Father Son 75 CB200T Rise From the Ruins
- Thread starter Texasstar
- Start date
crazypj
Split personality, I fake being smart
Kop just sent me an e-mail to jump in before you do something real dumb and break stuff for no good reason.
The XS runs a MAX oil pressure of 17psi, usual pressure is around 12psi, you need flow not pressure on a ball/roller bearing motor.
The rods must be slotted, the oil squirters in lower crankcase just jet oil in the general direction of big ends
As for 175/200, it's similar, there is no pressure feed to big ends, cam bearing issues are exactly the same as 350 and 360, the fix is the same as well
175 really likes a long shallow taper reverse megaphone exhaust, doubt 200 would be much different?
It needs to finish about half way up with tyre sidewall. probably 30" long with 2"~3" reverse cone, 2.5" dia outlet
Take a look at the systems Honda built for the race bikes, none are short
The XS runs a MAX oil pressure of 17psi, usual pressure is around 12psi, you need flow not pressure on a ball/roller bearing motor.
The rods must be slotted, the oil squirters in lower crankcase just jet oil in the general direction of big ends
As for 175/200, it's similar, there is no pressure feed to big ends, cam bearing issues are exactly the same as 350 and 360, the fix is the same as well
175 really likes a long shallow taper reverse megaphone exhaust, doubt 200 would be much different?
It needs to finish about half way up with tyre sidewall. probably 30" long with 2"~3" reverse cone, 2.5" dia outlet
Take a look at the systems Honda built for the race bikes, none are short
simo
Been Around the Block
crazypj said:
Hi Crazypj this is an image from my cb175 FSM showing the oiling profile on the cl/cb/sl175 the oil is pumped through the separator and check valve then to the big end bearings ( since it's after the pump doesn't this mean its pressurized ?) and finally to the cam
My concern was that the oiling slots in the xc125 con rods (same as the xs650) would affect the oil pressure to the head, since the stock cb175/200 con rods have no slots to allow external oiling
But I'm happy to be wrong and simply being alarmist
Attachments
crazypj said:
That's close and I may be splitting hairs here, but the big ends are fed oil under pressure - but that pressure is extremely low. They are not splash fed like a C100 single. Oil is fed to the main bearings and as it exits the mains, it is guided by a slinger plate on the bearing which sits inside a groove machined in the flywheels. Oil travels mainly by centrifugal force into the big ends.
But agree 100% that roller bearings need volume and not pressure to work. Typically the big ends are not slotted but the oil basically travels across the width of the rod and "leaks" out the inside edge of the rods.
Rollers do not need a high pressure oil feed and can survive with very little oil pressure or volume.
simo
Been Around the Block
simo said:
So back to this? Since the head is only supplied oil on the tach side and the cam/journals are oiling 'sensitive' , wouldn't it make sense to get the oil to the cam first and let the crank take what it's given by oil passing back to it in a reversed flow
. Or just do a needle or ball bearing conversion and leave the oiling stock?
Texasstar
Can't is a four letter dirty word
Thank you guys and for Crazypj jumping in on this thread. Crazypj and Teazer we are very excited to see what happens on the dyno with both a short reverse cone and a long reverse cone. We are ordering the builders kit from Columbia Mandrel bends and two long megaphone and reverse cones from Cone Engineering. However we will buy the parts and weld them up ourselves.
Also thanks for the fix for the cam oiling so we can use the yamaha rods. Instead of Harmon and Collins we can call it the Kop, Crazypj and Teazer Roller rocker cam. We learn so much from your posts. It would seem to me from reading your posts that once again it is finding the right balance. Too much oil is going to cause a loss in hp and not enough is understood. The way the 3rm bike handled this was with an external pump but what I am understanding is the needle bearing on the cam will require less oil to handle the additional heat/friction issues and does less oil volume and pressure mean less crankcase turbulence? One do we need to add an oil cooler? Two does anyone have a picture of the roller rocker arm? Also I can't find anyone on the web that has done the Isotropic finish on the rocker arms and cam and whether or not this is a good option to handle more rpms reliably. Teazer you alluded to that that Harmon Collins roller rocker arm was "old technology"... now since we are restricted on design and can't do what Honda did with the CRF what would be the best direction to head for our rocker arms? As you may remember we had stress fractures on our stock rocker arms the last time we pulled the motor. I am expecting the same this time. The question is how do we keep making power up to or beyond 11k reliably?
