ESE's works engine tuner

[wobbly]

The VHM pistons have a radius like the orange corner.
But in answer to the squish questions, the head should follow the piston shape ie dead flat with no taper except a tiny divergence of just 0.1mm.
As I discovered with a flat top the piston will hit the squish inner edge first if running real close to clipping at peak rpm.
And as i have already said several times, in my testing a flat top is completely useless without a toroidal chamber.

[seattle smitty]

What a great site! Four separate discussion topics running concurrently, jumping from one to another, all interesting.

[TZ350]

What a great site! Four separate discussion topics running concurrently, jumping from one to another, all interesting.

Yep, just like a large house party with interesting people.



The EFI is going better than ever but the evening ended in a woopsie .....



I was able to do several really good all gear runs with the bike coming back onto the throttle very nicely.

But my dreams of being the first persion to run an EFI 2T in a real F4 race on Sunday vanished when I felt the familiar overrun death shudder,



Getting pretty hot, interesting stain at the top of the combustion chamber where it looks like the transfer streams sweep up into the head.



Very dry in the bore and scratches that look like evidence of the ring ends butting up from over heating and the ring scraping the bore clean. Know more tomorrow when I get the cylinder off. It will be interesting to see how much oil there is in the crank case.

[adegnes]

Another subject for the party-people...

I've ordered one of these for testing:

CE-i 100 with sensor SE-1

http://www.power-spark.de
Manual here http://www.power-spark.de/downloads/...ngl_2011_1.pdf

Seems like a good unit, has it's limitations, but for my use (variated engine) it should suffice.

Some features and limitations:

- 4 programmable ignition maps (and 10 preprogrammed maps - non of them seemed very useful, maybe for small rc engines)

- no computer needed, programming is done with a magnet(!), seems slow and weird but hey, no computer needed.

- Four adjustable rpm-points only (actually just three, the first point has to be 0rpm), this is very limiting for most, but for my variated setup it's ok.

- Easy setup; there's a "sensing mode" where it notifies you when it senses the magnet - just lock the crank at 75° btdc (what the manual say's it should be) and rotate the flywheel until the magnet is sensed - tighten up, done. If you manage to fuck up, you can adjust the 75° to something else, but anything under 75 limits how much advance you can run at high revs. (they give an example; if you set it to 70° btdc you can "only" run 35° advance @ 26500rpm, yeah thats gonna be a problem.)

++

I also asked Ignitech what they would charge for a dccdip modified to be used with an hall sensor - same price as the regular unit. So if this Power-spark is no good, I'll just get the tried and true Ignitech, and reuse the hall sensor pickup.

I'll post a small review when I get it up and running, if anyones interested.

[TZ350]

Interesting Ignition, I would like to know how it goes when it is up and running.

[peewee]

And as i have already said several times, in my testing a flat top is completely useless without a toroidal chamber.

that was my plan. do you have any guess what the radius should be ? while im thinking of it do you have a guess where to start with comp ratio ? 50% band should be good for starters eh ?

[peewee]

im gonna give this a shot and see if i can fill up the kicker and roof alittle. if its sucessful it will be permanent and impervious to any fuel because i want to use methanol. if it doesnt work ill weld the door back on and use epoxy

[TZ350]

im gonna give this a shot

I like your style.... very Bucketish.....

[adegnes]

I like your style.... very Bucketish.....

+1
.....
.....
....

[seattle smitty]

Ditto that! Peewee, are you using the low-temp rod for all of these operations? What specifically is this rod, what is the working temperature, what pre-heat do you use? I was skeptical of the idea of using a low-temp rod when you first brought it up, just because I have seen erratic results with some (more than one brand) of that stuff myself, but you could make me a believer if this holds up. I'm even more skeptical of using epoxy fillers inside an engine (esp. one that runs real racing fuel rather than parts-cleaner) but again, people are making it work, amazing.

FWIW (repeat repeat), you should be able to buy pre-fluxed (external) aluminum gas-welding rod at a welding supply house. You couldn't use it to re-contour ports, but it's stronger than the low-temp stuff and has its uses (building tanks?) once you learn to gas-weld aluminum, if you aren't TIG-equipped. The old-timers had to flux-coat their own rod, a dull chore, and I was delighted to discover the pre-fluxed rod.

[peewee]

Ya lowtemp rod. Melts around 730f or so according to the packaging. So far im liking it

Hts2000, durafix, alumalloy. I think theyre all pretty similar or maybe the same. I been getting it from ebay. Used the bbq for preheat

[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?

Is 1.4mm from piston top to ground electrode enough?

Bump

Should I switch to surface gap plugs?

[TZ350]

Bit of quick work with a file and a light hone and everything is all good, even re used the piston ring, 2T's are so easy to work on



Dyno runs from from 100 to 20%, looks OK so hopefully back on for Sunday.

[adegnes]

Bit of quick work with a file and light hone and everything is all good, even re used the piston ring, 2T's are so easy to work on



Hopefully back on for Sunday.

Always nice when it works out like that!

[Tim Ey]

Is your squishband included in the copper gasket? It looks that way...