New case halfs

[fireburns99]

Hey guys, I brought the topic of manufacturing new case halfs awhile back since we all know that at some point the supply of oem honda ones will be gone. Well I've gotten the equipment i needed to copy the oem ones, so here is where i am at.

I am in the process of talking to casting companies to try and determine the cost, and the amount of cases that would be required. I am still trying to determine the feasability as well as the demand for them. So if i was able to reproduce them would people be interested?? I would also get with C-Leigh Racing to discuss the possibilites of strengthening known weak points, would you guys be interested in these?? I'm just trying to gauge interest before i invest too much money and time.

So if this project does continue i will need a couple of people to volunteer case halfs that i can 3-D image. What i need are a left half and a right half. I know that some of you guys have undamaged ones laying around. I realize that you will be shipping them to me based on faith, and if there are any concerns or if you are interested please PM me. All I am trying to do is make sure that these machines live on.

So if you guys have any input please feel free to email me nick.ubrun@gmail.com, PM, or post here. Any help or comments will be appreciated.

I am also working on getting examples of what the 3-D scanner can do. When i get these examples i'll be sure to post them.

Thank you for your time.

[C-LEIGH RACING]

Nick,
I would be glad to help.
Neil

[Aceman]

Did you mean cast or billet? Honda still makes cast cases unless you're worried about them discontinuing them......

In either case, I give you props. I wish I had the resources/skills to undertake a project like this.:cool:

[fireburns99]

Although Honda still has them now, how much longer do you expect them to carry them? They have discontinued every other part, so when there out, there out. Plus I intend to improve on the original design adding material where the stock cases were notoriously weak. Hopefully this would allow me to outsell the orignal Honda pieces.

I would be casting them. But it would be fairly easy to do a run of billet cases as well, although they would be CNC machined. And the billet cases would proabaly carry a hefty price tag, and would probably be reserved for the drag guys.

And i appreciate your help Neil. I'm still dialing in the 3-d scanning equipment, but i plan on hopefully getting a rapid prototyped model (http://en.wikipedia.org/wiki/Rapid_prototyping) to you within a few months so that you can mark trouble areas.

[Rich250RRacer]

I've always wondered if it would be possible to re-engineer the right case half to incorporate the drive gear to run the power valve governor from an 86-91 CR250. Of course, the clutch cover would also need to be changed, but the work may be worth it since these CR's were very strong running motors and the power valve system worked well. The biggest problem would be room for both the PV governor and the counterbalancer. Just wishful thinking on my part, but it's the way Honda should have done it.

[fireburns99]

Originally posted by Rich250RRacer
I've always wondered if it would be possible to re-engineer the right case half to incorporate the drive gear to run the power valve governor from an 86-91 CR250. Of course, the clutch cover would also need to be changed, but the work may be worth it since these CR's were very strong running motors and the power valve system worked well. The biggest problem would be room for both the PV governor and the counterbalancer. Just wishful thinking on my part, but it's the way Honda should have done it.

Hmmm, thats an interesting idea. I may need to try and find an old CR motor to rip apart, and see how much room would be needed. But if it is simply the right case and the clutch cover that would need a re-design than it shouldn't be too bad. It would offer a nice cheap alternative to the aftermarket powervalves. The kick starter would ahve to be redesinged as well to make it a forward kick.

I'm not real familiar with the CR motors, how much room would be needed? Would the water pump have to be moved? And how much bigger is the counter-balancer?

[250Renvy]

I remember seeing you post that before, but I forget if you are doing it for school or are you a professional in the related field?

If it's school and you have highly trained professors I think your best bet would be to map a complete engine because there are many parts in the kick start and shift shaft that are discontinued.

Another idea, if you are in it for the learning is to map and redesign a CR500 or CR250 motor to have a counter balancer that way the powervalve will work. The idea is that there are tons of CR250 used parts as well as parts in production. Although the hard part would be picking a year since they modify the bike motors almost every year.

I think the CR250 top end fits on a TRX bottom so if you could figure out how to make the powervalve work that would be a good idea too.

PM me if you have the capacity to buy new cases and we could figure out a way for me to buy them off you when you are done.

BTW the Left and right case covers are discontinued already.

[fireburns99]

Originally posted by 250Renvy
I remember seeing you post that before, but I forget if you are doing it for school or are you a professional in the related field?

If it's school and you have highly trained professors I think your best bet would be to map a complete engine because there are many parts in the kick start and shift shaft that are discontinued.

Another idea, if you are in it for the learning is to map and redesign a CR500 or CR250 motor to have a counter balancer that way the powervalve will work. The idea is that there are tons of CR250 used parts as well as parts in production. Although the hard part would be picking a year since they modify the bike motors almost every year.

I think the CR250 top end fits on a TRX bottom so if you could figure out how to make the powervalve work that would be a good idea too.

PM me if you have the capacity to buy new cases and we could figure out a way for me to buy them off you when you are done.

BTW the Left and right case covers are discontinued already.

I am currently a 4th year mechanical engineering student. I am doing this as a side project with the intention to supplying fellow 250R riders once the oem ones run out. While I'm not planing on getting rich off this venture, i want it to be worth my while.

If i do design for a CR top end i will also have to design the kick starter. Most likely reverse engineering the stock one to fit the new right case IF i go that route. I'm currently looking for what people want as well what could be the most useful. But since the 88-91 CR top end fits it is the most likely candidate at this time.

And i am working on creating new cases that are stronger than the oem to sell, so when i'm done they will be for sale.

And thanks for the information on the oem cases. I thought they were discontinued like everything else 250R.

[Rich250RRacer]

Originally posted by fireburns99
I am currently a 4th year mechanical engineering student. I am doing this as a side project with the intention to supplying fellow 250R riders once the oem ones run out. While I'm not planing on getting rich off this venture, i want it to be worth my while.

If i do design for a CR top end i will also have to design the kick starter. Most likely reverse engineering the stock one to fit the new right case IF i go that route. I'm currently looking for what people want as well what could be the most useful. But since the 88-91 CR top end fits it is the most likely candidate at this time.

And i am working on creating new cases that are stronger than the oem to sell, so when i'm done they will be for sale.

And thanks for the information on the oem cases. I thought they were discontinued like everything else 250R.

Using the TRX bottom end would be the way to go since you already have the forward kick. The main problem is the counterbalancer. The governor for the power valve would have to go right where the balancer is. The 86-91 style top end would be the one to use, especially since the CR and the 86 TRX use the same rod. They were the same stroke too if I remember correctly. I think the cylinder stud configuration is the same or close. Like I said before, it's really just wishful thinking, you would almost have to redesign the whole motor. If the idea still intrigues you though, find an online microfiche for the 86-91 CR and look at how it's set up.