Kp-Mini Self-Destruction [Build]

[deadwood83]

KLR rad is a no-go. I had my brother measure his bike before I ordered it. I am beginning to seriously doubt his measuring skills.

Exploring other possible options for a rear fit. The pusher fan (SPAL) is the perfect size but that KLR boi is too thicc (width).
Can see it is about 1/2 inch too wide (after adjusting for my lousy positioning for the photo)



In all likelihood, I will move the horn and put some other rad up front like so:



I will not be able to use my fancy pusher fan, and will have to locate a fancy puller fan. The head also needs porting. There's something to be said for velocity vs area, but this is pushing the smaller ports argument too far.



I was going to have the frame totally stripped today and the new (rear) suspension installed but no. WHoever at Lifan had the 15mm ugga-dugga decided they were in a bad mood. I can literally lift the bike with the socket and not have the nuts break loose. My brother has a battery powered milwaukee that I will be borrowing. Throw in a little bit of my own Knipex and it's a party. We'll see how my cat continues to react to foul language.

[deadwood83]

Progress can be summed up in one picture. I introduce:
Kp-Mini 300 BUCA-K.



More to come as I progress. The secret to breaking those nuts was a 200lb man and a 3'+ breaker bar.....

[grumpyunk]

Look at it this way.. you now know a 15mm can handle 200X3 ft-lb of tightening torque. That is if you were standing on the breaker bar..
I came in late to the build, but am making the assumption you are replacing the powerplant with a water cooled version that has more displacement. And you are changing the gears inside. Speaking of, did you find that they fit or are they still "Turned over to airline" or "Left shipping center"? A whole lot of 'magic names' to cover the fact that they are on a ricksha somewhere between Shenzen and HK. Maybe.
tom

Added
Just brain fading, but it they had put the inlet/outlet of the radiator at opposite corners, you could have used 'thermal convection' to cause the coolant flow. Colder coolant will flow downward, and into the engine, hotter upward and out to the upper inlet. The design you have depends 100% on pump flow to cause coolant movement. If they had placed the fittings at opposite diagonal corners you could have had thermal assist at least. FWIW. You may not need a fan, unless you drive slowly or in heavy traffic. Is there provision on the engine/head for a coolant temperature sensor?
tom

[deadwood83]

Originally Posted by grumpyunk

Look at it this way.. you now know a 15mm can handle 200X3 ft-lb of tightening torque. That is if you were standing on the breaker bar..

I wasn't standing on it, but rather sat on the bike and used it like a kickstarter. I do not b elieve they can really take that much torque. I suspect if I set up a jig and examined roundness, stretch would rear its ugly head. I will be using new fasteners for safety sake.

Originally Posted by grumpyunk

I came in late to the build, but am making the assumption you are replacing the powerplant with a water cooled version that has more displacement. And you are changing the gears inside. Speaking of, did you find that they fit or are they still "Turned over to airline" or "Left shipping center"? A whole lot of 'magic names' to cover the fact that they are on a ricksha somewhere between Shenzen and HK. Maybe.
tom

Sort of! It's hard to call this engine a liquid cooled version since the only common parts are the mounting bolts, drain plug, and sprocket.


In short:
Displacement: 149cc -> 278.5cc
Valvetrain: SOHC-2 -> SOHC-4
Cooling: Air -> liquid
Compression Ratio: 9.1:1 -> 11.1:1
Trans: 5-speed -> 6-speed (engine is offered in both 5 and 6 speed, but only 5 speed is avail on alibaba)
Bore X Stroke: 57.3X57.8 -> 74X65
Highest gear ratio: .938 -> .854
Power: 12.8hp -> ~27.5-30 (after head, exhaust, cam)


For the parts from taobao, I used an agent (Sugargoo). They are coming via DHL express. Label tracking does show that it has not been received yet, but reddit posts and youtube videos do show people receiving their goods from the agent. They also took photos of all parts before repacking.

