ESE's works engine tuner

[DaisyB]

You chaps are the most ingenious s.o.bs

The inlet divider is a go for sure.

The exhaust idea is brilliant but my first thought was about heat path & ring catch. Having said that the notch top & bottom of the port & relieving might do it. I've got to get the barrel de-nikasiled (if that's a word) then I could make a spacer to fit over the exhaust flange with the bridge as part of it, sliding up in machined grooves, bore barrel, take it out, relieve & re nikasil..... I just have a niggly thought in the back of my mind that the rules do actually outlaw bridged exhaust ports, but that may be welded in ones on cast iron barrels from years ago. Need to check.

Wob, can't move the barrel 180 (although we do that on "smallframe" Vespas often enough) as the stud spacing isn't square.

Thanks for your head-space for my problems chaps, often difficult to think outside the box when you work on them all the time.
Dave

[husaberg]

I do like the inlet idea though. You can see the tech inspector going "Hey that's not. . .um. . .well. . . Yeah ok, good one"

Muzzy was latter failed on a tech inspection when it didn't stay with the manifold.
He did like to push the rules hence the gear wine of the ZXR at times......

In the Bell book there is a decent write up on achieving legality with the best combo of parts in relationship to std class rules with the KT100. There is always "wiggle room" in measurements of std parts. deck heights etc etc..

[koba]

Wob, can't move the barrel 180 (although we do that on "smallframe" Vespas often enough) as the stud spacing isn't square.

Can you run a longer rod and a thick 'spacer' that just happens to reverse the stud position to allow the barrel to be reversed?

Might need a pic...

[TZ350]

Can you run a longer rod and a thick 'spacer' that just happens to reverse the stud position to allow the barrel to be reversed? Might need a pic...

..............

[TerraRoot]

or turn the barrel 90 degrees and have a nice inlet and exhaust port!

[F5 Dave]

The bottoms of the transfers might not flow so well though

[TZ350]

OK, after talking (by email) with Matt of Ecotrons it looks like the Chinese after market injectors I brought of Ebay don't have the dynamic range for a 2T at 12,000 rpm.

Until I can build an injector test rig that measures their actual flow under real conditions I have moved on to another part of the project.

The idea is to sandwich the barrel and head (block of alloy in front of the engine) between the two industrial heat sinks with two electric fans assisting in clearing the heated air and the other heat sink bolted over the head area. Lots of copper of course to transport the heat quickly to to the outer fins and ducting to catch the breeze from the bike moving through the air.

Copper wire will be packed inside the cylinder water jacket for heat transport from under the exhaust port duct and thermal paste and a touch of oil for heat transfer from the cylinder walls to the copper and the heat sinks.



Now that I have a pretty good idea of how I might reliably cool the cylinder and exhaust tract area. We are looking at a fuel injected, reverse cylinder, air cooled, late model RGV250 cylinder bored out +1.5mm for the max oversize capacity allowed (130.5cc) for an F4 air cooled cylinder. 130.5cc is 12% more total capacity than allowed for a 100cc water cooled F4 engine. And that is the easiest 12% more power you will ever get.



Impressive transfer ports and variable blow down time area. I might even try to make a variable length pipe for it.

The plating is useable and the plan is to run it as is, to prove (or otherwise) the concept. If it works then I will port it and have it bored to 57.5mm and re plated.

I think this is a VJ22a SP cylinder and I need a set of three blade power valves for it. Can anyone help (sell me a set), even a tip on where I can buy after market ones would be good.

[richban]

even a tip on where I can buy after market ones would be good.

Even the after market ones are a grand. Sketchy is making some so maybe he is your best bet. His are 2 piece not 3. But with an ignitech you should be able to get them working nice.

[TZ350]

His are 2 piece not 3. But with an ignitech you should be able to get them working nice.

Thanks Rich, 2 piece, is that two sliding elements or one?

[sonic_v]

OK, after talking (by email) with Matt of Ecotrons it looks like the Chinese after market injectors I brought of Ebay don't have the dynamic range for a 2T at 12,000 rpm.

Until I can build an injector test rig that measures their actual flow under real conditions I have moved on to another part of the project.

