Donor Gearboxes

[el chupacabra]

So I’ve just finished building my first engine and have my eyes set on the next. I’m hoping to get most of the CAD work done over the winter and maybe start manufacturing next summer. So at the moment I’m just trying to source a suitable crankcase, gearbox and clutch so I can get the ball rolling when I run out of things to do on other projects.

The plan is to use 4x Chinese YZ85 barrels and crankshafts with a custom lay shaft joining it all together. Hopefully it’ll make 100+hp

So what kind of gearboxes do you think would be a good or bad idea?
-I keep seeing cheap Hyosung GT650 motors which are rated at about 55nm and have 6 gears
(Cheap but unsure about the quality)
-I’ve also been looking for some 600cc bottom ends but everyone wants the earth for them
(Too expensive and most have oil fed through the centre of the shafts, I’m unsure if I can delete this feature without sacrificing reliability)
-I could use a 450 MX gearbox
(Probably too fragile, plentiful and light weight, may need a bigger clutch, probably only 5 speeds)

Here’s some pictures of the last engine.
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[jato]

This sounds interesting... I'd be curious to see some sketches of the layout - v4/square//stepped?
re gearboxes ebay is a happy hunting gound . recently i bought a late (ish) low k gsxr1000 gearbox complete with shift shaft, selector with guides and detent , bearings and even a front sprocket all for 139 usd. Gear ratios will be a deciding factor with those cylinders - a gsxr 600 gear set likely will be the ticket. peak torque values with your engine won't be too high - maybe a 400 gearbox would be ok, esp if you speed up the primary ratio ( and save a bit of wieght for the same horsepower capability).

[el chupacabra]

I’ve found a few cheap gearboxes, the only downside is I need the cases too so I can get all of the shaft centres and other dimensions. The layout will be a cross between an rg500 and an rgv500, I don’t think the yz85 cranks will handle being geared together so they will all drive the layshaft rotating in the same direction which will drive the clutch. once I have the pieces I’ll be able to sort a 2D cad drawing and see how it will fit into a bike. I’m thinking 90 degree V and firing the cylinders in pairs.

All I want to do is make the cases, 4x primary gears and a layshaft, nothing too ridiculous.

[F5 Dave]

I'd steer well clear of a Hyobang. There's a reason why you see so few of them on the road compared with just a few years ago.

You'll probably have to spin it a bit faster to get that sort of power, probably peak at 12 at least. Top end parts should handle it fine as long as confidence in crank.

600 clutch would handle the power.

[husaberg]

TL or sv Suzuki.
Suzuki always had the best boxs
there was one on TM as while back complete with shifters for $125

The other option is Ducati the 900/916 were all pretty much the same and cheap as well if you look around.
you want something narrow, Across the frame 600s are not narrow.

For the crank find yourself a two RD200 twin cranks
they have lab seals they have a kind of odd girdle set up but far easier then trying to gear together 4 yz85 cranks
they also have a spineless primary
i have the dimensions somewhere.
352212

They run 20mm pins and commons sizes for the YZ's 14mm piston pin

The other option is to do a single crank like a NSR500 they have more room than a twin crank and are a simpler set up.

[Grumph]

Gearbox width Suzuki V twins vs across the frame fours is pretty much identical. I'd still look for a GSXR600. Even the early ones will work in your application.
But in pretty much every 6 speed I've seen there's oil up the shafts. Where a gear in the center of the box runs on a bush on the shaft, you've got to lube it.
A small oil pump driven off the back of the clutch wouldn't be hard to arrange. You could even semi dry sump the box. Oil level well below the spinning gears with pressure fed shafts and a spray bar.

[jato]

This project sounds really neat. a few years ago a nephew got a new KX85 and it was left with me on the farm for a while - what a neat engine .. It'll be a rocket. each crank having something like a 9 or 10mm wide gear meshing with a single 20ish mm wide layshaft gear would be a tidy and light setup. do the yz's have a bridged exhaust? the bottom cylinders might give the bridge a bit of a hard time being on the thrust side. 20:1 maybe

[F5 Dave]

Just trying to visualise this whilst scoffing an éclair.

So the layshaft would drive the primary clutch and the RH cranks would both drive it, so will need to be a fair size gear, then the LH cranks would pick up in the centre in same fashion? Then lop the tapers off both RH cranks which will make them a different weight.

Will make it fairly wide. And fairly long even if you stack the layshaft. And have to drive cylinders backwards. Or have I got this wrong?

[el chupacabra]

Well I’ve got a 1997 gsx600f gearbox lined up, so maybe that’s the ticket. $400 and on the other side of the country (Auckland) I’d rather see it first though.

I’m thinking about stacking the gearbox to make it a bit shorter and lopping the tapers off the RHS cranks. I’ll only know the size once I order the Chinese crank and cylinder and have the gearbox in my possession. Surely it can’t be any bigger than an RG500

There’s a shop down the road that will hobb and harden the gears for me from en36 at about $300-400 a gear or I can make them myself and have them harden them for me for about $40 each.

I’m going to lost foam cast the cases again but pay a foundry to pour it this time.

[el chupacabra]

I’m thinking a cross between these two set ups in terms of the crank gears. Except offsetting them slightly so I can run the nuts recessed inside.
For the oil pump i have a bunch of Honda C50/pitbike ones floating around I can use as I want the sprocket side of the engine to be have a cassette style gearbox and I will drive it off one of the input shaft gears with a plastic/steel gear. Kind of like the last engine pictured.

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[jato]

gear spacings - years ago i measured lots of race bike gearboxes and noticed to get the best out of a higly strung 2 stroke 1st was pretty high and the rest had diminishing drops in rpm as you shifted up. if this bike is headed for manfeild then i reckon you might need to have first close to 50% of top gear and a gap no bigger than around 15% to second 12% to third and so on. i've previously found a motorbike gear ratio site that had all the gear ratio's of just about every sport bike made. could be worth a look. it shouldn't be too hard to find a set of cases to measure up if you went with something like a sports 600 gearset. I want to come and watch this race... do the std yz cranks have keys or splines on the drive end? $40 to case harden a gear sounds real good.

[Grumph]

I’m thinking a cross between these two set ups in terms of the crank gears. Except offsetting them slightly so I can run the nuts recessed inside.

If the shafts are splined, just retain the gears with circlips. Least space needed. Yes, splining required but you can save a little $ by machining the gear blanks yourself. Any time spent at home is cheaper than having someone else do the whole job.

Been there with close ratio conversion gearsets for Aermacchis. Last batch arranged by someone else - and roughly twice as expensive as the gearcutters did it all.

[el chupacabra]

The late model yz85 cranks are splined, but the earlier ones have a single keyway. I guess I’ll be able to figure the total width out when I have the crank in my hand. They are only $140 each shipped for the early model cranks, so pretty cheap and I’m not too concerned about hacking them up.

The plan will be to have it drop straight into my other RGV250 using the stock engine mounts as it will fit an Aprilia too and there might be a demand for something like this way down the track if the prototype isn’t too much hassle to sort out.

[el chupacabra]

Thank you aliexpress 352217

[F5 Dave]

So you are going to run the cranks facing each other in 180 deg rotational symmetry. [Edit, should that be axial?] Its not so much the gearbox as the cranks you may have to stack and run the front counter rotating (forwards) to the rears (geared off) which would help thrust on lower as Jimmy alluded to.
Also means easier on the brain for ignition if running a 4 way ignitech with two pulsar coils on one flywheel? Heck. We need power to generate enough for the ignition.

I'm having the odd beer so my already diminished brain power is even more shakey compared to these other two real world experts. If they say something, Listen.

[el chupacabra]

I just modelled the whole crank assembly up and it was a little over 300mm wide but then fusion crashed before I could screenshot it and share the layout. I’m thinking both cranks spinning in the same direction so I can space them apart more and make the engine slightly shorter.

[husaberg]

https://www.trademe.co.nz/a/motors/motorbikes/parts-for-sale/clutch-gearboxes/listing/3968576866?bof=6EikuEfh


this is interesting no idea what a tiger 800 is it a twin?

the guy that did the bsa vtwin a the norton rotary at EMU engineering i am prety sure used one of these he will have a CNC map for it.
https://www.trademe.co.nz/a/motors/motorbikes/parts-for-sale/clutch-gearboxes/listing/3966110025?bof=6EikuEfh.

The triumph ratios are not actually bad, better than the firestorm.

[jato]

https://www.gearingcommander.com/index.htm I don't want to hijack the design or anything but i looked up a gsf 600 gearbox and the gears are spaced way too far apart for a track bike- first is only 36% of top so there will be big drops in rpm heading down the back straight

[el chupacabra]

Hmmmmmm. I haven’t bought it yet, maybe it’s back to hunting. I preferably want something common so if I decide to make another it’s not too hard to find parts. Maybe an sv650 will pop up in my price range.

The triumph looks good, but I’ve never seen one before and don’t want it to be a mission to find parts, the VTR gearbox would be good if it had the clutch and cases.

[F5 Dave]

https://www.trademe.co.nz/a/motors/motorbikes/parts-for-sale/clutch-gearboxes/listing/3968576866?bof=6EikuEfh


this is interesting no idea what a tiger 800 is a twin?

the guy that did the bsa vtwin a the norton rotary at EMU engineering i am prety sure used one of these he will have a CNC map for it.
https://www.trademe.co.nz/a/motors/motorbikes/parts-for-sale/clutch-gearboxes/listing/3966110025?bof=6EikuEfh.

The triumph ratios are not actually bad, better than the firestorm.
800 is a triple. I'd not be looking at bikes with broad spread power and road orientation as a shopping ground.

That site posted looks like a great resource.

[jato]

Rainy day so i had a good look at Gearing Commander - some of the earlier suzuki 400 (impulse?) look real good but probably hard to find more than one. late model YZ125's have TZ like ratios but not so sure how a 125 gearbox would handle two 85 's firing in pairs ... in theory if you speed up the primary ratio say 35 - 40 % then the torque peaks would be no more than a 125 single. some (early) yamaha gears have been tested at rockwell 64 or greater and would shatter with a determined mid race shift... it'd be interesting to find a late model yz gearbox and do a hardness test on them. otherwise the gsxr600's have reasonable ratio's - first around 45% of top and bullet proof . maybe 40 or 50 % bigger/heavier/stronger than needed but common and easy.

[el chupacabra]

The more I look the more it looks like the only suitable gearbox is something from an mx bike. But I’d be limited to 5 speeds. Unless I use a 125cc box and maybe a bigger clutch, but that could be a hassle.
Most nz tracks would only require a top speed of ball park 240kmh.

I do recall reading the rsw250 uses the gearbox from the rsw125 and even the rsw500 used the same gearbox. Maybe a 125cc mx gearbox might work. . .

I could hang out for a gsxr600, but I’ve given up on Sv and other tourer gearboxes as the ratios look horrible.

I could find another rz350 gearbox and use a banshee first gear but they are getting a bit expensive and I don’t really want to pull my motor apart to measure the cases.

So many options

[F5 Dave]

Shipping is a bit ouchy these days but pretty good deal I'd think.

https://www.ebay.com/itm/275180642136?hash=item40120b5f58:g:~WYAAOSw78ZiFpK E&amdata=enc%3AAQAHAAAAsNHZs2TcJLBijlN1lH0GeKO3ChcDs suwSQCmKWsnLq9xwtQuB3WV36Vx%2B8186n0xHIDGSZANSnEN4 z8FQJThaXrOPsp6LGiY2xS15hUi0gebsdY7RCBqoJQBjxyta2a bD2RJM6B4kdmDsxai%2BMJxpb6f%2Fxrjh9G%2Btr7bETxuaBe RpbhMQONtkknkWAGOX59iwmKPLk%2Fg%2B95evs6O85%2FD0w7 pAzqva9P%2FPWTnmw37TF35%7Ctkp%3ABk9SR8jYqZS-YQ

Maybe same seller has a clutch.
Hmm, he does, combine shipping and not too bad.

[husaberg]

800 is a triple. I'd not be looking at bikes with broad spread power and road orientation as a shopping ground.

