Cr250 cyl on a Atc bottomend

[NOS_350X]

Ok, got the stuff back, got it ready to try and drill and tap the new stud holes.

Here is what i have done, Welded the stud holes up, Welded up the 2 watter passages under the cyl. We drilled a hole in the back of the water jacket and welded on a fitting from a KTM.

http://i59.photobucket.com/albums/g285/NOS_350x/GEDC0078.jpg
Stud holes welded up,

http://i59.photobucket.com/albums/g285/NOS_350x/GEDC0079.jpg
Extra material on the side for the stud to grab, I will be using a Helicoil to add strength, With the consistancy of welding not as good as what we have stock the spacing and larger thread size of a helicoil will be much stronger and less likely of stripping.

http://i59.photobucket.com/albums/g285/NOS_350x/GEDC0080.jpg

This shows the water passage welded up, Compare to the other pic of this cyl and you will see it.

http://i59.photobucket.com/albums/g285/NOS_350x/GEDC0083.jpg

This is the fitting on the back.




Now all this work isnt very pretty but it should work. Im looking for function and a awesome combination.

Also a side note here, This was a BRAND NEW engine, this engine had never been ran before and was completely new.

[Red Rider]

Extra material on the side for the stud to grab, I will be using a Helicoil to add strength, With the consistancy of welding not as good as what we have stock the spacing and larger thread size of a helicoil will be much stronger and less likely of stripping.Yeah, it's difficult to get a good weld on these cases because of all the impurities that get thrown into the case casting process. Good luck with this project, I'll be watching.

[KRAZYKANE]

so iam just checking but you are trying to put a newer year head on a older bottom end .what are you hoping for other then bigger piston .i undertsnad .maybe what sparked it .just wondering i think it great no matter what way you go with it .i like the idea of poeple making things better or faster .

[NOS_350X]

First off this is not any bigger than a regular 250r cyl (its just a bit bigger than a std bore 250r) This will be exactly 250cc's

Second this port layout is modern, well more modern than a 250r cyl.

In Karts they are getting 60hp out of these cyl's with out going really extreme.

I have 5 bottom ends and 6 of these new style cyl's i figured wtf ive herd good things about it i might as well give it a shot.

[KRAZYKANE]

oh ok thats awesome good luck with it and hope it works for you and if so wanna sell one .and just saying didnt mean anything by it i was just wondering .

[ridetrikes250R]

definently a cool idea, I hope this thing is a runner...

[MagicJames]

11 days later and still no update?

[NOS_350X]

I have some drag races this friday, I was hopeing to get the engine done for that but the weekend before last my gf got really sick. I spent the whole weekend in the hospital, instead of working on the engine, Ill be looking at another week or 2, or 3.

[MagicJames]

Does this cylinder have the same reed cage as a 250r atc?

I looked at the pictures and it looks like it might.

Otherwise I have a boyesen reed cage for a cr 250 that is different from 250r reed assembly.
You can have it for cost of shipping, has a broken reed and needs new.

[NOS_350X]

let me see a pic, The bolt patter is the same but design is a bit diffrent.

Ill take the cage, shipping about 5-6 bucks? paypall addy?

[MagicJames]

I think it came off of an 02 cr250

[audioworks04]

Any updates?

[disco]

OK, I just read this thread. This is all nonsense. There's no way any of this is true. If Nick is trying to sell us he has a girlfriend... What a bunch of BS! :P

[factoryX]

any updates?

[ridetrikes250R]

last time i talked to nick he mentioned that he was in the middle of his race season and had some tracks a good distance away from him!

[NOS_350X]

Last week i was down by you Adam, in Ontearo, This weekend i will be up in Oregon and Washington.

[jenndnn3]

Are you gonna stop and say hi??

[NOS_350X]

Going to try. Honestly dont know if i have time. Also dont know whos going to be with me, Running into Kent WA and Portland . One cyl let go on the shee in the main in ontiero so im trying to get her going by tomarrow.

[jenndnn3]

pm some detials of when and where if you get the chance,,you have a place to sleep, if you need. Though I know I am like 2 and half hrs away from Portland..

Good luck on the shee,

[factoryX]

hey, any updates?

[NOS_350X]

Yesterday i went and visited one welder, going to another this week. In the next few weeks this thing could be going if all goes well

[factoryX]

sounds sweet.

[NOS_350X]

Cleaning the shop up a bit, Then i can do some drilling, HOPEFULLY it will be good this time

[NOS_350X]

Well i got the bottom end together. (well center cases) still have to do the clutch, counterballance, kickstarter, all that sutff. BUT the cyl looks like it will hopefully hold. only time will tell.

[NOS_350X]

put on the cyl right now, UGH, the skirt of the cyl hit the crank, and the pistom came up above the cyl, I have a head cut for a stroker, so that would work, BUT i need the spacerplate to clear the skirt of the cyl to clear the crank. I got a few, hopefully one will work.

[crackshot]

What is the purpose of all this work?

