Putting things in places they ought not to be (250R Hybrid Motor build)

[Billy Golightly]

Lookin great Billy!! Man I wish I could do stuff like that..

I'm not too sure if you've gone over this before or not but: Are you going to add any material to the counter balancer? Or will it be fine as is stock?

I'm going to leave it as is at this junction, perhaps sometime in the future I might do something more, but unlikely for now.


I also was originally going to run a +4mm crank with a KTM rod on it that is heavier duty, but in talking to a few people, I think thats over kill for running pump gas and a non-drag racing application. So I'm just going to run a drop in 4MM Crank.


I will take some good pictures later today and make a more expansive write up, I did quite a lot to it this weekend.

[atc007]

I can just HEAR this knarly barking out of a turn!! Anyone who knows anything about these will know a 1/2 mile away. That aint no Honda!

[atc007]

I never imagined you would end up with intake clearance issues around the kicker housing.. Looks close!

[SUPERBEAST]

this thing is going to be a beast when you get this done billy

i also read that you said you would have to get a stronger tranny, do you think you would put a billet trans in?

[Billy Golightly]

No change on the transmission anticipated - possibly a lock up clutch or something might be required but I will be leaving much as I can stock.

So here is the photo summary of what I got done this weekend basically;



I did some transfer ramp match work, by bolting the cylinder onto one half of the case and then basically working the die grinder and stuff around the seam of the case, spacer plate, and the cylinder. Ended up getting it matched up perfectly. I had it close but its a good smooth transition now. The little ball type de-bur bits are great for awkward angles and places like that. I might still come back with some flapper wheels or something to smooth it up a little bit more but I'm content to run it as is also.



I also machined the shift shaft hole, and seal area on the case that had been repaired. I had originally built this up with weld many many years ago as a set of junk cases that were given to me, and for me to practice on the aluminum welding at the time. I didn't need to do much besides just machining it out. I turned the case over wit hthe stator side down, ran a drill bit through from the inside to get centered and cleaned out the shift shaft area first. Then I unboltd the case from the table, turned it stator side up, used the drill bit to center up in the same hole, swapped out to a large 2 flute endmill and made a plunge cut for the seal that I had bought specifically for this. Its within about .004 of the seal diameter from what I remember when I was trying to size things up before purchasing. Turned out pretty nice.



I also, as I have documented elsewhere and shown, had to weld up my OEM drain plug hole because it was stripped out. I machined a nice little flat place for the head of the bolt to sit down on, and then drilled and tapped it 12x1.75 which I will just use an off the shelf bolt for that'll be shortened.




This back water neck ended up being a bigger pain in the ass than I thought it was going to be, but after several build ups, and machine back flat operations to get it positioned where I wanted, and then trying to drill and break into the water jacket without getting ontop of the back head stud casting, I finally got it. Didn't turn out internally exactly how I wanted, but it worked. The water neck is $30 from ESR and simplified my life a lot in this particular arrangement.



Last week I had shown how I had slugged and welded the OEM spark plug hole. I ended up getting it drilled and re-tapped. Unfortunately, it looks like I should have angled it a bit more than I did (~5 degrees) because it is awfully close to the frame though it does clear it, I'm not real sure how a plug boot is going to fit around it yet. I will probably have to dimple the frame a little bit which is unfortunate because I could have probably avoided it by angling the hole a bit more than I did... You can also see the welded together and welded on 90 degree water spigot neck that went on the front of the cylinder. I had to do a lot of build up work around the front of the head in order to get a suitable place to position that piece before I could drill into the water head and reach a water jacket. Its positioned right in the front, so hypothetically the coolest water coming fresh out of the radiators will hit the hottest side of the topend first, before swirling to the back.



Topend bolted to bottom cases with the water necks and re-configured/angled spark plug for the first time. You'll also note the nice shiny and freshly machined aluminum down by the shift seal and shaft area.





Misc. Photos outside, comparing to a stock 250R motor. The stock motor will be donating a lot of pieces into the transmission and bottom of this motor when it comes time to assemble. As it sits now I need to do the following things; Buy a 4MM Stroker crank, all new case bearings, get the cylinder plated, build a pipe. Basically all the big ticket high money items...