That site posted looks like a great resource.

hi

you might be surprised by the Triumphs ratios, i was.
RZ350 is
2.571
1.777
1.318
1.083
0.961
0.889 or 1.68 spread

TZ which is of course crazy close
1.933
1.421
1.125
0.962
0.870
0.815 or 1.118 spread

Trumpy is a pretty reasonable
2.21
1.86
1.50
1.28
1.13
1.04 or 1.17 spread

These are far closer then a 85Mxer
which a is a range of about 2.5 to .885. for an old Cr80
these are so much closer then a MB50 its not even funny like 3.0-0.885

these are the YZ85.
Gear Ratio – 1st Gear: 27/11 (2.454)
Gear Ratio – 2nd Gear: 32/17 (1.882)
Gear Ratio – 3rd Gear: 26/17 (1.529)
Gear Ratio – 4th Gear: 22/17 (1.294)
Gear Ratio – 5th Gear: 26/23 (1.130)
Gear Ratio – 6th Gear: 25/25 (1.000)

the old pommy shitter turing Triumphs is a closer ration box than a std YZ85

i would also wager there is a few other ratios that fit the Triumph from other models as they were all about commonality plus god save the queen etc they won ww2 with triumph motors powering the Aux electrics on Lancaster bombers

[jato]

or a bit closer and cheaper? https://www.ebay.com/itm/190806880112?hash=item2c6cf9ef70:g:6vkAAOSwD8ZZ6Nx d&amdata=enc%3AAQAHAAAAoGkbWHcz9n2HST%2BaelZboTM2Egs ePo3HU7rNMr7HGQu%2BhkyIdPe%2FZvMbudYPGrGOYGLfzr%2B rlk8W1IDuf6Ch6bF8PU4xyb5ys0UT3ozp7PxzCKPh2EIRxWCtd Dc3R9CUeL3tyWhmW%2Fath5ses5xe9YVe9m8T4kfdBhqpf8Ie6 8bXAdXANtsr56%2B6rsZnHj7bNZ5IjoItlCAFfY9FIzsVaYo%3 D%7Ctkp%3ABk9SR4S5_ZS-YQ
so many to choose from - do 600's have back torque limiters? (i've never worked on one) for a recent project i used an early nineties gsxr 750 clutch - very simple and light - i think the 600's have a lot of interchangeable parts with a thousand other models.

[Grumph]

I'd go 600 size box. It's sized for about the amount of torque you'll get. Much lighter than the Triumph boxes too.
In my experience the main criteria isn't the overall spread, it's the top 2 or 3 gears. The ability to pull through the gaps 4-5, 5-6 is paramount.
That's why the TZ box is so close in the top 3 - 4 ratios. No torque to pull big gaps.

When we went from a 12% gap 4 - 5 in the Aermacchis to an 8% gap it meant the things would keep accelerating in top. Std box it simply died at top end.

[jato]

this clutch looks appealing - its got the little 34T gear that slides onto splines on the back of it - good for driving a little oilpump that can circulate oil to the shafts and your cast-in spray bar above the gears - a 230 crf pump and gear will mesh spot on , or just about every suzuki fourstroke pump. the primary gear most likely will be module 2.25 or maybe 2.5 so easy to get cutters to match for your layshaft... https://www.ebay.com/itm/144835709703?hash=item21b8e18b07:g:RJwAAOSwYXFjiPH M&amdata=enc%3AAQAHAAAAoD0XsS7D%2FlB53dDB0gv3n4LvKU3 nMTlMd34y8ojR579yqswWVMd%2F%2F%2BBvurv9%2FPLUDXJDs yuT4zfJDn0TLylWUv7IKQDvgTiYG28tfsiLrCMyXTzt5Uwopwl JjNmzdPeXm6%2F5WjWNWUnvYozsLalgeVCGpqRg%2FI8DUtgdJ cP%2BIhGM254lm3c3wCD2DrsxbESAmmczx6ZsMOb1pjz4S1%2B LVUI%3D%7Ctkp%3ABk9SR5Tnjpa-YQ

[jato]

Agree regarding the last few gears - bit of a headwind and shifting up with a drop in revs to the bottom of the powerband and you are a sitting duck

[el chupacabra]

Bike busters in nz have a 1996 gsxr600 box for $275, I’m going to see if they have the clutch and any other parts. Although I don’t think I’ll be able to work out the shaft centres accurately without the cases.

I’ll see what the triumph dude can do the lot for.

[F5 Dave]

Someone like Ozzy will probably have spare gsxr cases sitting around in the pool or know who has.

[jato]

when previously recording the positions of the shafts/selector/guides and shift shaft on jap bikes so far there has been a pattern emerge - eg gsxr 1000 shaft centers 68.00mm shift guide to selector drum 34.00 centers - a bit of dummying up would confirm your calculations .

[husaberg]

What would be cool is a NSR250 box dry clutch option its also a cassette box.
it also gives the option to upgrade to NF5 RS250 gears later.
Pretty sure a guy did all the cad mapping one as well.

std they are wider spaced than a Triumph...
but dif years are different ratios
https://nsr-world.com/specs/nsr250/

[Grumph]

What would be cool is a NSR250 box dry clutch option its also a cassette box.
it also gives the option to upgrade to NS5 RS250 gears later.
Pretty sure a guy did all the cad mapping one as well.

IMO not a good option. RS250's seem to break 2nd gear on our circuits in NZ.

[el chupacabra]

I’m wondering now if that gsx600f will be fine other than the less than ideal jump from first to second. Seeing as it’s cheap and it’s a complete motor with carbs. The spacing between 3-4-5-6 looks pretty good, 2-3 maybe a 2,700 rpm drop from 13,000rpm. 1-2 is a big drop of around 4,000rpm

I do have an RGV VJ21 cassette sitting around with a munched 1st gear but I feel like all these old 250s are worth far to much to be pinching parts from and impossible to find spares for.

It’s a shame I don’t have the connections with people that will lend me parts so I can measure them over a few months or sell them to me cheap.

I definitely don’t want to be smashing gears.

[F5 Dave]

If it's a roadbike that will be fine. But it's not so it will be a Why didn't I start off with the right bits? Every time you try launch or in the hairpin.

[husaberg]

https://www.trademe.co.nz/a/motors/motorbikes/parts-for-sale/engine-components/listing/3961213015?bof=6EikuEfh

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Cramp used this series gearbox for project lionheart the homebuilt 500 v twin into a TZ250 frame.
he has the tool for the primary gears
ian.r.cramp@gmail.com as its a odd modulus
Is this what you were meaning with the separate cranks initially.
352227
the bits i have start here and carry on.

https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130295249#post1130295249

[jato]

I see a YZ 125 has a big reduction from crank to input shaft... so, knowing that as we speed up the primary drive ratio you transmit the same horspower but at a lower torque loading on the clutch and gears, if we were to change the ratio from the std YZ 125's 3.37:1 to say 2.25: 1 then we will be able to handle the torque peaks of two pairs of 85's no problem at all. with the inertia of 4 cranks(even though they are smaller than the std 125) the speed of the engine within its 360 degrees will be more constant than a single, which will also help being "kinder" than a single on the clutch and gears . Total clutch speed would be just over 5700 at 13000 engine revs which is a lot lower than a lot of clutches. A good cush drive in the back wheel as well as the std dampers in the basket would save any big shocks engaging gear. the little oil pump and a spray bar cast in would complete a light raceworthy set up . i expect the new primary drive gears needed would fit in with the need for a layshaft as per design. if you were worried about total heat soak into the clutch on a tight track you could easily fit a slightly bigger clutch such as a rmz 250 one (i have some under my bench you are very welcome to if needed).

[el chupacabra]

If it's a roadbike that will be fine. But it's not so it will be a Why didn't I start off with the right bits? Every time you try launch or in the hairpin.

You’re 100% correct, I should just take my time selecting the right bits. I do appreciate all the advice from everyone as well as I would have just jumped on the gsx gearbox without thinking about the spread.

I’ll keep my eye out for a 125mx bottom end or something 600 supersport related as they’re probably the only suitable ones. That triumph one might be ok, I’ll have another squizz over that today and look at the ratios.

I’ll also do a quick 3D model of the layout maybe tomorrow using some known dimensions and show you guys what I’m thinking as a picture paints 1000 words.

[husaberg]

You’re 100% correct, I should just take my time selecting the right bits. I do appreciate all the advice from everyone as well as I would have just jumped on the gsx gearbox without thinking about the spread.

I’ll keep my eye out for a 125mx bottom end or something 600 supersport related as they’re probably the only suitable ones. That triumph one might be ok, I’ll have another squizz over that today and look at the ratios.

I’ll also do a quick 3D model of the layout maybe tomorrow using some known dimensions and show you guys what I’m thinking as a picture paints 1000 words.

For what it's worth I went through all the common 600 and 400 stuff none of them are actually very close ratio. I could find anyway.
Even the VFR400's and CBR's
125mx gears are tiny compared to road stuff or the 2 stroke proddy stuff plus lots of late stuff were 5 speed.
If the trump or Ducati doesn't suit ,if it was me i would just use a VT250 they are decent size ,made for a narrow bike and were used on factory std bike up to 45 HP so might work at a pinch every wrecker in NZ a=is full of them and the gearbox's are not the reason why.
they have plenty of permeations and were used manual and hydraulic clutch and left and right actuation.

[el chupacabra]

I’ve had a google of the vtr gears and they look fairly narrow like the 125. I just remembered i do have an RG150 complete sitting in my mates lock up. . . I wonder if the gears with a new primary drive ratio will work. I did want to make a 125 gp chassis for it though but maybe it’s a worthy sacrifice.

[husaberg]

I’ve had a google of the vtr gears and they look fairly narrow like the 125. I just remembered i do have an RG150 complete sitting in my mates lock up. . . I wonder if the gears with a new primary drive ratio will work. I did want to make a 125 gp chassis for it though but maybe it’s a worthy sacrifice.
The VT gear are indeed narrow, but are a much larger dia gears than the 125's.
They run a large id Primary i am using the clutch on a design i will never complete.
the early f's and posily others are closer ratio.
all of them are of course smaller than a 250 proddy.

[el chupacabra]

I guess the vtr gears may also take more abuse with a dedicated gearbox oil and not sharing it with the engine.

[jato]

looks like the RG 150 1st gear would be ok following the cows... another option is if you found a gearbox with 5 of the 6 gears looking good then build a new one to the ratio you want 1st is often easy to build a new driven gear with a corrected profile to "match" the existing main shaft

[el chupacabra]

352237

This doesn’t look outrageous from the triumph and it’s only $250 for the lot. With half of the crankcase included. Husa was probably onto a good thing from the start. Does anyone have any bad experiences with the triumph gearbox? Otherwise I think this looks like the best option.

[husaberg]

looks like the RG 150 1st gear would be ok following the cows... another option is if you found a gearbox with 5 of the 6 gears looking good then build a new one to the ratio you want 1st is often easy to build a new driven gear with a corrected profile to "match" the existing main shaft

if you wanted to do this this site https://novaracing.co.uk/
go to manufactures and the list options
make them as do other Asian sites but normally for little underbones

[el chupacabra]

if you wanted to do this this site https://novaracing.co.uk/
go to manufactures and the list options
make them as do other Asian sites but normally for little underbones

They make some nice kit but are definitely expensive and even the close ratio gear set for an sv isn’t as good as the tiger 800. . . Hmmmm maybe it might be getting some British bits, I’ll sleep on it.

I’m all about trying to do this for as little money as possible. In my mind I’m always more likely to finish projects that aren’t a massive financial burden. If I need to spend money though it will happen, I’ll always look for a cheaper option though.

[F5 Dave]

Thailand for most Triumphs. Just sayin.

[husaberg]

Thailand for most Triumphs. Just sayin.
Well I'll admit i never knew that, but i guess lots of poms were not born in England as well Plus if KB's poms are anything to go by were are better off with anything but poms.
https://timeless2wheels.com/14015/triumph-thailand-made/
Ducati would be my my first choice i can imagine one lasting long enough to wear out the gearbox...

[F5 Dave]

Had 3. 1050s made by Dave and Rob. Next two by Aisoon and Chao Fah.

Yes I googled that.

[el chupacabra]

I’ll take my chances with Thailand, I mean the cylinders on my RGV Banshee are Chinese haha. But I’m pretty set on those triumph ratios now. I’ve messaged the fella to make sure it is all there and I won’t be looking for bits then I’ll buy it and start the painstaking process of drafting the whole thing. Then printing a prototype. Printing all of the gears and mounting the water/oil pump etc.
maybe I’ll use a GSXR water pump. but gear drive it off the layshaft primary and mount it on the clutch cover.

Then I’ll into casting once I’m 100% sure the design will work and I’ll try get as much as possible done in the casting so I don’t have to do as much machining.

[el chupacabra]

The triumph gearbox will be here tomorrow lunch time, the ball is rolling.

[husaberg]

Well ducks nuts or dogs breakfast?

[jato]

actually it would be interesting to know the wieght of both the shafts with all the gears fitted (no bearings) that info can be stashed away for future use ...

[el chupacabra]

The mans van broke down on the desert road so I should see my gearbox on Monday. Here is a rough layout I quickly modelled to give you guys an idea of what I’m imagining, the number of teeth, the gear width and gear module are subject to change. Once I know I'll be more than happy to share any weights and dimensions.

I'll get my hands on some real cranks before drafting the cases.

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[husaberg]

The mans van broke down on the desert road so I should see my gearbox on Monday. Here is a rough layout I quickly modelled to give you guys an idea of what I’m imagining, the number of teeth, the gear width and gear module are subject to change. Once I know I'll be more than happy to share any weights and dimensions.

I'll get my hands on some real cranks before drafting the cases.

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Have you seen how a later TZ goes spine gear in side of gear?
will post a pic.
yours is like a TZ750.

[el chupacabra]

No I haven’t, but if you have a photo I’m interested.

Here’s the donor engine.
352340

[husaberg]

352345
TZ750

352341352342352343352344352346
later tz250's

Shouldn't your cranks also be contra rotating?

