The International CBX Owners Association

i just received a broken (snapped #5 rod) 79 CBX motor that i purchased a week ago ! the intention is a research platform
from which i hope to answer questions i already have about parts interchangeability with other Hondas and those that will surely
arise in the course of the reaching the goal of building the ultimate O.E.M. parts hotrod CBX motor ! it will also serve , i hope ,
as a mock up to be able to provide "pre-degreed" cams for those who want the benefits but don't have the tools or know the
process . it makes a difference regardless of year model ! i'v already answered a few questions i had and with some research
there should be a lot more to come ! i want to do for a CBX what i did on my CB900F ! more later!

bobcat

I always marvel at the mechanical talent we have on this site. Good on ya, bobcat.
Just remember to include an easy-speak version when you are reporting back so some of us will be able to understand.

+1 to all that. Pass the popcorn, looking forward to this!

N.

Good stuff bobcat, can't wait!
Ar.

As the CBX is not really a new bike, many, many things have been done with it already. A lot of it is just buried in history. But there were big bore motors, turbo motors, blower motors, nitrous oxide motors, fuel injection motors (including water injection), flatslide carb conversions, "hot cam" motors and many other things. A lot of time, rideability suffers while ¼ mile time is the only thing that improves. I am working on a (slow progress) project myself right now.: A 70mm bore with high compression and a flowed head together with flatslide carbs. All I do is digging through old stuff and see what others have done before.

I'm up for the cam timing thread...

bobcat wrote:i! it will also serve , i hope ,
as a mock up to be able to provide "pre-degreed" cams for those who want the benefits but don't have the tools or know the
process .
bobcat

bobcat, its good a good idea in theory but you can only degree cams while they are in the motor you'll be using them in, the cam chain stretch is different in all bikes and this affects the cam timing.

I am well aware of all the factors and variables that affect cam timing and those things are taken into account when
degreeing cams , thus requiring a lot of detailed info. about the motor that the cams are being prepared for so i can
duplicate the motor on my mockup ! for example : stock or aftermarket gaskets, any milling ,new or used cam chains,
mileage on the motor etc. . keep in mind this is a new project and concept !that's why its called R&D ! but ,i am confident
that this can be done. i have tested ,duplicated and proven the specs. i use and now aim to do it from the mockup motor !
by all means, all input , questions or criticism are humbly welcome . My goal is to make the riding experience more enjoyable
by getting the most out of what you have !
bobcat

Being in the CBX community as long as I have I believe most owners that want that kind of degree of tuning for their CBX's will most likely degree the cams themselves or have someone do it local with the cams in the bike, but thats just MHO.

go for it ! does anyone know what specs. are ideal ? i was given a lobe center chart years ago by a person with HRC
connections. it took me a while to learn how to use it but it verified everything i learned prior to having it !
basically , optimal cam timing starting point (lobe center)is determined by only two factors : ROD LENGTH (measured
big end center to small end center bores) vs.(cross ref.) 1/2 of stroke . this ,on the chart , yields the ideal "starting point"
which ,used by itself is better than stock. variations for motor configuration do not vary far from that. usually learning
the "WHAT" and "HOW" are followed later by the "WHY" .
skeptics welcome ! bobcat

JEFF ,
you still have to remove the cams to make the necessary modifications in order to make them adjustable !

respectfully, bobcat

bobcat wrote:JEFF ,
you still have to remove the cams to make the necessary modifications in order to make them adjustable !

respectfully, bobcat

I know, I have done it before, you need to slot the cam drive gears to make them adjustable. My point is that most people wanting this type of fine tuning will most likely do it themselves or have someone local do it with the cams installed back in the bike, that way all variables will be eliminated and or considered while degreeing the cams.

me thinks you are missing something here ! the CBX is unique in the fact that you cant slot the cam gears(sprockets) as the sprockets
are what the bolts thread into . the cam FLANGES must be slotted ,unlike any other OHC motor i have ever seen ! all others you slot the sprockets
as the threaded bolt holes are in the cam flange. with ALL DUE RESPECT, I submit that ,although i am a "newbe" to the forum , i have been around
the track a few laps ! if you feel the need to slot the cam gears, keep me posted !i'd like to know your procedure !

bobcat

EMS wrote:As the CBX is not really a new bike, many, many things have been done with it already. A lot of it is just buried in history. But there were big bore motors, turbo motors, blower motors, nitrous oxide motors, fuel injection motors (including water injection), flatslide carb conversions, "hot cam" motors and many other things. A lot of time, rideability suffers while ¼ mile time is the only thing that improves. I am working on a (slow progress) project myself right now.: A 70mm bore with high compression and a flowed head together with flatslide carbs. All I do is digging through old stuff and see what others have done before.

i'm not looking at building the "world's fastest CBX" ! just doing what i have done in the past : a STRONG running RELIABLE motor that doesn't cost big
$$$$$$ in less reliable and unpredictable aftermarket parts ! where do i submit my resume ?

Bobcat:
I, for one, welcome any input you may have with your project. I'm happy with most of the engines I have put together with stock stuff, for the most part, and to see them running well as they are supposed to. But reliable mods, especially with Honda parts, would be nice to results from. The problem is that standard, necessary internal parts (chains, tensioners, seals etc) are getting hard to find. Look forward to hearing what you find!

Dave