[El Camexican]

Last week I had shown how I had slugged and welded the OEM spark plug hole. I ended up getting it drilled and re-tapped. Unfortunately, it looks like I should have angled it a bit more than I did (~5 degrees) because it is awfully close to the frame though it does clear it, I'm not real sure how a plug boot is going to fit around it yet. I will probably have to dimple the frame a little bit which is unfortunate because I could have probably avoided it by angling the hole a bit more than I did...

Before you take a to your frame have you considered finding a shorter plug with a similar heat range? Heck, what plug were you planning to use? 250R or SkiDoo? Also, if you were planning to use a ¾ reach, maybe you could use a ½” reach and recess the plug hole in the head by 1/4”? Our old 440 Moto-Ski used a Champion L78 I recall and I think it was only a ½” reach. I’m assuming a shorter distance from the crankshaft centerline to the top of the plug should solve your frame clearance.

[Red Rider]

Looking very nice Billy! All of the welding/machine work on the cases reminds me of what I went through for my CR250 HPP cylinder install on the ATC250R engine, though your project is just a tad bit more involved. When I did my project back in 2001, it would have been nice to have all of the machining equipment at my disposal that you currently do. I was obsessed with making all of the welding on the cases look as factory as possible, thus there was a lot of grinding/sanding/smoothing after the welding process. What are your plans? Are you going for a factory appearance, or a Frankenstein look?

[Billy Golightly]

I don't know. I'm more the frankstein look type personally, but the plan is to put this in a chrome frame eventually. The joke is it'll be the first "nice" bike I'll have ever built.

Problem is, I can't really decide if I want a frankstein motor in a nice shiny bike, or if I want the whole thing to be nice and shiny...

[Billy Golightly]

Before you take a to your frame have you considered finding a shorter plug with a similar heat range? Heck, what plug were you planning to use? 250R or SkiDoo? Also, if you were planning to use a ¾ reach, maybe you could use a ½” reach and recess the plug hole in the head by 1/4”? Our old 440 Moto-Ski used a Champion L78 I recall and I think it was only a ½” reach. I’m assuming a shorter distance from the crankshaft centerline to the top of the plug should solve your frame clearance.

Yeah, I might end up having to run those smaller plugs that are like $30 a piece worst case scenario. Planning on the 250R plug, so something like a B9ES.

[Billy Golightly]

Just bought one of these since they were on sale; http://www.harborfreight.com/12-inch...l#.Ux5FxIWQr08


Got a good excuse to start on the pipe now

[Mosh]

Ronnie would be eatin this stuff up. Hell of a project. Reminds me of the Z engine that Chainsaw did up years back.

If I can make a suggestion? Maybe talk to Jason Hall about his over size CB bushings for the big end bearing. I have a feeling that big piston is going to bounce that bearing around pretty hard and now would be the time to beef the bore up.

[Billy Golightly]

Ronnie would be eatin this stuff up. Hell of a project. Reminds me of the Z engine that Chainsaw did up years back.

If I can make a suggestion? Maybe talk to Jason Hall about his over size CB bushings for the big end bearing. I have a feeling that big piston is going to bounce that bearing around pretty hard and now would be the time to beef the bore up.

Thanks man, and yes I think he would...this is sort of my own personal Mantis motor I think. I'll check into that, I hadn't ever heard of over sized counter balancer bearings, that probably wouldn't be a bad idea.

[oscarmayer]

awesome work billy. keep it up. that thing looks like a monster compared to the 250r. you sure your gonna be able to use it's power when it's done? something tell sme it will spend more time wheeling than driving. hahaha

[C.J]

You can always paint up the cases a nice shiny black and that will hide the welding and machine marks a LOT.

I LOVE chrome frames (currently working on a chrome project as well) so I'm gunna tell ya what you want to hear so i can see this thing in a chrome build lmfao

[Billy Golightly]

About 1/2 of the way done on Version 1.0

http://snapwidget.com/v/677644250894149022#.UyY-EoVhrPN