[Ripperton]

Oil tank is out, with 600ml of oil topped up to the brim it weighs 1 kilo. Glad to get rid of that but wont be riding for a while cause the tank isnt going back in.
0.6 liters of oil makes 30 liters of premix at 50:1 ratio. With a 9 liter tank it would go for 4 big rides. but Im estimating the bike is now running on about 20:1.

 

[Ripperton]

Oil filler hole gets a blanking plate / badge which will have TBI premix engraved into it and whatever oil ratio I end up with like 50:1 or 40:1
The cylinder is off to check piston and bore wear and and to plug the injector holes and fair the inner surface of the transfer port.

 

[Ripperton]

This is where Id really like to put the injectors, just downstream of the reed block.
Theres instant exposure to heat from the crank and rod and the atomised fuel doesnt have to condense on the throttle butterfly or reed petals giving optimised fuel preparation and economy. Fuel is injected at 45 degrees to the flow of air minimising the deceleration of the incoming air. In TPI, fuel is injected in the complete opposite direction of air travelling up the transfer ports which slows the air down, not good at low rpm.

 

[Ripperton]

And CCI was born. Crank Case Injection is just too good to let go. It has the best fuel preparation of all 3 systems. Should give the best fuel economy and cleanest running.
These 2 blocks will be glued either side of the crank case split line but not glued together so cases can still be split later, maybe 1 or 2mm gap.

 

[Axzon]

And CCI was born. Crank Case Injection is just too good to let go. It has the best fuel preparation of all 3 systems. Should give the best fuel economy and cleanest running.
These 2 blocks will be glued either side of the crank case split line but not glued together so cases can still be split later, maybe 1 or 2mm gap.
View attachment 112591

Same spot the reed block is fitted in carbi 2 stroke bikes. So an obvious place to fit the injectors. This makes me wonder why KTM did not fit them there when they developed the TPI engine?

 

[Ripperton]

OMG here I am ranting about how injectors create such finely atomised spray patterns, then I actually test each injector spray pattern.
My bike has 2 different injectors by part number. One is a 4 hole and the other is a 6 hole with different connectors.
Both of them basically just piss a stream of solid fuel out and eventually it diffracts into a spray as it passes through the air.
Worse than a carburettor. The 6 hole has a slightly better pattern diffracting earlier, lower injector in the pic photoshopped.

 

[Ripperton]

False alarm. I tested with about 5psi fuel pressure and used a 3.8v LiPo cell to trigger the injector solenoid.
Then went to test fuel tank pressure.........45psi !!!!!!!!!!
So with 45 psi into the manifold the injector would not trigger with the 3.8v LiPo cell, not enough grunt for the solenoid.
Got 13v into the solenoid and it triggered and produced a much better spray pattern so happy with that.
KTM spares say one injector is for idle and the other is for the top end. Maybe the 6 hole doesnt flow as much as the 4 hole but gives finer spray pattern.
4mm aluminium cross section of CCI injector block with injector center line (red).

 

[Ripperton]

CCI blocks in position on crank case. After glue has set, 4.5mm drill bit goes down the small holes and drill through the crank case followed by a 6.8mm bit for the injector.
CCI blocks in cnc router being pocketed 27.5mm apart.

 

[Ripperton]

Waiting on the 3M Scotchweld 1838 structural adhesive from my ex Qantas engineer buddy Ive plugged and faired the injector holes with push fit and loctite aluminium plugs.
Fairing job is a little rough but should be better than a pocket left by bought plugs. The plug is threaded from the outside so it can be extracted by a pull hammer.

 

[Ripperton]

Premix jug ready for mixing fuel like a real beast man. Takes me back to the 70's when I was a kid on my YZ80 E.
CCI injector blocks get relief notches for the crankcase pressure sensor hose. Had to trim the cylinder too.
Piston rings are filthy but not worn out yet, 40 hours.

 

[Ripperton]

So this is one of my injectors, 4 holes...

And heres one on ebay with the same body and oring size for $100.... with 16 holes !!! Time to do some research.

