ESE's works engine tuner

[F5 Dave]

So, gearbox oil cooler? Whether the drag would be worth it.

Dyno, 20l container, battery oil pump replenishing the gearbox. In filler - out sump plug. Could monitor external temp . Would give you several runs at correct water temp but lower than normal bottom end temp to tell if worth pursuing an on track solution.


Geez Kens concern about leaks would knotch up a few levels.

[jamathi]

Maybe the next step would be two separate liquid cooling systems. One configured to cool the incoming charge. The other to deal with the heat from combustion.

A friend of mine, named Herman Meijer, did this 50 years ago! On his own self designed engine, made from solid aluminium.
It was not particularly successful...
2 radiators, 2 water pumps, very complicated.
The water passage on the inside of the transfer walls gave 0,5 HP more on the Aprilia RSA
I am convinced that we would have had still more power with the transfers cooled on the outside as well!!!
And by cooling the C-port side as well....
We once measured the temperature of the cylinder bottom flange.
I don't remember the exact temperature, but it was frightening, about 100°C
It was measured at the back side.

[husaberg]

So, gearbox oil cooler? Whether the drag would be worth it.
.

i think according to to Cameron On the KR250s they ran at Daytona one year they lowered the gearbox oil level as the oil was heating the rear crankcase enough to cause an alarming amount of power fade.
I think they even added a baffle to keep the very hot oil away from the crankcase.

[philou]

Cylinder head for tm kz



Nostalgic bultaco engine

[SwePatrick]

In our surroundings around us, what are the best media to isolate heat?

[jonny quest]

Didn't old Rotax square cylinders basically have water around the whole outside of cylinder?

I know this is ineffective because of. Let's say stale water movement?

[AndreasL]

Hi all,

Going through my "2 stroke files" I realized that I couldn't find my FOS-zip...that i'm (almost) sure I downloaded. All of them.

KiwiBiker to the rescue I thought and tried the original link Ken posted at page 2169...
https://drive.google.com/drive/folde...of?usp=sharing
But no luck as it was over 1 year ago this was first posted. So that's understandable.

Anyone having access to the 2.2 GB of information to share?
Thanks in advance!

Please help me.

[Wos]

I am no physician

But what about the idea of water aerosole cooling outside the transfers? ... using it only to overtake your competitor would reduce the volume and weight of water carry with...

Finns and air outside duct

Know some irrigation jets for plants that spay drops of a few 1/1000 mm ...4 liters a/ hour...at pressure 4 bar ...in german called nebeldüse...fogg jet

I use this jets to cool down the inlet temprerature of my house Ventilation system...very effektiv




Grüße Wolfgang

[Flettner]

Or, what about atomizing fuel on the inside of the transfer ports, TPI.
E85 would be a good fuel / refrigerant for this.

[wobbly]

The Rotax cylinders had about 1/2 the transfer duct length "under water ".
If the plastic printed water covers are a sucess , I plan to then extend the test to reroute all the water into the cylinder on each side of the boost port, as there is a cavity already there.
Having all the water enter directly above the boost , then flow forward over the transfer tops was worth exactly 1 Hp , so the combined test should be quite revealing.

[ken seeber]

I am no physician

But what about the idea of water aerosole cooling outside the transfers? ... using it only to overtake your competitor would reduce the volume and weight of water carry with...

Finns and air outside duct

Know some irrigation jets for plants that spay drops of a few 1/1000 mm ...4 liters a/ hour...at pressure 4 bar ...in german called nebeldüse...fogg jet

I use this jets to cool down the inlet temprerature of my house Ventilation system...very effektiv




Grüße Wolfgang

Wolfgang, here is my very first post on ESE in Jan 2014:

"I worked for quite some time at a company called Orbital Engine Company in Perth WA. In the early days of the development of a 3 cyl 1200 cc DI two stroke engine, we decided that the engine, which for simplicity reasons had to incorporate exh valves operating on a single axis parallel to the crank, therefore necessarily the cylinder scavenge axis had to be normal to engine longitudunal axis. This is unlike the skewed scavenge axis which is quite common on multicylinder outboard engines. The skewing allowed the transfer passages to "nest" in to each other allowing the cylinder spacing to be minimised.

