ESE's works engine tuner

[senso]

Thanks for that image Frits, I had already spent a lot of time in search of it(or a similar one), I will print a template in paper and also follow what Wobbly said, and I will only grind it above the transfers.
In fact, the first time I touched the cylinder it was almost straight, but after the cylinder stood alive for 1.5 years, I decided to put a new ring on, I hogged the intake to try CR80 reed cage(saddly its the 2 reeds version) and I carefully measured how much the casting had from the exhaust duct to the cylinder top(its around 22.2 mm in that one), then allowed 2mm of wall thickness and went mad, the idea was just to see how much time it would live, it still went through 60-70l of gas before the frame gave up, but the piston never seized.

So now I want to squeeze the little crm engine a bit more, and I'm loving all the ideas that have sprung, so next weekend I will talk with my machinist to shave 2mm off the top of the cylinder so I can it the magical 190º exhaust timing.

Wobbly, about the exhaust area, yes, its without the angle of the duct, after all those factor counted, it seems really small..
Regarding the metal spraying, can it be done after final machining(I assume not, so I can't do it in this cylinder)?

And again, thanks to all of you.

[TZ350]

Start of the mighty Team ESE super RG50 project. Sketchy made this head insert for us to try, maybe we could have done it on the lathe but we wanted at least three the same with a variety of insert profiles. In the end CNC is the only way to get repeat ability and like Flettner, Sketchy makes a really good job too.

The drawings were done by Kel and are a copy of the Aprilia bath tub head, Kel has also drawn a RG50 head insert based on Wobs toroidal design. There will also be a 14mm and 10mm plug version so we can do a back to back test to see what plug size is best.

If anyone wants to try a head insert for their own RG50 then they are welcome to have Sketchy run one off using our drawings.

[F5 Dave]

Very nice, those RG heads warp if you remove too much from them. Mine ended up being a slab of metal, but that would be great for testing. Anyhoo that engine is on the shelf for the time being.

[jonny quest]

Running a domed piston? You should try the Yamaha hybrid flst top with chamfered edges. Yz125 style. I'd guess .5hp gain over domed.

[Frits Overmars]

One thing I would add re port widening is that it is a mistake to go directly to the straight sides ( even as shown in Frits drawing). In the vast majority of cases the best way forward is to simply widen to the max above the transfers, leaving the bottom of the port completely stock.There is no gain at all making the port wider below the transfers and alot to gain by reducing the duct volume, and helping to prevent direct short circuiting from the A port front edge.
If you are going all out,then raising the floor to get it several mm above BDC and increasing the bottom corner rads does both - reduces the volume and the short circuiting.

You're quite right Wob. I drew the top and bottom shapes identical to keep things simple but in reality the shapes should look more like the ports below.
(I know it's still not a perfect drawing, but hey, what can you do with MS-Paint).

[peewee]

Not sure what rods you're using but alloy "braizing" rods have been around for a while and I used to use oxy acetylene quite successfully.

If you're managing with MAP gas but are a bit short of grunt then track down a half a dozen refractory bricks and build a little wall, (and roof?) around the work-piece leaving just the weld area exposed.

Just be careful of getting it too hot, may even be a good idea to track down some thermo-crayons or similar from your local welding supplier.

i stand corrected. was reading the hts website and it says oxy acetalyne will work fine. im assuming most of the low temp rods dont use any type of flux but i seen some that was self fluxing or is all the low temp rod self fluxing ? http://www.ebay.com/itm/Hobart-Low-T...3D261754892020

ordered a bunch more of the hts stuff today as i had ran out yesterday.

[TZ350]

My two year old crm 50 cylinder retired after running for 30 minutes with no cooling and still managing not to seize.

That is very interesting, virtually air cooled. I am trying to convert a water cooled cylinder to air cooling and would like to know more about the circumstances around how yours was being run, was it being thrashed? was there any water left at all or was it dry? I would love to know more.

[TZ350]

Running a domed piston? You should try the Yamaha hybrid flat top with chamfered edges. Yz125 style. I'd guess .5hp gain over domed.

Yes domed piston, a piston with champhered edges would definitely be worth a try. Do you know how the head is shaped? does it match the champhered edge of the piston?

[TZ350]

The EFI lesson I learnt last month was, that to get the greatest range of tune ability I needed to use the smallest injectors possible that will still do the job. I know, pretty obvious, but there you go.



I read the Ecotrons EFI manual and saw that the map must have as many even steps as possible and I thought that meant dividing the rpm range up as evenly as possible, seemed logical, but wrong again.

The bike bucked around swapping between the staged injectors as the EFI struggled to jump from one cell to another on the steeper parts of the fueling curve.

I guess what they really meant was that the changes between cells need to be as even as possible.

So I don't need even spacing between the rpm break points and can have big or small gaps between them so long as there are no big steps between adjacent cells.

That means I can straight line it between say idle and where the fuel demand just starts picking up around 7,000 rpm. And once again use a straight line after peak torque where the fuel demand is relatively steady again.

The straight line does not have to be horizontal, it can tip up or down, its just a line between two points on the map that may be several thousand rpm apart but covers an area of relatively similar fuel demand.

