ESE's works engine tuner

[Kickaha]

Below the Swissauto and sometimes BRM later the ROC later on known as the pulse?
If you look at the bottom of the 3rd page at the lower of the 3 pictures. You will be able to see what Wob and I were talking about with mikes (RGV100) crankcase mods being reminiscent of the Swissauto.
Note the Weight 36kg with airbox and carbs and oil.

Ta for that, always wondered how it was positioned in the sidecar

The sidecar I passenger on would have originally had one of them lovely two stroke thingys in it although more likely Krauser/ADM

[Kickaha]

Couldn't find a Swissauto but here's the Krauser

[Buckets4Me]

E.S.E Factory rider takes a spill (need to stop her racing in the lesser classes)

"
Avalon Biddle
Not racing today after bike seized in practise yesterday and flicked me off so didnt go out in qualifying. Sorry guys "

[TZ350]

A seizure, that's bad luck Av, after all your effort to get there.

[TZ350]

.
I have been doing a bit of dyno work with Bucket to find out what inlet layout is the best for our Suzuki GP125 engine and 24mm carb.

We know that on a 4-stroke the best inlet shape starts larger and tapers down increasing the gas velocity to a maximum just before the valve.



The question is, what is the best shape for a 2 smoker?

Should the 2-stroke inlet taper down like the 4-stroke, go straight or diverge at 1 deg or maybe 14-15 degrees.



Whats best, stay the same 24mm carb to 24 at the rotary valve which is pretty much the standard Suzuki GP125 setup.



Or taper out from the 24mm carb to something bigger at the rotary valve, and should it diverge by 1 deg or much more.



Or very little taper, going quickly from 24mm carb out to the 32mm inlet and then finishing as 34mm at the rotary valve.

If the carb rules were open this probably wouldn't be much of a problem but being restricted by our racing class rules to a 24mm carb, and for our BMEP/RPM target the simulation software specifies a 36mm carb equivilent port size at the rotary valve. So the shape of the inlet tract has become an issue and we have been putting in some dyno time to find out what works best for us.

Also Bucket has come up with an imaginative way of having a variable crankcase volume (CCR) and inlet tract.

[husaberg]

.
I have been doing a bit of dyno work with Bucket to find out what inlet layout is the best for our Suzuki GP125 engine and 24mm carb.

We know that on a 4-stroke the best inlet shape starts larger and tapers down increasing the gas velocity to a maximum just before the valve.

I have no idea about the ports,
but what does strike me as being interesting is that compared to the aprillia/Rotax disk valve 125 pic I posted a while back.
Your crank wheels would seem to to be more in the way of the incoming charge.
I will post the pic for comparison.
Of course this could be because the pic is an old one before you machined them to a smaller diameter? Just a thought.

I bet the Aprilia is a much larger diameter disk valve.
So it is open wider for greater percentage of the time/area than comparable timing would have a smaller disk.If that makes sense.


Also with your valve covers can these be shortened to use with the pumper carb.
Even if it ends up being (the Pumper carb) bolted direct to the cover on an angle if necessary to avoid the spline just a thought I suppose the primary gear and the clutch cover is in the way. Shame its on that side.Is there any way to modify it to shorten it more?

Found this on the Web I wonder what happens when they get fuel soaked.

http://www.bsagoldstar.co.uk/about/about.htm

Phil's first motorcycle was a BSA Bantam Major which was soon replaced with a 250cc Ariel Arrow Super Sports. Phil tuned this by putting balsa wood in the balance holes of the flywheels to increase crankcase compression.

Innovative idea mustn't have had any Cork?paint them i guess?

[TZ350]

..... but what strikes me as being interesting is that compared to the aprillia/Rotax disk valve 125 pic I posted a while back. Your crank wheels would seem to to be more in the way of the incoming charge. I will post the pic for comparison. Of course this could be because the pic is an old one before you machined them to a smaller diameter?

I would be interested in seeing the photo for comparison. A std the Suzuki is flat faced, I had the inlet face machined back at 45 deg and built the floor of the inlet port up with Devcon. It is an old photo. Later the balance holes were plugged and the wheels were reduced 2mm overall to increase the case clearance.

The plugs reduced the BF below 50% so I had to get a bit aggressive with the drill press to get back to the 50-55% range that seems to suit my bike.

