ESE's works engine tuner

[wobbly]

DSE, here is a quick sketch of my meaning.
I have tested the low boost port floor, with and without a hole in the piston.
With this system, the EGT is always lower ( due to more lost charge out the Exhaust, from the boost port ) and leaning it down does not gain back the power.
In the KZ engines we have been as high as 685*C EGT running C12 in the USA and have never had issues with the piston crown overheating.
We always have timing edge deto, well before the piston dome is in trouble , and that is with 50+ sprocket Hp.

[DSE]

DSE, I assume that your 'jumper' is what Wobbly calls his 'ski jump', the hump at the bottom of the exhaust duct. And yes, is there is such a hump, cooling it will be good.

Wobbly already commented on your exhaust drawings, so I will concentrate on your transfers. Contrary to what you have drawn, the A-ports should have larger axial angles than the B-ports. You may want to take a look at the 'leaning tower of Pisa' story below for both the axial and radial angles.

I also noticed that the inner radii in your transfer ducts, indicated with Ri, can be made be way larger than they are now; see the constant-radius inner radius in the A-duct drawing below.
Attachment 356682Attachment 356683 Attachment 356684

Mr. Overmars, I apologize to you for the incorrectly worded question.
I did not convey the essence in detail, I wanted to ask you about the cooling of the jumper in the exhaust duct of the cylinder.
In the photo of the 3D model of the cylinder, I made the appropriate sections to make this cooling channel visible. In fact, it won't be possible to get such a channel in the cylinder casting, so I thought about making it by drilling.
This is a cylinder of a go-kart engine, with a volume of 193 cubic centimeters.
This is just an example, since he is one of....the ones I did.
The models of the gas distribution channels that I listed above are the engine that I want to make, with a cylinder displacement of 250.
The stroke of the piston is 65 mm, the cylinder diameter is 69.5 mm.
I read about the Leaning Tower of Pisa carefully. Conclusions will follow.
I've taken into account your comments on the geometry of the channels, and I'll redo the 3D models over the weekend.

[DSE]

DSE, here is a quick sketch of my meaning.
I have tested the low boost port floor, with and without a hole in the piston.
With this system, the EGT is always lower ( due to more lost charge out the Exhaust, from the boost port ) and leaning it down does not gain back the power.
In the KZ engines we have been as high as 685*C EGT running C12 in the USA and have never had issues with the piston crown overheating.
We always have timing edge deto, well before the piston dome is in trouble , and that is with 50+ sprocket Hp.

Thank you, I read it carefully. There is something to think about.

[DSE]

DSE, here is a quick sketch of my meaning.
I have tested the low boost port floor, with and without a hole in the piston.
With this system, the EGT is always lower ( due to more lost charge out the Exhaust, from the boost port ) and leaning it down does not gain back the power.
In the KZ engines we have been as high as 685*C EGT running C12 in the USA and have never had issues with the piston crown overheating.
We always have timing edge deto, well before the piston dome is in trouble , and that is with 50+ sprocket Hp.

How do you track it?

[wobbly]

DSE, we have the best power EGT and the RAD from the test on the dyno.
Its easy to track the EGT, up to the point with one jet leaner , the temp does not increase.
That is the deto limit.

[DSE]

I use thermocouples, type K. The ones I made myself, the cases.