500 cams

michipons

michipons

Hero member
Location
Palma de Mallorca
Hi!

As I am now looking for a 500, doubts are arising.

I understand that S1 camshaft are those from  the Montjuic, what are the standard street camshaft? S4?
If mounting an S1 in a normal 500 cylinder head, is that a reason to have the bike with very poor low range?

The second generation of 500 engine has the balance shaft, but there was another improvement in the cam area... what was it?
As far as I?ve seen, both have this needle bearing in the center of the camshafts...

Miguel
 
S4 is the stock cam, all-rounder that works nicely for what it's designed for.  As with any sports/racing cam, certain deficiancies can be expected at low revs with the S1.  To fully exploit these, hi-comp pistons and a dreadfully anti-social exhaust are required.

Outer cam bearings can be either needle rollers or plain alloy bushes.  I prefer bushes, they won't terminally kill the cam journals when things go wrong upstairs (although buggered cam journals will be the least of your problems in such a case).  They also run a lot quieter than the needle rollers.  I've seen so many bodges in this area it makes my head spin!  These engines definitely have a heat issue, especially around the exhaust valves.  Center bearing is common to all.

A Formula/Atlas oil pump can be retro-fitted to improve oil flow, perhaps a good idea in a hot climate.

Unless you're going racing, a stock engine chugs along nicely.  Not as hairy-chested as a triple, but it can hold its own on small twisty roads, the chassis is brilliant.

Far more important than cams would be a complete carb overhaul and an ignition system that is both reliable and provides a proper advance curve with a consistant idle.

piet
 
sfcpiet said:
S4 is the stock cam, all-rounder that works nicely for what it's designed for.  As with any sports/racing cam, certain deficiancies can be expected at low revs with the S1.  To fully exploit these, hi-comp pistons and a dreadfully anti-social exhaust are required.

Outer cam bearings can be either needle rollers or plain alloy bushes.  I prefer bushes, they won't terminally kill the cam journals when things go wrong upstairs (although buggered cam journals will be the least of your problems in such a case).  They also run a lot quieter than the needle rollers.  I've seen so many bodges in this area it makes my head spin!  These engines definitely have a heat issue, especially around the exhaust valves.  Center bearing is common to all.

A Formula/Atlas oil pump can be retro-fitted to improve oil flow, perhaps a good idea in a hot climate.

Unless you're going racing, a stock engine chugs along nicely.  Not as hairy-chested as a triple, but it can hold its own on small twisty roads, the chassis is brilliant.

Far more important than cams would be a complete carb overhaul and an ignition system that is both reliable and provides a proper advance curve with a consistant idle.

piet
Click to expand...

Great, thanks Piet for the advices... I thought that alloy bushes were only fitted in later balanced shaft engines, and the previous all with bearings... but apparently some earlier engines have also alloy bushes, so it is not necessarily connected?

I am happy with a stock engine, but one of the 500 I have seen was mounted with a S1 shaft, (don't know the reason) and he said that because of that the engine was not good in the low range, being one of the reasons for selling cheaper. But of course, what you say makes lot of sense, open exhaust and good pistons....

Carb overhaul is a must, and the easy part. About the ignition system... any advices? DMC, Sachse or something different? has Red special iginition systems for the 500?

Thank you,
Miguel.

I have seen several, but those are my last candidates, one is "totally" restored (the red one) don't know how or by whom... and the second looks quite original but will need some work done. Of course I am happy of your inputs

I found this one:

https://www.milanuncios.com/motos-clasicas/laverda-500-371447463.htm

And this one:

https://www.milanuncios.com/motos-clasicas/laverda-500-s-316798478.htm
 
You'll find bushes and needle rollers randomly spread over the entire production span.  Every self-proclaimed expert knew better and replaced whatever was fitted with the other bits.  They then proceeded to destroy the top end with haphazard, careless installation of said bits... not adhering to factory oil recommendations and oil change intervals didn't help either. :D

piet
 
Just remember that if you decide to change from standard to S1 cams the head will need grinding to clear the cam lobes and it?s best done before you fit the head and find you either need to remove it or hope you?ve plugged every way grinding dust can find it?s way into the engine.
 
lavgert said:
Hi Miguel,
meanwhile I fear that I will have difficulties in deciding which Laverda model to drive on my next Mallorca vacation ;)
Ciao, Gert
Click to expand...

Hi Gert!

I hope so!! that would mean that I am back to work! and of course, it would be a honour!

Finally after some up and downs and loosing some good opportunities, I have a winner, It is all done except paying. But if no surprises this will be at home in one or two weeks. It is a 500s, frame number 2751. No the best bike, but good price and I hope I have some fun repairing ridding and why not, some experiments! The bike is operational despite I am planning to make some restoration when I have finished the 3C project.

Please feel free to give me your impressions!

Miguel

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aahh! yes, it is true, he actually put a screw to lift it up because he liked it more this way... :-\ Still don't have the bike at home... I have to pay it today!

Do you see any big inconsistencies ?? For me it looks quite original, even with factory tires.

PHOTO-2020-11-27-16-18-47.jpg


 
Paul Marx said:
:D :D :D :D :D

Or a Goldwing.

Paul
Click to expand...
A Trek or a Merida?
The bike looks pretty genuine and unmolested if a little neglected. If the inside is similar it should be ok, keeping in mind what Piet has already said. Due to age it will need refreshing stuff like brake seals etc but a ride will show up any stuff like that. It does look like a good buy.
 
just found this
https://www.ebay-kleinanzeigen.de/s-anzeige/laverda-500-formula-exhaust/1587103824-306-385
 
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