[NOS_350X]

What is the purpose of all this work?


To have a fast 250r.

Not that it isnt already fast. Just faster, and a smaller engine than im currently running. :thumbsup:

This is just something i wanted to do I had all the parts laying around, so its costing me VERRY little.

I also want to be able to say ive done it.

[factoryX]

okay, any new updates?

[NOS_350X]

Well i sepnt several hours on this last night. Had to cut up a spacerplate just to make it fit, Then i had to port the spacerplate, to match the porting of the CR cyl, then to the case of the atc bottom.

Then, i realized all i had was atc gaskets, So i cut them up to make them fit. Now its not anything that will last very long but should be good to give me an idea if this thing will run good, Then i will proceed by taking it appart and getting the proper gasekts and doing things right.

Now my main wait is for O-rings for the head, I cut up an unknown head to make it work. Everything is looking to go good.

http://i59.photobucket.com/albums/g285/NOS_350x/IMG_7344.jpg

http://i59.photobucket.com/albums/g285/NOS_350x/IMG_7345.jpg

[MagicJames]

Very nice. Now run and order gaskets and give us a ride report!!

[jadleybray]

Run down to Napa and get some material and make your own, should be able to get several thicknesses

[NOS_350X]

Ok, well i got a clutch part that i got to pickup too. Going to try and find the 0-rings for the head then too. Maby next weekend it might be close to going. I still have to get a addaptor to use an ATC pipe on it. (the cr pipe is male, ATC is female)

I picked up a Pro-X cyl the other day. So tonight i started working on that. Tomarrow i will be picking that up too. Should be able to finish that motor and get it i the bike for this weekend.

[ATC.250R]

have you got this thing going yet?

[NOS_350X]

Ive been running the Pro-X cyl for a while now. ready to get back looking at this CR. O-rings, and a pipe addaptor. Hmm, just need some money.

[NOS_350X]

Ok guys, I herd the thing fire tonight. Its in a bike, ill get some pics later, still have to do some little things, but hopefully this weekend it will be completly running.

[NOS_350X]

Got the engine in the bike, Went to test ride it and the clutch was slipping (i did get to ride it and the thing sounds SUPER GOOD). I did something wrong internally on the cluch but I dont know what. The cylinder is leaking watter where the water inlet was welded on. So i will have to take care of that issue too.

UGH, few more days before a test ride.
http://i59.photobucket.com/albums/g285/NOS_350x/IMG_7412.jpg

http://i59.photobucket.com/albums/g285/NOS_350x/IMG_7411.jpg

[badchevelleman66]

Sweet!!!

[shandawg]

Are you running the 89 clutch mod?

[NOS_350X]

honestly i dont know.

I have several of them but i dont know whats in what engine.

[NOS_350X]

Ok, got the clutch issue figured out. Filled it up with water and it didnt leak. Took it for a quick spin out on the drag strip. Feels real strong, We will see Tomorrow in the daylight how it runs for sure. I will also need to do some jetting, along with a few swaps on the bike. (axle, swingarm forks) :iluvu: :burnout: :thumbsup:

[NINJA]

I've been watching this one Nick, as i have the same cylinder sitting on my shelf and have test fitted it onto my bottom end in the past. I'm surprised more people haven't tried this. Really curious to see what the power characteristics are.

[shandawg]

I got that bracket we talked about fabbed up and I'll ship it to ya lickity split just PM me your address.

[NOS_350X]

I've been watching this one Nick, as i have the same cylinder sitting on my shelf and have test fitted it onto my bottom end in the past. I'm surprised more people haven't tried this. Really curious to see what the power characteristics are.


Well i would bet yours is a bit different. :salute: :lmao: This one has powervalve blockoffs (a plate pressed in there to make them stationary) it also has a steel sleve inserted into it to make it boreable. It has some ESR porting :shrug: with a little bit not me work done to it. :headbang:

Before i really get to ride it i will already tell you, Its not worth it. :chuckle: It is a TON of work. Im doing it just to say i have, and to have something different. Also because i can. For somone to come to me, and wanted me to make another it would cost WAY more than its worth, Just get a ESR cylinder, Hell it would probably be even cheaper to do a puma for what i feel i would have to charge. Although i feel you are knoledgable enough and can figure things out well enough to do it, and Having the parts laying around makes it easyer. If you do decide let me know there are things i would do differently.

[NINJA]

Well i would bet yours is a bit different.
I wasn't talking about my weiner:salute: :lmao:

No, I'm aware of the differences your cylinder has over a stock one. I know it wouldn't be "that" easy. Too bad yours is ported, I was really curious how rideable that setup would be utilizing a stock cylinder that's been blocked. I imagine the lowend power suffers quite a bit considering it was originally designed for power valve use, but the topend power is prolly fantastic.

[NOS_350X]

Well after my ride yesterday i think im going to love it. It did start leaking water after i made 2 passes so im going to take care of that tonight. Then i will put it all back together.

