ESE's works engine tuner

[F5 Dave]

2 piston rings! Well that blows my theories out of the window.


Nah I got nothing, just wanted to appear like I was contributing.

[Flettner]

Hey guys,check this one!!
Give emphasis on the 90mm center to center rod.
I guess that if crankcase don't communicate with tranfers,a long rod isn't needed for bigger case vol!

Why not a short rod, better dwell, as the side load on the piston is not there, it's all taken on an oil feed guide under the piston. This (rod length) is more telling than any thing else, the spacer is almost cetainly to hold this guide (like a large valve guide) as the spacer is NOT needed for a long rod. Easy to seal off the bottom end. 199 exhaust timming I see. If the piston is not touching the bore any more can the exhaust port be wider? How wide before the rings become a problem? It's a pitty we still need rings!

[wobbly]

199 Ex timing is the CIK allowable limit - most all the engine building companies simply put this into the homologation
papers so they dont actually give away the timing they use in reality.

[TZ350]

I have a ti project coming up soon that will go to Zenith. I'll share it with you if it is successful.

Even sharing unsuccessful projects has its merits, we would be interested in those too. As lot can be learned from a project failure and how you went about it, because failure is just another step on the path to success. Win or lose, please post details.

[Flettner]

So I'll share with you what I learned quoting some EBM projects through Zenith.
1) Materials - You can't use aluminum ! Which is really annoying isn't it.....
Aluminium has a vapour phase temp too low for EBM. Basicallly If you tried to do it, you'd inadvertantly create a kind of vapour deposition vaccuum metaliser, coating the entire cabinet in aluminium.
Most materials EBM'd are stainless steel, titanium, or inconel. I believe copper based alloys would be possible, and probably Tungsten. Rocket engines and acid pumps and that kind of thing are what tends to get built in the main.
2) Distortion is controlled with a proprietary method of modelling 'fins' and webs onto the parts to balance them thermally during the build. These are sort of 'stitched' onto the part, and are broken away once the part is completed. This controllled cooling enables much finer forms than can be achieved with SLS. Remember we are talking about titanium and inconel here. SLS of aluminium may not have these distortion issues, but Ti certainly does.
3) Resolution and surface texture is comparable to SLS. Porosity should be much lower but is a compromise with build speed.

I have a ti project coming up soon that will go to Zenith. I'll share it with you if it is successful.

I don't know what to make of it all, we are forever sorting out problems for people getting stuff 3D printed, both plastic and metal.
A recent project involved titanium fingers being printed, we were told the print would be down to 0.05mm, no problem. So the customer turns up with the parts but wants us to machine a 0.5mm slot in them that had only partly printed, where is the 0.05 accuracy? So we have much difficulty holding these parts ( other surfaces also needed machining ) Finally after a lot of time and cost we finish the parts only to have them distort milimeters after some post treating process. Cost the customer a fortune and it all went in the bin! I did tell them at the start that they should just get the parts laser cut out, quicker, cheaper and in the long run more accurate.
It seems to me that the process is a bit like a real small tig welder so there WILL be stress in the final product. Any subsequent heat will cause distortion. Old school has it that you machine the part close to size, stress relieve, then finish. If you are going to print parts for engines I think you will have make the part, stress relieve then finish machining, like we do now.
Not saying don't do it just saying this is one of our experiences, I would get them to put their claims in writing.

[Flettner]

199 Ex timing is the CIK allowable limit - most all the engine building companies simply put this into the homologation
papers so they dont actually give away the timing they use in reality.

SO, is the 11 ports and 90mm rod also " allowable limits " ???

[husaberg]

SO, is the 11 ports and 90mm rod also " allowable limits " ???

One or two of the KZ engines has a 110mm rod. So I think not.
Some have PV's too so they must be allowed those as well.
Remember your bellows gear shift boot seal idea I wonder if a bleed high up could move this and lower the cylinder pressure at the same time Two Birds one stone KISS

[Flettner]

11 transfers and 1 exhaustport!!!

Is it high position transfer ports we see around/above the export?

Very interesting!

Thanks Lef16 for sharing.

11 transfers? are some perhaps unders and some overs, two rows, high pressure and low pressure? Or just lots of little ones?

[wobbly]

A PV isnt allowed in the KZ2 class of 125 CIK engines, and the idea of nominating the number of ports is there
so that although its allowable to remove metal ( NOT adding it ) you cannot increase or change the number of ports
from that stated in the homologation papers.
Rod length is open, but is specified as homologated, but then cannot be changed.

