Another no-Monster build thread

[MonsterHPD]

How time flies …. For various reasons I have not run the bike since 2021, one reason being somewhat disappointing dyno results, another me spending a lot of time transplanting my tuned ST2 motor into the SSie frame of our rain bike.

2022-05-08 11.05.13 by torbjörn bergström, on Flickr

It´s almost the same motor, but a lot of small things that should fit, didn´t without modification of some sort, like the rear header that suddenly interfered with the new crankcase:

20220215_154120 by torbjörn bergström, on Flickr

However, most time consuming was adapting the ST4S loom to the bike, in order to use the Nemesis / Microtec ECUs on the bike:

20201027_154413 by torbjörn bergström, on Flickr

In the end, the bike was ready for the start of the 2022 season, and I ran it at some track days thru May and June, adjusting suspension, and doing some on-track mapping. Unfortunately, during one such session, an overly enthusiastic Aprilia V4 rider decided to overtake 2 riders behind me at the end of the main straight, forgetting about the 90° right-hander at the end of the straight. Further, instead of taking the escape, he decided to try making the turn, but only partly managed the turn, but managing very nicely to torpedo me just exiting the turn. The ones he overtook estimated the speed differential to be something like “at least 70 kmh”, I just remember a dull “thud” and suddenly seeing my own feet against the sky.

All things considered, it ended far better than it might have, but the bike needs quite a bit of repair work, and I spent 2 nights in hospital due to some diplopia. I was subjected to al sorts of head scans etc., but the found nothing, whatever that might mean …

2022-07-09 10.48.32 by torbjörn bergström, on Flickr

2022-07-04 14.20.38 by torbjörn bergström, on Flickr

Anyway, this left me with just the M800 to ride for the rest of the summer.

So, back to the HYM1100. After the track day season, I did get to dyno the bike, first with the Proservice / 50 mm TB combo, then (due to disappointing results) with the Biggelaar heads and stock TBs (with slightly less, but still disappointing results).

HPD1100 power by torbjörn bergström, on Flickr

I do not have an explanation for this, other than that the various parts thrown together did not harmonize very well, and that I had turned the piston tops down slightly to lower compression a little. Which does not really explain the dyno result with the Biggelaar / Stock TB results, which were markedly worse than last time.
One thing that I can notice is that the torque curve is “wavy”, with a low point right where max power occurs, at about 8000 RPM. Running the bike with just the headers increased power by approx. 6 HP, so there´s something to be had by getting inlet and exhaust systems work im harmony with the rest of the motor.
At that point, I decided to not run the bike again until I had the downdraught heads on the bike, and that is now my main aim for the coming winter.  

For reference, below some flow numbers as measured on my flow bench:

HYM_DS Flow measurements by torbjörn bergström, on Flickr

On might think that the heads with the higher flow numbers would yield the highes power, and in an "optimized" combo the highest flowing heads might well have the highes power potential, but in this case it did not turn out to be the case. In fact, the "best" heads (Pro-service) with the biggest (50 mm) throttles turne out to show the lowest power on the dyno. It´s important to remember that the flow bench can only tell you what is most, not what is best. At least I hope that I have learned someting from this that I can use later.       

However, since I did not want to torture the M800 for another full track season, I decided to get the HYM motor running again. Which, hardly surprising, turned out to be more work than I had anticipated.

Last winter I had the Biggelaar heads skimmed 0.5 mm, in order to get a more squish-band type of combustion chamber:

2023-05-24 16.31.25 by torbjörn bergström, on Flickr

This, in combination with the Pistal pistons, gave a CR of about 13.5:1, which I found a bit over-optimistic. So instead the stock pistons were dug out and adapted; to get a decent CR, I decided to delete the base gasket, but this in turn necessitated the valve pockets to be machined for clearance. It also necessitated machining the squish part of the piston to get the proper squish clearance. In the end, the CR is somewhere slightly above 11:1.

2023-06-18 13.22.18 by torbjörn bergström, on Flickr

I had also intended to test the ByThe cams, but that did not work out; after I had ground the closer shims down to get 0 closer clearance, I had 0.6 mm opener clearance with the thickest opener shim I had.  So that will have to wait for the next stage 😊
    

While I was at it, I did some re-shaping of the combustion chamber, basically as a “de-shrouding experiment”, checking for changes in flow numbers as I went. I did see some slight improvement when opening up the chamber slightly on the “outside turn” side, but also some loss while opening up on the cylinder wall side of the chamber, behind the inlet valve so to speak (where the modeling clay is in the pic):

2023-05-29 15.13.45 by torbjörn bergström, on Flickr

With all said and done, I ran the bike at the latest track days. Due to rain and slick tires the first day was all M800, and the second day was mostly spent mapping to get the bike to run properly. The map I stared with was pretty OK at high load / WOTish load, but awful in the off-throttle/on-throttle situations, making exiting turns pretty awful. However, by the last session of the day, I´d managed to sort that pretty decently, and the last turn of the day was a real joy. Sooo nice to ride the bike in at least slight anger again. I´m looking forward to the next few track days.

