Clatter

Maestro, SEI-V
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72degrees
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Re: Clatter

Post by 72degrees »

Just as well you had a look inside. I've never heard of problems with a cam follower (for Norbert = ventilstossel ?) on a Morini before - at least on 350s. Evguru reports they rarely show any wear.

My hill climb engine rebuild featured shells supplied by NLM but that's a 350 so perhaps a different size? Seems OK so far <touches wood>. Timing side roller main bearing is a common 'tuning' mod. Lightening and 'balancing' the crank has been done by at least one person.

You might consider a 'hotter' cam if the 501 is running an Excalibur J cam but, as far as I can see form the Dutch Morini club list, you may already have a much sought after L5!
norbert
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Re: Clatter

Post by norbert »

So you meen the cups or the rods?

Here you can see some worn cups with pitting that I used for a trophy for the "Stammtisch of the year" (Stammtisch means the table of the tribe) given to the Stammtisch that made the most km to come to the meeting.
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I once had a broken rod on a trip. Suddenly one cilinder did not work. The aluminium rod was broken just where it enters to the lower steel part. The rod fell aside and did not make any noise at all, just the rear pot refused to work anymore. Went on to a meeting 60 km with the front one and then found out the reason.
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There was some kind of Voodo happening. When it happened I stopped to do the usual things (looking for sparks and if the gasoline enters to the carbs). Both things were ok, the motor started on one cilinder without problems. And then I found this little broken bike dirctly underneath the motor in the dirt! :shock: You can imagine that? I was realy disturbed! I decided that there must be something wrong with the valves, took of the gasoline from the rear carburator and went on 60 km to the meeting, where I found out the reason of all. The little pendant I still keep together with my minature Morinis :wink:

Later I remembered that for some days before I have noticed a new sound like a very a high but not loud plingelingeling, without any idea what it could be. The truth is that I allways wonder how diferent theses motors may sound :lol:
Last edited by norbert on 05 Jul 2017 22:37, edited 4 times in total.
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72degrees
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Re: Clatter

Post by 72degrees »

norbert wrote:So you meen the cups or the rods?
Cups.

I've had a rocker strip the thread on the adjuster with comedy noises results, but otherwise no problem with the cups or rods - yet. Now I'm wondering if the mechanical noise form the project engine might be cam followers. They looked OK considering the state of the big ends on that engine. I'll be changing the oil for the first time since the rebuild before the next event, so I'll be checking the filter very carefully.
norbert
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Re: Clatter

Post by norbert »

I think usualy there may be some pitting where the cup is in contact with the cam. It´s the first time I hear of a broken cup (well, there´s always a first time). Normaly you have a light mark in form of a ring, I guess because the cups are turning around. But I don´t see a reason why even stronger pitting should afect directly the shells of the big end. If its realy broken, then there must pass some parts the oil"filter" to come to the shells.

As I understood Pedro the problem and noise came up suddenly. So that may have been the broken cup. Maybe the problem of the wasted shells is a thing apart :roll:
Well thats pure especulation, don´t have that much idea at all :wink:
pedro
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Re: Clatter

Post by pedro »

The part that has failed is the walls of the follower, where they fit inside the crankcase, all four were a very sloppy fit, but one had broken up completely on the walls of the part where the pushrod sits, I will need to get the crankcase wear lined back to original spec, I think that was the first failure at Cadwell then bits of metal were flying about which led to the big end going, it will be interesting to see what the damage to the crank is, but that will have to wait.
MickeyMoto
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Re: Clatter

Post by MickeyMoto »

Are the followers set at a slight angle so when the cam raises the follower it rotates a little for even wear? Have you checked the cam yet? Was the L5 cam ever used as standard in a 501? Are the valves slightly further apart in a 501 engine? Maybe a clue there?
norbert
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Re: Clatter

Post by norbert »

As far as I know the L5 cam was used in the Camel 501 and Coguaro.

The valves in the 501 heads are more apart than in the 500 and 350! Therfore the axle of the rockers are 71 mm long, in all the other heads only 69 mm. The washers esp. the thick one is placed in another way to seperate the rocker a bit. This way the free end rocker can be situated more or less centrical above the valve. This desafortunately is not exactly the same with the rocker situated between the two blocks, the center of the rocker is not exactly above the valve. To fix the axial play of the free end rocker we have the slutes block. The axial play of the rocker in between only can be regulated by trying to find some of the thin washers that will do the best. If you have some old spare units, it may be worth looking for that special washers, they are often but not all of the same thickness!

I began to uso two of the sluted block in every head. The advantage is that the rocker axle will not be damaged. There are people that recomend to put the axle that way that the rockers do not run over the grooves (not necesary) to give the rockers a longer live. Especialy if you have rectificates the rockers (the "tubes" inside) it ´s worth a try, I do so. But if you use the unsluted block you will find out that the axles are often damaged exactly where the unsluted block was situated. Then you cannot mount them the other way.
EVguru
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Re: Clatter

Post by EVguru »

The exhaust valve guide was moved outboard by 2mm on the 501 heads and this is really obvious when you look at them from the top, the guide is very noticeably off centre in it's boss.
The exhaust rocker is moved out a corresponding amount with a 2mm spacer.

There should be enough clearance between the rocker posts and their studs to allow them to be moved towards each other to adjust the side clearance of the inlet rocker. Sometimes the posts are really tight on their studs, to the point of being difficult to slide on (meant for the early 6mm studs?). I've had to drill them out to a clearance fit a couple of times.

