Another no-Monster build thread

[MonsterHPD]

Its good having the Germans so close to consult, they are doing great parts and making good power with 2 valve motors.

Yes,
there are many 2V track bike projects in Germany (as well as Kämna, of course;; I have not checked in detail but presumably because of a suitable race series. One bike for sale now, not very dissimilar to mine, but based on an 848 frame, weighs in at 136.5 kg dry, motor 51.8 kg. Corresponding numbers for mine are about 162 kg / 62 kg, respectively.
That shows 1) the difference in weight between up-to-999 Ducatis, and 848/1098 onwards, and 2) the difference between a determined effort to focus on weight, and a more relaxed approach (mine).

Still is interesting to see the difference. Basically my 749-based bike has all the "normal" light parts, and compared to a 749 /999 it´s pretty light, but not compared to what could be achieved. Next time .....

Anyway, Covid19 diversion project is ongoing, ring gaps (and squishy) to be adjusted. First observation upon dissasembly: My goal to start rich / safe seems to have been achieved ...

20200427_194333 by torbjörn bergström, on Flickr   

[Duck-Stew]

Lookin’ good otherwise!

[koko64]

Impressive power to weight numbers.

[MonsterHPD]

Just in case someone´s still interested, time for an update.

As I took the top end apart, I noticed that one of the rails of one oil ring looked a bit strange, and closer inspection showed it was half broken. Presumably the damage was done when assembling the motor; since the lower end of the liners in a HYM motor is irregular in shape, getting the pistons with rings to enter the cylinder without one or other ring end snap out and snag on the liner was very tricky, and very frustrating. And obviously not entirely successful.

Anyway, looking around for piston rings, it turned out that I could buy a set from Kämna, but they did not have them on stock, and Pistal could not deliver until mid-june.
At the time, Covid19 was at its height in many countries, including Italy, so I had my doubts about that delivery promise.
Here in Sweden, track days were cancelled with no re-start plan, so I decided to park the track bike for this year.

As it turned out, the package from Kämna arrived in late June, and track days have been carried out pretty much as usual from early july onwards.  But by then, I had already decided to park the bike, and started investigations to make a pair of down-draft cylinder heads for the HYM motor.
I found some inspiration in a thread on the Ducati.ms forum, and I´ve had a lot of info from the person behind that thread.

https://www.ducati.ms/threads/my-aircooled-1100-downdraught-heads.728303/#post-7050557     

As I have a scrapped cylinder head from a friend to try this out on, I have started to do some CAD drawings for a cylinder head jig to hold the head on the milling machine. If this test ends favourably, I will go on with the proper heads during the winter. If not, I´ll assemble the motor again as-is, more or less.

I have alredy started hoarding parts, first up a set of throttle housings from the RS Monster:

2020-07-30 17.19.26 by torbjörn bergström, on Flickr

If I decide to go on, I will probably order cams and valves (inlet +2 mm, exh. +1 mm) from Kämna.

 And, to (hopefully) avoid the assembly problem next time, I´ve made an improved (?) version of the piston ring compressor sleeve:

20200526_200917 by torbjörn bergström, on Flickr

As there will be lots of small issues to solve and parts to fabricate, and it may not be finished in time for next summer.
Further, the motor in our trusty old rain bike decided it was finally time to go (80k or so km, last 20k or so as a track bike).

2020-07-22 19.52.47 by torbjörn bergström, on Flickr

So we are now working on some necessary modifications in order to fit the tuned ST2 motor I´ve had in the corner of the garage since that project petered out around 2012, 2013. That should hopefully be enough to be fun on our tracks, and a bit faster than the M800.

2020-08-19 19.21.46 by torbjörn bergström, on Flickr

Hopefully, at least one of these projects will be in working order for next summer 

[Duck-Stew]

Nice update!  I’m curious to see what becomes of the cylinder heads

[MonsterHPD]

Nice update!  I’m curious to see what becomes of the cylinder heads

Well, so am I :-)

[greenmonster]

Further, the motor in our trusty old rain bike decided it was finally time to go (80k or so km, last 20k or so as a track bike).  

Ouch!
What happend, valve broke off?

[MonsterHPD]

Yes, a valve broke, after some persuation by the piston ....

It was actually a bit strange. The cam pulley had worked loose, but the nut was still in what seemed the normal position on the cam, and it was not loose, still
green-Loctite locked to the cam. It´s been there since 2007, so it did come as a bit of a surprise ....  

[MonsterHPD]

Hello, all.

Covid still raging, I hope you are all well out there.

I suppose it would have been possible to get more done in this time, but as noted before, life is not just motorcycles.