Kind regards,
Torbjörn.                      

[koko64]

Thanks for sharing. It really shows how the different ingredients of the recipe have an effect and must be compatible. Cheers.

[MonsterHPD]

So summer is now over, at least here, and the "garage season" has started.  As expected, the bike did not not turn out to be a rocketship, but once I got the mapping reasonably sorted, it was very enjoyable to ride, nice to be back on the bike again.

At the Mantorp track with its uphill dragstrip (there´s a shicane leading in to the straight) the GPS showed a top speed of 215 km/h, and at the 1 km straight at Anderstorp the GPS showed a best top speed of 226 km/h, corresponding to roughly 8500 rpm in 6th gear.

Anyway, first rough installation mock-up of the horizontal cylinder with downdraught cylinder head. Obviously, unless I build my own frame, there will be some compromises  to be made ....

2023-09-29 16.05.19 by torbjörn bergström, on Flickr      

[koko64]

How did the winter build go?

[MonsterHPD]

Well,
the winter build has not happened yet. My plan was to have the downdraught heads finished and installed for the the 2024 summer, but this will most likely not happen. The downdraft project has reached a point where I need to investigate further before I decide how to proceed. So for now, my plan is to use basically the same set-up as last year, however I want to test the ByThe cams, and the bigger throttle bodies, this time with inlets tuned acc to (yet to work out) Lotus simulation results.  After all, I need something to ride this summer 😊

A lot of time after last summer has been spent on updating the flow bench. With the downdraught heads, the flow increased sufficiently to necessitate a 4th vacuum motor to maintain the 28” H2O suction level. I´ve also realized the worth of being able to check / manipulate what´s happening inside the inlet during testing, and a remark from Ducati.ms forum friend "Highflyer" provided the push needed to actually do that. Finally, the higher flows necessitated I move to the next bigger HFM size (internal Ø 62 mm, as opposed to 50 mm), now placed in the suction pipe instead of before the inlet.

2023-11-23 21.19.24 by torbjörn bergström, on Flickr

Another item I´ve learned, is it´s very convenient to have some method to develop the porting without ruining the actual heads in case you take a wrong turn. Here also, Highflyer provided input, as well as a post by Tony Foale on the Facebook group “Porting & Gasflowing Cylinder Heads, Manifolds and Induction Systems”: Make a plaster cast of the port / combustion chamber, and work on that.
That took a few attempts, the first attempt was a genuine “plaster disaster”, the 2nd was half OK, the 3rd (the #2 in the pics) was pretty OK, and worked very well, maybe too well, on the flow bench. I also copied Tony Foales “shim system") to set valve opening, very convenient.

20231127_143323 by torbjörn bergström, on Flickr

2023-12-12 09.56.10 by torbjörn bergström, on Flickr

Gips#2_25_231230 by torbjörn bergström, on Flickr

Anyway, flow bench results as per below. Flow numbers are in cubic metres / hour, as that´s what Bosch uses in their conversion HFM signal / air flow , and because it´s actually a better measure on air flow than CFM as related to engine operation.     

Flow numbers_240112 by torbjörn bergström, on Flickr

It has been my target to see what flow is possible while keeping port dimensions as small as possible, and the “best” Plaster#2 port is remarkably “simple”.

2024-01-01 16.00.49 by torbjörn bergström, on Flickr

2024-01-01 15.57.34 by torbjörn bergström, on Flickr

On the other hand,  it´s important to remember that the flow bench can only tell what´s more or less, not what´s better or worse. So it´s important to try to learn more, and I think Darin Morgan has a lot of good information in his Youtube videos, not least on the subject of wet flow, not much info to find on that, and not possible to test in my flow bench. 

Next thing to do will be another plaster model to try to translate as much as possible (within “aluminium limits” ) from the “Plaster#2” results.   Ideally, I would like to avoid any welding, but maybe it will be at least a tempting alternative …. On of the decisions delaying progress. Or at least further action 😊

Well, that´s it for now, I think.
Kind regards,
T

[koko64]

Thank you for sharing a fascinating journey. Appreciate it.

[Howie]

 

[greenmonster]

.Thank you for sharing a fascinating journey. Appreciate it.