[el chupacabra]

Thanks, that looks like ass to machine haha. . . I guess once I know how wide the gearbox will make the engine I’ll be able to decide how much effort I put into making the cranks narrower.

I’m also thinking about if I want to do a 2 piece crankcase with a cassette trans on the sprocket side or a 3 piece case with the vertical stacked gearbox like the triumph.

My philosophy is the cheaper/simpler I can make it the more likely it is to be completed.

[husaberg]

..............
352347

[el chupacabra]

I’ll spin them in the same direction and fire them in pairs 90* apart. I’m pretty sure the RG500 spins in the same direction.

352348

[husaberg]

I’ll spin them in the same direction and fire them in pairs 90* apart. I’m pretty sure the RG500 spins in the same direction.

352348

352349
i would have said no but it looks as if they do

352350

[F5 Dave]

I’ll spin them in the same direction and fire them in pairs 90* apart. I’m pretty sure the RG500 spins in the same direction.

352348

So from this picture there's a layshaft with primary gear visible behind the carb driving the clutch it looks like. . . On my phone screen in the sun on the deck ..

[el chupacabra]

Yeah, that’s the plan, have the layshaft drive the clutch exactly like the RG500 although all of the gears will be straight cut. I don’t think the engine will be too long as the layshaft is almost between the cranks. It might be quite tall though, but 85cc cylinders aren’t particularly large.

[F5 Dave]

So your concern is multiple cranks and the coupling. Else the logical would be drive it off one crank end and counter rotate driving other crank direct. It is tempting but you are probably right if you don't have a custom crank designed to effectively transmit 4 cylinders power through one joint.

Not totally keen on backwards for both, but you'd be very unhappy if you created something that just broke at the weak spot every 2nd meeting. Life is a compromise. Lots of oil as Jimmy sez, and aim for completion.

[Grumph]

i've got a good broken-apart drawing of the RG500 with 4 separate cranks if it helps. From Vic Willoughby's Racing Motorcycles book. I can if needed photo it and post it here.

[el chupacabra]

i've got a good broken-apart drawing of the RG500 with 4 separate cranks if it helps. From Vic Willoughby's Racing Motorcycles book. I can if needed photo it and post it here.

That would be awesome, it’s always good to see how other people have done things.

[Grumph]

I apologise for the flash bounce. Can't turn it off on this camera.
If you're coming up for the CAMS meeting I could loan the book.

[husaberg]

There is some pics on robinsons book not sure where it is though......

[el chupacabra]

I would appreciate that but I am not going to any CAMS meeting, unless that's the same time as motofest as I may heading to that.

Tonight I took some rough measurements and pulled out the gearbox, it is a fairly substantial unit. Can anyone tell me what the split gear on the clutch is for?

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[pete376403]

If the split gear is the same size as the one it backs on to, and if it is radially spring-loaded, then it is to reduce backlash/ clutch gear rattle

[el chupacabra]

Thanks, I was thinking it would be for something like that, I cant recall any other bikes I've worked on having something similar.

Jotting down some known dimensions to get a rough idea of size.

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[husaberg]

Thanks, I was thinking it would be for something like that, I cant recall any other bikes I've worked on having something similar.

Jotting down some known dimensions to get a rough idea of size.

352372

H100 and MB5 Honda's have them on the counter balancer shafts.
352375
5 o'clock

if it was me i would use that extra space to push the top crank back widen the v out ...........But if it was me it would also never leave the drawing board....

[jato]

exciting progress here - once you've got a good set of drawings you are halfway there...the yz85's are case reed? or just the later models? it'd be interesting to overlay the reed valves and intake boots on to your drawings and see how the intake air path looks - 90 degree is good for balance but depending on the layout the intake air may have to turn quite a bit. we need to have a whip-around so you can work on it day and night...

[F5 Dave]

If anyone needs a givealittle page set up for projects, it's you. And Neil.

Hope the rain doesn't cause you any more drama up there.

[el chupacabra]

The Yz is case reed, handily. My mate has some nsr250 carbs which are arranged in pairs that I can pinch, hopefully I can find another set as two little banks will be nicer than 4 individual carbs. I’ll have to offset the reeds or inlet manifolds slightly to get them right so the carbs aren’t stacked above one another.

But first I’ll do an accurate model of the gearbox, I’ll try use my mill like a CMM and confirm what I’ve found with digital callipers.

[F5 Dave]

The NSR carbs are small and big at the same time. Honda do thier double cable thing and it can take quite a bit of awkward real estate.

[husaberg]

The Yz is case reed, handily. My mate has some nsr250 carbs which are arranged in pairs that I can pinch, hopefully I can find another set as two little banks will be nicer than 4 individual carbs. I’ll have to offset the reeds or inlet manifolds slightly to get them right so the carbs aren’t stacked above one another.

But first I’ll do an accurate model of the gearbox, I’ll try use my mill like a CMM and confirm what I’ve found with digital callipers.

Yamaha did this with the YZR500 V4 ow..?whatever it was in 98
352379

Honda mounted the reeds side on with the NSR250.
352378
And you of course know this as you mentioned you have a RGV.
352377


The NSR carbs are small and big at the same time. Honda do thier double cable thing and it can take quite a bit of awkward real estate.
They start at 24mm for the MVX250 and go to 28 i think for the NS and up to a nominal 32-34mm i think for some of the NSR250's
352381

they are nicely made carbs but yes use a bit of realestate but height not width. As you say.
the old GT380 first ones had a linkage that could adapt to a std VM i think. okay no
but they would be about the right size..

352380

but TZ750s just had cable splitters....
352382
https://www.worthpoint.com/worthopedia/yamaha-tz750-throttle-cable-assembly-1787831373

[Grumph]

The NSR carbs are awkwardly laid out as they come. Lot of real estate on the left taken up by the cable drum etc, then the fuel feed is on the right.
The set i adapted for the bucket, I drilled and tapped the fuel gallery for an entry on the left under the cables and plugged the right hand end.
On the bucket the rhs was hard up against the frame. It's probably possible to make one set with everything on the right if you need them to be mirror image.

[F5 Dave]

MC18s are 28mm and I think they stayed pretty small.

[el chupacabra]

So my height gauge has showed up and I have since put it to good use, getting the engine measured up and drafted little by little. The gearbox does appear to be on the heavy side around 6.5kg.

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[el chupacabra]

Quick Update, I'm starting the design by drafting up a cassette gearbox, here's a couple of hours work, obviously I'll be able to print this and refine it. I've yet to add the shift fork guides and other minor features.

Here's an RGV cassette for comparison. This one is a whole lot heavier and it seems a whole lot harder to incorporate into a cassette style gearbox.

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[F5 Dave]

RGV gearbox die with 50hp so maybe bigger is useful for reliability.

[husaberg]

Quick Update, I'm starting the design by drafting up a cassette gearbox, here's a couple of hours work, obviously I'll be able to print this and refine it. I've yet to add the shift fork guides and other minor features.

Here's an RGV cassette for comparison. This one is a whole lot heavier and it seems a whole lot harder to incorporate into a cassette style gearbox.

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Cassetes are cool and all but wouldn't horizonal split be easier and provide most of the benefits?
From memory the britten lower case was basically a sump, flip it up and whip it off..... a lot like a VT250 actually...
i assume that's what the trumpy was going off the bearing....
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[el chupacabra]

Horizontal split isn’t off the cards, although I think a 3 piece crankcase might get complicated with the twin cranks and a lay shaft, I was just trying to emulate what everyone else does with twin crank bikes seeing as it works.

Hmmmm soo many decisions.

[husaberg]

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first 3 Cagiva last 3 RGV late.


https://www.kiwibiker.co.nz/forums/album.php?albumid=4842

https://www.kiwibiker.co.nz/forums/album.php?albumid=4848

https://www.kiwibiker.co.nz/forums/album.php?albumid=4861

https://www.kiwibiker.co.nz/forums/album.php?albumid=4845

https://www.kiwibiker.co.nz/forums/album.php?albumid=5064

https://www.kiwibiker.co.nz/forums/album.php?albumid=4837

https://www.kiwibiker.co.nz/forums/album.php?albumid=5017

[el chupacabra]

Thanks for that, that’s an awesome amount of reference material.
I think the cassette is the way to go at the moment. It seems like a common theme.

[husaberg]

Thanks for that, that’s an awesome amount of reference material.
I think the cassette is the way to go at the moment. It seems like a common theme.

Well yes on a GP bike yes as they have about 8 ratios to choose from for each gear and a minimal time to change between practice sessions.
it was also no cost bared exercise
I am not 100% sure triumph has that many options....i think they did alter some ratios. second third maybe;)
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[el chupacabra]

I’m not running a cassette to change the ratios, I’m more concerned with ease of manufacture and ease of assembly. Although it’s a bonus if I kinda commercialise it in the future. I also don’t want to make the cases out of too many pieces as I’m sure that won’t make them any stronger and possibly harder to machine.

Also I can print and test my cassette relatively easily which is also nice before carrying on with the rest of the design.

But if someone were to show me a design that makes my design simpler, I’ll be all over it. I could do horizontally split but I’m not 100% sure how I’d lay it out as the layshaft might make it real long.

[husaberg]

I’m not running a cassette to change the ratios, I’m more concerned with ease of manufacture and ease of assembly. Although it’s a bonus if I kinda commercialise it in the future. I also don’t want to make the cases out of too many pieces as I’m sure that won’t make them any stronger and possibly harder to machine.

Also I can print and test my cassette relatively easily which is also nice before carrying on with the rest of the design.

But if someone were to show me a design that makes my design simpler, I’ll be all over it. I could do horizontally split but I’m not 100% sure how I’d lay it out as the layshaft might make it real long.

That's why i like single crank, as by brain is to small.... It also makes it shorter by making it wider. gives more room for intakes as the cylinders are opposing It also cuts down on the gubbins needed. What are your plans for the ignition?

[el chupacabra]

Just running a zeeltronic 4 channel unit with two pickups off the standard 85cc flywheel. Nothing fancy.
The only reason for the 4 cranks is to do away with a custom crank. I can see that being an expensive exercise especially for a high wear item when it’s 85cc and you want to be revving the nuts off it all the time.

[el chupacabra]

352565

Here's a picture for a sense of scale, I'm going to see how it compares with my Banshee motor, RGV motor and RSV1000 motor before carrying on in case it is too long to accommodate.

I'll need to order the cylinder and crank soon if it looks like it'll fit in a bike.

Also it looks like I will need to remove a lot of mass from the gears as they could make the whole rotating assembly quite heavy.

352566

[husaberg]

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I am sure you have consdered this but you can shorten the engine by opening the v making it taller the NSR was about 113 degrees. okay 112 :)
352570352571
You can get the rear yzr500 dimensions by scaling off the wheel rim.

You could also bring the the gearbox closer by driving the clutch off one the outer cranks
But having the extra room allows space to watercool the cases.
352569
You could also bring the gearbox countershaft forward about 20 degrees by tilting it forward which will shorted the length to the countershaft

[el chupacabra]

I have been contemplating using a direct crank to clutch setup but it’ll be a disaster with the 85cc cranks. Using a stroked Banshee crank and making a large V twin popped into mind but that wasn’t the point of the project. . . Hmmm V3 using 1.5 banshee cranks joined together and sx150 cylinders. . . Seeing that BSL 500 on the weekend was pretty neat and got me thinking.

But then It has to be a V4. So much more appeal tiny little pipes and cheap parts.

The Banshee engine and RSV1000 engine are about the same length. The only thing is it might be a bit tight in an RGV250 chassis as the spars are only approx 240ish mm apart. So I don’t think the length or height will be a problem. I still might open up the V angle too, although I am worried about the balance if I do so.

[jato]

The cranks and layshaft look compact - the rest of it not so much...what is the layshaft to clutch center distance ( and gear sizes)? how many main bearings? I recall the RGB 500 gearbox was extensively drilled for lightness (even the gear dogs had about a 2.5mm hole right down the middle of them) selector drum looked like a bit of cheese. and they were bullet proof too. lightening a gearbox that has already been heat treated would be do-able but an extremely slow and expensive process - the carbide drill might only handle 2 holes before its toast. ponder ponder

[husaberg]

The cranks and layshaft look compact - the rest of it not so much...what is the layshaft to clutch center distance ( and gear sizes)? how many main bearings? I recall the RGB 500 gearbox was extensively drilled for lightness (even the gear dogs had about a 2.5mm hole right down the middle of them) selector drum looked like a bit of cheese. and they were bullet proof too. lightening a gearbox that has already been heat treated would be do-able but an extremely slow and expensive process - the carbide drill might only handle 2 holes before its toast. ponder ponder

You could do some complex math on the balance,
but as the Yamahas were often at 70 degrees which is 20 less than ideal at 110 that's the amount same less than ideal only in the opposite direction.
Your gears can incorporate a balance shaft as well.
352572

Also that Aprilia is at 60 and so was the Bitten.

[el chupacabra]

113mm off the top of my head. Clutch centre to layshaft.

