ESE's works engine tuner

[lodgernz]

Lodger, part of the answer lies in the introduction of many fully synthetic race oils, they all started to appear around the time that GP racing converted to Unleaded fuel.
Motul 800 Elf 976 etc.
Unleaded is best when operated rich, with less compression and more timing.
Up to that time the most widely used oil was semi castor Castrol 927, in fact I know for sure that many teams with oil sponsors actually secretly substituted this so as not to upset anyone.

In the tests I did ALL the fully synthetic oils LOST power when run in the KT100 up at an EGT of 650*, no matter what the oil ratio was, compared to the HTX 909.
What you have to realise is that all the synthetics, when tested in a Timken/Falex machine, have huge oil film strength, but the instant they loose this film and are overheated, they break down into their component
constituents, that are NOT actual lubricants at all.

The very old R30 castor oil has probably 1/10th of the film strength, but when its overheated and breaks down, those component chemicals still operate as lubricants.
And I know some experts have rubbished the Falex machine as being unrealistic in a 4T, but empirical evidence in a 2T shows exactly the same characteristics as the machine demonstrates.
When a synthetic film is broken down, it tears the shit out of everything, a Castor type fails sooner, but the wear pattern is perfectly smooth on the test shaft.

In the KT100 test at very high run temps, I was seeing really premature piston skirt wear using Motul 800 and several other full synthetics - plus the obvious power losses.
I had used Maxima 927 in the USA with 110 race gas in World Champ Jetski's, as the HTX909 was not compatible and would separate out very quickly.
Both are semi castor mixes, and that seems to be the holy grail in 2T race engines operated out at the limits.
HTX909 separates real quick in AvGas, the Maxima doesnt, but both those oils are perfectly fine in pump gas, or the unleaded fuels mandated for CIK or FIA racing.

Thank you Wobbly. Excellent reply as always

[wobbly]

So as Neels STILL hasn't access allowed here on KB, he has asked me to post this new video.
Can Admin please spend some Xmas time and get this sorted for him.

https://www.youtube.com/watch?v=zItXBc0gRvw&t=13s

[lodgernz]

Ha ha, I already use what is called a Hyper Coating,a thermal barrier coating usually used for retaining heat in exhaust systems.
See here :http://www.hpcoatings.co.nz/ExhaustH...erCoat_Extreme.
I just happened to see the inside of a special race engine at TM that had a black " coating " of some sort.
The legality could strictly be questioned, as a basic rule of the class is " no added material ",but the coating has never been questioned by tech.
Let alone the clear thermal barrier coating in the combustion chamber, that you cant see when oil residue is burnt onto its surface.

JanBros - the big problem with trying to replicate the STA and or bmep of the Aprilia is that this engine was R&D'd to death on both the dyno and the flow bench.
The STA numbers nowhere near match,as the Blowdown Cd is hugely affected by the port exit geometry,and this works way better than the raw numbers generated by the simply calculated area.
Then you have a plethora of tiny details ( such as PWM powerjet operation ) and unless you replicate all of this synergy,the numbers you are trying to simulate in your own project are stuff of daydreams.

Wobbly, please forgive me for reviving a very old post. Can I just ask if you have ever used HiperCoat Extreme to line the combustion chamber?

[wobbly]

I have used the thermal barrier coating in several scenario's - after successfully HPC doing the pipes on my GT R35.
The testing I did on the piston and combustion chamber surfaces immediately gave a huge deto increase on the dyno, something I had not envisioned at all.
After the shock, I did some serious dreaming about the issue, and finally came up with the fact ( after prompting from Mr Overmars ) that the coating, in doing its job
of preventing heat from transitioning thru to the base material, was creating a super hot boundary layer surface in the squish band.
Thus causing much worse deto than before.

So - easy new test, stick both items in the lathe and remove the coating from the squish area with wet and dry.
Boom, instantly hotter EGT, power increase, and no more deto than previously.

This was used for the first time in the " Stock " Jetski class at the Havasu Champs.
The tech guy looked at the pistons with a very black oil layer in the middle and said " Wow, no wonder you guys won, that piston has been hot as hell ".
Never thinking to check if some cheating bastard hadnt cut the skirts short on one side as well.

So, yes coating the piston center only, reduces the thermal loading, and coating the combustion chamber only reduces the thermal transfer of heat energy into the water.
Sadly ceramics are specifically outlawed in KZ racing, so I have never actually done that - though how the hell anyone could detect a clear coated surface I dont know.

[lodgernz]

I have used the thermal barrier coating in several scenario's - after successfully HPC doing the pipes on my GT R35.
The testing I did on the piston and combustion chamber surfaces immediately gave a huge deto increase on the dyno, something I had not envisioned at all.
After the shock, I did some serious dreaming about the issue, and finally came up with the fact ( after prompting from Mr Overmars ) that the coating, in doing its job
of preventing heat from transitioning thru to the base material, was creating a super hot boundary layer surface in the squish band.
Thus causing much worse deto than before.

