Project Ninja 282cc

[Gastydel23]

Hello riders!

I recently bought a Wiseco piston kit 66mm 12,5:1 for my ninja. The idea is to get 42hp.

Up today this is the bike configuration:

- Full M4 exhaust
- Dyno jet
- K&N pod filter
- Pre Gen CDI (15k RPM and 42 deg I think)

Yesterday I port the head:





Here are the pistons side by side:







The only problem I'm having is with the sleeves. Originals have 68mm (outside), and with the 66mm pistons the wall would be only 1mm thin. So the obvious thing would be to replace the sleeves with 66mm interior and 72mm outside diameter (3mm wall like the original), but the carter only have space for a 69mm sleeve (see picture)



So... I was thinking to make the 72mm sleeves BUT the part that goes into the carter leave it in 69mm.



Opinions?

Thanks!

greeting from Argentina!

[csmith12]

Welcome Gaston!

Good luck with your project!

[allanoue]

I would ask @Racer x for input

[bruce71198]

Welcome, good to see some more engine builds. I run 4mm overbore on stock sleeves without any problems, yet. I have run into some people who say the cylinder wall may crack and hydro the engine.
I hope you reach your 42hp goal but I think that figure is optimistic.

[Gastydel23]

Originally Posted by bruce71198

Welcome, good to see some more engine builds. I run 4mm overbore on stock sleeves without any problems, yet. I have run into some people who say the cylinder wall may crack and hydro the engine.
I hope you reach your 42hp goal but I think that figure is optimistic.

Thanks all!

Bruce71198, how long have you been using 4mm overbore in your bike?
I know 42 hp is very optimist, 40 would be ok too jaja

[RacinNinja]

Is it a common practice in these motors to leave the valve guide ground off like that? What does it do for valve life?

[Gastydel23]

Originally Posted by RacinNinja

Is it a common practice in these motors to leave the valve guide ground off like that? What does it do for valve life?

The flow is much better without it. Valve life....I hope a lot

[RacinNinja]

There is no doubt the flow is much better. At the same time, the valve stem is given more opportunity to flex. I'm going to look into this more....my curiosity is peaked.

[Gastydel23]

Originally Posted by RacinNinja

There is no doubt the flow is much better. At the same time, the valve stem is given more opportunity to flex. I'm going to look into this more....my curiosity is peaked.

The valve guide is 36mm long and I ground off 8mm more or less

[bruce71198]

Originally Posted by Gastydel23

Thanks all!

Bruce71198, how long have you been using 4mm overbore in your bike?
I know 42 hp is very optimist, 40 would be ok too jaja

I have been running this set up on one of my track bikes for 2 seasons now. I had some head gasket issues at first. Now that I have that sorted its been rock solid.

[RacinNinja]

Originally Posted by bruce71198

I have been running this set up on one of my track bikes for 2 seasons now. I had some head gasket issues at first. Now that I have that sorted its been rock solid.

Good to know, thank you! Are you running oversized or stock valves? Upgraded springs with high spring pressures?

[Gastydel23]

Originally Posted by RacinNinja

Good to know, thank you! Are you running oversized or stock valves? Upgraded springs with high spring pressures?

Stock valves.
I won't upgrade the springs (customs issues), so I'm going to add a washer in each spring to gain some pressure.

[bruce71198]

Originally Posted by RacinNinja

Good to know, thank you! Are you running oversized or stock valves? Upgraded springs with high spring pressures?

Stock 300 head, it has bigger intake valves from the factory, stock springs and valves no porting yet.

[RacinNinja]

Originally Posted by bruce71198

Stock 300 head, it has bigger intake valves from the factory, stock springs and valves no porting yet.

Sorry for the side track but thanks!

[mgentz]

Stock sleeves should be fine. Ground guides are fine.

I hope you get all that you are hoping for.

[Gastydel23]

Valve grinding day




I went to the machine shop. They tell me it is not possible to put bigger slevees since they are secured by orings and could not modify that area to accommodate the new ones, so he's going to grind the originals.
He asked me about the clearance between the piston and cylinder. I look for it in the website of Wiseco and found no data.
Can anybody tell me what clearance I need?

Thanks!

[bruce71198]

Originally Posted by Gastydel23

Valve grinding day




I went to the machine shop. They tell me it is not possible to put bigger slevees since they are secured by orings and could not modify that area to accommodate the new ones, so he's going to grind the originals.
He asked me about the clearance between the piston and cylinder. I look for it in the website of Wiseco and found no data.
Can anybody tell me what clearance I need?

