250r to 380r monster

[Daddio]

This idea is finally becoming reality. A few years ago 1upfront bought a cylinder from an odyssey 350 with the intention of putting it on an aircooled 250r. Since then we have kicked around a few other ideas and he finally decided to go forward with this project.
It will be using the odyssey cylinder bored to 82mm and to top it off it will be running a crank from an 85 250r to give it a 72mm stroke. He had the cases bored so the crank and the jug would fit. and had the crank machined down on the ends to match the aircooled crank specs. It still needs a few small mods but it is shaping up.

http://i416.photobucket.com/albums/pp245/lhdunlap/100_0885.jpg

http://i416.photobucket.com/albums/pp245/lhdunlap/100_0887.jpg

This is with half of the crank in with the piston and jug attached to check for fitment. The piston comes right to the top of the cylinder like it should but the cases will need to have a little more taken out because the piston skirts hit the cases on the down stroke. It won't take much though.

http://i416.photobucket.com/albums/pp245/lhdunlap/100_0889.jpg

http://i416.photobucket.com/albums/pp245/lhdunlap/100_0894.jpg

http://i416.photobucket.com/albums/pp245/lhdunlap/100_0890.jpg

These cases are for mock up only they were junk but he didn't want it ruin a good set if it didn't work out.

[Billy Golightly]

Awesome work guys. I love seeing stuff pieced together from different motors like that. It actually takes some skill and understanding of how things work instead of just throwing the bolt-in crap on there.

[Billy Golightly]

PS, were you guys already running a full circle crank? If not you should see some benefits from that as well.

[Daddio]

PS, were you guys already running a full circle crank? If not you should see some benefits from that as well.
No, he found this one on ebay for cheap. It needed to be rebuilt so it was the perfect candidate.

[1upfront]

Here's a pic of both style crankwheels, I originally bought the liquid crank for comparison to see if it was even possible to use and found that the drive end/important end had identicle splines only longer so all we had to do there is have it wacked off, also the bearing size is the same and the splines are timed right for the counterbalancer not that it will be completely effective with such a large stroke lol, the flywheel key is timed right for the ignition timing too lol
Stock crankwheel on right
http://i416.photobucket.com/albums/pp245/lhdunlap/100_0876.jpg
Here's a pick of both style crankwheels together it gives you an Idea of how much larger the stroke will be.
http://i416.photobucket.com/albums/pp245/lhdunlap/100_0880.jpg

[300rman]

PS, were you guys already running a full circle crank? If not you should see some benefits from that as well.

very true. my crank is a balanced full-circle, and it is definitely noticable.

[1upfront]

Along with the crank and cylinder mod I'm upgrading the clutch to the 89 clutch upgrade with alittle machining to the 83 pressure plate and the throwout rod. Then I'm installing a new billitt basket on a welded/reinforced factory gear. Here's pics of the new parts.
small washer not pictured
http://i416.photobucket.com/albums/pp245/lhdunlap/100_0896.jpg
http://i416.photobucket.com/albums/pp245/lhdunlap/100_0665.jpg
http://i416.photobucket.com/albums/pp245/lhdunlap/100_0664.jpg

[freaksfix]

I have been looking to go bigger with my drag bike, but just cant seem to come up with a way that wont cost a ton in the long run.. I only get to run it at TF and maybe one other race a year so I realy dont wanna drop alot of cash on it. The Mugen's are way to rare and costly, and the 300's have way to many problems finding parts to complete them.

If this is something that could be done and the cost is'nt to crazy id like to go this route myself.. If not Im always on the look out for a cr480.. So keep us posted on this im very interested..

[Enginerd]

Daddio and 1upfront, you guys rock! :w00t:

I just bought an 84 250r about 3 weeks ago to replace the one I sold 10 years ago. I was already looking for more power and bought a great FL-350 top-end on Ebay. I knew case machining would be required, but I didn't know anyone who had done it. I also didn't know that the later 250r crank would fit with mods.

Then to top it off.....you two come up with an upgraded clutch basket too?:beer

Like I said, you guys rock! I am attempting this exact build, and would love to be able to consult with you two to get the benefit of your knowledge and experience.

It ironic, I was just going to try to contact you 1upfront, to see if you had tried this yet. I guess I know now!:D

[1upfront]

Here's the intake and carb I'll be running it's a 40mm lectron with oversizes bowl and a sand scorcher intake, I'll just buy a 40mm boot for the intake and port it to match.
http://i416.photobucket.com/albums/pp245/lhdunlap/100_0928.jpg
http://i416.photobucket.com/albums/pp245/lhdunlap/100_0925.jpg

[bigpimpin]

if you can get that to work that's one badass setup

[Daddio]

if you can get that to work that's one badass setup
I have little doubt that it will work. I'm more sure now than I was a month ago. After a little more machine work it will be ready to send out for port work. :beer

[Enginerd]

After a little more machine work it will be ready to send out for port work. :beer

May I ask who you will have perform the porting work. Flotek maybe. Were you happy with the port work they did on the 300.

(sorry for the bad punctuation. My question mark key quit working on my laptop.)

