500 Oil flow

[LaverdaIan]

Anyone who has been watching will have seen we had a cam bush sieze and rotate on the Montjuic racer last weekend..
Not sure as to cause yet but does anyone have a diagram, or can advise as to how the oil flow from pump to cams is generated..?

I'll wait here..
and thanks.

Ian

 

[Vince]

Ian I mentioned a cam bearing mod in the race thread written about in Classic mechanic Mag years ago, I found this tech doc from the Pommy club that gives dome detail PLUS lots of other entering 500 info as well as triple info, well worth a read.

https://www.iloc.co.uk/membership-services/benefits/library/iloc/technical-1/technical-topics-updated-2010/383-1-engine-gearbox-clutch-updated-2010/file

 

[sfcpiet]

Ian,

The oil flow is almost identical to that of the triples, just without the cooler. The oil is pumped to the gallery at the cylinder base, from where it is divided. One part is directed to the centre main bearings from where it is spat into the slingers, supplying the big ends. The pistons and liners are lubed by oil flung from the big ends. The other part rises up the stud bores directly to the cam bearings. Excess from there lubes the cam lobes, followers and valves.

piet

 

[Gareth99]

Oil flow up the barrel stud holes can get blocked by crud and I've seen some top ends where there is only one clear oil feed to the cams. Luckily the flow was so high that the oil went everywhere it needed and with open needle bearings that was enough.

If you're using bushes, you need the oil in the right places - a blinding glimpse of the obvious.

My first 500 race bike had the galleries blocked in the cases, and external oil lines from the rear of the barrels up to the head. The cam ran in a bronze bush that extended out through the cam cover (where the rubber grommet sits) and so the oil went directly into the bush.

I'll send a photo to show you what I mean, and it worked a treat until the bottom end blew up at Mallory Park.

 

[LaverdaIan]

Thanks Piet and Gareth.. motor has not been fully apart for some time, may be a clue here.
I will keep you posted as we go..

 

[Preben]

Giuseppe Andregetto makes some upgrated cam buckets for the 500. I bought this from him for my 500 Formula. I just finished the restauration of the bike and have yet no experience of the reliabilety of this conversion. His conversion is much like the cam buckets used on the triples. Giuseppe explained problems with the original type 500 buckets. They are to soft and will loose their shape when you tie down the cylinder head.
Regards
Preben

 

[Dellortoman]

Hey Preben. I think you mean cam bearing blocks, not cam buckets.
The 3 cylinder engines have a similar problem. Red makes new bearings for those too.

 

[LaverdaIan]

Hi Preben,
I have a set of those blocks for my Formula also.. they are a good alternative to the original units.. I have done my first shake down runs with the Formula motor and no problems found.. I would like to get another set of these for the Montjuic now..