CB/CL160 Engine Rebuild + Looking For a Piston Kit

[NeeksRR]

So first off, I swear I looked around the forum/internet for recommendations before just posting up asking for help

I have my first build thread going right now (link is in my sig) and originally the plan for the engine with to just get it freshened up with new gaskets and some paint to make it sexy. Though after removing the top end, plus reading Sonreir engine threads I decided to do it right the first time. The barrels looked a little beat up and was told that I would need a 2mm over bore just to get the bumps out. Right now there is .75 kit with over sized valves. There was a little play in the valve sleeves and being that I have nothing to compare the valves too, Im not sure the condition and if I should save them.

Last night I went to a friends Dad's house because he has loads of parts for the CB/CL160. We ended up shoot the shit for awhile, he showed me his vintage cb160 that he races off road (fucking...awesome bike). He opened up a big box of shiny new engine parts and pulls out, what looks brand new, head and give it to me for free! He even offered me some new looking barrels that I didnt even know you could take out, haha.

I havent measure the cylinder barrels yet, but Im assuming they are "stock" size, which I hope, because the head gasket I have (ebay) is for a stock 160 engine.

Anyways, Now im stuck at what to do with the top end with the valves and what not and what to do about pistons. Ive looked on ebay and the internet for a kit or site that looks reputable but nothing solid. I did email a guy in the bay area about getting that kawi cam guide mod ive been hearing about, and found a guy in the northwest they sells race cam chains. So just waiting to hear back about that.

So I guess my questions are....

1. How much are valves, and where can I get them?
2. If I do an overbore where to get the proper gasket size?
3. How much is re-sleeving for the valves in the head?
4. Pistons kits and where to buy?
5. Does anyone know of some good connections with the northwest racing guys for parts and mods? (Seems like they would have some good tips since they race the balls off them, haha)

Sorry for so many questions...and PS. I have a spare frozen engine that ive been trying to break loose to see what parts are good in it.

Thanks guys!! ;D

 

[teazer]

CB160 uses smaller valves than a 175. They are probably still available from Honda. If not Kibblewhite makes stock and oversized valves.

CB175 and 200 use larger valves and those can be machined down to size or to make 1mm oversize valves from in a pinch.

Any 219 cam chain will work in that motor. If you want heavy duty, I suggest a BT05 instead of 219H but both will work.

Valve guides don't ear much but if they have to be replaced, you should probably upgrade to CB200 guides with seals.

 

[NeeksRR]

I checked out the kibblewhite site, some nice stuff there...but 500 bucks for a valve set might be out of my budget for now, lol.

I found this guy while poking around on ebay again last night...still more than i wanna spend but seems like solid product - http://stores.ebay.com/LESVintage-Advantage/_i.html?_armrs=1&_dmd=1&_ipg=30&_sasi=1&_sop=1&_vc=1

If I find a set of 175 pistons, will those work? Obviously with a bore, but I measured my cylinder barrels last night that the guy gave me, and they are a perfect 52mm, so I guess those are bored out too.

 

[Kanticoy]

Les at vintage advantage is awesome. Don't hesitate to use him.

 

[teazer]

+1 on Les at Vintage advantage. 175 pistons don't fit inside a 160 head, but any 175 or 200 head will fit a 160 with much better ports. You could use any upright 175 head and bore the 160 to take a pair of 175 pistons. 160 intake manifolds will not fit on a 175 head, but that's not too hard to solve.

 

[carnivorous chicken]

You can also try Vicious Cycle up in PDX. They are at the epicenter of the CB160 sloper racing scene. Got a cam chain from them and a few other goodies I couldn't find elsewhere when doing my CB160.

 

[NeeksRR]

Awesome, I'm glad he is a good resource. I didn't see any pistons from him but I'll shoot him my list of goodies I'm looking for. Ill aslo check out the other site. Thanks!

 

[teazer]

All those Portland based sites are a little out of date for some reason. Powroll have some really lumpy pistons that they claim will fit a CB160 but I have zero experience with them to know for sure.

You can use CB500 56mm pistons as long as you fit different liners anc can machine pistons, barrels and heads ( and rods). You end up with 202cc and about 10:1 CR if you are lucky.

There are 56mm pistons on the market for 175 motors and fortunately 175 barrels drop straight on - more or less and 175 heads work too, so you have lots of options.