[TZ350]

The system Bucket and I tried for pumping the fuel that would pool at the bottom of the plenum back to the tank. The plexi glass was something I think Kick suggested so we could see what was happening inside. We were also going to try a straight shot from the side but then things were getting far to wide.

[F5 Dave]

But it didn't work did it? that pump won't be self priming & as soon as you suck air, which you will regularly, it will stop working.

but I can't think if a clever way to do it, unless you just had a low level drain tank with a one way valve.

[TZ350]

but I can't think if a clever way to do it, unless you just had a low level drain tank with a one way valve.

Tried the low level drain tank idea but there was too much fuel.

But it didn't work did it? that pump won't be self priming & as soon as you suck air, which you will regularly, it will stop working.

No No worked very well as a scavenge pump, its a case pulse pumper and re-primed itself easily, like cart pumper carbs will, as long as the diaphragm flapper valves are wet with oil/fuel .......

The FZR 3LN tank has a handy tank air breather on the bottom that I was able to plug onto, the breather exits above fuel level inside the tank. But like you say, it sucked a lot of air, enough to pump the tank up, even with a 3mm breather hole drilled through the filler cap. You could see the tank expand. It also frothed the fuel going back into the tank.

Also the fuel frothing in the tank probably wasn't helped by a bad crank vibration problem I had at the time. The vibration was OK at 10-11 where I was making power before, but became severely crap at 13, but with the crank re balanced to a 52% BF the vibration at 13 is much better now.

As the scavenged fuel had a very high percentage of oil in it, I started to wonder how much oil was actually going to the engine. Although I had touched 30rwhp I was starting to feel very uncomfortable sitting on a bike that was jumping around at 13,000 rpm like a demented jack rabbit, spilling fuel out of the filler cap, wetting me, the bike, hot exhaust and dyno.

If I go there again I will try a sump like you suggest with a much smaller pump, like something fashioned from a small weed eater carb. Or use the tank pressure from this one for feeding the kart carb. Husaberg has talked before about pressurizing the tank to get good fuel flow through the Tillotson carb.

[F5 Dave]

well I stand corrected about the pump. Would have thought that little thing would have not been able to get the fuel up that head.

It appears you were right & I was, perhaps a little less right than you were.

But the 'take home message' from this was that I was right.

Glad we cleared that up.

[TZ350]

Yes the pumps ability took me by surprise too and yes your right about the other thing also ... ...

[Gigglebutton]

the diaphragm flapper valves are wet with oil
I started to wonder how much oil was actually going in Although I had touched 30 I was starting to feel very uncomfortable sitting on that jumping around at 13,000 rpm like a demented jack rabbit

A bit homo erotic for a public forum guys

[husaberg]

Your welcome to nominate a dyno of your choice and have a friend come along with a video camera ... and of course you get to cover the dyno time, same rule for all .......

I know Dave loves boost bottles.

Pah! What a load of bollocks (no offense I mean the bolt on goodies merchants website). I love these descriptions of what is supposed to be happening & how it will cure the common cold etc.

Yamaha made these famous in the 80s on their MX bikes. But there is a reason you don't see them on modern high performance bikes. (well infact the RG150 has one, but in the form of a long rubber tube). They are really only useful as a plaster for a badly designed (or rather mismatched) pipe. TSR software will tell you how to design one for the area you are trying to affect.

So this is partially for him.
Could this be a place for one. It could even be of varying volume? possibly.
This could be accomplished with a diaphragm. Much like a pressure vessel on a Water pump you could even plumb it with a butterfly valve.
Could this be a create an effective Plenum chamber? Down steam from the carb.
Also a variable factor to crankcase volume? Musing aloud here. A lot of could's and Ifs but..............

. Husaberg has talked before about pressurizing the tank to get good fuel flow through the Tillotson carb.

Only regurgitating Jennings? I think? Was that the Bridgestone 350 with mcCulloch carbs stuff? No original ideas from me sorry.

[wobbly]

I have tested "boost bottles" between the carb and the reed.
They improve throttle response very low down in the revs off the pipe.
A couple of older quads used the idea, and one will hardly run at all off the bottom end if the bottle is removed.
But compared to a ATAC on the header they are virtually useless for improving power at the bottom of the useable band.
Whereas the wave/pressure action in the pipe is so much stronger that a flapper valve controlled chamber on the BSL500 gave 28% more power at around 7000 - was closed by 8000 and had virtually no effect at that rpm and up.