So - easy new test, stick both items in the lathe and remove the coating from the squish area with wet and dry.
Boom, instantly hotter EGT, power increase, and no more deto than previously.

This was used for the first time in the " Stock " Jetski class at the Havasu Champs.
The tech guy looked at the pistons with a very black oil layer in the middle and said " Wow, no wonder you guys won, that piston has been hot as hell ".
Never thinking to check if some cheating bastard hadnt cut the skirts short on one side as well.

So, yes coating the piston center only, reduces the thermal loading, and coating the combustion chamber only reduces the thermal transfer of heat energy into the water.
Sadly ceramics are specifically outlawed in KZ racing, so I have never actually done that - though how the hell anyone could detect a clear coated surface I dont know.

No such restrictions in Bucket Racing of course. When you say "the centre of the piston" do you mean just the area of the dome that is inside the squish band area?
Do you think the coating will last in the relatively benign conditions of a 100cc 2T Bucket turning out bugger all more than 22HP? And is it worth the trouble?

[wobbly]

Yes, keep the coating out of the squish band.
Technically reducing the thermal load on the piston, as well as reducing thermal loss to the water, is going to increase the energy in the combustion space.
I used the ceramic thermal barrier coating for pistons from HPC - no issues at all with adhesion or efficiency.

[lodgernz]

Yes, keep the coating out of the squish band.
Technically reducing the thermal load on the piston, as well as reducing thermal loss to the water, is going to increase the energy in the combustion space.
I used the ceramic thermal barrier coating for pistons from HPC - no issues at all with adhesion or efficiency.

Thanks Wobbly.

[wobbly]

And dont forget the test I did for Jan, ceramic coating the Exhaust duct.
His boss, the great leader, insisted that retaining the heat energy in the exiting Exhaust gasses would increase power - Jan disagreed.
When I finally got to do this experiment, the deto level went thru the roof and the 48Hp KZ125 engine lost 1.5 Hp.
But to stop the dangerous deto level, it would have to be jetted hugely richer - loosing way more power.
As it turned out WankerVeen was still convinced of his own superior cleverness with hot Exhaust ducts, but history tells a slightly different story with the absolutely pitiful performance of his
infamous 125GP engine project failure.

[diesel pig]

And dont forget the test I did for Jan, ceramic coating the Exhaust duct.
His boss, the great leader, insisted that retaining the heat energy in the exiting Exhaust gasses would increase power - Jan disagreed.
When I finally got to do this experiment, the deto level went thru the roof and the 48Hp KZ125 engine lost 1.5 Hp.
But to stop the dangerous deto level, it would have to be jetted hugely richer - loosing way more power.
As it turned out WankerVeen was still convinced of his own superior cleverness with hot Exhaust ducts, but history tells a slightly different story with the absolutely pitiful performance of his
infamous 125GP engine project failure.

While you are talking about heat and exhaust ducts, I thought I would run an idea I had after reading frits and your take on two stroke cooling. This is my idea. Take the coolant coming out of the bottom the cooling radiator and feed 50% of it into the area around the C port or ports, have this cooling tranfers and then using blanking plates have it travel into the cylinder head and then out of the engine. At the same time feed the other 50% of the coolant into the intake cooling jacket/s at the bottom of the exhaust port/ports like on Two stroke dirt bikes and using the same blanking plates mentioned before to direct this coolant down the exhaust port to a length equal to 150% of the bore diameter and then have it leave from it's own exit duct at the end of the exhaust duct. Only having it combine with the coolant in the pipe work going to the top of the cooling radiator. Does this idea have any merit? or am I missing something?

[wobbly]

That idea has merit, absolutely.
But another similar idea , that has just been finished in CAD as we speak, is to feed all the cold water in above the C port, and arrange the combustion insert such that nothing flows up anywhere into the head.
The cold water, having done its initial job, then flows forward over the entire Exhaust duct length, out to my suggested 150% of the bore.
It then exits this point, and externally, via a short hose enters the front side of the head, above the insert, crosses the chamber and exits out at the rear, directly above the cold inlet spigot in the cylinder.

Thus the warmest water crosses the combustion chamber, reducing the temp delta stealing heat energy from the inner combustion wall.
Cold water can also be plumbed to enter the bottom of the case, to cool the vertical channel, separating the gearbox, then upward as normal thru restrictor drillings underneath the Exhaust duct.
A concept proven in the latest winning KZ engines.
Another detail is that water , not only cools the space between the bore and the Transfer inner walls, but is also flowing completely around the Transfers outer walls within the cylinder - travelling
forward toward the ducts end exit hose.

The twin parallel circuit concept I proved worked perfectly , and easily , in the successful Jet Ski projects.
That is cold water in the cylinder with its own low temperature regulated outlet, and a second separated head circuit at more than double the cylinder exit temperature.
Doing essentially the same thing in series, I believe, is also a simple and achievable viable solution that relies on a single radiator cooler.