Cheapest is probably a stock 175 vertical top end onto a 160 bottom end. I guess they are less available than they used to be. A few years ago we used to get complete 175 vertical motors for $25 because there was no market for them. Now, not so much.

What racers do and what you want to do for the street may not be the same though. Our motors live from 6-10k and come apart once a year or so for inspection and changes and replacements. We have boxes of broken valve springs and smashed pistons and ruined heads, and generations of parts we tried that didn't work or were superseded with other changes and that's not a pretty place for a street bike to be.

What parts are you looking for, what's your budget and what's your intentions for the bike? If the budget is $2-3,000 you can get a 20HP motor that runs strong all day. If it's $2-300, decisions are different. If you want more than say 21HP the answers are different than if you would be happy with 15 and so on.

For example

Camshaft
New valves and springs
Rebuild crank
57mm pistons
New liners
Machine barrels for liners and bore/hone
Machine crankcase mouth
Lighten rocker arms
Light valve adjusting screws and Ti nuts
Lighten crank
Oversize oil pump
Heavy duty cam chain
Port and gas flow head
5 speed transmission plus case modifications
eIgnition
New coil
and so on.

It's easy to get lost if you don't keep a target in mind.

If money is no option there are some delicious possibilities in terms of pistons and valve train that involve novel squish bands and 180 degree cranks and changes to crankcase breathing and so on. There are anti reversion exhaust ports to explore and so the search for more everything goes on. I guess that's what doing drugs is like. The novelty of the first hit wears off and you start searching for a bigger hit and soon you are addicted to the drug of power. Then you will start to test different fuels and from there it's all downhill.

You'll start hanging out at the race track and in smokey dingy dyno rooms sniffing exhaust fumes with piles of data and dyno charts and before you know it you'll be checking out fuel distillation curves and SG numbers to get a faster or slower burning fuel that might lead to another elusive hit of HP.

Don't ask me to admit how I know these ugly truths. Stop while you still can. Step away from the motor and no one will get hurt. LOL

 

[clem]

^ Teazer, I need to copy and paste this to my brain.

 

[teazer]

Nail gun works well for that but tends to have some dire side effects.

Point I was trying to make a little heavy handed is that the path to speed is expensive, so it's really useful to work out what your objectives are and how far you want to chase them.

CB160 is a great little bike and a modest power increase might be nice, but let's not go mad.

 

[NeeksRR]

^Teazer....you're blowing my mind with all this info, lol! My brain feels like you are injecting 1000 gallons of moto juice in 5 mins, but with a little syringe

But man do I appreciate all the suggestions and help, its got me some good connections and Ive sent out some emails to these guys.

Powroll doesnt really seem to exists anymore, plus the couple comments ive heard about there customer service is horrible...but thats just what ive read.

For budget, if I can get the motor solid and dependable for around 500 bucks...Ill be more than happy. As far as power, I have other bikes that feed that need, and as much as I would love to race every 2 wheeled machine, this baby will be all show and no go

Heres my need for speed bike...This glorious shot was taken on my very first race. The guy behind me just couldnt catch me :

Now the waiting game...Ill read some more build threads while I patiently wait ;D

 

[teazer]

Mike Riddle has 55 and 57mm pistons http://groups.yahoo.com/group/california160s/message/1976 they both need larger sleeves and open up the crankcase and a 175 head.

 

[NeeksRR]

So Update:

I heard back from Vicious Cycle and they offer a .50 piston kit for 150 bucks and a cam chain for 35. Seems like a good deal to me and I can use another head I have, the others are bored out to much for them to fit. So as I wait for my next pay check, I've just been cleaning and prepping more parts for painting and fixing little things here and there. I will have an update on the build thread with that progress

 

[teazer]

As mentioned in that other thread, your pistons are already 0.75mm over. If/when you get the jugs off the other motor, measure them and maybe they will clean up at 0.5mm over. Or maybe the spare jugs you were given might be OK.

 

[NeeksRR]

Maybe Im confused about measuring the cylinder barrels and pistons...

The spare frozen engine I have, I managed to get the old pistons out and the barrels measured 50.1mm, the freshy looking head measured 52mm that the guy gave me.

So if I used the 50.1mm head, got a .50 piston kit, then would it be 50.5mm?

 

[teazer]

Yes. Stock is 50.0 1/2mm over is 50.5. If the barrels he gave you were already out to 52.0 that raises a few questions.

With any luck, the 50.1mm barrels will clean up with a bore and hone to take the o.5mm o/s pistons that Vicious has for you.