ESE's works engine tuner

[andreas]

Thank you Wob.
I expected such a reaction from BMB pipe with a perforated part. So decide to cut rear perforated cone with outer cylindrical part and made usual rear cone from 1 mm stainless, with expectation to lose the bottom, but increase the top power.
Results, lower bottom and only just a little better top.
I have another, the same BMB pipe, so this time I will try to make thinner 0.8 mm rear cone see if there will be a difference.

Add dyno with exhaust pipes. BMB is modified, with usual rear cone.

Your modified BMB pipe seems to be shorter than the rs- possibly 30mm? That is causing the power loss, not the thicker metal.

[jfn2]

That darn Wobbly, wouldn't you know he would name the exact plug that I'm using as the worst one of the lot. Right before I go on the dyno. Oh well!
Thanks Wobbly. Does anyone have a part number for the cap?

[katinas]

Sugaya pipe length, from piston skirt to the end of rear cone (connection with tailpipe), about 900 mm
Honda Rs copy about 815- 820 mm ( needed to check again)
Modified BMB about 45 mm shorter than Rs.

Andreas, yes modified BMB pipe is about 45 mm shorter than Honda Rs (mainly at the header) and the engine response is not unexpected. Unexpected was that when BMB length was equalized to Rs (with a 44 mm length header insert), the BMB stopped at 12500 rpm and again with lower power and nearly 1500 rpm less than RS.
This is why I want to try 0,8 mm thick baffle and compare two identical BMB pipes, just one with 1 mm, other with 0,8 mm thick rear cone, without any header inserts.

Jonny, don't know why but at the moment I feel, that untested 2t ideas leave like painful wounds. That's why you always want to finish all the monetary works as soon as possible in order to get back to 2t things. I think most of the members of this great forum feel similar.
I am still thinking that piston ported intake, with staggered side intake windows and some accommodation from inside reed valve directly to A at ex side must be tried. This eliminate big reed cage housing. Simplicity, without any additional moving parts and compactness is still biggest advantage of 2t. If only we weren't limited in time .......

Ngk cap for short plug TRS 1225, Add photos of Honda RSW 250 A kit generator, similar to NSR 500 pre 1992 big bang 292-68

[jfn2]

Thank you Katinas.

[andreas]

Katinas, yes that is strange.

[husaberg]

Add photos of Honda RSW 250 A kit generator, similar to NSR 500 pre 1992 big bang 292-68

Almost a Japanese Krober.

[WilDun]

Two questions :
Has bucket racing resumed since Covid?
Where does Bucket Racing happen in Auckland these days since Mt Wellington was confiscated?

[F5 Dave]

1. yes. In the civilised areas.
And
2. It doesn't.
I posted a while back news article

[WilDun]

1. yes. In the civilised areas.
And
2. It doesn't.
I posted a while back news article

And now a question I had meant to ask previously, but stopped myself asking (in the interest of national unity amongst strokers,) why are there so many Wellingtonians and Cantrabians in this neck of the woods? is it the lack of 2 strokes here? or does something else bring them here?

[crbbt]

with getting the spark plug to protrude further into the chamber,

couldn't the cylinder head be machined down where the spark plug washer meets the head rather than machine the plug itself?
where the rules permit

[wobbly]

Machining the head sealing face to drop the plug into the chamber , as I see it , only does half the job - that is the spark gap is closer to the chamber center , but that gap isnt exposed any more than " stock ".
The R7376 type plugs with the Platinum ground electrode are very " shrouded " by the threaded body end in this respect , so using the longer body and machining off an annular ring does a very good
job of exposing the ionising gap to the surrounding A/F mixture.
But I believe the real issue with dropping in the plug will be that you end up with a bunch of exposed threads , that are not surrounded by the head alloy taking away heat.
This problem was addressed years ago by NGK with their race plugs , they had about 3mm of the threads removed , and i remember seeing a bulletin by them saying the plug body should be intruding
1.5mm into the chamber.
But all this is conjecture , in my case the rules dont allow the body to intrude at all, threaded or not , so I hope the machined body idea is one of the few free lunches I am allowed.

[crbbt]

whoops I thought the machine work was only happening to the bottom side of the should under the spark plug hex

[jfn2]

Has anyone tried this spark plug? NGK 7282-10 2000

[katinas]

Racing plugs for 2t with 14 mm thread, 19 long. Like Wob said, all is far better than, say, semi-racing types, not only because of ground platinum tip, but different ceramic. They are very reliable.

NGK three on the edge of their list (not adjustable gap and all resistor type)
R6205 -platinum/platinum, short ceramic 15 mm, TRS-1225 plug cap, (R6205A-22 mm long) 16 mm hex
R7282 -iridium/platinum ground, short ceramic 15 mm, TRS-1225 plug cap, (R7282A- 22 mm long) 16 mm hex
R7376- iridium/platinum ground, usual long ceramic 38mm, std. plug cap, 21 mm hex (R7436 - 16 mm hex and smaller diameter of long ceramic, for smaller eye plug cap)

Denso all iridium/platinum ground (adjustable gap)
IAE01- short ceramic 15 mm, TRS-1225 plug cap, 16 mm hex
IA01- short ceramic 15 mm, TRS-1225 plug cap (22 mm long) 16 mm hex
IW01- usual long ceramic 38 mm, std. plug cap, 21 mm hex
IW06- usual long ceramic 38 mm, std. plug cap, (plug without resistor) 21 mm hex

Champion (not adjustable gap and without resistor)
N721- platinum/platinum, semi short ceramic - 26 mm long, 21 mm hex

[wobbly]

The 7282 short or long thread is the same as 7376 in its construction , just with a short body and a stupid price for it and the cap.
In testing they performed identically.