I considered running the layshaft lower and having the lower crank in front and the upper above the layshaft. I think this might be an issue with intake angles being too sharp though turning through extreme angles.

i have decided all of the gears I am getting manufactured will look like Swiss cheese haha.

[jato]

sketches-with-maths that i've done show that with twin cranks spinning the same direction you can have any vee angle you like but you have to time them to keep the residual imbalance of for example the top left cylinder constantly opposing the residual imbalance of the bottom left cylinder. no balance shaft needed and no rocking couple either . i'm 90% sure of the sketch. with little cylinders i believe you can get away with a bit but when/if you go to say a 250 cylinder you have to get the balance pretty well spot on

[el chupacabra]

At least how I plan on putting it together I”ll be able to change the firing order by taking out the balance shaft and rotating the cranks. So changing it up won’t be a hassle.

I”ll do another layout tonight with the lay shaft lower down and I’ll see what the intake angles look like.
But otherwise I’m happy with the current layout. It leaves a lot of room for the oil and coolant pumps.

[el chupacabra]

I love how quickly you can change things in CAD, here I have rotated the cassette 10 degrees CCW and lowered and rotated the crank 35 degrees CCW it definitely looks a bit more compact.
352581

[el chupacabra]

Here I’m after some advice as I’m thinking do I run a mechanically driven coolant pump from a gsxr600 or something similar. . . Or could I run an electric pump moving around 20-30l a minute, I seem to recall something mentioned about 1l per min per hp but I’m unsure if that is necessary.

Also I’m thinking about a small electric pump for the gearbox oil as it will speed up the design process immensely.

Let me know your thoughts or any experiences you’ve had.

[husaberg]

Here I’m after some advice as I’m thinking do I run a mechanically driven coolant pump from a gsxr600 or something similar. . . Or could I run an electric pump moving around 20-30l a minute, I seem to recall something mentioned about 1l per min per hp but I’m unsure if that is necessary.

Also I’m thinking about a small electric pump for the gearbox oil as it will speed up the design process immensely.

Let me know your thoughts or any experiences you’ve had.

Very few pumps are available that flow enough water and don't suck too many amps.
https://daviescraig.com.au/electric-water-pumps
7-10 amps needed


Kubota's have a neat little alternation with plenty of juice they are used on a lot of classic bikes.
https://www.as-parts.nz/product/1743350
352639

if you were heading the electric route
Look at pumps from EV or Hybids. or V8's like craig Davis.
That HP/h20 was based on GP experience i guess if you are 300HP a liter rather than 400/litre you could drop it the same amount % wise
You can also belt drive the pump with a toothed belt but whatever you do mount it as low as possible.
You can drive this of the ignition shaft or even off the end of the rotor like a KTM50.
352637352638

[jato]

only 2 cents worth of info but way back when the first watercooled rm125 came out 2 of us did some very crude observations and concluded there was an astounding waterflow for a puny little 125 - some thing like a healthy garden hose on half blast (or more) at full revs. maybe only 1 cents worth of info....

[el chupacabra]

Not a bad idea driving it off the crank end. Or even the layshaft. . . Or on the clutch cover using Yamaha banshee parts. Maybe the electric route is not really any simpler and won’t provide enough flow.

[F5 Dave]

I tried cheap pumps on my approaching 30hp bucket and eventually bought a decent arrangement which was an intercooler booster pump for some American car off ebay. Too long ago to be in my history. Was entirely adequate for the purpose and lives on 6 years after I sold the bike.

Ran off a CR250 8 pole stator and drove an Ignitech, shift light, det counter, shifter as well and voltage would not drop at all during all gears run on dyno.

Could be a bit meagre for 4 cylinders. But gives you an idea of what a decent stator can cope with.

[jato]

weight saving is always on offer if you can get one part to do more than one job - if you were to use something like a yz250f oil pump https://pronorthparts.co.nz/engine/oil-pumps-idler-gears/ and drive it of the back of the clutch then you could make a longer oil pump shaft and use that to drive the (gsxr 600?) water pump. the water pumps i've looked at all turn the same direction as the wheels and turn around 60 ish % of engine speed - the lay shaft may or not be suitable. the oil pump drive gears i've looked at so far have all been std module 2 so easy to fashion up a gear train if needed.

[el chupacabra]

I could make something integral to the cassette, I’ll have a play around when I get a minute as I have a few Honda c50 oil pumps around and I could run the parts in the cassette. Maybe running a plastic drive gear off of the transmission.

I’ll have a think about what I can do with the yz units too as they look fairly simple to implement.

That rgv cassette does have a pump I could use but I want to make it out of parts that aren’t unobtanium.

[husaberg]

I could make something integral to the cassette, I’ll have a play around when I get a minute as I have a few Honda c50 oil pumps around and I could run the parts in the cassette. Maybe running a plastic drive gear off of the transmission.

I’ll have a think about what I can do with the yz units too as they look fairly simple to implement.

That rgv cassette does have a pump I could use but I want to make it out of parts that aren’t unobtanium.

Rob from ESE was doing some stuff with these sort of pumps, not sure what he ended up doing.
they squeeze a tube
352640

https://youtu.be/AMiXme4bMUk

[Kickaha]

Maybe the electric route is not really any simpler and won’t provide enough flow.

They flow enough for F1 sidecars running 200hp, thermostatic controls and can be set for a warm down period after you stop

[el chupacabra]

I'm yet to make up my mind on the water pump situation but I have stared mucking around with integrating the Honda/Lifan pump into the cassette.

can anyone here tell me if the modules used in gearboxes are standard sizes or will they be all over the place?
1st gear on the output is 37 teeth and has an OD of 98.35 and a minor diameter of 88.2 this gives a module of around 2.54, the reason I need to know this is so I can manufacture the drive gear for the oil pump possibly from nylon or some sort of plastic. I've really answered my own question but maybe there's some handy tricks i don't know.

Here is a possible location for the pump. I'll relocate the bolt holes slightly further apart.

352655352656

[husaberg]

I'm yet to make up my mind on the water pump situation but I have stared mucking around with integrating the Honda/Lifan pump into the cassette.

can anyone here tell me if the modules used in gearboxes are standard sizes or will they be all over the place?
1st gear on the output is 37 teeth and has an OD of 98.35 and a minor diameter of 88.2 this gives a module of around 2.54, the reason I need to know this is so I can manufacture the drive gear for the oil pump possibly from nylon or some sort of plastic. I've really answered my own question but maybe there's some handy tricks i don't know.

Here is a possible location for the pump. I'll relocate the bolt holes slightly further apart.

352655352656

You can check by adding the tooth counts if they all add the same or close you can assume they are all the same.

Kawasaki used something like 4 modules in one gearbox for a Kr250
Bradleys book has some excellent stuff on gears.
352657
Fletner her makes them for a living.....
have a look at triumphs part fiche on line you might save yourself making one
Or you can just use chains like Honda did for years.

[el chupacabra]

No dice on the parts list. Hmmmmm. I’ll try and take some more accurate measurements tomorrow, because if I model the gears with .05 backlash I seem to get around 2.565.

That would be a handy book to have.

[jato]

re the tooth form do you know what the shaft center distance is, and the tooth count on ist drive?

[jato]

Acetal - magic stuff - very suitable for lightish duty gears

[el chupacabra]

The shaft centres are 68.05mm between the input and output. 16tooth and 37 tooth

[jato]

just entered 16:37 in my favourite gear calculator - something fishy alright - i recall the shaft centres are 68mm so module 2.5 doesn't work ... maybe there are still a few old school poms in the triumph factory

[husaberg]

No dice on the parts list. Hmmmmm. I’ll try and take some more accurate measurements tomorrow, because if I model the gears with .05 backlash I seem to get around 2.565.

That would be a handy book to have.

i was meaning to look for suitable gears? failing that put Honda gear on shaft job sorted
maybe email Nova and ask for help you never know they might help you.

[el chupacabra]

I’ve sent nova an email, here’s hoping someone is sympathetic to my cause. I’ll probably drop by the workshop doing the gear cutting and see what they reckon but it works out around 2.566

[jato]

... thinking about the c50 oil pump ... does the triumph have a spray bar as std that squirts oil into the mesh of the 6 pairs of gears? add in the feed to the centre of the shafts and possibly your own squirter for the primary gears - the little honda pump may not deliver enough. if Nova don't get back to you, you could cut your own acetal gear using a (imperial) DP10 cutter (equiv to mod 2.54)then do a few mock-ups on the bench to find a centre distance that gives a whisker of backlash and you'll be in business. FWIW a mate once took a bandit 1200 clutch gear to BOp gearcutters and the crusty old guru there commented that if the top of the teeth were trimmed back by 0.4mm or such then you would have a std (and common) mod 2.5 gear, and thats what they would make to run with the bandit gear.

[el chupacabra]

No spray bar that I’ve seen although I could run the oil level so that the gears have a very light splash to aid in lubrication. Probably not ideal for drag or oil life but probably better than not enough oil.

Hmmm I’m sure the old crusties local to me might know something, they have all the gear hobbling equipment and what not. Fingers crossed that someone knows what I need to know because when I make the gear to mesh with the clutch I definitely want the correct module.

[husaberg]

YZR ratio options
352662352663352664

plus patton 500gp crank
352665
352666

[el chupacabra]

I was thinking about doing the crank like the patton originally, although I wonder how much torque you can transmit through a single keyway. I’m sure I can google that right now haha.

I’ve finished designing the oil pump and am quite happy with the outcome. I’ll post the progress when I get home. Nova got back to me and explained the situation with the gears which was nice.

It’ll almost be time to 3D print the cassette and oil pump.

[el chupacabra]

Here's what I think could be close to the final oil pump, it will be driven off of first gear. I will need a small copper tube to feed the back of the output shaft bearing. The pump will be the Honda parts mounted in a custom housing with a custom drive shaft.

352712352713352714

[jato]

that part looks like it belongs in a race engine ... time to get a bit of ally plate then push "cycle start"

[el chupacabra]

I should have my own 3D printer tomorrow to speed things up.

Otherwise this showed up, check out the quality of the casting . . . It’ll work for mocking things up but maybe I go OEM when it’s time to get it running. I think the core shifted on them.

352761352762352763

[F5 Dave]

Hard to tell much from pictures with the exception of the boost port that looks entirely on the piss.

[el chupacabra]

The rest of the casting seems good so far. They refunded $35 after I sent them the photo so really it only cost $60 + Shipping so not too bad of an outcome for a mock up cylinder and piston.

I was planning on using four of these but if the quality is this hit and miss I might have to go OEM. I am yet to measure the port timing.

[husaberg]

The rest of the casting seems good so far. They refunded $35 after I sent them the photo so really it only cost $60 + Shipping so not too bad of an outcome for a mock up cylinder and piston.

I was planning on using four of these but if the quality is this hit and miss I might have to go OEM. I am yet to measure the port timing.

So thats 95$ with niksil plating??

[F5 Dave]

Well. . . Silver coating of some description. . .

[el chupacabra]

Yep, and a single ring piston . . . Still might buy 3 more haha. Hopefully this is a one off.

[Grumph]

You'd have to wonder where the ring pin is. Is that why the boost port is skewed ?

[husaberg]

13$ each for KTM85 cylinders with PV shipping only 10$ wtf.
but you will need a head as well. which for som reason id 80$ each?
https://www.aliexpress.com/item/1005003510825075.html
https://www.aliexpress.com/item/1005005402417497.html

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The beauty of the KTM as well as a PV they do a 105cc kit.

[el chupacabra]

I know Athena do a 112 kit for the yz which would take it out to 450cc.

The shipping is where they pump the prices if it seems too cheap.

[el chupacabra]

Now I can test fit everything before carrying on with the design

352816

[F5 Dave]

Sexy. Apart from your weird thumb.

[el chupacabra]

Thanks. Weird thumb aside it all fits together quite well. I’ll have to get a picture of it all assembled.

[F5 Dave]

Chest photo.

[el chupacabra]

352823

Here it is spinning like it should.

Time to design the rest of the engine.

[jato]

i'm not familiar at all with 3D printers - can the printed cassette plate be used as a pattern at a foundry? or can it be printed as one? if so i'm sure we could put together a wish list ...

[el chupacabra]

If I add the draft angles it could 100% be used as a pattern for a casting. I had only planned on lost foam casting but plastic patterns would be suitable for multiple castings.

[el chupacabra]

I've started chipping away at the design again and I am contemplating whether to integrate the lay shaft into the cassette plate or not and what bearing i should use on the clutch side, ball bearing or cylindrical roller. . .
I am thinking with the lay shaft I will have a single key way for each gear and it will be secured with a single nut on each. The shaft is looking fairly chunky, but I don't want it to flex. Any feedback on keeping the lay shaft separate or integrated would be welcome.

Also I'm thinking long and hard about how to install said shaft as it won't pass straight into the cases. The only way I can see it working is if the non clutch side of the shaft bearing is installed last, maybe I can put it in a small housing like this.

353065353066353067

[jato]

first things that comes to mind are you could have a single shouldered (NJ?) roller bearing on the left side of the layshaft and a ball bearing captivated in a pretty little housing 1mm bigger than the driven gear - then it would be easy to install as a unit. any thoughts on crank and layshaft gear diameters?