Originally Posted by grumpyunk

Added
Just brain fading, but it they had put the inlet/outlet of the radiator at opposite corners, you could have used 'thermal convection' to cause the coolant flow. Colder coolant will flow downward, and into the engine, hotter upward and out to the upper inlet. The design you have depends 100% on pump flow to cause coolant movement. If they had placed the fittings at opposite diagonal corners you could have had thermal assist at least. FWIW. You may not need a fan, unless you drive slowly or in heavy traffic. Is there provision on the engine/head for a coolant temperature sensor?
tom

The new planned rad does have in/out at opposite corners, but will still rely on pumping since the optimal outlet position is higher than inlet for bleeding and pressure purposes. No good way to fit a t-stat on this motor nor this frame. Too small. No provision for a temp sensor on rad nor engine. If I get really antsy about it, I can put one inline. I'll do initial testing with a 185F fan switch and gauge things by how much the fan comes on.







This will be largely an around-town bike, so traffic lights will be a thing. I will also be doing some canyon runs, and I would prefer having a rad fan rather than dumping from the overflow bottle


___________________________


In fact, (due to space constraints) I had to abandon my FCR idea. Held the carb to the frame.... it is taller than the top of the starter to the upper frame member. Looks like PWK or EFI will be the way forward.






To fit the engine, I did have to bend the coil mounts (red). I do not feel overly comfortable with the coil pretty much touching the fuel tank (which is grounded to the frame). GSXR coils are a coil on plug design and have a primary resistance of 1.1-1.4-Ohm. They are also found very cheaply on ebay and GSXR riders don't seem to swap them due to failures; just for mods. This may be a possible way forward.

I'll do some highly scienticious clearance testing with the front cowling and some TP/PT tubes.

I will have to shorten the petcock tube. It is literally just a threaded pipe, so figuring out the pitch and doing the work should not be overly complicated. Currently the petcock outlet would be below the carb fuel inlet, and on the wrong side (blue).

[grumpyunk]

If you don't go COP, moving the coils is somewhat a simple thing, requiring only longer primary and/or secondary wires.
I don't understand what difference purging air from the radiator would make choosing the inlet or outlet side. If you were to do a cross mount rather than having the tubes oriented vertically, the coolant pump would require a bit more flow than the other way.
EFI is available on aliexpress and likely alibaba and the vendors seem to understand their product and what it takes to make it work effectively. I think I have read some posts about installing, tuning and use that were positive. Once you get them set, they sure can be a lot less 'fussy' than carburetors.
Just off the top of my head, why not rotate the radiator 90 clockwise from the image, locating the 'out' relatively near the inlet to the pump(given IN marked in blue is the pump inlet). A longer hose from the hot outlet from the engine to the radiator inlet, but you would get convection movement.
The fan switch fitting could also be a temperature sensor fitting, and you could use a 'tape on' temperature sensor wrapped onto the HOT hose to regulate the fan. I think one can be made to work reliably, and if you really want it permanent, they can be installed 'in-line'.
tom

[Falkon45]

If you want, see if you can find a radiator for a lifan KPM 200 or kp200. It's two of them, and they're pretty small. Another is the RC 390 radiator. It's tiny in itself. Too small for the ktm, but should be perfect for that.

[JerryHawk250]

Hmmm! Reading all this is putting all kind of ideas in my head for the X22R. I got all kind of room for a NC250.

[deadwood83]

Rectumfriers! Arrgh!

One thing I have wondered is how the unit shipped with the new engine will wire in to the current harness. The new engine uses a ~220W 12-pole stator pushing 3-phase AC. Lifan equipped an 8-pole ~60-80 watt stator from factory. SPAL rates their 5.2” fans at about 4A (48W); Headlight is 15W max; tails are what, 10W? Blinkers, maybe 3W each for a total of 12W. So… my draw should be about 100-150W under the worst possible conditions. That leaves me ~75W to play with should I elect to go EFI. Assuming a 4A fuel pump, there should be no problem.



But that wiring.