I have progressed a bit with the down-draft project. The jig parts have arrived and worked as planned:

20201117_195912 by torbjörn bergström, on Flickr

The machining on the scrap head also went more or less as planned:

20201229_183719 by torbjörn bergström, on Flickr

I´m now waiting for some 6060 or 6068 alu bar to arrive to machine the weld-in stub. I will let this take it´s time, I plan on building a flow-bench so I´ll have some numbers to guide me while doing the finishing job.

For the coming summer, I will use the heads from a bike that ran on our track days 8 or so years ago, and via several owners landed in the hands of my buddy. The were made by a then-wellknown person and ran very well. They are ported and inlet valve is +1 mm, otherwise stock. Interestingly, the exhaust ports have also been filled out slightly so the port is effectively slightly raised.

20210106_152233 by torbjörn bergström, on Flickr

20210106_152607 by torbjörn bergström, on Flickr

20210106_164717 by torbjörn bergström, on Flickr
  
If you want to know more about this motor, you can check this thread:
https://www.ducati.ms/threads/graphs-of-the-1123cc-sc.86311/  

In the meantime, I decided to clean up the electrics and get rid of all the extra length of wires. The unused wiring was already removed, but the HYM wiring has a lot of wire in it ...

Start:
2020-09-30 08.48.12 by torbjörn bergström, on Flickr

Intermediate:
20201225_215108 by torbjörn bergström, on Flickr

Final (hopefully):
20210102_183953 by torbjörn bergström, on Flickr

It never turns out quite as nicely as you´d hoped ...

Well, that´s about the current status. Stay well, all.
  

[koko64]

Thanks for the update. Interesting links.

[diamonddog-2]

Fascinating.  Thank you for sharing.  Soooooo glad this forum exists and that I get to pick the brains of some REALLY talented people.

 

[MonsterHPD]

Thanks for the kind words. Don´t think I´m that talented, it´s mostly a matter of having been doing this sort of things for a long time, and taking good advice where it is to be found. I hope you may find this interesting, and welcome views and discussions, for me it has much to do with learning and echanging knowledge and experiences.

Abyway, I´ve machined a stub an done some test porting:

20210131_183835 by torbjörn bergström, on Flickr

20210212_094757 by torbjörn bergström, on Flickr

I have now started maching the "real" heads, somehow that made me much more nervous ..... crossing my fingers for my next workshop session :-)

For this summer, I intend to run the Proservice heads. I was a little concerned I´d have to machine the valve pockets, but I think I got away with it ....

Ventilfickor motor by torbjörn bergström, on Flickr

Ventilfickor mått by torbjörn bergström, on Flickr

The garage season is passing by very quickly, hope to have the bike in running condition when the riding season starts.

Kind regards,
Torbjörn.  

[koko64]

Great stuff. This reminds me of the Bye-Tye Therapy bikes downdraft heads and Carlo Benati's work.

[MonsterHPD]

Great stuff. This reminds me of the Bye-Tye Therapy bikes downdraft heads and Carlo Benati's work.

Well. I´ve had inspiration from many sources. I´ve benn thinking about a down-draft modification for a long time, and when my bike buddy suddenly foun himself with a HYM1100 motor he had no (obvious) use for, I bought it off him and so had to gt more specific.

Before then I had got the scrp head from another Duc club friend, and having done some tig welding tests on that I´ve come to realize I´d better find a solution with as little welding as possible.

At about that time, I found this thread on "the other" forum:

https://www.ducati.ms/threads/my-aircooled-1100-downdraught-heads.728303/#post-7050785

It sort of cathalyzed my thoughts on how to do it, and even though I will do the actual mod a bit differently, the general idea is the same. Unless I screw up along the way, the general goal is also the same, and I will most likely do NO welding on the head.

Highflyer (of the thread mentioned above) has been extremely helpful with advice and comments (and patience ...), and that has saved me a lot of time, effort, and probably cost. That also illustrates my statement above; I invite comments and discussion on anything I write, in order we all learn something in the process. The learning thing is the main driver for me.

I have not tried to pick the brains of Bythetherapy and others, they are after all commercial players and (probably ...) not interested to tell too much of what they know. I try to stay on the conservative side of things, and hope I will not learn too much the hard way .... fingers crossed :-)
      

[MonsterHPD]

While focus currently is on getting something running for this summer, I´m tinkering on the down-draft project as well. Somehow, the new projects are more interesting than messing around with the old stuff ...

Anyway, in order to assess if I can possibly do most of the port shape, or base material, in alu and use JB Weld or similiar just to fill out any gaps, I´ve made a cast of the raw port and the test stub: 

2021-03-26 09.22.03 by torbjörn bergström, on Flickr

It seems a bit tricky, but I´ll try and see if I can make a filler piece (part of the bottom bit of the cast in the picture) that I can weld to the front of the stub, and then hold it all in place with the stock flange screws. It will depend on if I can find a way to machine that odd-looking piece (without a CNC mill ...), and if it will then be possible to wiggle it all in place in the cylinder head.