+1

[Monsterlover]

 

[ENGAKATS]

Damn, I wonder how comes I missed the last update for almost half a year... 


Thanks for the updates Torbjörn, very insightful indeed!

Highflyer, being a homie, is high up in my "to call" list whenever I get the spanners out to work on my SS1000 


Looking forward to more news 

[MonsterHPD]

Well, thanks, glad you appreciate the posts. Maybe it´s time for another update,  I didn´t realize it´s already half a year since the last update until I saw the date on the post.…  

Anyway, after the last post I´ve made further testing on the flow bench, finally “installing” the +2 mm inlet valve in the plaster head. However, before then I had found a pretty good port shape,
but looking from the combustion chamber, the valve is “countersunk” into the chamber, creating a 90° ridge around the valve. It seemed an obvious final finishing touch to just dress the
corner to make a nice, gradual transition to the combustion chamber. Unfortunately, it just about killed the flow, but some curves and comments might be easier to grasp:  

 Downdraft plaster curves by torbjörn bergström, on Flickr              

The first green curves are a stock head, and the Biggelaar-ported head, respectively.
Plaster#2_24: The absolute best I managed on the second plaster head. Still stock valves.
Plaster #3_16: The #3 was cast from a silicone port cast off the Plaster #2_24, and many mods and measurements. Should be at least as good as P#2_24, theoretically ….    
Plaster #3_17: Same as _16, but that edge dressed …
Plaster #3_18: Same as _17, but +2 mm valve installed, same throat Ø (40.7 mm) as all previous tests.
Plaster #3_25: Same as _18, but throat Ø 42.3 mm.

Anyway, that’s where I gave up on having these heads on the bike for this year. I also realized I need to find a more precise way to assemble the various parts used for the plaster cast.
Plaster #3 was not quite right, the silicone port cast did not sit quite right on the valve, and some other small details. But so or so, there is obvious potential in the downdraught layout as far as air flow I concerned, I just need to learn more..      

2024-02-16 16.00.33 by torbjörn bergström, on Flickr

This is the area where material was removed between Plaster#3_16 and …_17.
So, this work will go on later when I get time over from my other projects.  

When spring started to get warmer, I realized I had to get at least one bike assembled in order to have something to ride this summer. The quickest way would obviously be to assemble the HYM1100 motor for the track bike again, but I wanted to at least test the Bythe cams.
The Byte cams have more lift and other timing, and required I get some thicker opener shims, luckily our Ducati dealer could organize them. Testing with model clay revealed I needed some further machining of the inlet valve pockets. Apart from that, assembly was pretty straightforward, and so far the experiment of re-using the head gaskets have not caused problems. Fingers crossed ….

I also wanted to use the 50 mm throttle bodies again. Since I had used them before, I had all the hardware needed; might not be the optimal solution, but I knew they worked.
So, with everything assembled, time to press the starter button. At first everything seemed OK, but very quickly I realized all was not as it should; the motor was very sluggish, was droning and only one header was really getting hot.

Symptoms very similar to when I missed the timing by one tooth on my M900, so that´s where I started. To make a long story short, it took me one week to check everything, finding nothing wrong, and one week doing other stuff , after I realized I needed a break.
Starting again, I tried to synchronize the throttle bodies, using my water column manometer. I managed to start the motor, but all the water was instantly sucked out into one of the TB´s. This did point in one direction, so I took out the TB´s and tried to synchronize them mechanically; sine there is one master TB with the idle adjuster screw, and one slave TB operated with a Bowden cable, and no positive stop, this is not so easy (as I was about to learn).

2024-06-11 14.29.56 by torbjörn bergström, on Flickr

With the TB´s back on the motor I tried again, with the same result apart from the water being sucked out into the other cylinder instead. In the end, I ended up rough-synchronizing  the TB´s by measuring the header temp; with idle at approx. 1600 RPM I got both headers to around 300°C, and hooking up the manometer again, I had about 20 cm water column difference between the cylinders, which I could fine-tune to get the normal behaviour with one or the other column ahead of the other depending on RPM.
The motor now runs OK, but it took me the best part of 2 weeks to find the solution to a basically very simple problem.

I´ve now ran the bike on two track days, spending most of the stints mapping the Microtec ECU, using the Microtec mapping ECU. The bike runs well, I can´t say if better or worse than last year, but at least it runs “nicely”    

447307105_8255920951103767_4413014182155953067_n by torbjörn bergström, on Flickr 

There are some track days coming, and I hope for nice weather :-)

Kind regards,
T.          

[Monsterlover]

Hell yeah

[koko64]

Good work compadre.