Story of one CB-1

[Velos]

Love what you're doing here but I've got a few questions.
Any reason for not using stick coils? (would take up less space)
How are the NOS injectors held in place on the rubber inlet manifolds? (normally they are fitted into a threaded hole)

Good luck with this and can't wait to see the end result

Spark becomes a “weak link” when dealing with N2O.
Therefore it should be stronger. Stock coils have a known problem of weak spark when using N2O.
In addition to this I need the space where stock coils were for installation of additional fuel pump

Those Venom injectors have a special retainer for installation into rubber manifolds.

[Pod70]

Cheers for the reply. I meant Stick coils (Coil On Plug) rather than the original coils though. Looks like you're using Dyna Coils which are very large

[VintageHunter]

Looking forward to seeing this thread when done. I'm diggin' the nifty mods.

[Velos]

Hi all!
It's time for some updates!

Nitrous routing is over:



Huge part of wire routing is nearly over. There are still remain little things to complete.
As a result - CB-1 got a new wire harness. Dyna 2000 ignition module, motogadget gauge and it's digital commutator, DynoJet wideband 2 lambda controller and Nitrous MaxExteme controller were interconnected with each other. I have also integrated a safety interlock schema (turns off ignition with side stand when bike is not in neutral gear).
All blocks, relays and other components have found their places:










All additional modules have their own fuse block:



I also decided to install steering damper from V-Max.
My solution is pretty "radical" :







There is also was a solution with cooling reservoir (have no photo yet).

And we had a first launch just few days ago!

VIDEO

After first launch we had several problems:
- cooling pump leakage
- thermostat leakage
- Non-OEM crankcase pan seal leakage

The engine is currently in "RUN-IN" period after re-assembly.
We made a first test on Dyno: 22 hp on the rear wheel on 7000 rmp



I am going to solve cooling system problems in the nearest time.
If someone knows about swapping cooling pump from CB400SF/CB400 VTEC - please, make me know.

[ptlcb1]

How much horsepower are you looking for?

[a_morti]

He's been having difficulty logging on. Post in the Facebook group for reply

[ptlcb1]

Okie dokie

[Velos]

Hi! I am back
Still have to use TOR, but I am able to log-in

ptlcb1

My goal is to pick up over 60 hp from the wheel w/o N2O.

Here are some updates.
After fixing cooling pump and thermostat leakages we continued run-in period.



We also decided to use new radiator CAP for 1.6 Bar to increase pressure inside cooling system.
These had lead us to a new problem: 30 years old cooling hoses didn't accept our idea as good
I have replaced them with a new silicone ones.

The other minor problem happened with my Motogadget breakoutbox - it stopped to send signals (neutral, temperature, oil pressure switch, etc) to Motoscope gauge.



It was working fine until we spilled some drops of cooling liquid to it.
It's strange, cause cooling liquid doesn't provide electricity.
I have ordered a new one and for now we will use some temporary lamps for oil pressure and fan (it is not very good to tune on a dyno without understanding what is going on with oil pressure and temperature).

I also have completed oil canister for breather.
I haven't done any photos, because I was too busy with FCR and ignition tuning.

Anyway - run in period is over now!

I played with different ignition maps on a Dyna2000. Step-by-step I made several increasing the ignition advance angle.
I started from default for NC23 20 degree advance and made and tested in total 11 ignition maps.
At the moment I am using pretty "angry" advance of 34 degree from 8000 rmp (NC23 in stock starts from 18 degree at idle and the maximum advance is 20 degree at the top).
This map allowed to pick up 57 hp from the shaft at 10000 rmp!

FCR tuning is not finished yet. It is not so trivial as I thought...
My FCR came from Yahoo and were installed on this bike:



Unfortunately I can't get any information about camshafts that were used on this bike. I even tried to find all sells of spare parts from this bike, but didn't find selling of engine... May be the seller will answer on my mail.

I am very interested in those camshafts because I was amazed about jet sizes used in that FCR:

Code:

F.Main: #132
F.Slow: #48 
A.Main: #200
A.Slow: #110

#132 main jet!!! For example: Dynojet stage 2 for 1000ccm Thunderace is using #130 main jet...

With #132 main jet and stock NC23 camshaft my CB-1 have a very rich mixture after 8000 (at this moment throttle is fully opened).
Again, step-by-step, we have lowered main jet to #105. And the mixture is stilll rich after 12000 rmp.
I don't want to lower it anymore, because stock CV-carbs for CB-1 and NC23 uses the same #105 main jet:

Code:

CB-1 stock:

F.Main: #105
F.Slow: #35

NC23 stock:

F.Main: #110 (1988 (J))  #105 (1989 (K))
F.Slow: #40  (1988 (J))  #35  (1989 (K))

IMHO - to fall lower then #105 with NC23 cams is incorrect way.
We have also tried to install #35 idle fuel jet - the bike didn't start at all

Then I started to search information about possible setups. I have found HRC power kit for NC23:



 This kit included special (!) camshafts, pistions, rods, ignition unit, carburetor jets and needles and many other interesting stuff.

When I looked at the HRC jets

Code:

NC23-HRC (camshafts+pistons):

F.Main: #135 - #142   
F.Slow: #39 - #42

I realized, that these jet sizes are very similar with those ones which were in FCR when it came from Japan.
I think those camshafts is exactly what i need. Of course it is already impossible to get HRC stuff, but I have ordered alternative from GF Racing (thank you guys!).
Camshafts should come in nearest two days.

Thats how I spent my last week )
Waiting for new camshafts at the moment.

[filterMan]

I'm very interested in your build, thanks for the update and please keep the posts coming.

Where did you buy your new coolant hoses from?

[Velos]

I'm very interested in your build, thanks for the update and please keep the posts coming.

Where did you buy your new coolant hoses from?

I bought it here - in local store in Moscow.
Guys from Subaru club are using them in their races.
They have different diameters, so I was able to collect all necessary hoses.
I believe that you can easily find hoses in UK: http://samcosport.com/manufacturer/honda/
There is a set for NC23 which is very similar with CB-1.





Transparent blue hose is for oil canister and breather.






Here is my best dyno test at the moment. I am waiting for new camshafts to continue tuning.

[Pod70]

Looks like you're getting there but the fueling is a bit all over the place.

When you get the GF Racing cams, you will need bigger valve shims as he grinds quite a bit of material off the bottom of the original NC23 cams. The shims in my NC23 are around 2.35 -2.55mm

[Velos]

Looks like you're getting there but the fueling is a bit all over the place.

When you get the GF Racing cams, you will need bigger valve shims as he grinds quite a bit of material off the bottom of the original NC23 cams. The shims in my NC23 are around 2.35 -2.55mm

I suppose that Valve clearance should remain the same, shouldn't it?
IN: [0.12-0.18] (NC23)
EX: [0.17-0.23] (NC23)