Sent from my iPad using Tapatalk
Also thanks for the fix for the cam oiling so we can use the yamaha rods. Instead of Harmon and Collins we can call it the Kop, Crazypj and Teazer Roller rocker cam. We learn so much from your posts. It would seem to me from reading your posts that once again it is finding the right balance. Too much oil is going to cause a loss in hp and not enough is understood. The way the 3rm bike handled this was with an external pump but what I am understanding is the needle bearing on the cam will require less oil to handle the additional heat/friction issues and does less oil volume and pressure mean less crankcase turbulence? One do we need to add an oil cooler? Two does anyone have a picture of the roller rocker arm? Also I can't find anyone on the web that has done the Isotropic finish on the rocker arms and cam and whether or not this is a good option to handle more rpms reliably. Teazer you alluded to that that Harmon Collins roller rocker arm was "old technology"... now since we are restricted on design and can't do what Honda did with the CRF what would be the best direction to head for our rocker arms? As you may remember we had stress fractures on our stock rocker arms the last time we pulled the motor. I am expecting the same this time. The question is how do we keep making power up to or beyond 11k reliably?
Sent from my iPad using Tapatalk
First you have to make power above 11k and that's not a trivial task.
The thing about bearings is that stock cam towers need a fair amount of oil to provide a continuous wedge of oil to ride on. Any break in that film and it's game over. Needle rollers don't need as much oil to operate, but you still need enough oil coming out of the cam to oil the rocker arms.
To reduce oil churn at the bottom end, polish and chamfer the crank wheels so that they carry less oil "threads" and modify the oil slinger plates so they are closer to the crank wheels to "peel off" more oil. Then fit a crankcase breather to reduce oil pressure or even try a PCV valve to reduce case pressure.
Just as an FYI, a buddy of mine blocked off the breather hose on his GS1100 and it forced oil out of every seam. The cases have to breathe.
You could grab a pair of CRF roller rockers and see if they might fit. No one typically cares what goes on inside your motor as long as it's the appropriate size. But remember that changing the radius of the roller/pad changes the came profile - We used to do that on Triumph twins.
The thing about bearings is that stock cam towers need a fair amount of oil to provide a continuous wedge of oil to ride on. Any break in that film and it's game over. Needle rollers don't need as much oil to operate, but you still need enough oil coming out of the cam to oil the rocker arms.
To reduce oil churn at the bottom end, polish and chamfer the crank wheels so that they carry less oil "threads" and modify the oil slinger plates so they are closer to the crank wheels to "peel off" more oil. Then fit a crankcase breather to reduce oil pressure or even try a PCV valve to reduce case pressure.
Just as an FYI, a buddy of mine blocked off the breather hose on his GS1100 and it forced oil out of every seam. The cases have to breathe.
You could grab a pair of CRF roller rockers and see if they might fit. No one typically cares what goes on inside your motor as long as it's the appropriate size. But remember that changing the radius of the roller/pad changes the came profile - We used to do that on Triumph twins.
kopcicle
antidisestablishmentarian
jump right to post #20
http://planetminis.com/forums/honda-crf110/188365-daniel-crower-racing-cam.html
~kop
http://planetminis.com/forums/honda-crf110/188365-daniel-crower-racing-cam.html
~kop
Texasstar
Can't is a four letter dirty word
<--"the roller rocker is out of the crf110 the non roller rocker is out of a crf 70 head. the non roller rocker is a 1:1 ratio. can any one guess what the difference is minus one has a roller? its the length from center of rocker pin to tip or rocker. the shorter crf110 rocker gives it a mechanical advantage for lift."kopcicle said:
Sent from my iPad using Tapatalk
