501 rear pushrods

[Tom]

Well this is going to be a tough one guys, one rear pushrod from my 501 Camel broke due to bad very bad motor building work by very wicked 'professionals' here in Holland, evil men they are.
The other was a bit slappy on the edges also. I have tried to adjust a pushrod from a 500 but i can't seem to get the heads off.
Somebody has one, uhh sorry two, in his shed or under his bed perhaps?

tomros@live.nl

Thanks, Tom

[EVguru]

Cut the heads off the damaged pushrod then drill and bore out the Aluminium. Get a new rod machined up.

Remember the ends aren't meant to go all the way on, there's room for them to shift if you get valve to piston contact as a result of a broken cambelt.

[norbert]

Hi Tom

remember that the pushrods of the 500 motor are longer than the ones for the 501 because the 478-cilinders are higher! Another diference is the axe of the balancines (spanish ) They are 71mm long instead of 69 (350 and 500) if I remember it well, and the distance washers are put in another order. The reason is that the center of the valves in the 501 heads are more apart to avoid the problem of the fissure between them (still happening ) That means that the puschrods are positioned a bit out of vertical.

I once took the longitudes of the diferent pushrods in mm (over all) the rear ones are more or less 2 mm longer than the front ones, as you know:


500 and 250T: 205/207 (I supose the 250T 205)
501: 202/204
350: 182/184

So if you don´t find a pushrod for the 501 and the broken one is from the rear cilinder, I would try a 500 one from the front

ciao norbert

[Tom]

@Paul: the shifting thingy of the heads of the pushrods is new to me, two of the three don't have a little play in the heads (the front ones don't) and one rear has got some play while the other one broke, so if you say that is normal (if i understood you correctly) i will not replace the slappy rear one!

@Norbert: Thanks for the tip and the measurements, maybe this makes my morini life easier! I have noticed that the pushrods of the 501 are not placed in 100 % vertical position, maybe this could be a 501 weakeness also and the reason that they brake. I am looking for the 204mm one, so if you say the front 500 is 205mm, than hey .. they can also be used.

Thanks guys, you are a good bunch!

[EVguru]

@Paul: the shifting thingy of the heads of the pushrods is new to me, two of the three don't have a little play in the heads (the front ones don't) and one rear has got some play while the other one broke, so if you say that is normal (if i understood you correctly) i will not replace the slappy rear one!

If the ends are loose, then the pushrods are junk and need new Aluminium sections.

The ends are not installed until the Aluminium section hits the bottom of the hole in the steel end, there is a gap.

This allows the rod to shorten if you get valve to piston contact. Hopefully you don't then bend a valve, or break a rocker.

[norbert]

I´ve done about 70 000 km with a 501 motor in my Rocinante, originally a ´81 K, since 2003 including twoo seasons without use.

In 2004 on the way to a concentracion suddenly the rear cilinder stoped working. Did the usual things: taking of the camara of the Dellorto to see if gasoline arrives and a look at the spark. Everything ok. I took of the gasoline pipe of the rear and decided to carry on instead of going back home (the concentration was only a 100 km from home) thinking that the problem must be about the valve sytem. When I first stopped to look after the bike I was a little scared, because in the dust under the motor I found a pendant: a broken motocycle This looked like Voodo to me!

At the concentration I foud this: a broken pushrod. As you see it broke exactly where the alloy part gets out of the steel part.

IM000165.JPG (252.68 KiB) Viewed 9727 times

Twoo weeks before I began to notice a strange high pling-pling sound at idling. There are so much noises with our motors that I decided to ignore it, because I could not find the reason. We had great fun to get the little alloy part out, because during our intents it fell down in the cup for the push rod

I changed it and never had problems with the pushrods again. I think it ist not a constructive problem but just bad luck. To me it looks like a infringement that took its time and finaly has broken. Probably it happened because the twoo parts lost their fixed conection. The pushrod fell apart and did not make any noise.

Once my timing belt broke. My fault because I put one of which I didn´t know how old it was, waiting for a new one. It broke at about 160km/h on the highway. The result was a bended valve, nothing more What a great motor we have! Thanks to Lambertini!!! Obviously braking the belt with the 350 motors the usual thing are bended pushrods. Happening with a 500/501 (in most casas the outlet one) valve is bended

k-DSCI0012.JPG (66.51 KiB) Viewed 9727 times

good luck!

norbert

By the way: The 2015 german meeting again will happen at Hockenheim so probably we will enter the circuit like a few years ago

[Tom]

Hello Norbert,

Thanks to your tip i found a set of 500 '204's' from Hendre of this board.
So hopefully my 501 will be up and running in a very short time!

Thanks again, Paul also, for the help and untill the next time!

Tom Ros

[Tom]

Huh! 204's are 501 stuff, means that Hendre got me some real 501 pushrods, wow!
Lucky me..

Tom