The followers are encouraged to rotate in the usual way, which is to have the cam lobe contact them a little off centre.
Paul Compton
http://www.morini-mania.co.uk
http://www.youtube.com/user/EVguru
pedro
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Re: Clatter

Post by pedro »

The motor is now apart, the very sloppy cam followers made us think that it would be necessary to have the crankcases sleeved where the followers run, however thanks to EV guru who supplied a good set of followers, it appears that the wear was entirely on the followers, the newer ones fit well. Possibly they were undersize to start with, I have no way of knowing.
The engine must have been Excalibur since it has surprisingly a J cam, I say surprisingly since this bike has always been livelier than my other 501 engined bike, leading me to think that it had a hotter cam, but it's not that. I would love to build it with an L5 if anyone has one they could be talked into parting with.
The big end is shot, but should be recoverable, the gudgeon pins are showing evidence of moving within the pistons. I'm not sure whether to go with the original timing side plain bearing, or go for a roller conversion, what do you folk think?
The bike does have a fairly hard life, regularly getting thrashed on a racetrack in "parades". Incidentally, my engine builder pal was horrified to learn that I was using Halfords semi synthetic oil, which he called some very uncomplimentary names, I did change it every few hundred miles, given the hard life it gets, but he feels that I would be better off with Castrol R, (He is a Ducati race engine man) However, I don't really want, or feel that I should need to go down that road. NLM swear by Motul semi synthetic, again, opinions welcomed.
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72degrees
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Re: Clatter

Post by 72degrees »

Form an orderly queue for an L5 cam!

I have a roller bearing conversion on the hill climb 350 motor but too early to report on long term use. I've used Halford 10w 40 in the 375 for a while with no obvious adverse effects but I'm going to put Motul15w 50 in the 'racer' now it's run in.
MickeyMoto
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Re: Clatter

Post by MickeyMoto »

Pedro,

The Excalibur was a quick bike. Mine would pull from 2500 to 8000 rpm in top gear, the speedo waving around the 160km mark. The engine is very tractable. If you use it on the road it is fine, on a track probably more interested in top end, I also think the exhaust setup assisted. All on 78 main jets... what do the manufacturers know, eh?
Haboola72
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Re: Clatter

Post by Haboola72 »

My camel 501 engine is apart with a rumbling plain bearing .
I've decided to replace like for like . Splitting cases can be a wrestling match , made worse if you have to heat the RH case to accommodate or release a roller bearing conversion . The plain bearing is an interference fit.
Also it's quieter.
The factory knew best.
pedro
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Re: Clatter

Post by pedro »

I tend to agree, I showed my engine builder pal the crank that broke when I had NLM's old race bike, "The Beast", his first comment was that it was obvious why it broke, so much strength was removed when the crank was machined to suit the new bearing. That was exactly where it broke. I think I will be sticking with the factory set-up.
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Re: Clatter

Post by EVguru »

Remember that the factory started out with a ball race on the timing side. They used a hardened steel sleeve on the crank that was a sliding fit the the inner race of the bearing to accommodate expansion. The problem was, that's a lot of precision tolerances to stack up; crankshaft OD, sleeve ID and OD. Where those tolerances were not held tightly enough, there were problems with the sleeve fretting on the crank, or wearing prematurely on the OD if things were too loose. If too tight, the bearing could move in the cases and become loose. The easy solution would have been the roller bearing direct on the crank, but that would have been an expensive option. The roller bearing is about 5 times the cost of the ball race.

When converting a plain bearing crank, you end up with a larger diameter shaft than the early version, because there is no need for the hardened sleeve. I think perhaps the problems with the roller conversion have lain with the crank grinder. In some cases they haven't left much of a radius where the plain bearing has been ground down. A spacer ring, or modifying the bearing inner race would allow room for a generous radius. In the last failure I saw, it appears that the fit of the inner race was too tight, causing the bearing to run hot and leading to the melting of the plastic bearing cage (which then caused a lot of overheating and bearing failure). Roller bearing cage failure has troubled a number of engine designs when stressed and a move to a steel or bronze cage helped alleviate the problem.

If the factory had taken the 500 engines to even the same state of tune as the Strada/GT, a claimed 100bhp per litre, then you would have been looking at 50bhp and the 500 would have had a better reception than it did. It's possible that the plain bearing is the limiting factor and the factory did indeed know what they were doing by going for a pretty soft spec for the 500/501.

The 125 single and 250 twin always used the ball race setup, not the plain bearing, but they were budget machines that were not necessarily expected to cover the same sort of mileages.
Paul Compton
http://www.morini-mania.co.uk
http://www.youtube.com/user/EVguru
pedro
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Joined: 04 Nov 2010 21:14

Re: Clatter

Post by pedro »

I took the crank, which has some pretty serious wear on the big-end which went (front) up to Nourish engineering which is near me, The owner, Chris Bushell of Moto Giro fame and a huge Italian bike fan, immediate reaction, with absolutely nothing said by myself, was "the oil has broken down" he ran a Morini himself for five years, for the kind of use mine gets, he is suggesting Valvolene 20/50 mineral oil. That's two people suggesting that the problem is down to oil, I certainly won't be going back to Halfords oil myself. It looks like the crank will be going up to SEP engineering in the midlands for underwater welding to bring it back to standard. Conjures up a lovely picture of a bloke with welding gear and a snorkel in a swimming pool, perhaps it's just me.
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