ESE's works engine tuner

[SwePatrick]

earlier in the day it would clean out and run pretty good then I went to a different spot and with same carb settings it loads up bad. turned one of the powerjet in alittle but maybe it needs to go more is the only thing I can think but I don't understand why it wouldn't run nearly the same. when I get it sorted out and running good I want to try nitro 10%. also I have some 2.5"x2.5"x16" chunks of 6061 to make swingarm extensions one of these days

You running methanol?

[TZ350]

when I get it sorted out and running good I want to try nitro 10%.

Yummm Nitro, yum yum.....

[TZ350]

... SSDD ...

Same Shit Different Day

Well all I wanted to do was try and see if the EFI software could see pressure changes in the expansion chamber and if so if I could do something useful with them.

The standard no porting modifications NSR cylinder was making a reliable upper mid twenty's very usable HP.

But I couldn't help myself and got stuck into a spare cylinder with the porting tool and leveled the top of the exhaust port off and ground the PV blades to suit. The extra blow down time area should be good for another couple of hp.

I also made a oval to round nozzle transition like Wobbly describe. I must not understand what Wob means because the new cylinder and nozzle made way less power than the standard cylinder. Disappointing but not a surprise, try something new and some of the horses always seem to bolt and go AWOL for a while to start with. So Nozzle or ported cylinder??? not sure which is the problem but changing out the nozzle was the easiest.

Next night I swapped out the nozzle for the original straight through adapter and ran the bike up on the dyno expecting better things. But no, same shit different day. Now the beast can hardly pull the skin of a rice pudding and fell over at 8,000 rpm, lean as bat shit. I pored in more fuel 20%-50-100% and more, whatever I tried it still dropped dead at 8k or so.

So now I have a list of things to check:- chrome pealed of the bore, massive air leak at the adapter, maybe one of the high speed fuel injectors has dropped dead, EFI software calibration file has become corrupted, that's happened before. Trigger coil playing up, ignition coil/cap breaking down, bad plug. If these problems were real shit this bike would have diarrhea.

Anyway I am no closer to knowing if the EFI software can see changes in the internal pressure of the expansion chamber.

Maybe I will get there tomorrow night......

[jonny quest]

Probably would be wise to put on your original test cylinder

[peewee]

You running methanol?

yes vp M1. do you have some good advise ?

[Grumph]

yes vp M1. do you have some good advise ?

Get yourself a water content testing kit - and use it frequently.

[SwePatrick]

yes vp M1. do you have some good advise ?

Actually yes.

I dynoed mine 211 cc engine this weekend, a drop in peak power from earlier.
But it was expected as i have been aiming for wider powerband.
61.86hp at the wheel and 36.11nm, average power is 41.79hp from 6000rpm to 13000rpm.

However, my first advice is make sure spark is in center of combustionchamber in all axis, XYZ.
Index sparkplug carefully 'opening' towards boost.
Then check your reed petals, i had a brand new v-force3 to test.
16 pulls and the petals were soft as rubber.
Best power and torque however with my heavily modified boyesen radvalve.
0.45mm polini carbonit petals with no additional blades at all, no dampening petals either.
std it's a '4 blade' setup, i´m running two big blades.
Ported a lot and welded it straight(straight shot for the carb into cylinder)

Try to map down where the engine is lean or fat in throttleregister.
Then modify your meteringrod/needle in carb to suit this.
Mine is very very crisp in lower throttleopenings, this doesn´t wet down the crankcase at all(no need to rev it clean).
But i also as is running a Keihin PWM carb, they´ve got a separate idlesystem, i can let it be very lean on idle.
As for now i run '100' jetsize on lowspeed and '245' on highspeed, and my homemade powerjet is fully open, dunno the flowrate on that.
Powerjet is also located from bottom and up a third of carb bore.
This to react early and maybe lean out more at top

There are some more hp lurking in my engine as i´m a bit small on the carb(40.5mm as we speak)


So my main advice is: spend a lot of time get the fuel distribution correct.

Rgds.

[G Jones]

Closer to (my) home, the F350 sidecar class now seems to be flooded with Banshee motors, but, previously, there were Yam V-twin 350s and at least one competitor (John Crick?) had a 350 RGV. Some, or all, of these may have come from George Hardwick (GHR) who has unfortunately now died and his website is gone as well.
NB. I've no involvement or experience with F350 so the above is just based on reading reports in BSN, perhaps Mr Jones may correct me if I've misremembered.

OK - been a bit busy so missed this...
I think "flooded" would be a slight exaggeration - lucky to get 2 or 3 bikes turn up these days - there was one reasonably successful guy running a Banshee motor - which was originally built by a well known UK "tuner" as a hill climb bike at something like 525cc capacity - that was running in our series as a 350...
That bike has now been sold to a guy - I think in Sweden...
As far as I know - the GHR was a V twin TZ with 350 cylinders made by George - the current owner ran it for the 2010 season - far as I know - not been run since - 2010 was the last season we had a credible turn out of 2 strokes in the UK - only place we can get a race is in Europe now - the UK series was modified to try to get more people interested (due to falling grids) - you can now run anything with carbs - so a 350 TZ is not anywhere near....
Just for information - there is another George Hardwick bike that makes an occasional appearance in the uk - that one has a Hon*a twin of around 500cc in it - didn't look that close due to it's heritage - sooner stick rusty needles in my eyes than look closely at a Hon*a...

