seem to be just perforated metal (Stainless Steel?) screen.
Was there one on your 650 engine? The parts manual from 1975 would have been 500R builds with the 600cc engine.
There were no screens on either of my 650 engines which were from a 1985-88 build time.
John

fiat500 said:

Notwithstanding the fact that Toshi's suggestion makes sense and is evidence-based, my current and every other 500 I have owned, came equipped with both items.
I will check but despite having one with a stainless thing that cracked at a weld, I'm not sure they have any wire-wool filling.

Click to expand...

Mine is cracked also at weld joint but also filled with wire-wool which is thick and i don't believe it can escape to the rocker area. It think it is good to have.

As I say, I will check mine. It is listed as an oil condenser suitable for 500cc on Axel Gerstl. I am not sure now if one was fitted to my 650 but it was present on the 600. I had a thought being that the 650s came with that strange, plastic "silencer" which I have not seen properly explained and is often removed if the engine is fitted to a 500. Possibly that component supercedes the purpose of the oil screen. Therefore it is not needed on the bigger engine.
Also, I always perceived that the helical, mesh flame-trap was fitted in the air-cleaner end of the smaller rubber pipe on the 500. I see it described as fitted in the metal spigot of the rocker cover on the 650. So a slightly different system there. I have observed previously that the original 500 oil cap has a very fine gauge of spring compared to those, presumably made for the 650 which are available now. As you can tell, this level.of minutiae interests me and I would love to be able to unravel the thinking behind these sorts of details.
Can you tell I am away from home with nothing to do?

I don't think the one on my 500 engine has any wire wool or anything inside? I think it is original as well?

The one on my 650 engine is new last year I think and it definitely has nothing inside, dare I say it but for a pattern part it actually seems better constructed than the original one. Having now publicly stated that! I will probably find it mashed up inside the cylinder head in a few years time

Apologies to Toshi 975.
My old and broken one splits to display metal wool as he described.
The way it's assembled the wool is not really at risk of falling out but he's right...you really wouldn't want it inside your engine.

I am going to order one. I think it will be fine not being 30+ years old.

John