ESE's works engine tuner

[Wos]

3mm is needed as a minimum to have sufficient load area supporting the ring face with lubrication.
This works in 125 and smaller cylinders - I have seen a 50cc race cylinder with 2mm Aux bridge widths and it wore away slots in the ring.

Ouch!!! 😞

Thank you so so much for warning us from wear of the rings!

Its a given buyable tuning cylinder that has around 2 mm bridge that has small main under 65 cordal ...its strong called relieable... ouch!!

My idea was to minimice bridges to get 68 percent because i thaught this is more effective than widen aux!?? Isnt it? 😉
Long therm project...
Tanks for advice...

Have a nice day wobb...got to sleep now here in europe 😉 😀

Thanks for advice

Wolfgang

[wobbly]

In a T port it seems that 2.5mm is the safe minimum , as the chordal width of each side is alot smaller than that of a 70% main.
It is very important to get the T port bridge relief shape and depth correct though when going this thin.

[Wos]

In a T port it seems that 2.5mm is the safe minimum , as the chordal width of each side is alot smaller than that of a 70% main.
It is very important to get the T port bridge relief shape and depth correct though when going this thin.

Wob good morning ...Tanks for reading back my edited questions! 😉

In case of butterfly we often have lubrication Support from bores in piston at bridge mid under ring...think.. minding 😉

Do you think, this is possible/ effective at a narrow bridge that devides main from aux to avoid heavy wear of rings to??

Many thanks!!

Wolfgang

[wobbly]

Yes it works , there have been several examples of lubrication holes and slots in pistons over the bridges each side of the boost port - some Aprilia pistons had this.
This is because of the heavy thrust forces from rod angularity.
I have put lube holes each side of the main port ,over the Aux bridges , on a big overbore Banshee based engine , as again the thrust and ring tension was wearing
the piston and bridges badly.

[SwePatrick]

I wonder how long those hydraulic pumps will last without oil to lubricate them

Sadly enough, not to long...
I ran methanol and 6% oil blend through one when i was trying EFI on my bike.
I seized quite fast....

But i ran my pump driven by crankshaft as i had normal efi injectors and fuel pressure regulator.

It seized between the gears and the housing, i expected it to seize at the shafts though, as there were no bearings.
When it seized it grinded off small aluminium parts from the housing, and clogged up the system.

[SwePatrick]

High pressure gear pump for my electromechanical fuel injection system arrived from china.

Attachment 354982

Ignitech Dccdip1/2race has input for TPS, and can output PWM.
Looks like I'm stuck with four throttle position points, and five rpm points which is restrictive, but might be enough when WOT at pretty much constant load is all that matters anyway.
I'm assuming there's interpolation between these points, can anyone confirm?

Attachment 354981

You see where I'm going with this?
No RAD compensation, if only the Ignitech could accept TPS and some other sensor simultaneously.
Easy enough to shift the whole map according to conditions, or even have the pwm signal pass through an Arduino that modifies it based on RAD.

How do you compensate for increased demand of fuel when 'the heat comes'?
My experiance is that when nitro burns hot, you need to 'put out the fire' with more fuel.....
Not doing so often results in damage.

And you cant run 'this' amount of fuel from the start, as it will 'drown' the engine, and it will never come up on the pipe.

[Wos]

Yes it works , there have been several examples of lubrication holes and slots in pistons over the bridges each side of the boost port - some Aprilia pistons had this.
This is because of the heavy thrust forces from rod angularity.
I have put lube holes each side of the main port ,over the Aux bridges , on a big overbore Banshee based engine , as again the thrust and ring tension was wearing
the piston and bridges badly.

Hey wobbly thanks!

I think the bigger the mass of piston the the bigger the forces and the bigger bore the bigger tilt of piston !?
And the power you gain..the load on piston crown...

Which would be the best solution to help narrow bridges wobb?

Like in picture where bores going thru piston?

Thanks so much

[jbiplane]

https://youtube.com/shorts/KkIgSOC0y...4koZ6-MNlCcp3R
A question. What is the best sealing material nowadays for air cooled cylinder head?
I use 0.4mm aluminum and copper sheets, but may be exist other still available variants?

[wobbly]

Yea , here are the bridge lube holes for each side of the boost on a RSA.