[husaberg]

A PV isnt allowed in the KZ2 class of 125 CIK engines, and the idea of nominating the number of ports is there
so that although its allowable to remove metal ( NOT adding it ) you cannot increase or change the number of ports
from that stated in the homologation papers.
Rod length is open, but is specified as homologated, but then cannot be changed.

What class do the Vortex 125 that have these race in?

I have seen KZ1 mentioned as well whats the difference?
Only reason I noticed it was that it seemed to block of the Sub ports.

Added the balance shaft because it had the factors and dimensions

oh I see its KF2
https://en.wikipedia.org/wiki/KF2

[peewee]

hi frits can you offer some help with a few questions. is there a rule of thumb for how far back in the tunell the exit angle should be and how can we apply the rule of thumb for different size or length of tunells ? for example if we're using the rsa tunells and apply that to a larger engine. i found a radius calculator that will make it faster to transfer the radius to paper then i can trace that to something more rigid like a piece of alloy and use that for the template

the other question and maybe you can only give a estimate but if for example the inner radius is 30mm then would i make the outer wall radius just alittle bigger , so the tunell gets just slightly smaller as it goes to the exit ? this appears to be how the rsw is but then again its only a 2D drawing

[husaberg]

hi frits can you offer some help with a few questions. is there a rule of thumb for how far back in the tunell the exit angle should be and how can we apply the rule of thumb for different size or length of tunells ? for example if we're using the rsa tunells and apply that to a larger engine. i found a radius calculator that will make it faster to transfer the radius to paper then i can trace that to something more rigid like a piece of alloy and use that for the template

the other question and maybe you can only give a estimate but if for example the inner radius is 30mm then would i make the outer wall radius just alittle bigger , so the tunell gets just slightly smaller as it goes to the exit ? this appears to be how the rsw is but then again its only a 2D drawing

I am not Frits, but I do recall a 70% nozzle from memory 4t use a similar principle.

[peewee]

what do you meen 70% nozzle ? im gonna look more at the rsw drawing tomorow and try to figure how much larger the outer wall radius is than the inner wall

[husaberg]

what do you meen 70% nozzle ? im gonna look more at the rsw drawing tomorow and try to figure how much larger the outer wall radius is than the inner wall

Look at the bottom of the transfer port and then the entry to the cylinder.

CSA?? Enlighten me Wob; I do not have that much Kiwi.
Anyway, I can guess that you mean the duct entrance at the cylinder base and yes, it is a bit smaller than the duct exit. But the entrance is open all the time and the exit isn't.This is going to be semantics: of course there is flow from the case into the cylinder, but not in one go. A particle, registered at the crankcase entrance, will show up in the cylinder after four to five crankshaft revolutions, as Wobbly implied.

Jan the maestro himself wondered on a forum somewhere ,about something I realised ages ago,the volume that is held sitting in the transfer ducts is that - that ends up in the cylinder. The case simply refills that volume - there is no " flow " as such from the case into the cylinder even when the pipes big diffuser negative pressure ratio, is creating the max bulk flow around BDC.

How do you find out? Label that particle with radioactivity.
On second thought: don't try this at home.

CSA is a term used in 4T port nomenclature to describe the smallest Cross Sectional Area, usually the venturi under the seat.
But in the Aprilia the CSA at the gasket line is well bigger than the actual CSA down further into the duct, that - is smaller than the chordal flow
area of the port.
Yes, the port is always gradually opening, gradually closing, or blocked, never really thought about that in relation to the duct feeding it.
But I have recognised in the past that really well designed cylinders ( like Calvins Cheetah for the RZ/Banshee ) seem to perform much better than
you would expect from the severely crap duct geometry ( small and very little inner wall ) due to the narrow bore centres.
They have a ton of port area, but the duct volume is very small, simply as there is no room and I believe the the small duct entry/exit ratio plays a large part in
allowing the system to work so well.
Same design route taken by Team Roberts in the Rainey era,they dynoed the factory cylinders to death ( and had a Czech CNC flow visualiser ) and the ducts on those
500s had a huge amount of epoxy added.
Their technology showed up later on the 250s that finally gave Yamaha a title with Jaques on board - that TZ was seriously fast at the time.

[peewee]

ok i know what you meen. hopefully frits will chime in about how far back in the tunell the exit angle of the floor and roof needs to be, referencing my picture above