In our case, we developed a compact transfer port layout that had 100 mm bore centres with an 84 bore. To compare its performance with other 400 cc engines (of the day 100 years ago) we set up a Suzuki PE400 engine in one of our test cells. We made some trial cylinders with our scavenging system (the X porting system we called it), these being able to fit on to the PE400 lower half and this allowed us to directly compare the watercooled X system with the air cooled PE400 cylinder and head.

Getting back to the story, it became clear, as expected, that the air cooled engine very quickly lost its performance as it warmed up. This fact is also well known, particularly in go kart engine circles where air cooling it still used for certain classes (eg Yamaha KT100J and KT100S). Compared to a bike with a gearbox and a half decent exhaust, these have a low specific output, say 18 hp for 100 cc.

So, how to combat this? Firstly we blasted it with strong air flows and this helped, but the best was was to put some micro irrigation jets in front of the barrel and head. The latent heat of vaporization of the water did the rest, quickly bringing the performance up to that of a cold engine.

Getting back to the issue of Kel's cooked 125 air cooled engine, I can offer the following uptions:
1. Carry a small tank of water on the bike with this spraying or dribbling over the motor
2. If you perspire enough, have a catch arrangement inside your race suit and run this via a hose to the engine
3. For karting, I have often wondered if a small "leak" incorporated into the pressure side of the Walbro pumper carb (which is usually in front of the engine on piston ported inlet engines) might be beneficial to allow fuel to flow/trickle over the engine and evaporate. Some tech dudes might see some safety issues with this one however.
4. Back to the racesuit. You could also drink lots of water before your race and, in conjunction with a good controllable diuretic and a hose connected to your good self, perhaps cool the engine that way. Might smell a tad though.


Thanks Ken Strike Products"

[Muhr]

I made some engine mounts where I thought it could work. Then I thought it might be fun if it fit on some frame in this world. Does anyone have any suggestions on a suitable bike for an engine like this? And in that case if anyone has the measurements.

[Flettner]

wouldnt this be easier?

[wobbly]

Re the aircooled. There are readily available thermodynamic analysis calculations to determine the efficiency of finning with air flowing over them.
Basically it comes down to the thickness of the fin , the spacing and the surface area.
A 4mm spacer " heatsink " isnt going to do jack shit , unless it has a heap of added area for air to flow over it.
A thick lump like that will simply absorb heat slowly , not radiate it.
Two 1mm plates with a 2mm spacer between them would be technically superior.

I assume that your regulations specifically say you cant water cool the engine , that being the cylinder and head.
One possible work around would be to use an oil cooler for the gearbox , but have oil pumped up thru the cylinder stud holes and around the case.
This sort of extra "cooling " as per Suzukis original patent of doing all the cooling of a 4T using oil only , I am running this in a XR 200cc based engine ( loosely ) to be used in a 1/4 sized speedway
dirt car for kids racing.
Being enclosed inside the bodywork , the aircooling is not very effective , even with proper ducting and copper extended gaskets , but pumping cool oil thru the cylinder studs works wonders.

[Condyn]

That is a creative solution. The rules state that no liquid cylinders are allowed. You just gave me a few other ideas.... It is for a world championship class oval racing snowmobile ran on ice. 440cc. The heads have not been manufactured yet, they are the only external engine part that can be fully custom. The crankcase must maintain dimensions with the exception of adding reeds to it. And the cylinders must have factory casting numbers in place. I will take a look at the thermodynamics before designing the fins. As I have removed fins from the cylinder and welded in auxiliary exhaust ducts I am sure that will come in handy knowing what should work best. Just trying to do whatever I can to shed heat.
I was greatly inspired by Jeff Henise work with your guidance several months back on his land speed bike. I asked myself “why has nobody done this for this class?“
Thanks wobbly.