Cannonball DIYs a CG

[Davezilla]

Very true... if solid oak pucks will grip strong enough in the wet then all I'd need to do is get an oak plank that's 5/16" thick and let the CNC do the rest... I could also CNC the cecnter of the puck out of aluminum but leave a ridge around the outline and amke the pucks fit inside the pocket on the aluminum so the bonding cement would only have to hold the lining on the aluminum and teh outline ridge would take all the side load if the solid wood ones work but don't last due to the side load and shock from dumping the clutch.

An oil groove would help, but I'd try it first without it and see how much grip it has. On the oak linings, I might add a cross groove so there's 4 smaller contact points and the oil can squeeze out quicker. I think holding power would be about the same but the quicker or slower squeeze out might make the engagement point more controlable.

 

[cannonball2]

The DIY saga continues. Not sure what the deal was but the clutch bearings would not fit the case. Heated the case to about 300 degrees and froze the bearings. Crank bearings dropped right in. Trans would not and were not a light tap fit either. I almost felt the cases were machined for the 5/8x13/8 bearing as these will drop into the 6202 hole literally. Took a bit of careful work with the Dremel and a sanding drum the get the light tap fit I was after. Crank has .020 side to side play with out the .044 gasket installed. figuring I need about .050 of shims. Cant easily find 15mm shims but did find 5/8(1mm larger in dia.) in either .010 or .005. here goes more $$! This may account for some the noise these engines make with the drive gears as the crank may float changing clearances.

I wouldn't recommend this type of kit to any but the seasoned builder with good tool access. However building one in this manner allows you to find/fix/change things for the best engine one of these can be from a properly assembled, reliable engine stand point. With the issues the lax manufacturing of the things causes its amazing they run as well as they do.

Last thought. I see no reason to run the case gasket as long as the crank has adequate clearance. Removing .040 of gasket would have the effect of stuffing the cases a bit. A good sealer like Halomar would work fine .

 

[Davezilla]

Wow... the bearing hole was that far off? At least its not too hard to fix,but it can be annoying on a new kit. I'm sure something like Yamabond would seal the case halves well enough to eliminate the gasket... it'll most likely work better... of course, there's also Suzukibond, Harleybond, Hondabond, etc case sealants and I'm assuming they're all the same stuff,or very close to the same if not, but I know they work really well. My friend swears by Harleybond at his shop. Just use a lone q -tip to clean up the squeeze out from inside the case before it starts to cure... I'm assuming the Halomar is the same stuff or similar too and it should work just fine.

 

[cannonball2]

Ordered some Yamabond 4 for sealing the case with no gasket. This gasket was way thicker than normal and would require several more shims to center the crank. As it is with out the gasket will take 3-4 shims vs. 8-10 with it. The cylinder studs and the jug fit as they should also with no gasket.

Have had the clutch puck soaking in oil since I made it and the glue shows no signs of loosening. I agree that ATF is probably a excellent choice for the clutch, but am leaning toward motor oil. Was thinking a thicker weight like maybe 40 might shut up the gears a bit. We don't experience much cold here so it shouldn't add cold start drag. Time to mod the side cover for drain and fill/level holes. Planed the outer plate flat. was fairly un-level. Hope this works, like the idea of not greasing the gears periodically.

 

[brown]

Here is the direction I would consider.

http://cometkartsales.com/L-and-T-Clutch-Oil-Quart.html

In fact I may try it with the stock CG clutch pucks this summer.

Back when I raced Karts all the 2 stoke classes used a centrifugal oil bath clutch and they worked great for that application.

 

[cannonball2]

What do you know about the product, they give no specs.

 

[brown]

Only that it is what Karts use when running a wet clutch. There are other manufactures of the same product. I should have found one that had specs listed with it. I just did a quick search. I will try to find something with more details.

 

[brown]

After some more reading in on some Karting forums there are two basic theories.

Clutch oil can be replaced with Synthetic ATF generally type F is thought to be better or use the more expensive clutch oil products.

Most Clutch oil suppliers don't seem interested in sharing their specs.

Here is a link that does post the specs for their product.

http://www.bakerprecision.com/neo/clutchoil.htm

I would fear that motor oil wouldn't bite enough. I really like you idea and will be watching for your results. Good Luck.

 

[cannonball2]

Ok, ATF it is.
Heres a pic of the clutch cover. At the angle the engine sits on the bike the lower bolt is about the lowest point. I just dremeled a slot for the drain when the bolt is removed. Will get a fiber washer for a seal.
Used a 1/4 flange head bolt and a cork gasket for the filler, have to pump the oil in with an oil pumper can. Should cover the lower 25% of the gear. May not need even that much.
There is a slight possibility oil may seep past the clutch actuator rod and over to the chain side. The grease on the bucking bar may stop it. Also centrifugal force may throw it off the clutch before it gets there. Remains to be seen. Worst is it lubes the chain automatically.
Now if the oak would just get here.