Thanks!

Race bike or street bike?

[Gastydel23]

70% street / 30% race

[mgentz]

What o-rings?

[Gastydel23]

Originally Posted by mgentz

What o-rings?

Between the block and the slevees (top end) there is an oring that seals the water circuit

[Racer x]

If you are referring to sealing the new sleeve to the old cylinder block you can use this ..
http://www.valco-hylomarproducts.com. I have read about it but not used it personally.

If you bore the stock sleeve it will go below .050. That is very thin. I have that and have not run the engine yet. But my fear is the bottom half of the sleeve will crack and slide down.

[bruce71198]

Originally Posted by Gastydel23

70% street / 30% race

.0025"

[Gastydel23]

Cylinders!



Stock pistons:


Wiseco pistons:


The slevees are really thin (1mm), lets see how they handle the presure


Cometic gasket for 66mm pistons (fits perfectly)


I'm really happy with the honing

[Racer x]

Nice job on the boring.

[2fiddy-trackpair]

Love to see this thing when it is finished, I bet it is going to be a hoot.

[Mohawk]

Looking good, but not sure I'd trust a 1mm wet liner !

I'm working on a similar build, with ZZR250, the same engine as the old Ninja 250. I have picked up my reworked block today with 2.5mm walls & 66mm bore, i used ZZR600 liners, bored out from 64mm. Will use ZX6R 66mm pistons & 2 base gaskets to avoid to high a compression ratio ! Everything else will be standard for now, but I have a few tricks I developed on previous builds that should boost power More when its built.

Does anyone know if the Cometic 66mm head gasket will fit the old engine ? They only list a 64mm bore for the old engine !

Thanks

[bruce71198]

Originally Posted by Mohawk

Looking good, but not sure I'd trust a 1mm wet liner !

I'm working on a similar build, with ZZR250, the same engine as the old Ninja 250. I have picked up my reworked block today with 2.5mm walls & 66mm bore, i used ZZR600 liners, bored out from 64mm. Will use ZX6R 66mm pistons & 2 base gaskets to avoid to high a compression ratio ! Everything else will be standard for now, but I have a few tricks I developed on previous builds that should boost power More when its built.

Does anyone know if the Cometic 66mm head gasket will fit the old engine ? They only list a 64mm bore for the old engine !

Thanks

Here's the liner out of the block. Note that there are 4 steps in the liner measuring 70mm at the top then 69.3mm then 68.5mm then 68mm at the skirt. 1mm is plenty thick where the piston is at its slowest speed.
The old and new head gaskets are different and not interchangeable.
I also included a picture of the orings in the block, one is also visible at the top of the liner.



[/IMG]

[Mohawk]

Thanks.

Are those the standard liners ? or is that a larger diameter replacement liner ? That you have step turned the OD down.

If original, then that top O-ring will leave very little metal with a 66mm bore, it's also at the highest pressure during combustion & is exactly where most iron liners crack when used in high compression motors.

Agreed 1mm is plenty at the base, up to about 70mm bore, larger than that & you'd want more meat.

I had mine bored through so 71mm OD liners, this will require a minor trim on the crankcase mouth to fit.

[bruce71198]

Originally Posted by Mohawk

Thanks.

Are those the standard liners ? or is that a larger diameter replacement liner ? That you have step turned the OD down.

If original, then that top O-ring will leave very little metal with a 66mm bore, it's also at the highest pressure during combustion & is exactly where most iron liners crack when used in high compression motors.

Agreed 1mm is plenty at the base, up to about 70mm bore, larger than that & you'd want more meat.

I had mine bored through so 71mm OD liners, this will require a minor trim on the crankcase mouth to fit.

That's a stock liner, stock bore.
The only 4mm over cylinder I've seen that failed split long ways into the water jacket. It may have been due to an off center bore job.

[Racer x]

The one problem I found after boring the stock liners was getting the rings in. It is a bit tricky with the chamfer gone.

[Mohawk]

I won't have that problem on mine but may need to relieve the crankcase mouth a little.

[Gastydel23]

Finally, I finish assembling the engine.

Just like Racer X said, getting the rings inside the cylinder was really hard. There is not a lot of space for your fingers and also, most important, there is no chanfer to "guide" the ring. But after 2 hours, some finger cuts, bloode and a lot of bad words, they finally fit.








After that, everything was very fast: head gasket, cylinder head, some torquing, cams, more torques, valve cover, carburetors, cables, some gas and it started with out problem.





