Topic: Needle roller conversion for CB/CL/SL350 /250 twin cam journals

[AshimotoK0]

Thinking of doing my own cam bearing conversion to needle rollers and bought all of the parts mentioned in the posts below but got Timken not INA components.

http://www.hondatwins.net/forums/48-engine-discussion/27829-cb250-350-cam-bearing-bushing.html

http://www.hondatwins.net/forums/48-engine-discussion/26551-will-someone-here-machine-set-new-cam-bearings-me.html

http://www.ebay.com/itm/1968-74-Honda-CB250-350-Cappellini-58-cam-support-bearing-conversion-EXCHANGE-/160935833577?pt=Motorcycles_Parts_Accessories&vxp=mtr&hash=item257885efe9


However, have seen on a post on here somewhere that these is not enough oil flow for needles. Any opinions welcome please. I do have the machining services available to carry out the conversion to the necessary precision. This is just for a road bike 1969  CB250K0 not for racing.

Parts cost £50 not $50 over here (even with huge discount) but maybe Timken more expensive than INA

Cheers ...... AshD

[TimV840]

Hey, I road race a couple CB350s. One stock, and one with a modded engine with the needle roller conversion. Neither have oil mods. No issues with either after a few years of (ab)use.

Good luck,

Tim

[grcamna2]

I'd like you to keep this thread going so I can learn how this mod works out for you AshD.I'm VERY motivated to modify my 72' CB350K4(which has the bigger volume oil pump,bigger than previous older models)twin w/ the same thing.I'd like to know all the details please. 
  I wonder if someone could rig up a Cappilini-clone top oiling system w/ oil filter w/o too much expense ?

[AshimotoK0]

I'd like you to keep this thread going so I can learn how this mod works out for you AshD.I'm VERY motivated to modify my 72' CB350K4(which has the bigger volume oil pump,bigger than previous older models)twin w/ the same thing.I'd like to know all the details please. 
  I wonder if someone could rig up a Cappilini-clone top oiling system w/ oil filter w/o too much expense ?

Will certainly keep the thread going. Need to find some decent 312 style rockers & shafts though, as every one I see on Ebay USA seems  has pitting, scoring to some degree. I don't really understand it, as back in the day I had K2,K3 & K4's  that did considerable mileages, as I used them for commuting to work, but didn't get damaged like that. Yet you get them on Ebay USA from motors that did supposedly sub 10k miles but are badly damaged. Maybe it was just me changing the oil !!
Problem is I have had some bad deals on Ebay (mainly UK though not USA) and postage and import changes from USA to UK really bump prices up, so hard to take a 'gamble' on them.

I really want my bike ('69 CB250SS  (K0)) to look standard externally so not really considering the external oiler but hey it's and interesting engineering challenge so let's talk about it here.

What a brilliant site / forum this is !!

Cheers ... AshD

[grcamna2]

I know what you mean about that ebay,even if you get the $ for the parts back it's very disappointing.I would actually prefer not having to use that top oiler thing(which I think looks more like a Racing Only style mod)device from Cap.
  I've heard of cam grinding co.'s that'll hard face the cam and rockers and i'll need that done also on a few of mine,I use the same 312 rockers and camshaft.
 I used that link and went onto hondatwins last night and noticed member "captb" has already done this same mod. Has it been easy to speak w/ him or PM back & forth for tech ?
           This is an EXCELLENT forum !
This is the thread for me AshD,thanks for creating it. 

I just looked at that ebay link you have at the bottom of your first post,the item looked like a great Deal ! All the work already done ! I'd like to try to find similar or see....,if I can ask that hondatwins.net member "captb" to help.......

[AshimotoK0]

I know what you mean about that ebay,even if you get the $ for the parts back it's very disappointing.I would actually prefer not having to use that top oiler thing(which I think looks more like a Racing Only style mod)device from Cap.
  I've heard of cam grinding co.'s that'll hard face the cam and rockers and i'll need that done also on a few of mine,I use the same 312 rockers and camshaft.
 I used that link and went onto hondatwins last night and noticed member "captb" has already done this same mod. Has it been easy to speak w/ him or PM back & forth for tech ?
           This is an EXCELLENT forum !
This is the thread for me AshD,thanks for creating it. 

I just looked at that ebay link you have at the bottom of your first post,the item looked like a great Deal ! All the work already done ! I'd like to try to find similar or see....,if I can ask that hondatwins.net member "captb" to help.......

