ESE's works engine tuner

[Dutch Fisher]

Perfect example is SAE 2001 01 1797/4218.
This showed real time data against Optimum Power Technolgy's 4 stroke sim package ( I can use that as its free to Uni engineering depts )
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If your local Uni upgraded to Automated Design, you could use the other editions

[Dutch Fisher]

The idea of cooling the outer walls of the transfers was an attempt at proof of concept - but was a fail , why , still eludes me .
Jan had already proven cooling the inner walls from bore heat was worthwhile , and the outer duct area runs at least twice as hot as the water.
It would have been easy to run cooling this way in a new cylinder design , for the next homologation , or any project from scratch.
I know having all the cold water enter the cylinder from the boost port , and running forward over the transfers first , makes 1 Hp , so that alone is
worth looking at directing flow to run forward from the gearbox insulation gallery, over the mains ( under the transfer feed area ) and up into each side of the boost port.
This makes sense , opposite to the old , usuall way of cooling the Exhaust duct first.

With the thinking cap on:

Are we wholly certain as to what cooling the inner transfers does. Yes 1 Hp gain, but why? There is a cause (the cooling of the surrounding metal), but are there more than 1 effect?

A thought: Does cooling the inner wall therefore produce a temp gradient in the transfer stream were-by the inner flow of the stream is cooled and energy is taken out reducing the molecule excitement.
The effect being a reduction in energized eddies and a (poss) thinning of the boundary layer in the inner wall so as to assist the "turning of the corner" as there has to be a pressure difference across the area of the stream, inner wall to outer. The lowering of the outer wall temp having no effect as the outer wall is the "wall of death" for the stream.

[andreas]

Some cap you got there, gives me the giggles by proxy.

[husaberg]

With the thinking cap on:

oddly enough the dutch caps here are to prevent the fishy's.

[Dutch Fisher]

Some cap you got there, gives me the giggles by proxy.

oddly enough the dutch caps here are to prevent the fishy's.

Welcone to the wonderful world of Northern English colloquial expressions
My thinking cap is modelled on the Fred Dibnah design (google him)

[TZ350]

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More from "2 Stroke Stuffing".
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[SwePatrick]

You'd need a long hose . Don't pass that guy on the inside.

There are a lot of wireless technology today, just invent hoseless

[Muhr]

Have felt that the connecting rod that I initially chose for the project was a bit of a shortcut that did not feel really good. developed for an engine with a clearly more favorable environment than what I intend to expose it to.
This is now taken care of with a billet rod also got 1mm more that I wanted, to 89 mm.
So now I can nerd away with 48h in the tumbler and then DLC coting

[Frits Overmars]

Have felt that the connecting rod that I initially chose for the project was a bit of a shortcut that did not feel really good. developed for an engine with a clearly more favorable environment than what I intend to expose it to.
This is now taken care of with a billet rod also got 1mm more that I wanted, to 89 mm.
So now I can nerd away with 48h in the tumbler and then DLC coting

DLC coating a two-stroke rod? Last time I checked, DLC would not reliably stand more then 250°C, and I fear that things can get quite a bit hotter in a two-stroke big end bearing

[andreas]

I can't really grasp how the balancing works. A tandem counterrotating 0* firing delay has no vibration, 90v conterrotating 90*firing delay also good, boxer counterrotating 180* firing delay good yes? Parallell twin vibrates due to rocking, but why doesn't a same directon rotating 180* firing delay tandem work?

[Vortex]

Have felt that the connecting rod that I initially chose for the project was a bit of a shortcut that did not feel really good. developed for an engine with a clearly more favorable environment than what I intend to expose it to.
This is now taken care of with a billet rod also got 1mm more that I wanted, to 89 mm.
So now I can nerd away with 48h in the tumbler and then DLC coting

Hi there,
Just as an information, in the current OK engine from Vortex who makes easy 16.000 rpm a DLC treated connecting rod (104mm) performs without any problems, but the needle bearings are definitely NOT running on DLC coated surfaces.
According to the current status, DLC can be used up to max. 350 deg.C
Here it was only to be able to omit the silver shims, use a 5mm shorter crank pin and stiffen a lot more the crankshaft.
It's probably easier for the process to coat the whole conrod and then hone the bearing surfaces.

Cheers

[Muhr]

DLC coating a two-stroke rod? Last time I checked, DLC would not reliably stand more then 250°C, and I fear that things can get quite a bit hotter in a two-stroke big end bearing

Thanks Frits! I've been thinking about what you can expect in terms of temperature when setting clearances between surfaces if, for example, you were to try experimenting with Hydrodynamic bearings. Can't say I have any idea but usually don't see any major discolorations.

[Muhr]

Hi there,
Just as an information, in the current OK engine from Vortex who makes easy 16.000 rpm a DLC treated connecting rod (104mm) performs without any problems, but the needle bearings are definitely NOT running on DLC coated surfaces.
According to the current status, DLC can be used up to max. 350 deg.C
Here it was only to be able to omit the silver shims, use a 5mm shorter crank pin and stiffen a lot more the crankshaft.
It's probably easier for the process to coat the whole conrod and then hone the bearing surfaces.

Cheers

Here are a few more examples

[wobbly]

A 180* Tandem with same crank rotation would need an intermediate gear - just to make it work that way.
But balance wise , it would mean that when the crankwheel counterweights were at TDC/BDC they would form a rocking couple , just like a Parallel Twin @ 180.
Then when at 90* the two out of balance counterweights ( any number less than 100% BF ) would both be facing opposite each other ,forward or backwards - cancelling the horozontal resultant.
The intermedate gear needs to be the same size as each crank gear , making it too big to drive the clutch - and a balance shaft off that gear cant kill the rocking couple , as its in the same plane.
Thus another small gear is needed to drive the clutch - result is no advantage over a concurrent firing Tandem , but an extra power consuming gear/bearings , and less big bang tyre grip.

[SwePatrick]

What have i missed with dlc coating.
Diamond like coating, Why coat the whole rod?
Why even bother when not coating bearing surfaces?

Why not make an aluminiumrod with inserts for the needlebearings?
And no,, they won´t breake if using new tech, old alurods had a lifespan.
But new alloys make them way wey more reliable.
Watched a guy on youtube that had them in his engine for 9 years and none of them breaked.(1000+ Honda engine)