 

[cannonball2]

OK! The wet clutch works! At least the first crude attempt. The jacka$$ on ebay has yet to even ship my 1/8" oak to make the bonded cork pucks. Decided to try the solid 1/4 oak like from the days of old. Got enough at Lowes to do probably 10 clutches for $1.96, cheap enough. Just sawed the pucks and finished by eye not very uniform but usable. Soaked them in oil a while then put them in the clutch. At first the engine just wouldn't turn over to start. Adjusted the clutch flower nut all the way til it stopped. Almost started but just slipped too much. Was just about to can the idea when I decided to remove the pop up spring under the flower nut. That gave one more full turn on the nut, that's all it took. Started right up and worked as a clutch should.
With less than 10min to seat the pucks it will pull from a dead stop, accelerate at full throttle and choke the engine down with brake with out slipping. Action is silky smooth. This was with 30wt motor oil, didn't have any ATF. Will run the oak a while to see what progresses. I can only imagine the cork lined pucks will be better.

Im stoked!

 

[cannonball2]

Clutch experiment continues. Rode the oak clutch for about and hour. Was working great. Really feels just like an M/C clutch, smooth on the engagement, not grabby like the dry clutch. The take up with the stock linkages is just fine. At the end of the ride I noticed a bit off slippage, started to get a bit worse. Went home and tore it down. Wow, shot my self in the foot on this one. I had forgotten to clean out the "miracle" grease my neighbor had given me for the gears. Has Teflon in it. It finally dissolved into the oil ruining the clutch pucks. Had to totally dismantle everything and clean it.
Went ahead and made a set of cork pucks using wood from a paint stir stick which is gonna be too soft to last a long time probably. Used ATF this time. The cork works much better, seems even smoother and has a bit more grab.

This is going to be the way to go. Just need to make the oak/cork pucks and I think its finalized. In the meantime will run the too soft pucks just to see how long they will last. The modded clutch cover works well, drained the oil nearly completely and there are no leaks. Am running 3oz of ATF, the gears and the bearings in the clutch basket love it.

 

[Intrepid Wheelwoman]

A very worthwhile experiment CB. I'm sure many others are going to follow in your footsteps

 

[cannonball2]

Thanks for the support IWW!
Jury is out until this conversion gets some time on it but it shows real promise. Changes the whole character of the bike. Things to remember here are the this is a stock engine with stock compression. Don't know how this might work with a high output engine. However I have yet to add any additional tension to the clutches main spring, which I have seen necessary on such engines with the dry clutch. If the softer wood pucks survive normal use then the oak pucks should be fine for most uses. Of course a material like aluminum would be better, but I wanted this to be able to be done by anyone with just basic hand tools. Its cheap enough to do/experiment with a set of pucks costing less than maybe $.50.

 

[cannonball2]

Well got the .005 shims and set the crank side to side play at .002. Had a whopping .022 with out the gasket! Treatland must have sent the light wrist pin by stage coach still waiting for it. Once its here the final assembly can begin. I have found as most have Im sure that there are many subtle variations between these engines. NEVER assume things will directly swap, cases and covers maybe. Actually the sprocket side cover had the retaining pin lower than my FH engine so the clutch arm/cam wouldn't fit-wow!

Got a bit more riding on the wet clutch before the rains set in. The only thing I will mod on the next set of pucks is to cut a groove across the face to allow faster oil squeeze out. On pedal starting it takes a second to turn the engine over presumably because the oil is trapped briefly before the clutch plates wipe it away. Otherwise its working great.

 

[Rudz]

Definitely an interesting modification, I hope this holds up long term

 

[cannonball2]

Its a mod that I will use in both engines. Its simple enough to do. I will run the soft wood pucks until they fail(or not) then finalize the design as to puck materials and oil grooving.

This only adds to the refinement of the CG, and reduces maintenance to the gear set and I assume helps the crank seal since its bathed in oil. One of the requirements is good casting of the gear side of the engine cases. My FH engine was actually surfaced. The engine in the box was not and needs a bit of minor work for a good seal surface. The cover can of course be planed on a flat surface with sand paper. Also there are thicker gaskets out there(or use a few thin ones) which will work on less than perfect cases.

Maybe some one will CNC some aluminum pucks-hint hint Davezilla!

 

[cannonball2]

Finally got the light wrist pin from Treatland. Its a full 3grams lighter. Big terms in piston weight. Takes a lot of drilling to remove that much from the piston itself. Tapped the cases to accept 1/4 20 case screws. Got full threads to the bottom of the holes. Don't think the whole of China owns a bottoming tap. Just cant see bolting the cases together with those cheap A$$ combo screws. Bonded the cases with Yamabond 5(said4 earlier), no case gasket. 5 is especially for cases.
This is a GT5 engine. Rode a box stock one yesterday after a new install and it was the smoothest CG I have ridden. Hoping this one is to.

Wont be long now!

 

[Rudz]

I want your engine. Lmfao

 

[Davezilla]

Maybe some one will CNC some aluminum pucks-hint hint Davezilla!

I'm all over it... 3d model has been made and the G code is just a few mouse clicks away.... just waiting on those plates of 1/8" thick 6061 T6 to come in and I'll cut enough to make 3 or 4 sets for each of us to experiment with. Hopefully I will have the aluminum Tuesday or Wednesday but I'll check the tracking in the morning....

 

[mapbike]

im watching this fellas

I have made a few sets of very good pucks for myself and even for a memeber here that used them on his race bike with great results.

Problem is that super tough friction material is solid heck on tooling to make the pucks and it very time consuming.

at one time bairdco thought he was gonna have access to a water jet and he was gonna make them that way but I guess that never materialized.

Ive thought about the solid aluminum pucks myself but just never tried it.

I like the wet clutch set up cball2, keep the info coming on this project.