Sport with an excaliber CS engine

350 Sport & Touring, 500 Sport & Touring
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Eddie
Posts: 1
Joined: 13 Aug 2015, 14:41

Sport with an excaliber CS engine

Post by Eddie » 19 Aug 2015, 13:58

First off, I would like to apologize for not being able to post in Dutch; I use a translator to read different posts and do enjoy all the information and ideas available on this site!
Here is my story - I have recently purchased a 1978 Morini Sport that was undergoing a restoration by the previous owner. The chassis is an A3 serial number and the original papers reflect that it was registered in Barcelona Spain in February 1978 as a Sport. I am going to follow the 1977 look as I really like the black and red look and I cannot really assure when it was built, only when it was registered. Maybe it is a 1977 bike and not 78, who knows...
The challenge I know have is to make something nice from someone’s unfinished project that consists in a good chassis and aluminum (grey color) wheels along with boxes of assorted parts that some match the Sport and others are from a Strada.
Currently I am now targeting my engine and I have found that it is not original to the frame I have. What I found is that I have a newer engine (painted black at the factory and not by the previous owner) with Gilardoni Nikasil cylinders, an “M” camshaft, electric start “Ducati” flywheel and the newer style crankshaft. The engine does not have the “S” stamped under the front cylinder, but a CS stamped on the lower engine case indicating this engine is from an Excalibur.
I am ok with the Excalibur engine as far as technical updates, but worried the performance will be lacking in comparison to a true Sport. My idea for this engine is to have it wet blasted to remove the paint and show the aluminum, simulating a 1977 model bike. I know if I do this I´m missing originality but my budget cannot afford a new engine due to all the other bits and pieces I still must invest in.
Here is my question for the experienced; does someone offer higher compression sport pistons for the Gilardoni Nikasil cylinders?
Maybe I should just finish the bike and start to enjoy the experience of owning a Morini 3 ½ but I can’t help to think that maybe now that I’m working on the engine, I can up the HP´s and make it a bit more fun.

350-v-twin
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Re: Sport with an excaliber CS engine

Post by 350-v-twin » 19 Aug 2015, 18:37

Hi Eddie,

Nice to hear from you, and most important: W E L C O M E to the forum of the Dutch Moto Morini Club.
Most of us speak/write English, so we'll do our utmost to help you out and get one more beauty back on the road!!

Later engines indeed lack the "S" under the front cylinder, but the bearings of the later engines are better and the ride is much 'smoother'. In fact already the K-type bikes lacked the S on more than one occasion.

I have just finished restauration of a 1975 3½ Sport and used the original earlier engine. It does not have Gilardoni of Nikasil cylinders. The German dealer Wolfgang Tritsch sells 390cc pistons, 'made in Germany' (by Wössner). Perhaps there is a way to get the Nikasil coating, after the re-bore to 390cc? We should ask Tom, here on the forum. The 350cc bores I used needed a re-bore at 0,07mm precision for the new pistons, but that is without the Nikasil coating.

German friends warned me this weekend to not ride the bike in for 500km's, but use a 1.000 to 1.500 km period for riding-in the new pistons. In fact I chose the M camshaft, as it gives an excellent spread of torque over the whole range.

Last Sunday I made my first 200 km's: excellent!!

hombre
Posts: 834
Joined: 10 Mar 2009, 10:13

Re: Sport with an excaliber CS engine

Post by hombre » 20 Aug 2015, 21:20

Welcome to our exclusive community ;)

The M-cam is probably the best choice, but I believe the Sport is more fun, if I were to open it up I'd go for an S-cam and the higher pistons. I have no idea if these are newly available.
I have read on the British forum however that without higher compression an S-cam is of no use. I haven't tried it myself...

Tom
Posts: 662
Joined: 26 Mar 2009, 09:23

Re: Sport with an excaliber CS engine

Post by Tom » 29 Aug 2015, 11:40

Somewhere i heard that there was no difference between 1983 and onwards 3 1/2's regarding the engine, which was definitely true for the 500 engines. That meant they all had the same camshaft and pistons, not knowing if this was sport (a higher edge or 'Heron' principle on top of the piston) or strada size. The only difference was cosmetics. But, looking at the 1984 Kanguro engine, which also had Gilardoni's and the rev counter (red line at 8500 rpm) i think the pistons are sport. But honostly, i don't know a thing about for instance a strada's 1984 engine, hence the fact that they are so rare.. so the period 1984 onward is a bit of a black spot for me. Judging the fact that the story of the Dart 350/400 is a rather complex one (different barrels and heads on different occasions ), i think you might come in for a surprise regarding your Excalibur CS engine.

Exalibur/New York 501 and Dart 350/ 400 rev counter are all red lined at 8500 rpm, this might be another clue that all pistons 1984 onward were Sport type.

Good Luck!

hombre
Posts: 834
Joined: 10 Mar 2009, 10:13

Re: Sport with an excaliber CS engine

Post by hombre » 29 Nov 2016, 11:02

Looking at the picture it's about reckless behaviour too :p

Tom
Posts: 662
Joined: 26 Mar 2009, 09:23

Re: Sport with an excaliber CS engine

Post by Tom » 29 Nov 2016, 11:27

Is the bicycle a Morini?

350-v-twin
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Re: Sport with an excaliber CS engine

Post by 350-v-twin » 29 Nov 2016, 13:08

Ik heb die boodschap met de getekende afbeelding verwijderd. Off-topic en misschien wel besmet met een of ander virus.
Heel soms beland zoiets op het forum. Vaak blijkt het een eenmalige actie te zijn van de afzender die vervolgens nooit meer iets te melden heeft. Account verwijder ik vervolgens ook! Safety first :|

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