 

[Ripperton]

Here is BRC TBI throttle body with 2 side by side injectors. Beautiful casting but not as good as CCI.

https://brcracing.ca/brc-throttle-body-injection/

 

[Ripperton]

Blocks are glued in with 3M Scotchweld.
Conrod view with injector holes and reed valves in the background.
The yellow bolt is in the injector socket and shows the spray angle and direction.

 

[Ripperton]

Testing leftover glue in fuel to see if it degrades or dissolves. Seems ok. This stuff took about 5 hours to set, left the bike out in the sun.
2 attempts at making fuel manifold brackets. The first ones flexed and allowed the manifold and injectors to bounce up and down in the sockets due to crank case pressure and vacuum.
The second ones needed the crank case bolt hole to be drilled through and tapped from the other side but held the manifold more solidly.

 

[Ripperton]

It runs.

 

[Axzon]

It is alive!

 

[Ripperton]

It sure is alive. I mixed up 2 liters premix at 40:1 and took me back to when I was 8 years old with my YZ80E. I even used a calculator lol.
Took it down the park and let it run higher in the revs, some times it cuts out or flat spots but I did get it up to powerband and felt the ex valve open.
But down low its so crisp and toey just wants to go and sounds great, different sound.
Theres a few things that need changing right away like injection timing is now probably 180 degrees out. I think TPI injects on the down stroke but now I need it to inject on the up stroke.
The small hose that goes from the cylinder base to the crankcase pressure sensor is now maybe 15mm too short because I cut about 8mm off it before the job and now the hose connects straight to the sensor without the frame that the sensor used to sit in, maybe another 7 or 8mm. Supposed to be 100mm long. This will have an effect on the way it reads.
When I first got the bike I tried a much longer hose like 20cm so as to protect the sensor from water if I swamped it but it did something similar like this so put the standard hose back on.
Idle is also hunting and sometimes revs higher then back to normal.
Totally feel the need for different injectors as far as spray pattern is concerned. The narrow stream of the TPI injectors may be intended to get fuel down out of the transfer ports to the crank against the direction of air flow but now Im injecting with the air flow and much closer to the crank so could now afford a broader finer spray pattern for better mixing and vaporisation.
Made an alloy fuel line elbow to keep the line away from the exhaust. God those clamps are ugly.

 

[Axzon]

It sure is alive. I mixed up 2 liters premix at 40:1 and took me back to when I was 8 years old with my YZ80E. I even used a calculator lol.
Took it down the park and let it run higher in the revs, some times it cuts out or flat spots but I did get it up to powerband and felt the ex valve open.
But down low its so crisp and toey just wants to go and sounds great, different sound.
Theres a few things that need changing right away like injection timing is now probably 180 degrees out. I think TPI injects on the down stroke but now I need it to inject on the up stroke.
The small hose that goes from the cylinder base to the crankcase pressure sensor is now maybe 15mm too short because I cut about 8mm off it before the job and now the hose connects straight to the sensor without the frame that the sensor used to sit in, maybe another 7 or 8mm. Supposed to be 100mm long. This will have an effect on the way it reads.
When I first got the bike I tried a much longer hose like 20cm so as to protect the sensor from water if I swamped it but it did something similar like this so put the standard hose back on.
Idle is also hunting and sometimes revs higher then back to normal.
Totally feel the need for different injectors as far as spray pattern is concerned. The narrow stream of the TPI injectors may be intended to get fuel down out of the transfer ports to the crank against the direction of air flow but now Im injecting with the air flow and much closer to the crank so could now afford a broader finer spray pattern for better mixing and vaporisation.
Made an alloy fuel line elbow to keep the line away from the exhaust. God those clamps are ugly.
View attachment 112694

Does those black hoses have a bigger inner diameter than the original injection hoses? If so, that could affect the fuel injection pressure and timing.

 

[Ripperton]

Axzon, Nope same 8mm injection hose that was on the TPI. Should be able to reuse the original clamps they look neat.

 

[Ripperton]

Test ride shows what happens when I open the throttle.
Oil has wadded the muffler so it sounds crap right now. Have new packing to fix that.