Yes 'captb' is very helpful and told me to contact him if I need any help. If you look on the site he has also torque tested to destruction some cam fixing bolts and recommended torques with red Loctite to use at low torques. Really good stuff!! I have just changed jobs and our premises were flooded with tidal water in December so we had to get a new milling machine, which our guy is still getting to grips with. But will definitely do the mod and post everything on here. I think captb only paid $50 for his parts.

http://www.hondatwins.net/forums/48-engine-discussion/23363-cam-bolts-torque-test-cb-cl-sl350.html

Cheers... AshD

[grcamna2]

I'm Very motivated to do this modification to my Engine for the purpose of Longevity.

AshD, I'm also 'bilbikek411' on the "twins" forum,I couldn't seem to get a reply for so long that I thought no one was interested;I'm glad I was wrong. 

I checked that ebay link you put on your first post and it doesn't look like they're available there. 

[bill440cars]

       Glad I happened on this! Pretty cool to find that efforts are being made to made these lil 350s last longer and perform easier, at thaty.

[AshimotoK0]

New link:

http://www.ebay.it/itm/1968-74-Honda-CB250-350-Cappellini-58-cam-support-roller-bearing-conversion-/360850195062?pt=Motorcycles_Parts_Accessories&hash=item5404590276&_uhb=1

They obviously have had problems with the 'service exchange' side of things and there is a price increase. Don't forget though that you also need to precision machine your own cam journals, which 'captb' found tricky.

Not surprised 'captb' just want's to do his own as it seems like a lot of time and patience is required even by a skilled machinist. It will be few weeks before I can get our machinist to have a go, but he is definitely a precision guy and a perfectionist so I ill keep you posted ... but please be patient !!  Captb, do you have any dimensions of the machined bore and journals? Did you heat the aluminium covers to expand for insertion or just a press fit?

Anyone tried the phosphor bronze insert method out of interest. I obviously want to try the needle roller method (already £50 invested!!) but interested in all engineering solutions. I hate this throw away world and having to expose myself to people selling the stock parts, as 'serviceable' but only fit for the junk (bin for UK guys).

Captb ... a massive thanks from me personally for sharing this with us !

Cheers.....ashD

[grcamna2]

New link:

http://www.ebay.it/itm/1968-74-Honda-CB250-350-Cappellini-58-cam-support-roller-bearing-conversion-/360850195062?pt=Motorcycles_Parts_Accessories&hash=item5404590276&_uhb=1

They obviously have had problems with the 'service exchange' side of things and there is a price increase. Don't forget though that you also need to precision machine your own cam journals, which 'captb' found tricky.

Not surprised 'captb' just want's to do his own as it seems like a lot of time and patience is required even by a skilled machinist. It will be few weeks before I can get our machinist to have a go, but he is definitely a precision guy and a perfectionist so I ill keep you posted ... but please be patient !!  Captb, do you have any dimensions of the machined bore and journals? Did you heat the aluminium covers to expand for insertion or just a press fit?

Anyone tried the phosphor bronze insert method out of interest. I obviously want to try the needle roller method (already £50 invested!!) but interested in all engineering solutions. I hate this throw away world and having to expose myself to people selling the stock parts, as 'serviceable' but only fit for the junk (bin for UK guys).

Captb ... a massive thanks from me personally for sharing this with us !

Cheers.....ashD

AshimotoK0,
  I Thank You for starting this thread  This last post you made speaks exactly to what is closest to my heart for my favorite little CB350 twin.
I hope your machinist is able to do this,I'm all for it. You're my hero. 

I also "hate this throw away world" and don't like discarding the Original camshaft bearing towers that are scored from the past.My goal is to keep my Original camshaft in great condition.
This CB350 of mine is a KEEPER. 

[grcamna2]

Hey, I road race a couple CB350s. One stock, and one with a modded engine with the needle roller conversion. Neither have oil mods. No issues with either after a few years of (ab)use.

Good luck,

Tim

Thanks for this encouraging post Tim.I Needed to hear that  .

[AshimotoK0]

Pointed captb  (and others) on the Hondatwins site to this post
cheers ...... AshD

[grcamna2]

bump

[grcamna2]

Hey, I road race a couple CB350s. One stock, and one with a modded engine with the needle roller conversion. Neither have oil mods. No issues with either after a few years of (ab)use.

Good luck,

Tim

Thanks for this encouraging post Tim.I Needed to hear that  .

Tim,
 The 2) CB350's you race, You race a stock one also ? Do you mean All stock in that class w/ No mods ?

[TimV840]

Tim,
 The 2) CB350's you race, You race a stock one also ? Do you mean All stock in that class w/ No mods ?

VRRA P1-350 class.