[el chupacabra]

They are module 2 44 teeth on the crank and 36 on the layshaft. I can’t really do much about the diameters as I need the 2.5:1 ratio. The 44 tooth gear is almost the same diameter as the cranks. This means the layshaft will need to go in on an angle till it clears the casting around the crank. Otherwise I can enlarge the gears to 50/41 teeth but the whole engine gets a whole lot longer.

Maybe I could make that pretty little bearing housing threaded and locate in the cassette from the inside, making assembly easier avoiding a press fit when placing the cassette plate on.

I’m just waffling now but there are a few challenges to work through.

[jato]

a 34T layshaft gear is not a possibility? you could then use a 72mm ball bearing with no pretty housing needed? the 2.5:1 is set in stone?

[el chupacabra]

I could muck around with the sprockets a tooth or two to get the same result. The little housing is a good way of stopping the bearing spinning while making it easy to install. I could always make the shaft a slip fit instead. I’ve thought up a way to install the shaft which will involve off setting the gears on the cranks to the LHS of the motor as far as possible so I can place the shaft in before sliding it into the NJ cylindrical roller.

I’ll model it and share it. Are there any drawbacks of a slip fit? I’ll probably have to do the same with the output shaft from the triumph on the sprocket side.

[Grumph]

I wouldn't do a slip fit on the output side bearing. Very high loads there and it could easily turn to custard.

[jato]

while not ideal from a tech point of view as greg mentions a slip fit (output shaft into output bearing) is a practical neccessity for a cassette style gearbox and for a relatively low use thing they appear to survive ok. as always its the minor detail thats important - an output shaft of a big enough diameter, ground to give something like 5 to 8 microns clearance in the bearing bore, and potentially the presence of the thin o-ring on the outboard end of the inner race. some 500 gp bikes i've worked on had done hundreds of hard hours and the output shaft was still happy enough with this arrangement.

[Grumph]

Fair enough. My experience is coloured by large heavy posties - aka racing couches. That bearing is probably the highest loaded on a chain drive bike.

[husaberg]

Lateral location of the gearbox shafts shouldn't be a big issue as it anchored on the mineshaft with the side play contained with the clutch.
plus on the countershaft with the drive sprocket and in the cassette box itself also with the inner housing.
About a week ago i posted a pic of the Honda RS750 countershaft its a separate piece than than the countershaft which i believe is a result of its original part of the shaft drive set up on the XLV750.

353073

353070353071
353072


Note it actually has a Chain primary unlike the XLV750R gear primary
that gear isnt a kickstart gear its the final drive...
353080
All or nearly all motorcycle gearboxs are simple sliding fits
bearings are cheap...

[el chupacabra]

Interesting, I thought slip fits wouldn’t cause too much grief. Are all cassettes a slip fit?

There is always option B which would entail no cassette and splitting the cases like any mx bike horizontally, essentially two halves and then having a third piece which holds the 4 cranks.

This might be far simpler to assemble but I’m unsure about the strength differences. I’ll model it with a cassette first and see how it goes although I don’t exactly have interchangeable gears so the cassette probably won’t come out anyways.

[el chupacabra]

So I went to a 55/40 tooth crank to lay shaft and 28/87 to the clutch 2.26:1 For a top speed of about 260kmh @13,000rpm.

Here's the latest design update, the cassette is now a lot larger. I am using the NJ roller bearing on the clutch side, between this and a ball bearing the shaft should stay centered as all of the gears will be straight cut. I will have to remove a lot of meat from the crank gears to make them lighter, they can likely also be thinner being such a large diameter.

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[el chupacabra]

Slowly but surely making progress. 353211

Still a lot to chisel away before patterns are made.

[jato]

looking good! a friend is asking if 125 cranks and cylinders could be shoehorned into the case...

[el chupacabra]

Thanks. An Athena 112cc kit should bolt in with no additional work. Good for Hp somewhere in the low 30s making the bike 450cc. I am unsure about a 125, the cylinder could be made to work but the 54.5 vs 47.8 mm stroke might be harder to accommodate without a redesign of the lay shaft gear size.

[el chupacabra]

A couple of hours at the PC and a few wines later, we have some more progress with some small hurdles to overcome, namely how thin the case is by the RHS crank wheels (about 2.0mm).
There also isn't too much meat for studs in between the cranks. The Lower engine mount is a bit ugly too.

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[el chupacabra]

353219

This is with the cassette plate in position.

[jato]

More good progress! should we send a couple of casks of wine and wait for the result? re case strength in recent times i've had quite a few (mostly KTM) engines arrive at the workshop that have cracked or broken in use - anaemic gusseting and thin sections trying to contain lots of power and merciless gearshifts... some of those ktm sections were slightly under 2 mm thick. compressive loads maybe ok but in areas in tension more strength is needed. the bottom mount is crying out for something alright.

[el chupacabra]

I'm sure twice the wine consumption would half the development time haha. I've beefed up the areas as I was worried about being able to flow aluminium through such a thin area when casting as 2.5mm will be close to the limit and I don't want to push it. I could always add material during the casting and remove it with and end mill during machining to make sure the pour is successful.

I have also started laying out all of the studs and everything is pretty straight forward apart from the upper cylinder where the case studs get close to the cylinder studs. I say stud but it will likely be recoiled for a cap head. I'm wondering if a slot where i have highlighted in the last picture would be a good solution to get access to a bolt with a spanner and not having the cap head in the transfer port guide. . . hmmm, things to think about.


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[jato]

For the upper cylinders' rear case bolts would an option be to have 4 studs coming into the gearcase cavity (visulising 4 back-spotfaced pads in there with loctited flange nuts so nothing goes visiting the gearmesh) another (not ideal but practical) option could be to cant your proposed capscrews forward 10 degrees or so to give clearance to the cylinder studs.

[el chupacabra]

I could make a sub plate that holds the studs for the cylinder, or I could make a large blanking plug for the case stud that is threaded and has the cylinder stud in it centrally. Or thread the plug so the cylinders can be secured with cap heads for the top bolts.

I’ll investigate tomorrow before I carry on. I want to be able to take the cranks out without removing the gearbox. I also don’t want to make general assembly too difficult, it might just work how I have it designed. I plan on using O rings instead of silicone to seal the case halves.

[husaberg]

betcha that single crank suggestions looking mighty attractive now:msn-wink:
Yamaha changed the crankcases pretty much every couple of years v angles intakes etc trying to get the best compromise between flow and compactness.
they also had to run special offset carbs and ugly intake rubbers
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Normal Honda do stuff not the easy way just as a form of corporate masturbation, but not with the NSR's.
the Honda has a sight loss to slim the engine but tiny compared to the YZR.
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4 of the 6 petals only
What i do notice though with yours having the cranks in all the same direction this should pick up soe power compared to contra rotating cranks that have one side fighting the intake flow

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Kawaski

RD200 47mm stroke
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[el chupacabra]

In a perfect world i would make a single crank with flying webs or twin cranks geared together. But one of my key design constraints is to be able to use off the shelf available spares. (The 20mm shafts on the YZ85 crank would definitely be too weak for 120Hp)

Im all for changing the design if something gets pointed out that I’ve done that could be improved. But here’s the design philosophy I want to follow:
Must have available fast moving spare parts (YZ and Triumph)
The less custom parts inside the crankcase the better
Must be rideable by a half decent club level racer (600cc level power not 1000cc levels)
Must be deigned for longevity and ease of servicing
Power to weight ratio of 1:1 would be nice

I could always make my own crank wheels for the clutch side and beef them up. Hmmmmm but then the off the shelf cranks won’t drop in and I’d still need at least 3 custom gears manufactured.

[el chupacabra]

I almost rolled it right back so like Honda the rear cylinder studs would also be the case studs. But that would involve re modelling the intake ports and changing the V angle to 80 degrees. So I came up with this not so elegant solution, but not so difficult to implement.

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[husaberg]

In a perfect world i would make a single crank with flying webs or twin cranks geared together. But one of my key design constraints is to be able to use off the shelf available spares. (The 20mm shafts on the YZ85 crank would definitely be too weak for 120Hp)

Im all for changing the design if something gets pointed out that I’ve done that could be improved. But here’s the design philosophy I want to follow:
Must have available fast moving spare parts (YZ and Triumph)
The less custom parts inside the crankcase the better
Must be rideable by a half decent club level racer (600cc level power not 1000cc levels)
Must be deigned for longevity and ease of servicing
Power to weight ratio of 1:1 would be nice

I could always make my own crank wheels for the clutch side and beef them up. Hmmmmm but then the off the shelf cranks won’t drop in and I’d still need at least 3 custom gears manufactured.

i was being cheeky not trying to show disrespect to your design
i get it but i strongly disagree 20mm would not be enough Aprila rsw125 was that size for years only the very last rsa was 22mm crankpin
The Barton engines were also 20mm pins on three cylinder 480's or so. at over 100 plus hp.
or are you meaning the wheel shafts?
if thats the case pretty sure cr and ktms were beefier 22 i think?
you are right off the shelf is great. RD200 would not be that easy to find that''s for certain .

[el chupacabra]

I was meaning the wheel shaft part of the crank the primary gear is keyed to. On my banshee the bearing ID is 25mm, on the YZ it is 20mm. I was thinking a 20mm shaft with two Gears, the coupling and primary drive would be a weak link. (Picture to help show what I mean).

it’s easy enough to make a crank wheel on the lathe with a longer shaft to run a support bearing but that’s a lot of work. Use the original magneto side wheel and maybe bore one of the magneto wheels to make 20mm and key it to the 20mm primary and join the cranks so to have 2 instead of 4

Also, don’t worry about causing any offence, I welcome the criticism or other ways of doing things better. I appreciate all the pictures as I use them as a visual guide to make sure I’m on the right track.

353269

[husaberg]

I was meaning the wheel shaft part of the crank the primary gear is keyed to. On my banshee the bearing ID is 25mm, on the YZ it is 20mm. I was thinking a 20mm shaft with two Gears, the coupling and primary drive would be a weak link. (Picture to help show what I mean).

itÂ’s easy enough to make a crank wheel on the lathe with a longer shaft to run a support bearing but thatÂ’s a lot of work. Use the original magneto side wheel and maybe bore one of the magneto wheels to make 20mm and key it to the 20mm primary and join the cranks so to have 2 instead of 4

Also, donÂ’t worry about causing any offence, I welcome the criticism or other ways of doing things better. I appreciate all the pictures as I use them as a visual guide to make sure IÂ’m on the right track.

353269

Early KtM85 is 22mm shafts both sides.
Late ie post 13 is 25 and 22mm they have a very nice cylindrical roller on the 25mm side NJ 205
later ones are 20mm crankpin earlier are weirdly 22 pin.

The Honda CR80/85 IS 22MM mainshafts either side.

all the rest YZ RM and KX are all 20x52x15. bearings.

the other thing with KTM cranks is they have a keyed rather ten splined primary drive gear.
353270
https://www.mitaka.co.uk/CATALOGUE/MX_CRANKS.htm

[el chupacabra]

That’s good to know about the KTM cranks, it’s a pity aliexpress don’t sell 85sx cranks. They do sell cylinders though, minus the power valves, hopefully the lack of a power valve on the yz don’t make it too much of a handful.

[husaberg]

This was a homebuilt 100cc twin based on the Aprilia Rotax v twin.
353271

if you are set on the YZ stuff you can make up atac valves
353276353272353273353274353275

https://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=307606&d=1420439042

[F5 Dave]

So if we could just group up about thirty of those in a row. . .

[el chupacabra]

Now that 10cc motor scaled up to 100cc would be a neat idea using some good bucket legal cylinders and an mx85 gearbox or the like.

I've though about using ATAC chambers on the rear cylinders to start with obviously later on once it is running. As the cylinders fire in pairs the chamber can probably be shared.

[F5 Dave]

Picking up some old RG50 cases sometime back I did consider a Vtwin conversion. But I'm done racing for now, no point getting more projects beyond what I'm going to ride myself.

[husaberg]

Now that 10cc motor scaled up to 100cc would be a neat idea using some good bucket legal cylinders and an mx85 gearbox or the like.

I've though about using ATAC chambers on the rear cylinders to start with obviously later on once it is running. As the cylinders fire in pairs the chamber can probably be shared.

It was a 100cc i just ran out of ink.

[el chupacabra]

I was going to say the cylinders looked a bit too detailed. Its looks like a PLA 3D print more so than aluminium.

Here's an update after removing a heap of material. Luckily I will be lost-foam casting and won't need any cores.

Also, It appears that the lower crank will push oil around probably foaming it up quite a bit, I will probably make the sump slightly deeper so the oil pump can pick it up and spray it around. . . or just see what happens.

The cases alone would weigh 24kg, time to cut even more weight. 7kg is what the upper cylinder part weighs.


353278353279353280

[el chupacabra]

Major cock up . . . I forgot how big the clutch is . . . Oh well, time to rotate the lot forward and lift up the lay shaft, there is a good 4-5 hours down the drain.

At least I haven't made any parts yet.