The first pass, It sputtered a little then cleared up slightly after about 30 ft and pulled the frontend up. So i let off a bit to shift it came down and i got back on it and it came up extremely fast. The next pass it roasted the tires off, Never had a problem comming up though :chuckle: In all honesty it felt faster than the 310. Once i get all the bugs figured out and jetting dialed in i will set up my drag strip and see how it does with the times compared to my banshee and 310.

[NOS_350X]

Well today i went to my local motorcycle salvage yard, picked me up a cr250 pro circut pipe, I will cutt off the flange that mates to the cyl and weld on a flange form a atc. Right now it does not seal very well.

Then down the road i will cut off the flange from a stock atc pipe, and weld it onto the cr250 pipe, with some more cutting and such i will have a pro circut pipe for the atc.

On another note about the cylinder, I hate to say this but it was going to be the best/easyest option. I Jb welded up the watter leak, We will see how it does.

[badchevelleman66]

Well today i went to my local motorcycle salvage yard, picked me up a cr250 pro circut pipe, I will cutt off the flange that mates to the cyl and weld on a flange form a atc. Right now it does not seal very well.

Then down the road i will cut off the flange from a stock atc pipe, and weld it onto the cr250 pipe, with some more cutting and such i will have a pro circut pipe for the atc.

now the pro circut pipe was built for the powervalves to be working will that affect and power band of that pipe ???

you ready for me yet???

[NOS_350X]

Anytime you can get over come on over, Just gime a call.

As of right now im not planning on running the PC pipe. I will get to it down the road.

I would think with a cr ignition, Cr250 carb, and cylinder, the pipe eventually should do perty good with it.

[badchevelleman66]

you still have a pt hi rev??? think with the porting that would be best lol but you have enough to choose from

[NOS_350X]

Im working on getting a OOF pipe for it. Darren currently has the ptr pipe, at Rasor it had a date with a rock. So i gota get the dent out. Once thats done i will try it. Right now i figured ESR, with mainly Esr porting would be a good match.

I got another Rolling chassis R, SOOO im going to build a 3rd one up, once im done with this project. I think im going to make that one a Low rpm bike. Hmm, FUN.

[badchevelleman66]

i think ya should find another 500!!! :)

[NOS_350X]

Ok guys, well i had this thing at the sand drags friday night. I will start by sayin there is a TON of tuneing still to be done with the ignition, carb, pipe all that stuff.

BUT, This thing ran STRONG, In pratice i made a 3 passes, one agenst a 440ex and 2 passes agenst a 250r with a CT 350pv engine. The 440 wasnt even a race. The 350 really wasnt doing that well agenst me eather. In the races. My first race was agenst a 4mill Banshee I know the owner perty well and its a decent running bike super long swingarm and an alright motor. At the end we couldnt tell who won it was so close.(but i lost)
the next race was the same 250r i beat in the pratice, Won that, Anoter race agenst a 250r with an ESR 330 kit, beat him, then had to race the same banshee again and i red lighted.

Now the 250r's (the 330 and 350pv) are both duner bikes. They are not setup to drag race as well as my trike.
BUT my engine is a dang 250cc!!!!! This motor is AWESOME, and i still have a lot of tuneing to do to it. Running with bikes that are 100cc or more larger i cant complain, Im seriously already thinking of building another one.

I will try and get times and pics soon, stuff should be up later this week.

[Mr. Kasey]

so wouldn't it be WAY easier to map the porting and just do a atc or trx cylinder?

since you have the powervalve is blocked off there is no advantage ????????

[KRAZYKANE]

so do you still think its not worth it .like you said i few post back

[NOS_350X]

you cannot copy this porting in the atc cylinder. One of the many reasons is the tripple exhaust port. A powervalve only has an advantage if you want lowend power. Otherwise its just a pita. Not what im looking for.


Krazy, If you have the stuff laying around or could get it cheap, i would say it is well worth doing.

[jenndnn3]

Glad you like it Nick...
You have been working on this a long time...

Look forward to picts..

[jadleybray]

You can tripple a stocker as well. Cool project none the less.

On another note, what kinda #'s were the R's runnin?

[NOS_350X]

5.9-5.7 and this is a slow track compared to others.

I think tuneing it on alky, Pipe and other things i can get into the low 5's with a 66.4mm bore and 72mm stroke, Do the math guys that is a SMALL engine for a drag bike.

[NOS_350X]

I made some changes, I put a strut in the rear, Went to a Ptr pipe, and went to alky. Today i made about 30 passes playing with it and stuff. fast pass of 5.6, didnt have any run in the 6's and before i did. So im happy with the power.

There was a problem, I get to the track and the bike wont start, I mess with it ALOT, and i dont get a thing. Finally i decide to pull the plug and flip the bike completely over and turn it over while doing this the pipe POURS watter out. Soo i have to get watter leak fixed the crankcase and pipe where completely filled. Soo looks like a teardown this week.