"HONDA CB/CL/SL/350 twin cylinder machines, in order to be eligible for Period 1 GP, are limited to
stock original equipment engine internal and external parts as originally fitted to these models. No parts
designed for another model of Honda or any other motorcycle may be used. No aftermarket components
are allowed except for valve springs and slider style camshaft chain tensioner (as manufactured by Bore
Tech or similar). Carburetors cannot be greater than 30mm choke size and may be any Period 1 legal
model, round slide Keihin or Mikuni. Ignition systems may be after market and/or electronic. NO
MODIFICATIONS WHATSOEVER by any machining or chemical process may be made to the engine,
intake tract, carburetors, or any other engine component. The only modifications allowed are the removal
of the electric starter, alternator components and the fitting of a racing style exhaust. The rolling chassis
must be of a racing style as per Period 1 rules. Modified Honda CB/CL/SL 350 twin cylinder machines,
which deviate from the use of stock original equipment engine components, are moved to the Period 2
Supervintage Lightweight class."

I run 4th over(1mm)pistons, 28mm early CB750 carbs, PVL mag ignition, KPMI valve springs, slipper cam chain guide, close ratio 5th gear and I think Jemco exhaust with my own cans on the ends... so yeah, pretty much stock.

It's the bike I lent to BrentW for our Mosport(CTMP) round last August.

[grcamna2]

How many races do you have on the camshaft(stock?)and rockers ?
Did you do the roller bearing mod. to this engine ?

[TimV840]

quote author=grcamna2 link=topic=135219.msg1521640#msg1521640 date=1394990258]
How many races do you have on the camshaft(stock?)and rockers ?
Did you do the roller bearing mod. to this engine ?
[/quote]

Stock cam, rockers and cam end covers(no roller brgs).

I built the bike for the 2011 season. Our club runs 4 race weekends. I normally run 2 to 4 races on it per weekend depending on how many bump-ups I do. The last 2 yrs I've been lending it out to people who have never raced in the class, so not ridden quite as hard as I would....I would say it has at least 30-40 races on the (used with ?? miles)stock cam and rockers. Races typically last 10-15 minutes give or take... 10,000 RPM is about the most it sees.

And I run Castrol Grand Prix 10W40(non-synth oil) and usually change it(and clean the oil filter rotor) after every race weekend or every other weekend depending on use. Probably overkill, but I get the oil cheap.

FYI, there are about 15+ CB350s in the class(4-5 from our local group of racers alone) and none of them run a modified oiling system or cam brgs....I've heard that unless you're making 45-50+ hp, it's not needed....I'm running ~43hp on my modified 350(w/cam brgs, but no oil mod) with no issues...and it sees 12k RPM often. I'm not saying it's optimal, but it works for this poor vintage racer.

[grcamna2]

Hey Tim,
 I appreciate that great feedback from you as a Race tuner.I imagine the oil changes make a Big difference.

[grcamna2]

bump

[bill440cars]

quote author=grcamna2 link=topic=135219.msg1521640#msg1521640 date=1394990258]
How many races do you have on the camshaft(stock?)and rockers ?
Did you do the roller bearing mod. to this engine ?

Stock cam, rockers and cam end covers(no roller brgs).

I built the bike for the 2011 season. Our club runs 4 race weekends. I normally run 2 to 4 races on it per weekend depending on how many bump-ups I do. The last 2 yrs I've been lending it out to people who have never raced in the class, so not ridden quite as hard as I would....I would say it has at least 30-40 races on the (used with ?? miles)stock cam and rockers. Races typically last 10-15 minutes give or take... 10,000 RPM is about the most it sees.

And I run Castrol Grand Prix 10W40(non-synth oil) and usually change it(and clean the oil filter rotor) after every race weekend or every other weekend depending on use. Probably overkill, but I get the oil cheap.

FYI, there are about 15+ CB350s in the class(4-5 from our local group of racers alone) and none of them run a modified oiling system or cam brgs....I've heard that unless you're making 45-50+ hp, it's not needed....I'm running ~43hp on my modified 350(w/cam brgs, but no oil mod) with no issues...and it sees 12k RPM often. I'm not saying it's optimal, but it works for this poor vintage racer.



[/quote]

      Really Cool to hear "Straight up" input from someone who REALLY races these bikes!     

[grcamna2]

Yes !

[grcamna2]

bump

[AshimotoK0]

Hi .. I have not got round to having the machining done yet. Been away on a cruise for a week  and also been really busy as started a new job.

Will post as soon as I have tried it out.

Cheers .......AshD

[grcamna2]