353283

[husaberg]

Major cock up . . . I forgot how big the clutch is . . . Oh well, time to rotate the lot forward and lift up the lay shaft, there is a good 4-5 hours down the drain.

At least I haven't made any parts yet.

353283

Are you going to 3d print it in plastic minus as a test like these ones?
i was thinking he was going to 3d printed in alloy but He eventually CNC'd them in Alloy.
for the first one it might be a good option to as you will not need to remove so much metal afterwards and you can add in gussets etc.
but it would be good to print it 3d print minus 5% to put it in your hand so actually see. Well thats how my brain works anyway.
353284353285353286353287

On trick i learned from somewhere was to have a separate oil for clutch and Gearbox as you can then run two levels but i guess with a spay bar that will not be needed.

[el chupacabra]

I will print it and look at it all. Then I will use a cnc router and make it out of 4-5 layers of high density polystyrene all glued together, making it easy to machine all the over hangs.

I was up thinking about it last night, how the clutch will hit the RHS upper crank wheel. I will just translate the cassette to the right 15mm and make the layshaft a little longer problem solved.

[Grumph]

If you're going to the trouble of making a longer Layshaft, the alternative is a longer mainshaft and a dry clutch....

[husaberg]

I will print it and look at it all. Then I will use a cnc router and make it out of 4-5 layers of high density polystyrene all glued together, making it easy to machine all the over hangs.

I was up thinking about it last night, how the clutch will hit the RHS upper crank wheel. I will just translate the cassette to the right 15mm and make the layshaft a little longer problem solved.

You can extend the shafts its pretty common TZ has done it on the ESE thread and the Barry Hart Sparton had extensions welded on to fit TZ clutches. As the Sparton place was the forerunner i think to Dyson/Nova they had all the equipment to make their own gears and shafts yet they chose to just weld on bits.

[jato]

sorry to hear about the set back - considering the constant effort by the designer to be saving weight is it possible to use a smaller (lighter) clutch and not shuffle / enlarge the layout? assuming the clutch is running at 40% of engine speed or so it won't have so much torque to deal with. I notice the RMZ250 clutches piled under the bench here are 8 plate and measure 148mm OD. easy to make a gear for them too with their rubber dampers. also easyish to spline the hub to suit the triumph shaft. another 5 cent thought - how does the tyre width/chain/front sprocket/geabox to crank centres look ?

[el chupacabra]

I’ll get some dimensions when I slave away tonight. The clutch gear currently is 178mm. Overall It is currently smaller than the original triumph engine funnily enough. It might be 50mm longer to the lower spark plug. I think I can make it work without too much of a redisgn. I could Run the magneto on the RHS if I’m worried about total width. I’ll measure it up but it’ll only be 20-25mm wider at the most.

[el chupacabra]

I could just offset the upper cylinders too, it’ll make carb mounting more direct. But reeks of effort, I’ll see how much is involved when I get a chance to jump on the PC.

Future me will model the clutch gear so I can see it while designing haha.

[F5 Dave]

So what is wine choice tonight?

I'm a heathen and on a batch brew IPA we did at local brewery in a class. It's several steps away from home brew. Could do with a bit more fizz. Might leave it a week.

Enjoying this thread.

[pete376403]

Is there /was there a "what are you drinking right now" thread? So as not to derail (derailleur - geddit?) this gearbox one. (however, a Keruru "Country Mile" America Amber Ale is washing down pizza)

[F5 Dave]

Not far from you then. I've move to Heart of Darkness. The Agent.

TBH it's much better than what we made. 2 cans down.

Must get back to Brewtown. Just a distance.

[el chupacabra]

I've made the changes, it was not as bad as i though, when you think about a KR1 motor, they are massively offset to one side.

Here is an overlay of the original Triumph motor.

353293

[el chupacabra]

I didn’t see the latest replies before I posted, usually it’s a Shiraz, ‘jam shed’ is my favourite right now but tonight it’s sugar free Pepsi and Bacardi haha.

I feel red wine improves my creativity.

[jato]

There's the clue everyone - send kx cylinders and casks of cheap red and then we can sit back and see what emerges...

[el chupacabra]

So assembling this will have a 'funny'. the lay-shaft will have to be installed and then the cassette placed on after the fact as the part the cassette bolts to will interfere with the 40 tooth gear. I've chosen to put the NJ roller bearing on the RHS to make assembly easier and an adequate ball bearing would be too big.

Everything is still looking thick and heavy at this stage. The only problem with going too thin is it may cause issues with the aluminium 'freezing' during the pour. I'll double check but Im sure some of the sections on the V twin I cast poured ok at around 4mm thick.

353294

[el chupacabra]

1/3 scale

353306

[el chupacabra]

I’m wondering about how I’m going to do the coolant flow, I think it’s going to enter under the exhaust on the cases and work up to the cylinder head and then back to the radiator to simplify plumbing. I’ll try and place the feed so the distance from the pump to each pair of cylinders is equal.
This has me thinking about water pumps and my options. Any feedback or ideas would be welcome, especially as to what is and isn’t important or common failures you may know of.

Option 1 - make my own pump housing and impeller with 2 outlets, using standard seals and a bearing, run it direct drive from the LHS end of the layshaft. This will mean I will have roughly equal flow out to each pair of cylinders.

Option 2 - same as option one but tucked away under the motor and belt driven off the LH end of the layshaft.

Option 3 - use a pre existing pump either on the end of the lay shaft or belt driven under the motor, the problem being I will have to divide the flow with a tee. Pros are easy to replace and I could use one with sealed bearing so it can be under the motor. Also this means less custom parts.

China has a whole heap or maybe I use one off a gsxr 600 or the like with sealed bearings. The later gsxr ones just seem to have a plain bearing. Maybe I could make just the inner housing for a later gsxr one as they are so cheap or at least use the seals and impeller.

353323353324353325353326

[jato]

SV650 pump - twin outlet , common, easy. they run anti- clockwise looking at the inlet of the impellor which may influence where it is fitted. 50 or 60 % of engine speed should be plenty of flow... you'll likely want to make your own back plate with outlets aiming the right direction.

[jato]

16 usd plus no doubt heaps of freight https://www.ebay.com/itm/401832873308?

[husaberg]

R1 includes the oil pump
353327

R^6
353328

it seems to be common to uprate these water pumps
BMW S1000rr Water Pump
353329

https://jetprime.com.au/jetprime-enlarged-water-pump-for-bmw-s1000rr-r-xr-2009-2018

[Kickaha]

Davies Craig remote electric pump, thermo switch controlled and can be set to have a cool down period when you switch off

[el chupacabra]

I know a 600 moves around 60L/min @10,000rpm, I'm torn between the booster pump from Craig Davies 30L/min and using an R6 water pump geared somewhere off of the gearbox or crank, I know that spinning it at 1:1 will be far too much so I cant run it directly on the end of the crank, extra losses and maybe cavitation will be consequences. I know slow water will leave HP on the table but slow down development. That electric water pump looks very tempting.

Or maybe I can do something like this. even though it is 1:1 . . .

353331


Hmmmmm. . . after writing this I've decided electric pump it is. Why add a whole other custom assembly when I don't even have a finished prototype. High performance can come later.

Now I can Ignore all of my worries associated with cooling the engine and move onto cleaning up the model, potentially making some patterns and the crank coupler blanks and maybe the lay shaft, should the lay shaft also be en36 or will plain old 4140 be sufficient?

[Grumph]

EN36 Hardens nicely and better core strength.

[husaberg]

for joining the cranks
this is the Harley Aemacchi 250RR they had a 350 version at 74HP, not sure what the 500 crank looked like.
note how they joined the cranks.
353335353336353337

[el chupacabra]

That’s pretty simple. I’ve seen something very similar on a speedway setup for 2x Cr250s mated together. 353343353344

The only difference is that mine also shares a gear as part of the coupling. I think a press fit should be ok and I’ll probably use a tool like this to remove it, like the ones you use to take the roller bearings off a KTM crank.

353345

[husaberg]

Hi what are the pics of? the speedway cr250x2?

here is the yankee 500 made out of 2x 250cc Ossa's by Ossa usa or something.
353354353355353356

[el chupacabra]

Pretty much exactly what I’m doing minus the huge chain and it’ll spin the other way. I wonder how reliable the setup was.

[Grumph]

Pretty much exactly what I’m doing minus the huge chain and it’ll spin the other way. I wonder how reliable the setup was.

Pretty sure the dirt version did several 3 day trials and may even have done a 6 day. Good way to test how tough it was.

[el chupacabra]

We will see how it goes. on another note I am about to add a front engine mount, does anyone have any thought on through bolts vs threading the engine on each side individually?

I'm always a little worried about inducing stress into a trellis chassis via tightening the engine mounts. I think one side will have a fixed spacer and the other will use an expanding spacer like a Yamaha R6. So the frame doesn't squeeze onto the engine. I can't help but think 6 steps ahead of where I currently am.

353363353364

[Grumph]

Not keen at all on engine mounts threaded into cases. Not good practise IMO. Far too much chance of fretting and cracking IMO.

[jato]

Being a bike designed to race - reliability closely followed by light weight . you can design a subtle amount of flex into the hangers for the top engine mounts. robust "doweling" of the cases is assisted by all those main bearings so i'm sure you wont have CB 900 troubles.

[el chupacabra]

Here's what I've come up with, 10mm straight through, directly in-between the main studs.
353365353366

Also does anyone have any engine weights on hand for comparison?

So far the Crankcases (17.811kg) and Cassette (1.32Kg) weigh a combined 19.1Kg without cylinders/pistons/cranks and I know the gearbox weighs about 6.5Kg minus the clutch.

[jato]

hmmm that through bolt with its washers and nut is just on .25 kg . versus 60grams for a pair of 35mm m10x1,25 into helicoils,

[el chupacabra]

I'm not too sure if you're being sarcastic or not haha. An RG500 is apparently 55kg and an RGV250 is around 32kg. Hopefully I land somewhere in between there.

[jato]

Just weighed my TZ 250 (L spec) engine 27.1 kg (no carbs or ignition stator) around 70hp . if you were to add 6kg for another pair of cranks and another 3kg for cylinders (it already has a layshaft) then you could say just under 40kg would be ok but 35kg should be achievable being your engine has 85cc parts.

[husaberg]

i have one if you want to see it in the flesh but they are a disposable item on any BMW ask at a specialist and they will find one for you'

I found a rather interesting variable speed electric water pump.
I even have a couple here now thanks to a benefactor
Its used on all manner of BMW's as the primary water pump.

The specs are 2kgs and 125 liters /minute.


It needs a controller to operate in variable speed mode but I am pretty sure something could be bodged up with a 555 circuit and a piggy back. Or an Arduino circuit.
http://www.nomad.ee/micros/pwm555.html

or
https://www.maximintegrated.com/en/app-notes/index.mvp/id/3530
http://www.reichelt.de/ICs-MAX-1000-9201/MAX-6653-AEE/3/index.html?ACTION=3&GROUPID=5470&ARTICLE=115924&OFFSET=16&SID=14VVq3JawQATYAAHPOtpM0258660c7c3713fe135246538 1224c40&LANGUAGE=EN



http://www.tecomotive.com/download/manual_tinyCWA.pdf
The manual for this controller gives out the important specs

if you go to the original post you will see the the pics.

[husaberg]

I've started chipping away at the design again and I am contemplating whether to integrate the lay shaft into the cassette plate or not and what bearing i should use on the clutch side, ball bearing or cylindrical roller. . .
I am thinking with the lay shaft I will have a single key way for each gear and it will be secured with a single nut on each. The shaft is looking fairly chunky, but I don't want it to flex. Any feedback on keeping the lay shaft separate or integrated would be welcome.

Also I'm thinking long and hard about how to install said shaft as it won't pass straight into the cases. The only way I can see it working is if the non clutch side of the shaft bearing is installed last, maybe I can put it in a small housing like this.

353065353066353067

had you considered inserting the cassette from the countershaft side a lot of bikes did this. it simplifies the casting as well.
353370353371353372353373

also in there is the patton version 1 joiner

[husaberg]

if you were going to make the gears and couplers would it be easier to just maker the center of a flying web. You mentioned a flying web early on.
Still use the rest of the parts?
353377353378353379353380353381

Like the JBB

[el chupacabra]

I initially wanted to insert it from the sprocket side, but setting up the shift star mechanism will be a lot harder, I can always change the design later fairly easily should I decide.

I'm pretty interested in the pump. . . what kind of current does it draw?

In regards to the flying web crank, I recall asking on the ESE thread about it a year or two ago when I was dreaming ideas up. If i recall correctly, someone said they had a short service life and were very expensive, I can't remember if that was due to the material used or the hirth coupling.

I would probably need to run larger diameter big ends to make the crank more stable and it would detract from the off the shelf *cheap parts philosophy.

[husaberg]

I initially wanted to insert it from the sprocket side, but setting up the shift star mechanism will be a lot harder, I can always change the design later fairly easily should I decide.

I'm pretty interested in the pump. . . what kind of current does it draw?