Edit , re the head seal on an aircooled - the worst case scenario for this was solved many years ago when we were permitted to run Methanol and thus very high compression.
The copper or alloy gaskets were useless , so I tried two fixes , both worked , but I ended up using both as insurance.
First both surfaces were lapped dead flat on a surface plate , then the first test was to create a " flat labyrinth " seal by machining 3 shallow grooves in the head 2mm wide , 1.5 apart.
This worked just fine with no failures , but I noticed that as the head was not pinned or dowelled in place , when it was reassembled the witness marks on the cylinder were not concentric.
Next was to pin the head and use a single empty groove , then a 2mm Viton O Ring outside that. The groove depth was 10% less than the diameter and the width was 20% wider with the OD matching.
This also worked perfectly and was used later with a petrol head , so excess temp on the O ring proved not to be an issue.

[Wos]

Yea , here are the bridge lube holes for each side of the boost on a RSA.

Wobb...are you sure?

From my view that are bores for lubrication c to b ports 😉 bridges ...hmm 😉

But good to know even that was done wow 😉

Frits or Jan told us never!? 😉

[wobbly]

Well the holes are directly over the bridges each side of the boost port - not sure what the slot actually does , but the picture was published ages ago by Frits.
If you look closely you can see the boost bridges have left witness marks on the piston skirt, directly over the holes.
Here is another one showing Frits Torlon piston plug as well.

[Wos]

Well the holes are directly over the bridges each side of the boost port - not sure what the slot actually does , but the picture was published ages ago by Frits.
If you look closely you can see the boost bridges have left witness marks on the piston skirt, directly over the holes.
Here is another one showing Frits Torlon piston plug as well.

Ok wobbly

Maybe the slot is for a kind of ventilation to ducts?...maybe to help oil flow?

Please help us Jan ... Frits 😀 😉

Thanks to all 😉

Grüße Wolfgang

[Pagi]

Wobbly, Frits,

I have a question about port A, B, and C.
Is there a volume relationship between these port and the displacement? If so, what is the distribution between them?

[wobbly]

I think your wording is a bit confusing , as I don't believe " volume " compared to " displacement" are the correct way to look at the elements of tuning you are examining.
The two engines that have had the most development effort put into them , and also have had the rewards gained from that work , are the RSA and the TM KZ.
In essence the only real difference between the two are the KZ's lack of a PV and its idiot straight line mandated ignition.

This gives rise to a differing approach to the scavenging regime and as well as slight differences in the port chordal widths, even though they have the same bore/stroke/displacement.
The RSA had reverse transfer stagger , as this regime favors top end and overev, as well as enabling a higher STA of those ports , due to the total width of the B/C being greater and thus gives extra area
when they are lifted to be the highest.
The KZ has normal stagger and the boost port width is slightly wider , giving a greater powerband width at the expense of peak power.
That is more natural upper mid power and a more powerful overev capability.

Both have the transfers fully occupying as much bore chordal width as is possible within the limits forced by the maximal Exhaust Port width, but both have the STA needed to support the peak power
at their desired rpm.
The RSA made 55Hp at 13,000 and was regularly reved not much past 14,000 , whereas the KZ makes just on 50 Hp at 13800 and is reved to 14800 all day.
The Aprilia regime , including a narrower boost , has been tested in the KZ, and it gained an appreciable amount of peak power , but lost so much in the useable mid ( 10,000 ) rpm
it was way too slow off all the several 2nd gear hairpins.

Thus I believe applying the correct approach to the porting regime , and matching the STA of the Transfers and Blowdown to the required power/rpm define all the ports in a very narrow window.

Thus I dont believe " volume " as such is a useful metric when both engines have the transfers taking up all the available space , and both have the required STA but utilize that area in differing ways to suit the end use.

[Martin1981]

Wobbly, are there any news about the 3XV cylinder TZR 250 engine? Have you dynoed it yet and did it actually make 54hp/cylinder? It would be awesome. Those cylinders were never thought of being that capable.


Talking about that 3XV cylinders you found work so well.....are there any "cheap" "basic" 54.5mm stroke cylinders that good? I can remember once you said the 2004 Honda CR125 is a good cylinder to start with. Are there any other 54.5mm stroke cylinders you know of as good or even better than the 2004 Honda CR 125? Apart from the Aprilia RSA/RSW and the TM KZ cylinders of course.


Thank you for sharing all that knowledge! It is somewhat interesting and exciting.