[1upfront]

May I ask who you will have perform the porting work. Flotek maybe. Were you happy with the port work they did on the 300.

(sorry for the bad punctuation. My question mark key quit working on my laptop.)

Yeah Denny at Flotek does my portwork, headwork and flywheel lightening he does an excellent job.

[Enginerd]

Along with the crank and cylinder mod I'm upgrading the clutch to the 89 clutch upgrade with alittle machining to the 83 pressure plate and the throwout rod. Then I'm installing a new billitt basket on a welded/reinforced factory gear.
http://i416.photobucket.com/albums/pp245/lhdunlap/100_0665.jpg


I have a question about your Mitaka clutch basket. Can you tell me what application it is for, and where you bought it? I am guessing its for an 86-89 TRX 250R?!?!

Thanks sir.

EDIT: I found these posts here and on .ORG

http://www.3wheelerworldforums.com/showthread.php?t=84453

http://www.3wheeler.org/vb/showthread.php?t=32872

So.....I now know its original application is a 78-80 CR250, and it came from here: http://www.grampianmotors.co.uk/

and it uses the same plates as a Honda 300EX Quad.

My new question is: Did you ever have those +3mm clutch rods made? Also, can you elaborate on the parts and machining required to use this basket and plates in an air fooler?

Thanks again!

[Taiser]

E-freaking-gads, can't wait to see how that screams!!!

[300rman]

May I ask who you will have perform the porting work. Flotek maybe. Were you happy with the port work they did on the 300.

(sorry for the bad punctuation. My question mark key quit working on my laptop.)

I can also vouch for Denny at Flotek. did my 300, and it is great!

[Daddio]

I have a question about your Mitaka clutch basket. Can you tell me what application it is for, and where you bought it? I am guessing its for an 86-89 TRX 250R?!?!

Thanks sir.

EDIT: I found these posts here and on .ORG

http://www.3wheelerworldforums.com/showthread.php?t=84453

http://www.3wheeler.org/vb/showthread.php?t=32872

So.....I now know its original application is a 78-80 CR250, and it came from here: http://www.grampianmotors.co.uk/

and it uses the same plates as a Honda 300EX Quad.

My new question is: Did you ever have those +3mm clutch rods made? Also, can you elaborate on the parts and machining required to use this basket and plates in an air fooler?

Thanks again!

Yes we had them made from tool steel and had the ends heat treated. They worked out great. Any reputable machine shop should be able to handle that job.

[Enginerd]

The piston comes right to the top of the cylinder like it should...
http://i416.photobucket.com/albums/pp245/lhdunlap/100_0890.jpg


I meant to ask this earlier....

Are you just using a standard FL-350 piston during these mock-up exercises?

This wasn't any special piston was it?

[Daddio]

I meant to ask this earlier....

Are you just using a standard FL-350 piston during these mock-up exercises?

This wasn't any special piston was it?

It is the used wiseco piston that came with that cylinder.:naughty:

[NewfieBish]

this is shaping up to be a pretty cool project, can wait to see how this trike turns out!

[Enginerd]

This is with half of the crank in with the piston and jug attached to check for fitment.
http://i416.photobucket.com/albums/pp245/lhdunlap/100_0889.jpg


How much did you have to enlarge the crank area to fit the 85 crank?

Also, it has been mentioned that you may reduce the outside diameter of the 85 crankwheels by turning them on a lathe.

Any negatives to this??

[300rman]

http://i416.photobucket.com/albums/pp245/lhdunlap/100_0889.jpg


only issue that i could think of is that you are going to have ZERO crankcase volume.......might want to look into that

[Daddio]

How much did you have to enlarge the crank area to fit the 85 crank?

Also, it has been mentioned that you may reduce the outside diameter of the 85 crankwheels by turning them on a lathe.

Any negatives to this??

We are going to have material removed from the crank wheels for sure. This will be very easy because it is a cover made of much softer metal than the crank its self. The cases that are in these pictures are junk and are only for mock-up. We already thought about crankcase volume and when we do the cases that will be used on this build they will be machined to have the same clearance as the stock crank. We may not need to have the cases machined if we can have enough taken off of the crank wheels. That is the current plan but the Mugen isn't finished yet. It's taking up a lot of money right now.

[tecat-z]

Hopefully Hartley and Ron will have this completed, so we can see this engine in action at TF10. The Mugen 360 "if i rember correctly" sounded like a lethal combo too...:naughty: It's coming fast!:cool:

[Shorty]

We need update!!

[atcrider1]

any updates??????

[Shorty]

Hey could you mod one more 3rd gen 250r crank and one more set of those cases for me for the right price? And would the 72mm crank have head clearance issues with a dico 300r kit?

[BIG_RED-ICULOUS]

is there any new progress to report? I am intrigued by this build......

[200]

Has there been anymore progress made i was looking into doing this my self and i wanted to see if there was a running motor as proof that this will work.

[onformula1]

Any updates?, did you get it worked out?

[atc300r]

Thought I would bump this up .

[big specht]

I have his R motor project now. It's getting closer just got to get crank machining down. I have to take around .080 off the bottom of the piston to get it to turn over in the R cases