I found a rather interesting variable speed electric water pump.
I even have a couple here now thanks to a benefactor
Its used on all manner of BMW's as the primary water pump.

The specs are 2kgs and 125 liters /minute.


It needs a controller to operate in variable speed mode but I am pretty sure something could be bodged up with a 555 circuit and a piggy back. Or an Arduino circuit.
http://www.nomad.ee/micros/pwm555.html



or
https://www.maximintegrated.com/en/app-notes/index.mvp/id/3530
http://www.reichelt.de/ICs-MAX-1000-9201/MAX-6653-AEE/3/index.html?ACTION=3&GROUPID=5470&ARTICLE=115924&OFFSET=16&SID=14VVq3JawQATYAAHPOtpM0258660c7c3713fe135246538 1224c40&LANGUAGE=EN

http://www.tecomotive.com/download/manual_tinyCWA.pdf
The manual for this controller gives out the important specs

Mainly electrical....but its all in the specs:lol:
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https://www.fcpeuro.com/products/bmw-engine-water-pump-11517586925a

[el chupacabra]

15A is pretty significant, the most I can achieve with an 85 lighting stator is about 45 watts, some Chinese pit bike ones are around 100 watts. I'd need something with around 200 watts to make it work without killing the battery. I wonder if there are any decent stators I can hang off the side. Maybe I run something like that at 1/3 engine speed with a toothed belt instead of electrically.

At this stage I reckon I'll go with the 27L/min Craig Davies one as it only draws 2.5A which wont kill the small stator. If/when it isn't upto the job I will look to add something more significant, either electric or mechanical.

[jato]

Just weighed a SV 1000 based (twin outlet) pump complete and ready to plug into a 10mm spade drive - 660 grams. i would imagine if you started with a s 650 one you would be looking at 500 grams or so. no up rated charging system needed, controller or wiring and associated threats to reliability. sitting on the start line it needs to be light...

[el chupacabra]

I wonder where I can take the Spade drive from, without adding a sprocket to the lay shaft and another shaft as that will probably be what I will have to do then I may need to change the impeller as the lay shaft will have it spinning in the wrong direction. hmmmmmmm. Belt drive from the cranks seems like the simplest solution like the Tul Aris as it'll be spinning the right way.

An R6 pump has a nice built in ball bearing, I wonder if this could be changed with a grease sealed unit which could be replaced at regular intervals I'd make a bracket that could support it on the other side. Pulleys and belts are dirt cheap.

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[husaberg]

15A is pretty significant, the most I can achieve with an 85 lighting stator is about 45 watts, some Chinese pit bike ones are around 100 watts. I'd need something with around 200 watts to make it work without killing the battery. I wonder if there are any decent stators I can hang off the side. Maybe I run something like that at 1/3 engine speed with a toothed belt instead of electrically.

At this stage I reckon I'll go with the 27L/min Craig Davies one as it only draws 2.5A which wont kill the small stator. If/when it isn't upto the job I will look to add something more significant, either electric or mechanical.

Thats the max draw at over 116 litres a minute at pressure it draws les than 1/2 that at 50 liters/min its a very clever pump.
https://www.tecomotive.com/download/datasheets/CWA200_EN.pdf
Flow rate: ca. 116 l/min @ 0.45bar / 166 l/min @ 0.30bar

Ktm tpi models have 200w stators available.
honda VT250 ones are 200w

as are old pommy shitter inner rotor alternators which actually would look pretty trick
https://www.lowbrowcustoms.com/products/british-standard-wassell-200-watt-high-output-stator-for-your-triumph-bsa-norton

low output ones are even available here and are cheap
https://www.moto1.nz/collections/stators/products/bri4898650

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ktm outer rotors ones that are the same size as this inner is ie 75mm which is cr85 size can go over 100w

Looks like the std 12 Enfield from India was 120watts with similar set up with high output 200w kits available.
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https://www.ebay.com.au/itm/295061870502

[el chupacabra]

The stator size isn't too outrageous. Also, I could have the lay shaft extend out of the case and place a pulley on the end.

Here's a pic of the stator size and here's one of the proposed r6 water pump location.

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[husaberg]

I wonder where I can take the Spade drive from,

Ktm 50's drive their water pump off the mag stator its build into the cover.
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[jato]

if the pump had twin outlets it would be easier to get equal coolant flow to all 4 cylinders ... just saying . the sv based pump i weighed has a pair of 10 x 26 x 8 bearings in it. i would imagine the 650 would also use a 10mm shaft. not much side loading with a cute tooth belt

[husaberg]

if the pump had twin outlets it would be easier to get equal coolant flow to all 4 cylinders ... just saying . the sv based pump i weighed has a pair of 10 x 26 x 8 bearings in it. i would imagine the 650 would also use a 10mm shaft. not much side loading with a cute tooth belt

i agree electric looks cool but direct is better but the variable output functions of electric are also neat. and also lessen the need for radiator taping and thermostas cooling fans etc
A full noise all out gp bike needs over 1 liter/min/hp. although frits says later 3x more?
Jan Thiel was going to use an electric on the RSA, but there were none that flowed enough. He wrote it was one of the things he never liked, as it was added as an afterthought


The coolant flow through the RSA125 was 60 liters per minute. You can't talk about optimum performance though, because, who knows, even more coolant flow might have yielded more power, but that would have meant fitting an even larger pump, but none was available.
Adding anything to the coolant is not allowed in the rulebook (spilled additives might make the racetrack unusable for much longer than water would)


The engine was designed and made at Derbi.
And we assumed that the electrical pump used there would be sufficient.
When Piaggio bought Aprilia the engine went there, and Derbi was closed.
At Aprilia some very serious testing was done, with a big waterpump with variable speed.
The result of this test was: the faster the circulation the better!
For cooling as well as against detonation.
So the insufficient electric pump was abandoned.
And a mechanical pump with the same impeller as the Aprilia RSW was fitted.
It was not too beautiful, on the outside of the primary cover.
But we could not do anything else, as the crancases were already finished.
Making the pump inside, as on the RSW, would have meant a whole new design of the crankcase!
And there was no more time to do that.
The outside pump never gave any problems, not even when the bike was crashed!


n 2005 Aprilia and Derbi worked together for a short time on the RSA engine. We at Derbi used Aprilia cylinders, and Aprilia did some cooling tests for us. An electric central heating pump was used for this, with a variable output. This was done using a RSW engine. The electric pump used on the Derbi proved to be insufficient in a big way.... The RSW pump was good, but more water circulation gave more power.
So it was decided to give the RSA more water circulation, fitting a pump from a 250 Aprilia.
This may have caused a power loss through too much resistance.....quite possible.
No further tests were done I think.

Frits Overmars

You're welcome Carlo. The RSA125 had a coolant circulation rate of 60 litres per minute. The RSA250 obviously had more than that, but I don't recall how much more.
As a rule of thumb you might say that the optimum coolant flow requirement is one litre per crankshaft-HP per minute.
Like Jan wrote, a smaller pump on the RSA125 would have absorbed less engine power, but the accompanying rise to a higher coolant temperature might have nullified that initial gain. The RSA produced best power at 40° C and keeping this temperature low over the total duration of a race is very important for a two-stroke.


Compare two cooling systems, A and B. In system B the water flows three times as fast and picks up only half the amount of heat per liter, compared to system A.
Then system B removes 50% more heat than system A! And provided your piston clearance is OK, you just cannot have too much cooling. In the Aprilia RSA125 the water pump circulates 160 liter per minute. That is 3 liter per HP per minute!

Nowadays we have a fine solution for avoiding corrosion; it's called plastic. Saves weight too.

I don't know exactly how the NZ dollar is doing, but that sum will probably buy you two of these:
http://www.hvg-engineering.com/index.php?action=article&group_id=10000015&aid=127&lang=NL


You are right about the KTM (first picture) but I cannot recall any genuine Japanese racing bike with an electric pump.
The RSA125 was originally desiged to work with an electric pump. But as it turned out, none of the available pumps even came close to the flow Jan wanted, so a mechanical pump was fitted as an afterthought. Jan and I both feel that it is the ugliest aspect of the RSA engine. But it works...
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[jato]

Top references as always Husa! I don't want to Hijack el chap's design but it's good to have genuine info and reasoned discussion on the various design aspects ... Certainly there is a lot of power to be had from a cool running two stroke. This is an interesting exercise and it'd be great to see the result doing 1m 11 or so around manfeild ( very achievable i believe) so lets get this compact and efficient waterpump sorted...

[jato]

I wonder where I can take the Spade drive from, without adding a sprocket to the lay shaft and another shaft as that will probably be what I will have to do then I may need to change the impeller as the lay shaft will have it spinning in the wrong direction. hmmmmmmm. Belt drive from the cranks seems like the simplest solution like the Tul Aris as it'll be spinning the right way.

An R6 pump has a nice built in ball bearing, I wonder if this could be changed with a grease sealed unit which could be replaced at regular intervals I'd make a bracket that could support it on the other side. Pulleys and belts are dirt cheap.

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353386353387

The lay shaft is forward spinning isn't it ? could you have a plastic gear meshing with the layshafts primary drive on the righthand side ? maybe with the pump outlets built into the right casing. you could then spin the pump at the right speed...

[el chupacabra]

I’ll see what I’ve got for room on the RHS as a delrin gear won’t be too hard to make. And I could just place it on the clutch cover. Maybe I remachine the base of the SV pump so the water doesn’t re enter the engine through the cover.

I’ve already got a plan for how I’m going to cool it. I know the coolant should enter the head and exit under the exhaust last if I remember correctly. But the easiest way is to enter under the exhausts on each cylinder with an equal length tee junction. And also run an equal length tee on the heads and have them join back together entering the radiator.

Maybe I don’t use the dual outlet and use an R6 pump and run a Y splitter. Less parts to make. Hmmmm I’ll have a look when I get out of bed.

[husaberg]

I’ll see what I’ve got for room on the RHS as a delrin gear won’t be too hard to make. And I could just place it on the clutch cover. Maybe I remachine the base of the SV pump so the water doesn’t re enter the engine through the cover.

I’ve already got a plan for how I’m going to cool it. I know the coolant should enter the head and exit under the exhaust last if I remember correctly. But the easiest way is to enter under the exhausts on each cylinder with an equal length tee junction. And also run an equal length tee on the heads and have them join back together entering the radiator.

Maybe I don’t use the dual outlet and use an R6 pump and run a Y splitter. Less parts to make. Hmmmm I’ll have a look when I get out of bed.

My memory is the water should enter the cyinder and rise to the head last. Yamaha tended to be a bit suborn and do this in reverse.
It should preferably cool the cases first but that's a lot harder, There is special paint to isolate the cases. Available from EMOT


Having the cold water feeding in under the Exhaust duct is just as wrong as having all the cold water going into the head.
This change was made 2 homologations ago in KZ engines , where the simple but vey inelegant solution was to feed the cold water surrounding the crank , up thru a hose , and into the cylinder
above the top of the Exhaust duct from one side.
The best scenario is to have all the cold water enter the cylinder over the boost port , then run around the bore over the tops of all the transfers - cooling these first.
Then a portion of the return should be directed to a pair of small exit holes on each side under the Exhaust , the remining flow then exits up into the Exhaust side of the head , around the insert and back to the radiator.
This alone is an instant 1 to 1.5 Hp in 50.

Water flow and cooling in general is a very much ignored source of " free " power gains.
Having water flowing around the entire length of the Exhaust duct , where the plugging charge is retained , is super simple , but never done properly as far as I have seen.
These slots in the Exhaust exit surface ( done by hand many years ago in the pit with a battery drill and file ) cools the back of the spigot as well , and reduces the background deto level by around 20% - allowing alot leaner egt level at full power as a result.
This is much easier now with a small 75% exit area and a 6 axis CNC .


Sorry I didnt word my fist description correctly.
If the water is fed initially into the crankcase ( from the front in the Aprilia or the middle as in the TM ) then the main flow from there should be directly up into the cylinder
with a pair of large holes each side of the boost port ( NOT underneath the hot Exhaust duct ) . Another pair of smaller holes should also feed up under the Exhaust port , thus aiding flow around this area separately.
The only exit flow from the cylinder is up into the head directly over the Exhaust port. Thus keeping the water heated up by the Exhaust duct flowing away from the transfers.

This is possible for example in the TM , if the water in the cavity between the case and the gearbox is then also fed forward over the top of the mains ( thus cooling the transfer entry area ) and up
into the cylinder each side of the boost port.

This idea has been applied to old designs , like TZ250/350/750 , where the original flow was completely wrong - but this needs some form of separation plate or gasket between the head and cylinder.
Again , in this case all the flow enters the cylinder thru a new spigot welded in opposite the Exhausts , and all the cold water flows forward across the transfer tops , then exits into the head thru a pair of holes
each side above the Exhausts.

The test was done on a TM by extending the existing water feed hole around to above the boost port. A real 1 Hp free lunch , but not shown in the homologation papers , so probably illegal.
Thus I did the almost as good change , and forced all the cold water away from the Exhaust duct with a hidden manifold inside the cylinder - legal.