By straight lining where I can, I now have spare rpm break points to use to smooth out the map where the fuel demand is rapidly increasing with increasing torque.



From left to right on the model, the first cell covers 4,500 rpm the next 1,500 rpm and the next only 250 rpm but the steps between the cells are relatively the same, ie a smoother map. Anyway I hope this is what they meant.



I can now throttle on/off pretty well and do a series of part throttle runs, the last one is at 30% TPS, it looks a bit lean.

15-02-10 I Mod 24 RAM_MAP_LdTp_Tps_N.xls

Its not perfect but is running a lot better, so for what its worth here is the current Alpha-N map.

[kel]

a piston with champhered edges would definitely be worth a try. Do you know how the head is shaped? does it match the champhered edge of the piston?

Something like this http://www.pit-lane.biz/t118p20-gp12...tiques-ktm-frr

Can anyone tell me what the acceptable minimum distance would be from spark plug to piston crown at top dead centre for a 50cc cylinder with 41mm bore?

[wobbly]

I tested all this to death ( of pistons ) at BSL and the best power was had from a piston that had an angled squish ( at 7* ) then a flat top.
On the 59.6mm piston the squish was at 50% ie 8mm wide and this was how wide the angled area was on the piston.
The toroid chamber always made better power and was much more deto resistant than the domed pistons once I established that the optimum
distance from the tip of the fine wire earth electrode to the piston flat was 5.5mm.
This put the tip dead in line with the highly turbulent end gases exiting the squish band.
The idea of the angled edge came from the factory YZR 500 as this is what they used at the time, and was developed when they got themselves a Czech CNC anemometric flow test machine.
I just extended the idea to having the flat angled piston area the same width as the squish width.
And the piston and the chamber were then ceramic coated inside of the squish area only.
The angle on the piston edge would determine the distance of the plug tip from the flat piston would vary with the bore and plug chosen.
The idea works exactly the same as having a domed piston with a flat roofed bathtub ( ie as Jans Aprilia ) but better again.
So now ESE are making CNC inserts there is NO reason not to use the 7376 type 3/4", proper race, fine wire plugs from NGK.
VHM have started making flat top pistons with a radiused edge that make better power than the domed variations - but I dont know how clever they really are in that a domed piston with a radiused edge
may also do exactly the same thing.
BUT - I know for sure that a flat top WILL NOT make more power without a toroid.

PS - I discovered a bit later that the Pulse ( ie last version Swiss Auto ) used A kit RS125 pistons that had the domes machined flat,leaving the squish radiused, so that ended up as effectively the same thng.
But sadly they hadnt used a real toroid so lost alot of the big power advantage to be had with that scenario.

[adegnes]

Something like this http://www.pit-lane.biz/t118p20-gp12...tiques-ktm-frr

Can anyone tell me what the acceptable minimum distance would be from spark plug to piston crown at top dead centre for a 50cc cylinder with 41mm bore?

Me to. What is too close?

[Ocean1]

i stand corrected. was reading the hts website and it says oxy acetalyne will work fine. im assuming most of the low temp rods dont use any type of flux but i seen some that was self fluxing or is all the low temp rod self fluxing ? http://www.ebay.com/itm/Hobart-Low-T...3D261754892020

ordered a bunch more of the hts stuff today as i had ran out yesterday.

I don't recognise those, but that's hardly surprising, it's been a while.

It's worth getting a local supplier involved for some free expert advice in which rods to use for your particular application. You can get flux powders but flux coated rods have the advantage of a using a flux optimised for the application of that particular rod.

Probably the most common cause of local failure is inclusions in the original casting. Particularly sand cast stuff, a single grain can make a mess over a surprisingly large area. Take some time to inspect the cleaned weld area for wee craters and excavate them out.

Luck.

[F5 Dave]

The EFI lesson I learnt last month was, that to get the greatest range of tune ability I needed to use the smallest injectors possible that will still do the job. I know, pretty obvious, but there you go.



I read the Ecotrons EFI manual and saw that the map must have as many even steps as possible and I thought that meant dividing the rpm range up as evenly as possible, seemed logical, but wrong again.

The bike bucked around swapping between the staged injectors as the EFI struggled to jump from one cell to another on the steeper parts of the fueling curve.

I guess what they really meant was that the changes between cells need to be as even as possible.

So I don't need even spacing between the rpm break points and can have big or small gaps between them so long as there are no big steps between adjacent cells.

That means I can straight line it between say idle and where the fuel demand just starts picking up around 7,000 rpm. And once again use a straight line after peak
From left to right on the model, the first cell covers 4,500 rpm the next 1,500 rpm and the next only 250 rpm but the steps between the cells are relatively the same, ie a smoother map. Anyway I hope this is what they meant.

I can now throttle on/off pretty well and do a series of part throttle runs, the last one is at 30% TPS

Its not perfect but is running a lot better, so for what its worth here is the current Alpha-N map.

Yeah yeah all very well. But what if you put some BIGGER injectors in there. Surely that must be better

[speedpro]

Yeah yeah all very well. But what if you put some BIGGER injectors in there. Surely that must be better

Yeah, because putting in bigger main jets always makes more power, eh?