Topic: Building of a CB500 classic racer

[Howell]

It does look good Howell. Those large engagement blocks look indestructable, good work by Ellis.

By the way I got an e-mail from him yesterday that mine is also complete & ready to ship......wahooo.

Is that the same ?

[bwaller]

No Rene, mine is a modified six speed from a 360 twin. Ellis made a mainshaft & five other gears to tighten ratios some.

A poor mans gearbox....well sort of!

[valvolux]

Some pictures of the no 46 engine:

awesome bike mate, inspiring work. Would you be kind enough to give some advice on my project?
Can i ask, why did you use CR29's and not CR26's? I thought cr29's were a match 836cc kit on a 750. Wont it be a bit "over carbed" or is it not displacement, but cylinder head flow rates that govern the venturi size? By the way, what sort of push/pull throttle are you using? ive bought a motion pro, but ive read here on the forum they are too long.

cheers!

[MRieck]

No Rene, mine is a modified six speed from a 360 twin. Ellis made a mainshaft & five other gears to tighten ratios some.

A poor mans gearbox....well sort of!

I have to see pics of that Brent.

[turboguzzi]

Some pictures of the no 46 engine:

awesome bike mate, inspiring work. Would you be kind enough to give some advice on my project?
Can i ask, why did you use CR29's and not CR26's? I thought cr29's were a match 836cc kit on a 750. Wont it be a bit "over carbed" or is it not displacement, but cylinder head flow rates that govern the venturi size? By the way, what sort of push/pull throttle are you using? ive bought a motion pro, but ive read here on the forum they are too long.

cheers!

running 29's CR on my 500 racer too so allowing myself to answer. Wouldnt mount something as big for street use but on track they work well, just dont ever drop the revs bellow 6000... that said, my bike was perfoming pretty good on 26mm VM's (actually 27mm) before  I switched to 29CR's

[Howell]

awesome bike mate, inspiring work. Would you be kind enough to give some advice on my project?
Can i ask, why did you use CR29's and not CR26's? I thought cr29's were a match 836cc kit on a 750. Wont it be a bit "over carbed" or is it not displacement, but cylinder head flow rates that govern the venturi size? By the way, what sort of push/pull throttle are you using? ive bought a motion pro, but ive read here on the forum they are too long.

cheers!

Why we use those 29 carbs is because we found out on the Dyno and the racetrack that this is the best for our engines.
That is also depending how our engines are tuned.
For the trottle we only use one pull cable ,we use a Tommaselli.

[valvolux]

cheer for the reply guys, i really appreciate it.
Single cable eh - have I wasted money buying a motion pro then? I thought you need a push/pull because the vacuum suction wont allow the throttle valve to close with a single cable.
I have a hidden agenda, im really looking to pinch some tuning specs for the CR26 from someone, but its been a real struggle to find anyone who has run them on a bike similar to mine. 594cc, 58b webcam, stage 2 ported head, K&N filters. Must be someone out there.
Its come with a 105 main jet and a YY0 needle. It would be good not to reinvent the wheel if someone's done it all before. Anyone know anyone?

[Howell]

Some tuning pics:

Pistons 57 mm (Honda Dax)
Inlet valve 29 mm (Renault 1400-1600cc 16V)

[livefast_dieold]

Some tuning pics:

Pistons 57 mm (Honda Dax)
Inlet valve 29 mm (Renault 1400-1600cc 16V)

what are the blue screw for?

[turboguzzi]

regarding a throttle, our race tech inspector will not pass you with a pull only solution.

howell, I am curious about the blue screws too.....


TG

[Howell]

regarding a throttle, our race tech inspector will not pass you with a pull only solution.

howell, I am curious about the blue screws too.....


TG

Only one throttle cable is allowed by our classic bikes.
The blue hexagon socket head screws are used to fix halve pieces of aluminium pipe into the inlet and exhaust to get the right flow.
It is also fixed with JB weld , a cold weld compound:http://jbweld.net/products/jbweld.php
You can see it better how this is used on the picture of my CB750 head

[livefast_dieold]

regarding a throttle, our race tech inspector will not pass you with a pull only solution.

howell, I am curious about the blue screws too.....


TG

Only one throttle cable is allowed by our classic bikes.
The blue hexagon socket head screws are used to fix halve pieces of aluminium pipe into the inlet and exhaust to get the right flow.
It is also fixed with JB weld , a cold weld compound:http://jbweld.net/products/jbweld.php
You can see it better how this is used on the picture of my CB750 head

nice trick! do you flow tested the inlet? I was thinking that with such great inclination of the valves it wouldn't be necessary to add material on the floor of the inlet.

[Howell]

regarding a throttle, our race tech inspector will not pass you with a pull only solution.

howell, I am curious about the blue screws too.....


TG

Only one throttle cable is allowed by our classic bikes.
The blue hexagon socket head screws are used to fix halve pieces of aluminium pipe into the inlet and exhaust to get the right flow.
It is also fixed with JB weld , a cold weld compound:http://jbweld.net/products/jbweld.php
You can see it better how this is used on the picture of my CB750 head

nice trick! do you flow tested the inlet? I was thinking that with such great inclination of the valves it wouldn't be necessary to add material on the floor of the inlet.

This is the result of tests on the flowbench.

[kos]

Some tuning pics:

Pistons 57 mm (Honda Dax) WHAT IS HONDA DAX? Don't have that here in USA. KOS



Inlet valve 29 mm (Renault 1400-1600cc 16V)

[CB500Four]

Hi kos!

I think in the States it´s called CT70 TRAIL.
Here in Europe we have this mini bike with 50ccm and 70ccm.
There are a lot of tuning parts available.

Regards,

[Howell]

Some tuning pics:

Pistons 57 mm (Honda Dax) WHAT IS HONDA DAX? Don't have that here in USA. KOS

A Honda Dax (europe) is a Honda ST50/ST70 and this piston is from a big bore kit voor the ST , Monkey or Nice Honda's mini bikes.

[kos]

I dunno what your are talking about.. but a Hon CT70 does not have the same size pin diameter or is large enough to fit into a CB500/550 four....


KOS

[Howell]

I dunno what your are talking about.. but a Hon CT70 does not have the same size pin diameter or is large enough to fit into a CB500/550 four....


KOS

You are right if you are talking about the stocks rods.
But we use rods from a Suzuki GSX1000R with home made made bronze bushings to fit the piston pins.

[Kemp]

Are you using the crank from the CB650? If so, what length are the rods that you are using. What is actual displacement of the engine?

[Howell]

Are you using the crank from the CB650? If so, what length are the rods that you are using. What is actual displacement of the engine?

We use the 500 crank , the rods we are using are 5 mm longer than stock.
The engine is 512 cc.

[Howell]

Finally the sprayjob is done, there was a little bit delay in it because my youngest son moved to another flat last week.
I was asked to paint it and also to hang with wallpaper en put in a 70m2 parquet floor.
Now I can build up the bike, on the engine is still a little bit work to do.

[Sam Green Racing]

Looking good Howell. 

Sam.

[Howell]

Last week I have building up the chassis again.
Today we went to belgium to get two sets of Avon racetyres.
On the engine there is still a little bit work to do , but next weekend it will be ready.
So then we can work on the finishing touch .

[bwaller]

Very nice Howell, a good combination of components.

Does your 500 exhaust clear the 650 oil pan without modification?

[Howell]

Very nice Howell, a good combination of components.

Does your 500 exhaust clear the 650 oil pan without modification?

I had to grind it off at some places.