Top references as always Husa! I don't want to Hijack el chap's design but it's good to have genuine info and reasoned discussion on the various design aspects ... Certainly there is a lot of power to be had from a cool running two stroke. This is an interesting exercise and it'd be great to see the result doing 1m 11 or so around manfeild ( very achievable i believe) so lets get this compact and efficient waterpump sorted...
i dont want to hijack it either i myself prefer the simplicity of a driven pump mounted low.
if it needs to be under t driven by belt, kart and older f3 cars had special pumps for this it should go under the engine so it can self prime and to limit airlocks.

Ford escape v6 has a remote water pump
353408
https://www.trademe.co.nz/a/motors/car-parts-accessories/mazda/accessories/listing/4193743935
https://www.ebay.com/itm/254603938645

Or Jag353409
Jaguar Water Pump - Eurospare AJ88912
S-Type, Super V8, Vanden Plas, XF, XJ8, XJR, & more

or this one from the xj6
XJS AND XJ6 JAGUAR WATER PUMP - EBC10566-EBC10967 (INCLUDES BACKPLATE)
https://www.masai4x4.com/defender/radiator-grill-covers-land-rover-defender/XJS-and-XJ6-Jaguar-Water-Pump-EBC10566-EBC10967-includes-backplate-p34055611
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https://www.summitracing.com/parts/URO-010251/applications

[el chupacabra]

Maybe I need to take a trip to pick a part, I wonder how big that Mazda one is. It looks like something that would work.

If I run an R6/GSXR/similar pump off the clutch cover, I could run it faster At 80-100% engine speed. I do like the idea of a belt driven standalone unit though, for servicing and ease of integrating into the design. It could just bolt under the engine on a plate and either be driven from the end of the crank or layshaft depending on which way I need it to spin. The other benefit of belts is they can raise or lower the pump speed fairly easily.

[husaberg]

Maybe I need to take a trip to pick a part, I wonder how big that Mazda one is. It looks like something that would work.

If I run an R6/GSXR/similar pump off the clutch cover, I could run it faster At 80-100% engine speed. I do like the idea of a belt driven standalone unit though, for servicing and ease of integrating into the design. It could just bolt under the engine on a plate and either be driven from the end of the crank or layshaft depending on which way I need it to spin. The other benefit of belts is they can raise or lower the pump speed fairly easily.

looks like you need a puller

https://youtu.be/buciXVFfH-0
here is the size, its a big en but if you want flow....
<div style="width:360px;max-width:100%;"><div style="height:0;padding-bottom:56.11%;position:relative;"><iframe width="360" height="202" style="position:absolute;top:0;left:0;width:100%;height:1 00%;" frameBorder="0" src="https://imgflip.com/embed/7qiq5n"></iframe></div><p><a href="https://imgflip.com/gif/7qiq5n"></a></p></div>
It says to avoid the partial plastic one.
https://www.aliexpress.com/item/1005004102032453.html
https://www.aliexpress.com/item/4000987054104.html

[el chupacabra]

I don’t think I’ll be happy with anything available to be honest. Looks like I might have to make a something a bit custom. Maybe use the SV 1000 internals and have a dual outlet pump on the clutch cover or maybe just 1:1 off the end of the layshaft or tucked away under the motor running from a belt.

Does anyone have anything suitable kicking around? I’m more than happy to pay for it, or look around on trademe.

I should’ve just made it air cooled using TF125 cylinders haha.

[F5 Dave]

As long as you were happy with about 48hp and an extra 4" girth for the fins.

[husaberg]

https://www.trademe.co.nz/a/motors/motorbikes/parts-for-sale/radiators-radiator-parts/listing/4188418953
golly its huge vicar.

[el chupacabra]

OK, TF125 jokes aside. I think I've sorted it, here is a bracket holding 2x 6200 sealed bearings, I can bolt this to the motor anywhere holding the R6 water pump I've asked the wreckers about. I can either drive it from any of the cranks or the Lay shaft. I can decide on the exact pulley specification once the pump is in my hands and I can measure it and model it accurately. The pump will bolt to the back side of this and have its bearing replaced with a sealed one also.

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It could even be like this and I could hand pack the bearing with grease.
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[husaberg]

This the open flow specs of a 09 CBR600RR
353420
Count the teeth to see the reduction

This is a R1 pre 07
The resuts:
5-6000 RPM - 20.65 litres per minute. (5.455 us gallons)
8000 RPM - 34.43 litres per minute. (9.095 us gallons)
10000 RPM – 55.720 litres per minute. (14.72 us gallons)

[el chupacabra]

It looks to run at about 52% crank rpm give or take for the R1, I’m sure if you spin it too fast It could lead to cavitation in the pump or maybe it won’t, unsure but I could shoot for around 75%

[husaberg]

Flettner makes his own water pumps.
353421353422
But he does make is own practically everything:2thumbsup

[el chupacabra]

I wonder if he’s super concerned with flow. I’m sure 30L/min would be fine but it would leave HP on the table, how much is anyone’s guess. If the R6 pump is cheap enough I’ll just go ahead with that and change plans later if it is unsatisfactory. I’m not ruling out making my own pump but I want to avoid making anything I can, it’s either lazy or smart depending on how you look at it.

[el chupacabra]

$150 for a second hand R6 pump, scratch that. I’ll compromise and make half of a pump, I’ll make an inlet for a gsxr1000 pump, and If I’m not happy, I could probably make a new shaft as the impeller is removable if I still belt drive it or I might drive it from the Layshaft.


Part is ordered so I’ll start making more progress once it eventually arrives.

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[el chupacabra]

Otherwise, I assembled the clutch onto the input shaft today and found out there is indeed a sprocket on the rear of the clutch to drive the water pump that I am missing. I managed to contact the guy I bought the gearbox from and he is sending it to me. I may have designed the oil/water pump combo differently had I had this part at the start. Once everything was together I saw how far the clutch actually sticks out past the cassette so I needed to move the NJ roller bearing for the lay shaft out 16.6mm further so as not to create a weak point where the shaft would deflect. This makes the cassette look fairly wide at 46mm from one side to the other not including the protrusion for the shift forks.

This means after that panic where I translated the whole cassette to the right, I can probably shift it back around 10mm to make the engine slightly narrower or maybe I don't bother with only 10mm at stake.

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[el chupacabra]

Progress has been slow whilst waiting on parts. Today I have sorted out the oil feed to the output shaft, it is a 3 piece solution with the output shaft feed doubling as a bearing retainer. Drilling a hole through the case for an oil gallery just seemed like too much faff with such a long hole in order. All three of these parts can be made from 6082 on my small CNC mill and manual lathe.

353509353510353511

[el chupacabra]

The Chinese crank showed up today. I’m wondering whether to run the inside bearings with premix lubrication or lubrication from the gearbox oil. All it’ll mean is switching sides for the oil seal. I’ll need to make up some collars for the bearing to run on, I think 4140 should be ok as SKF say a minimum of 35 HRC is needed for rubber seals.

Any thoughts or preferences on the matter? As to which side to run the bearing.

353517

[husaberg]

The Chinese crank showed up today. I’m wondering whether to run the inside bearings with premix lubrication or lubrication from the gearbox oil. All it’ll mean is switching sides for the oil seal. I’ll need to make up some collars for the bearing to run on, I think 4140 should be ok as SKF say a minimum of 35 HRC is needed for rubber seals.

Any thoughts or preferences on the matter? As to which side to run the bearing.

353517

IMO on older small 2ts the bearing on the mag always tends to let go first. This is the one that is only petrol/oil lubed. I don't believe this is a coincidence.

[jato]

moving the main bearing 8mm to allow an inboard seal could see the crank flex 20% or so more at max revs depending on the rest of the crank's design. If lube of the bearing was going to be scant on the bottom cylinders it may give better reliability to move the bearing... it might be worth doing a sketch of the proposed crank layout and and then look at the loads and distances involved. i would guess that there would be something like 4000n of force on the crankpin at full revs. if you wanted to get an accurate figure we'd need to get some weights of reciprocating mass.

[jato]

...actually it would be interesting to see what balance factor the crank has - hopefully near to 50% for you setup

[el chupacabra]

I’ll measure the weight on Friday. I’ll also check the balance factor, hopefully it’s nothing I can’t fix with a couple of holes.

I’m thinking that the crank bearings will be replaced often enough that having them oiled by premix shouldn’t be a massive issue. At least it’s something that can be changed further down the track if need be by swapping the order of the components.

The GSXR1000 pump also showed up today, it’s bigger that I thought haha. Tonight’s job is to accurately model the pump and see where I can fit it on the engine.

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[el chupacabra]

The fit is looking promising, I will make some room in the bottom of the case for the drive sprocket.

353521353522

[el chupacabra]

The crankcase shape is modified and I have added a drive shaft for the water pump. It will use 2 x 61901 ball bearings and run the standard ANSI 25 chain (at least that's what I think it is without looking too hard), if it's slack I can add a nylon guide of some description.

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[el chupacabra]

Progress has been slow as I've been busy with my V Twin race bike prepping that for the coming season. Tonight I measured and roughly modeled the shift fork guide and selector drum bores.
Also another happy coincidence is that the local library has a 1200x1200 CNC router which I can use to cut my XPS foam for the casting so I will only need to flip the patterns once and machine the entire engine
from 1 large piece of foam in 2 set ups. Then I will glue all of the sections together.

353581353582353583

[el chupacabra]

Getting back at it, the lack of wine I've been drinking lately may have been the culprit. This is starting to look a bit silly with some no name 32mm carbs I found a model for online. I've also cleaned up the selector guides and the outside of the case. It's simulated to weigh 28kg minus Gearbox, cylinders, heads, flywheel and cranks. I'll need to do some strategic lightening prior to the first pattern, I'll have a think of anything I have missed and then it will be time to cut some foam.

353663353664353665353666353667

[el chupacabra]

Tonight I added the outlet for the oil to get from the pump to the inside of the input shaft. You can see where the 6x16x5mm lip seals which will be used to hold the 6mmOD 4mmID tube will be seated.
You can also see the cover for the oil gallery, I'll likely modify this as it is fairly ugly.

Moving on, I am thinking about how to actuate the clutch. I am thinking of using a hydraulic setup from a KTM Mx bike pushing a rod through the input shaft. Are there any obvious drawbacks to using this kind of set up vs a cable pulling on the clutch side as it seems easier to implement the hydraulic solution in my mind.

353687353688353689353690353691

[husaberg]

Tonight I added the outlet for the oil to get from the pump to the inside of the input shaft. You can see where the 6x16x5mm lip seals which will be used to hold the 6mmOD 4mmID tube will be seated.
You can also see the cover for the oil gallery, I'll likely modify this as it is fairly ugly.

Moving on, I am thinking about how to actuate the clutch. I am thinking of using a hydraulic setup from a KTM Mx bike pushing a rod through the input shaft. Are there any obvious drawbacks to using this kind of set up vs a cable pulling on the clutch side as it seems easier to implement the hydraulic solution in my mind.

353687353688353689353690353691

hydraulic or manual pusher is tidier anf less likely to be damaged in a crash.
Honda VT250 ran both set ups likely a far bit cheaper than KTM or Husaberg set ups.

353696
Honda CR's 250 and 500 at least used a cable push from the countershaft side.


there is also conversions for the cavble pusher CR set ups


https://www.aliexpress.com/item/1005004631078042.html?pdp_npi=2%40dis%21NZD%21NZ%2 461.60%21NZ%2440.67%21%21%21%21%21%402101c72a16946 697337748929ed101%2112000031558761745%21btf&_t=pvid:91462600-fe91-40a8-b23c-cbc33907dd22&spm=a2g0o.ppclist.product.mainProduct

can't complain about the price
52 nzd landed

[el chupacabra]

I'll keep my eye out for one from a VT250.

Tonight I thought it was best to see if the engine would even fit in a chassis without being 100m long before continuing. . . As you can see the minimum wheelbase will need to be 1440mm(ish) based on Bridgestone tyre diameters and an RSV1000R swingarm length. It seems bikes are only getting longer and longer, although now they also have over 220hp. I'm sure the V4R/RC213VS etc don't feel too bad although I've never ridden them obviously. Does anyone have experience with longer wheelbases and they make the bike feel or if it's less important than I think as I don't want to make something that is hard to turn or handles like a boat.
For reference:
RS125 1215mm
RS250 1340mm
RGV250 1370mm
R6 2014 1380mm (Best handling stock bike I've ever owned)
RSV1000R 1415mm (Very stable, preferred riding a 600/750)
S1000rr 1425mm
M1000rr 1457mm
RC213 VS 1465mm
Ducat V4R 1471mm

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[jato]

what year rsv1000r is the swingarm off? i have a 2010 one here and i recall it is around 540 or so, and horrendously heavy...
the yamaha tracer got a 60mm longer swingarm for 2019 and testers appear to all report no noticeable change in performance on tight winding roads ( for what that is worth) its wheelbase went from 1440 to 1500. scaling side on pics of fast gp bikes show the swingarm makes up around 45% of the wheelbase. re the clutch actuation i would go for whatever is lightest.