ESE's works engine tuner

[peewee]

Here are a couple more pictures to go with yours. They're Aprilia RSA, but you would know that, wouldn't you Peewee?

yes. i cant think of any better engine to copy

[lodgernz]

You are right, it was a mix-up of old and new versions. Thanks for pointing it out. Here is the correct version.

Cool, thanks Frits. Had me worried there for a minute...

[Haufen]

You are right, it was a mix-up of old and new versions. Thanks for pointing it out. Here is the correct version.
Attachment 339970

thanks. What led to these changes?

[yatasaki]

For aux exhaust ports being few degrees lower from main benefits power curve, but what if we have to use much lower angles, say 160-175°, is it better to open all ports at the same time to have all possible blowdown or few degrees after would benefit power, same as for larger openings?

This is exhaust ports arrangement for my endurance moped, aux are four degrees late, floor is 4 mm above transfers bottomline, as cylinder casting was like that.
Because dyno is impossible to reach around here I'm using straight road ,marked with two points, gps, mychron with plug temp and always same chain ratio. So small changes leading to bigger result is almost impossible to notice.
Hope not interrupting some serious talk here cause You guys are more R&D department...me.. trying to build competitive bike from semi-product but not giving up

[TZ350]

Because dyno is impossible to reach around here I'm using straight road ,marked with two points, gps, mychron with plug temp and always same chain ratio. So small changes leading to bigger result is almost impossible to notice. Hope not interrupting some serious talk here cause You guys are more R&D department...me.. trying to build competitive bike from semi-product but not giving up

I am impressed by your work, and the way you are trying to solve the problems of developing your bike, you fit right in here......

[Frits Overmars]

Some results from testing with direct intake from carb to transfers windows ( via crankcase )on Honda NS cylinder.

No problems with big end lubrication Katinas?

For aux exhaust ports being few degrees lower from main benefits power curve, but what if we have to use much lower angles, say 160-175°, is it better to open all ports at the same time to have all possible blowdown or few degrees after would benefit power, same as for larger openings?

I would think that all exhaust ports should have a minimum of 190° timing. So if your main exhaust port has 190° timing, the auxiliary ports should also have those 190°.

This is exhaust ports arrangement for my endurance moped, aux are four degrees late, floor is 4 mm above transfers bottomline, as cylinder casting was like that.

4 mm has no meaning to me without knowing at least your engine's stroke.

Hope not interrupting some serious talk here cause You guys are more R&D department...me.. trying to build competitive bike from semi-product but not giving up

I completely agree with TZ350. You fit right in.
I just wasted a couple of hours trying to keep up with all the rubbish that is written in a Facebook group called "2 Stroke research & development".
After that, it's a delight turning to Kiwibiker and meeting with some sense.
I wonder: would Einstein have had some Facebook-experience?

[yatasaki]

Feeling already warmer, thanks TZ and Frits..
Regarding exh duration...our mopeds (for serial class)are restricted to 16.5ish mm carb diameter, (widened dellorto SHA, Bing ) alltogether intake length 65-70 mm, mopeds are mostly 60 +/-2 cc, stroke 43. Anyone appears with duration more than 175° will use his clutch untill burn and will finish last. (Maybe gear ratios posted on previous page would explain situation further for rev drop) For open class you are allowed any diameter and any type of carb so exh duration are 180-194° BUT expenses between these two classes are at least trippled...
When asked "what are yours timings" nobody used to believe me.

[husaberg]

thank you sir. without any cutting or welding I believe these cylinders do a bit over 100hp on methanol, that's what ive heard any way. but I think I can do better than that. if nothing else, atleast Ill gain more welding and fabrication experience for later down the road on other projects . theres a few more things I wanted to do , like raise the exh floor since its so low but that would add a fair bit more time so I decided against it. transfers have very little up angle going into the cyl so ill likely put epoxy in there. ill keep updating as I go, will have five more days off work next week and should be able to make quit a bit more progress

I was meant to post this ages ago i think i described the construction only at the time.
Notice the oval to round transition
This is one piece but would be pretty easy to fabricate out of a thick wall pipe and flange. Pipe turned down on outside afterwards.

4 spring holes
3 turtle doves
two locating dowels
and two o-rings for belts and braces safety.

[andreas]

To find what you want, try the Google "site:" search option.



Also take a look at pages 1,500 and 2,000.

Thank you TZ. Was too busy reading on pit- lane and that dreaded fb site haha, will be searching for that gold now.

[andreas]

https://www.goodfood.com.au/good-living/entertaining/dinner-party-ideas-what-do-chefs-cook-when-they-have-friends-over-for-dinner-20170220-gugulj



Attachment 339887

This thread is like a good show and tell dinner party where people put something on the table to share, ideas, talk, and laughter with friends.

Enjoying whats on the table is good and sharing makes it better.

Andreas please tell us something about your project.

I very much agree. Say I'm backyard tuner, its a rd 125 converted to 175, 130/ 198 three port, yz 125 reeds, vm 38. I'm trying to get a good 'grip' on the pipe functions, this one I have is kind of based on Blair, This far I get good tourqe but it's reluctant to rev. Happy holidays. Pipe litterary welded on the parking lot.

[wobbly]

You are right again Frits, I have given up even going onto " 2 stroke R&D " site - as I told them im not interested in a dick measuring discussion
that seems to be the general tone of those self made men praising their makers.

[OopsClunkThud]

Question about transfer port profiles.

Having gathered that a constant radius and a tapering port area are desirable I've been working with two offset circles to define a shape that meets this. So far I've been sizing the rest of it to give the desired entrance to exit area ratio. But depending on the length of the port this can result in a wide range in the taper.

So, is there an ideal taper that should drive the design? Or is the area ratio more important? Or is it a balance where both are important? Or does the smaller radius needs more taper to keep the flow attached?

To illustrate the point I've drawn two "ports" with the same area ratio but vastly different taper.

[F5 Dave]

I very much agree. Say I'm backyard tuner, its a rd 125 converted to 175, 130/ 198 three port, yz 125 reeds, vm 38. I'm trying to get a good 'grip' on the pipe functions, this one I have is kind of based on Blair, This far I get good tourqe but it's reluctant to rev. Happy holidays. Pipe litterary welded on the parking lot.

Seems like a chunk of money but an ignitech can remove large swathes of ignition restrictions in a single move. Not sure local setup but there's a German shop bikeside that sell on ebay, I bought several CR250 ones when Wob couldn't get any at the time. They are all the same (DCCDI)P2 in that kit, but do check they are.
Hmm, looks like single but should be fine anyway

https://www.ebay.com/itm/IGNITECH-pr...cAAOSwbdpWWzV4


That header pipe looks a billion miles long.

[andreas]

Seems like a chunk of money but an ignitech can remove large swathes of ignition restrictions in a single move. Not sure local setup but there's a German shop bikeside that sell on ebay, I bought several CR250 ones when Wob couldn't get any at the time. They are all the same (DCCDI)P2 in that kit, but do check they are.
Hmm, looks like single but should be fine anyway

https://www.ebay.com/itm/IGNITECH-pr...cAAOSwbdpWWzV4


That header pipe looks a billion miles long.

Thanks Dave, I do consider a modern ignition, gonna look in the link. And yes it's rather long, it was intended for recreational use primarily and is shorter now.

[teriks]

I just wasted a couple of hours trying to keep up with all the rubbish that is written in a Facebook group called "2 Stroke research & development".
After that, it's a delight turning to Kiwibiker and meeting with some sense.
I Wonder: would Einstein have had some Facebook-experience?

I think I know which thread inspired that quote, amazing...