The Aprilia / Suzuki V twin that John Crick ran for a while - I bought the whole bike / spares - everything...it had a reputation for being fast but "fragile"
After a while of looking it over - the chassis I decided I couldn't work with - too many compromises for my own liking - so I sold it & carried on making my own (now completed)
The engine - no doubt - could have done something with it - but as I'm an old bastard already - didn't really expect to live long enough for it to be worth the effort - and the short stroke seemed to be the exact opposite of where my thinking was leading me....better for me to stick with what I know (TZ350) - we have well proven parts for everything - engine / gearbox / clutch - all readily available - crankcases too from road bike engines....

Gordon Jones had a set of rgv 350 cylinders that got sold to Richard Vanagas in the UK. I know where some TZ/TZR 350 Hummel cylinders/heads are for sale

I had a few people interested in those parts - including you and Richard - in the end I bundled the whole lot up onto a pallet & sent it to a guy in Ireland - far as I know he's in the process of building it into a solo at the moment - sure he'll let me know when it's up and running - last contact I had was when I sent him a few sets of pipes I had kicking around....

Right - back to wasting a load of time making a forced air crankcase cooling duct for the TZ....

[TZ350]

,

Ok got it going, pulled one of the high speed injector plugs off and things improved immediately. Turns out that the excess lean that only got leaner however much I enriched it was because the oxygen left from over rich misfiring made things look real lean to oxygen sensor.

Not as good as hoped but getting close to the same sort of power as the old air cooled motor.



Blue line, unmodified NSR cylinder, Red line, cylinder with the top edge of the exhaust port leveled off for more blowdown time area. Hmmm that didn't work as well as hoped. Found this before, when you create more blowdown time area than required for the engine speed you lose power everywhere and gain little anywhere, it is a real fine line.

Tonights effort was to find out what sort of changes in pressure signal can be seen in the mid section of the expansion chamber.



TPS, Yellow line, RPM Blue line and the Pink line is Map 998.4 to 1126 hPa's as measured at the dwell section of the expansion chamber... a difference of about 0.019 psi. Sure does not seem much.

[G Jones]

Any thoughts on crankshaft mass desirability ?
Reason for asking - I just happened upon some crankshaft pictures - mainly for Italian scooters - seems to be quite a few being sold of what they describe as "Bell Type" - similar to the picture - any other thoughts on any disadvantages - or indeed advantages ?

[Jannem]

My first post here. Great thread and learned already a lot by reading....

Perhaps a somewhat noob question, but how straight you can cut single ex-port opening roof? Aiming in the ballpark of 70% (perhaps little over) port width with rounding in the port to bore edge (approximately 2mm radius). 44mm bore.

Any rule of thumb to go by?

[EssexNick]

I've been wondering about this for some time. Pros: might be more case volume. Maybe better big end lubrication. Cons? Might cause more drag. I'm only guessing here, we need the wise ones.

[TZ350]

... how straight can you cut single ex-port opening roof? Aiming in the ballpark of 70% (perhaps little over) port width with rounding in the port to bore edge (approximately 2mm radius). 44mm bore. Any rule of thumb to go by?

Exhaust Port shape for ring life.

Attachment 314807

The post above links back to pictures originally posted by Frits that talk about port shape. Click on the little blue arrow thing or use "Thread Tools" at the top of this page to view all the images that have been posted on this thread, there are hundreds of them.

[Haufen]

My first post here. Great thread and learned already a lot by reading....

Perhaps a somewhat noob question, but how straight you can cut single ex-port opening roof? Aiming in the ballpark of 70% (perhaps little over) port width with rounding in the port to bore edge (approximately 2mm radius). 44mm bore.

Any rule of thumb to go by?

There is a rule of thumb, or more than one. But if you follow it blindly it might leave you with a damaged engine in the end.

I'd make that a bit dependant on the drilling bits you have available. It is far easier to make a radius of 5mm with a bit that is 10mm in diameter than with one which is 7mm in diameter. Are you sure you need an exhaust port that wide? No time to go step by step (and probably learn much more during the process)?

Other parameters influencing the port shape and max. width are:

• cast iron bore or plated aluminum bore? If the latter: are you going to replate after grinding?
• piston ring pin position (ideal: centerline midle of boost port).
• Piston ring thickness (thin is better) and material (less width for cast rings).

[wobbly]

Full circle cranks are the only way too go.
Only kicker to this is the possible scenario where there is no other option when looking for a big case volume increase.
The porckchop cranks have hideous " windage ".
Use full circle with plenty of alloy inserts to reduce the overall mass ( without affecting the beam strength needed to hold the pin and axle rigidly ) along with
alot of small Mallory inserts opposite the pin to get back the balance factor and increase the inertia.
Look at an Aprilia or a factory special TM KZ to see whats needed.

Re single Ex port width and shape - all depends upon the bore and ring width/depth ratio.
Your usual 54mm and above bore is limited to a max of 72%, below 50mm safe ports have been done at 75%.
Frits drawing tells you all you need to know about the shape, but the more you fill in the bottom corner radi,the less A port short circuiting occurs - way more
important than Ex Port STA.