New Reg/Rect:
Black = Ignition/VSense
Red = DC+
Green = GND
Yel X3 – AC 3 phase


Current setup:
Yel/Pnk– A/C 2-phase
Red – DC+
Green - GND
Red/White – DC+

So, the Red/White powers rear markers, headlight, and license plate light. This means the Lifan rectifier is just that, a rectifier only. It has no regulator capabilities. The new rectifier/regulator (as diagrammed above and verified with my Fluke multimeter) requires an input containing current battery voltage and control clamping on S1-S3 so as not to overcharge the battery.

There are two ways forward:
1. Try to find a new regulator/rectifier that takes 3-phase AC and outputs properly with double DC out, risk overcharging the battery, and leaking acid.
2. Add a splice to feed ignition voltage to the regulator tap in addition to powering the lights. Looking at the ignition contacts, they are Sumitomo 2.8mm style on maybe 18ga wiring (20ga worst case). For chassis wiring, that has a 12V rating of around 11A for copper. MORE than enough.Let's splice!



The other wiring work required related to connectors. The new engine came with Furukawa RFW sealed connectors. These ARE superior to the Sumitomo MTW style that Lifan ships with. However, I was faced with the choice of buying expensive connectors and rewiring everything… or just convert engine harness to Sumitomo MTW. I went the Sumitomo route so I wouldn’t have to buy new crimpers.

Originally Posted by JerryHawk250

Hmmm! Reading all this is putting all kind of ideas in my head for the X22R. I got all kind of room for a NC250.

Do it. NC250 + Big bore. I believe you may have the fastest X22R, but it could be faster.

Originally Posted by grumpyunk

If you don't go COP, moving the coils is somewhat a simple thing, requiring only longer primary and/or secondary wires.

Originally Posted by grumpyunk

This is true. My primary motivation for COP is to not require welding any more things to the frame since I do not have the tools nor experience to do so.

Originally Posted by grumpyunk

I don't understand what difference purging air from the radiator would make choosing the inlet or outlet side. If you were to do a cross mount rather than having the tubes oriented vertically, the coolant pump would require a bit more flow than the other way.

This is exactly why. I do not have any specs on the pump, so I want to make its job as easy as possible. My leads on a Boyesen unit died out, because Zong moved one fastener to the other side of the water channel on an 04-08 CRF250R/X pump design so I am locked into their design unless I want to pay $$$$$$$ to have one CNC'ed custom.

Originally Posted by grumpyunk

EFI is available on aliexpress and likely alibaba and the vendors seem to understand their product and what it takes to make it work effectively. I think I have read some posts about installing, tuning and use that were positive. Once you get them set, they sure can be a lot less 'fussy' than carburetors.

Available? Yes. General consensus online is that you buy the kit, get it running (poorly) then wind up swapping most components over time with Ecotrons or MS. If I go EFI, it will probably be the Kayo unit for the NC250 since they engines are rather similar in operation, and the Kayo seems to respond well to the 82/84mm big bore kits on the NC motors (283CC and 297CC; respectively). If I can make the NC250 cam swap work, the motor would be even more similar in operation (barring gear ratios).

Originally Posted by grumpyunk

Just off the top of my head, why not rotate the radiator 90 clockwise from the image, locating the 'out' relatively near the inlet to the pump(given IN marked in blue is the pump inlet). A longer hose from the hot outlet from the engine to the radiator inlet, but you would get convection movement.
The fan switch fitting could also be a temperature sensor fitting, and you could use a 'tape on' temperature sensor wrapped onto the HOT hose to regulate the fan. I think one can be made to work reliably, and if you really want it permanent, they can be installed 'in-line'.
tom

Nowhere near enough space. For reference, the distance from the reinforcement plates at the top of the front frame member to the top of the front mount is about 6.5". It would either collide with the bottom of the triple tree, or be the recipient of everything the front tire throws up and bend/break when going over speed bumps.