Today I made 160 miles (break-in) and there is a big difference. The bike sounds different and I can feel the extra torque and power coming from the engine. (I didn't pass the 9000 rpm yet!)

So far so good, water temp is not a problem for the original circuit and radiator/fan.
I was runing 112 jets, now I'm using 120. They are runing good, I will check them after the break-in.

Some interesting info: Original pistons have the piston pin displaced about 1mm. Wiseco's are symmetric. This difference make the engine more nervous, like asking for more gas all the time
Also the pistons don't hit the valves

Well that's everything so far, really happy with the results

[Gastydel23]

I weight the pistons also:

Std piston...........124,1gr
Std piston pin......34,8gr

Wiseco piston......152,8gr
Wisecon pin.........47,8gr

[Mohawk]

Looking good. Let's us know how it runs once up to full revs.
Is that a Yoshi M4 exhaust ?
Are you running the standard carbs ? The GPX250 used 32mm carbs ! Plus there is always the CR or Yoshi Carbs, but expensive.

Regarding the pod filter, you would be better building your own airbox with a ram air feed from the front of the bike. I plan to relocate the battery on my ZZR to the left side of the engine inside the fairings, then remove the stock airbox & fit a much bigger one, will be approximately twice the volume, this will give torque boost throughout the rev range. Pods have no head volume, they breath hot air from the engine & thus reduce power ultimately.

I've had good results with Yoshi style secondary velocity stacks on my 800, up from 95 to 120hp with just my own spec cams & big airbox mods & a performance exhaust. The Yoshi stacks don't add power but they do keep the torque delivery smooth.

[Somchai]

Originally Posted by Mohawk

Regarding the pod filter, you would be better building your own airbox with a ram air feed from the front of the bike. I plan to relocate the battery on my ZZR to the left side of the engine inside the fairings, then remove the stock airbox & fit a much bigger one, will be approximately twice the volume, this will give torque boost throughout the rev range. Pods have no head volume, they breath hot air from the engine & thus reduce power ultimately.

I agree with what you say, but here in the forum this could be like opening a can of worms!

[redkid]

Originally Posted by Mohawk

Looking good. Let's us know how it runs once up to full revs.
Is that a Yoshi M4 exhaust ?
Are you running the standard carbs ? The GPX250 used 32mm carbs ! Plus there is always the CR or Yoshi Carbs, but expensive.

Regarding the pod filter, you would be better building your own airbox with a ram air feed from the front of the bike. I plan to relocate the battery on my ZZR to the left side of the engine inside the fairings, then remove the stock airbox & fit a much bigger one, will be approximately twice the volume, this will give torque boost throughout the rev range. Pods have no head volume, they breath hot air from the engine & thus reduce power ultimately.

I've had good results with Yoshi style secondary velocity stacks on my 800, up from 95 to 120hp with just my own spec cams & big airbox mods & a performance exhaust. The Yoshi stacks don't add power but they do keep the torque delivery smooth.

Thanks the real reason not to choose the pods filter. I would love to see this! Do,you have any picture? Maybe it would give me idea to put on my bike.

[Mohawk]

I intend to remove the original airbox, the pre-gen Ninja & ZZR share the same parts, I already have a K&N in mine. When its back together I intend to dyno it as stock, then do the airbox dyno, followed by big bore & maybe some head work. If I can find an performance exhasut at reasonable cost I'll fit one too, as the stock headers are nearly rusted through.

With the airbox, the idea is to move the battery, remove the toolkit holder, open the space below & then make an airbox that uses as much of the available space, with ramair ducts to feed it. Will be a few months before this is done though as I'm busy & away with work for much of the next few months.

[Gastydel23]

well the bike have 1000 miles already and it's runing great.
I had to change some things:

- Main jets: I was using 112 dynojet jets when the engine was 250cc. I change them for 120 but i didn't realice that they where Keihin. So, I have to change them again for 120 dynojet because it was runing lean.

- Transmision: had to change the 45 teeth sproket for one with 42. The acceleration was really good but the top speed was 175 kmh (110 miles). With the 42 sproket i reach 190 kmh (119 miles)

My clutch is starting to slip when the bike is not at working temperature, so I order kevlar discs, plates and stronger springs.

I'm really happy with the bike
Soon I´ll be doing a dyno run to see the final numbers

[crazymadbastard]

BAD-ASS!

[bruce71198]

Originally Posted by Gastydel23

My clutch is starting to slip when the bike is not at working temperature, so I order kevlar discs, plates and stronger springs.

What are you using for oil?