The idea is to sandwich the barrel and head (block of alloy in front of the engine) between the two industrial heat sinks with two electric fans assisting in clearing the heated air and the other heat sink bolted over the head area. Lots of copper of course to transport the heat quickly to to the outer fins and ducting to catch the breeze from the bike moving through the air.

Copper wire will be packed inside the cylinder water jacket for heat transport from under the exhaust port duct and thermal paste and a touch of oil for heat transfer from the cylinder walls to the copper and the heat sinks.



Now that I have a pretty good idea of how I might reliably cool the cylinder and exhaust tract area. We are looking at a fuel injected, reverse cylinder, air cooled, late model RGV250 cylinder bored out +1.5mm for the max oversize capacity allowed (130.5cc) for an F4 air cooled cylinder. 130.5cc is 12% more total capacity than allowed for a 100cc water cooled F4 engine. And that is the easiest 12% more power you will ever get.



Impressive transfer ports and variable blow down time area. I might even try to make a variable length pipe for it.

The plating is useable and the plan is to run it as is, to prove (or otherwise) the concept. If it works then I will port it and have it bored to 57.5mm and re plated.

I think this is a VJ22a SP cylinder and I need a set of three blade power valves for it. Can anyone help (sell me a set), even a tip on where I can buy after market ones would be good.

As power is proportional to the percentage increase in bore diameter for a bored out two stroke cylinder the best you can hope for is an increase in power of 2.7 % for a 57.5 mm bore v's a 56 mm bore. 100 x ( 57.5 - 56.0 ) / 56.0

Seems like an expensive modification for such a small potential power increase!

What about go the other direction and sleeve down the cylinder to the maximum allowable capacity for a "100 cc" watercooled engine? This would also move your bore/stroke ratio in the right direction.

[Frits Overmars]

...130.5cc is 12% more total capacity than allowed for a 100cc water cooled F4 engine. And that is the easiest 12% more power you will ever get.

As power is proportional to the percentage increase in bore diameter for a bored out two stroke cylinder the best you can hope for is an increase in power of 2.7 % for a 57.5 mm bore v's a 56 mm bore. Seems like an expensive modification for such a small potential power increase!

And that is only true if you enlarge all port widths by the (new bore / old bore) ratio.
Just boring out a cylinder will not alter the angle.areas; it will only decrease the specific angle.areas and it will force you to lower the revs if you wish to keep the original time.areas. In short: the same power with less revs. But the larger bore will worsen the combustion chamber shape; combustion will be slower and it will heat a larger piston crown area, increasing the deto risk.

What about go the other direction and sleeve down the cylinder to the maximum allowable capacity for a "100 cc" watercooled engine? This would also move your bore/stroke ratio in the right direction.

Right!

[teriks]

Copper wire will be packed inside the cylinder water jacket for heat transport from under the exhaust port duct and thermal paste and a touch of oil for heat transfer from the cylinder walls to the copper and the heat sinks.

How about sealing the water jacket volume, evacuate the air, and partly fill the volume with a liquid other than water?
-Think heatpipe.
You might even end up with more efficient heat transfer (than the cu-wire thing) using oil only, that is if the water jacket allows natural convention.

/Thomas

[richban]

Thanks Rich, 2 piece, is that two sliding elements or one?

Sliding. I have some shagged old style ones you could have for a beer.

[husaberg]

How about sealing the water jacket volume, evacuate the air, and partly fill the volume with a liquid other than water?
-Think heatpipe.
You might even end up with more efficient heat transfer (than the cu-wire thing) using oil only, that is if the water jacket allows natural convention.

/Thomas

I think the rule says liquid.........
I have mentioned Paraffin wax before as it is common solid at room temp and during phase change it can buffer huge amounts of heat.
Rob have a gander at this.
http://en.wikipedia.org/wiki/Phase-change_material

Silver is not that dear is it..... Norton used it on the Works 500's and i think so did AJS with the Porcupine.
http://www.engineeringtoolbox.com/th...ity-d_429.html

[jasonu]

How about sealing the water jacket volume, evacuate the air, and partly fill the volume with a liquid other than water?

Liquid cooled F4 engines 104cc...