I am also not convinced convection forces will do anything with the coolants used in an engine. In the PC space, one overclocking group did make an effective convective cooler, but it required filling with either a very low flash point coolant, or having an extremely high pressure. In building heating systems using convective principles, there is typically a steam pump or other high pressure application. I think it might be bad if I let my bike get to the point where it is making a steam pump inside the engine.

Originally Posted by Falkon45

If you want, see if you can find a radiator for a lifan KPM 200 or kp200. It's two of them, and they're pretty small. Another is the RC 390 radiator. It's tiny in itself. Too small for the ktm, but should be perfect for that.

KPM and KPR radiators did cross my mind. However, this engine will have 40% more displacement and make ~53% more power. I do not believe the KP radiators would be sufficient. The KTM might! But my CB250 rad is already on order. If it does not work out, I will try and dig around more for RC390 radiator dimensions. Once immediate thought is that if the rad is too narrow, I would be unable to get a pull fan behind it next to the center support while being able to clear coolant lines and exhaust piping. Fans will not fit in front, because the back of the forks have about a 29mm clearance (longitudinally along the chassis) between the front frame member. A pusher fan might fit in the middle between the forks at the front, but then you lose effective area to the frame behind the rad.

It is truly a challenging balancing act, and I am thoroughly enjoying the challenge (even if I do get frustrated at times!)

[JerryHawk250]

I can get a complete NC250 engine kit with EFI that includes everything i need minus the radiator for under $1500. It's very tempting.

[culcune]

Originally Posted by JerryHawk250

I can get a complete NC250 engine kit with EFI that includes everything i need minus the radiator for under $1500. It's very tempting.

What would you throw it in?

[JerryHawk250]

Originally Posted by culcune

what would you throw it in?

x22r

[deadwood83]

Originally Posted by JerryHawk250

x22r

Hmmm. This looks a whole lot like CG mounting pattern (like the KP Mini). Not sure if the honking kicker mech and back of the NC250 would fit.




But you could do the CBS swap and we could explore this engine in tandem


That said, the only real thing you would gain is liquid cooling and 4 valves, with a loss of some Honda parts interchange.



Also, DHL texted me. They said I'm going to have a 6-speed transmission soon.

[Falkon45]

I mentioned the KP radiators, because it's actually two radiators. With the twin radiator confuguration, you could set them up like the VFR 800 rads were. Small, yes, but I believe those would be sufficient, unless you're running very high compression, and fueling on the lean side. My fan very rarely runs on the KPM. My KTM, on the other hand, was always at, or just below the "hot" line. They ran hot from the factory. The radiator is a decent size. I have mine off the bike. I can try and take some measurements for you. The fan is still attached also, so those will be close enough for you. I never did the FAL upgrade. I just used engine ice to keep overheating at bay.

[wheelbender6]

Originally Posted by JerryHawk250

I can get a complete NC250 engine kit with EFI that includes everything i need minus the radiator for under $1500. It's very tempting.

What is the HP rating on that NC250?

[grumpyunk]

The PC cooling is not a real comparison in that the fluid boils inside as you note, while the coolant in a bike cooling system should not get to the vapor state.
Model T cooling used no pump. It was all done by convection(perhaps the wrong word) where hotter coolant was less dense, colder more dense, so a thermal circulation of liquid coolant occurred.
If you heat the coolant in a radiator the hot coolant will attempt to migrate to the top, the colder coolant to the bottom. That is the effect that would reduce the load on the coolant pump and be a more natural effect. Free circulation...
A cross flow radiator back about 1967 was a big deal, and allowed lower hoods on cars. There was less convective circulation, so there was concern about overheating in lower speed traffic. I cannot verify, but think larger pumps were installed 'just to be sure'. I don't know if I was clear, but I was suggesting mounting the radiator in a 'vertical' orientation, with the tubes going up and down. There is a post about mounting an oil cooler, actually more than one, in a vertical mode on site. I was thinking off-center mounting, FWIW, but I do not have a machine to futz around with attempting of different spots.
tom