Aftermarlet bottom end?

[TheFontMaster]

The thread about the sabertooth kit made me think why people aren't making stronger aftermarket bottom ends to go with some of these crazy 400cc+ top end kits. Does anyone make an aftermarket bottom end. Even after what 20 years of the R being around you would think someone would have come up with something.

[wilkin250r]

Designing a bottom end is no small task. The tooling required to mold and machine the cases and all associated parts would easily exceed a million dollars.

This makes sense for manufacturers, because they'll sell thousands upon thousands. However, and aftermarket company would be lucky to sell ten thousand. It's just not worth it.

[punker69q]

The bottom end could be made from billet aluminum, without having to make a casting and the molds needed to make them, but machining a complete bottom end from billet would take something like 20-30 hours (rough estimate), resulting in a price tag of about 3000$ for only the cases.

[zedicus00]

yeah im still trying to talk one of my friends into doing a set of billet cases for me... every time i bring it up he changes the subject... hes a quad guy though and i know hes interested.. its just the time it takes to design it in the system to be produced by the billet mill is verry intensive and boring. even if u r just cloning sumthing. not to mention it takes a large chunk of high quality aluminum to hold up to being used for that

there are about 8 sets of billet cases in the wild produced by some guy i talked to once, eech set sold for over 2000$
there are 2 companys that produce a half set of billet tranny gears, to be used with the rest of the stock gears.

there are companys that produce aftermarket clutch parts and after market cranks...

the sadest part though is that most peeple are having better luck with new stock parts over a lot of the aftermarket stuff...

[250Renvy]

It would only be worth while if they made bigger cases for the 400 top ends. Otherwise just buy stock honda.

[wilkin250r]

The gears are usually okay, and there are heavy-duty gears available.

Me, personally, I'd like to get 20 people together and have Falicon make a billet crank for the 250r. When you get into big bores, the crank seems to be the weak link, anyways.

[beerock]

Its not as simple as making a stronger crank its the fact that the lower connecting rod bearing and wrist pin bearing dont hold up well to the 370+ size bores. onyl way to fix that is to use larger diameter bearings, larger wrist pins, and larger crank pins.Using larger bearings and pins shorten the throw of the connecting rod and makes the stroke less hence lowering the over all cubic centimeters of the motor.This is exactly the opposite of what a stroker crank is, stroker cranks moves the connecting rod further outward on the crank to have a longer stroke. they do that by using a smaller crank pin that is offset from the original position.(in my opinion not to smart) the machined internal case for the R crank does not leave alot of room to put a larger crank Inside. This is what would have to be done to make the 370+ bores more reliable. Its not the only factor though. A counterbalancer would have to be made to equalize the larger crank otherwise there will still be vibration issues, which long term cause premature wear of bearings etc.this doesnt mean it wont run for a long time, but you would have to maintain the conn rods and wrist pin bearings more frequently.

So, really to make a big bore 370+ R as reliable as a stock 250 you need custom cases machined for a larger crank, custom crank and custom counterbalancer. thats alot of cash. I would say 10k and it COULD DEFINATELY be done.

[punker69q]

If someone want's to pay 10k for a prototype I will gladly make it, I own the cnc equipment necessary to make those kind of parts :blah:

But honestly, i'm starting to think that my shop should make billet parts to replace the discontinuated parts from honda. Do you think there would be enough interest in this kind of parts?

[zedicus00]

i would say YES!...

i think i finally got my machinest friend ready to make some R cases, should i hav anything changed or anything??

would anyone else be interested in a set??

does anyone make a billet clutch cover? may hafta hav one of thouse dun too. OOOH i could hav it made with a quick change clutch setup...

[TheFontMaster]

Originally posted by zedicus00
i would say YES!...

i think i finally got my machinest friend ready to make some R cases, should i hav anything changed or anything??

would anyone else be interested in a set??

does anyone make a billet clutch cover? may hafta hav one of thouse dun too. OOOH i could hav it made with a quick change clutch setup...

I'd be interested in a set in about 2 years once I'm through college. I think from what people have said if you are going to change anything you are gonna want to make the cases accept bigger diamater berrings, and if you can make new transmission gears.:confused:

[zedicus00]

if u guys want solid tranny gears buy a new stock set an hav them cryoed...seriously, it works.

[punker69q]

Originally posted by zedicus00
i would say YES!...

i think i finally got my machinest friend ready to make some R cases, should i hav anything changed or anything??

would anyone else be interested in a set??

does anyone make a billet clutch cover? may hafta hav one of thouse dun too. OOOH i could hav it made with a quick change clutch setup...

Do you have access to a 3 dimensional measuring machine? Because this is probably needed to build an accurate 3d model of the case before you can make them. With this kind of parts you need every measurement to be perfect, and it's almost impossible to get it right without this kind of machine.

[zedicus00]

im sure he does. hes made other stuff for me b4 and its always been perfect.

[punker69q]

Those kind of machines are a little rare and cases are probably the most complicated parts to make. You would probably have to make a complete 3d model of them before machining them and this is very time consuming.

I don't want to discourage you from trying this project, but I just want you to know that this kind of project is not for everyone, event excellent machinist don't have the knowledge to succeed such a complex project.

However, if you want help, I will be glad to help you, I have some quite good knowledge in retro engineering existing parts and 3d modelisation of those parts and I MAY be able to have access to a 3d measuring machine.

Engine parts needs really close tolerance, sometime down to 1/10000 of an inch, so this is why everything must be perfect, or you may end up with a 2000$ pos part that won't work well.

[zedicus00]

my friend builds stuff like this for a living... we should be o.k. thanx for the offer though, if we come up with sumthing he cant figure out i will let you know.

[rebelbanshee]

http://www.mattoonmachine.com/cgi-bin/Mattoon.cgi/15-100.html

These folks make Banshee cases. Youd probably want a 5 axis setup to make these

[hondardr4life]

Mark Baldwin sells a 2nd through 6th gear aftermarket tranny kit.