So carb and injectors? Hedging your bets?
Don't you look at my accountant.
He's the only one I've got.
Great work TeeZee, but what is with the carb and fuel injectors? .....![]()
You can easily see if the open/close settings are correct as the servo is cycled up/down the instant you apply power.
Its way easy to set/adjust the servo if you disconnect the two power wires ( I use a separate plug ) leaving only the
3 wires from the feedback pot.
Then you wind the servo back and forth with grips on the pulley to establish the full up,full down mV positions, then program the numbers.
The trick on the dyno is to do 3 runs, full up,full down, and with the PV at 1/2 height in the cylinder ( NOT 1/2 way on the graph ).
This will show you when to start opening, when to be full open,and what rpm/mV to be at 1/2 height for best power everywhere.
Ive got a thing thats unique and new.To prove it I'll have the last laugh on you.Cause instead of one head I got two.And you know two heads are better than one.
Thanks Wob for the tips on setting up the PV.
F5 and Bucket, the dual carb EFI thing. The carb is so I can actually get to ride this thing and the EFI is so I can continue developing the fuel injection system. Its simple to swap, its as simple as turning the EFI fuel pump off and opening the fuel tap to the carburettor.
Also I want to do some back to back comparisons, 24mm carb vis 30 and EFI vis carb.
Dark Art, yes you are right 3,000mV not 300 like I originally posted. The servo's sensor range is 0-5Volt so 3Volts or 3000mV like you said.
Back to head scratching.
I don't understand why peak power is at 2500-3000rpm less than in the sim?
Saw close to 1200F/650C EGT when dynoing this time.
Should get the waves moving in the pipe.
Maybe it's the low exhaust timing/limited blowdown keeping it back? Engmod doesn't think so.
Meassured pipe wall temp in the belly, max 170C, should be more right?
Carb is still spewing fuel, but responds to jetting so it can't be that bad. Going much richer/leaner on the main = less power.
I've discovered a small pinhole in my header at the flange and one in the belly. Black oily goo is seeping out of both after a few runs. Normal? Is it dumping lots of unburnt mixture into the pipe, but then how can egt be ok?
Double checked ignition timing again, ok.
It will happily rev past 17k on the stand.
Perplexed.
Yep, 186°. My plan was to establish a baseline with minimal modification to the cylinder(just enough to make it work ok with my current pipe). Guess that's been done now, and I can raise it to a more sensible number like 195ish.
High revs, from around 11k. Closing at 87° now.
Good idea!
Your maximum power rpm is 12500 according to the dyno (and 15000 in the sim) so you can't call 11000 rpm high revs. An engine that is supposed to produce maximum power at 15000 rpm, is just waking up at 11000 rpm.
Disc closure at 87° aTDC is rather late so your carb spewing is probably blow-back rather than bounce-back, unless you have a very long inlet tract or a very small carb diameter.
You're right, and it is just waking up at 11000 both in the sim and real life, the only problem is in real life it's getting awfully tired at 13000,and goes back to sleep at 15000.
The spewing is out of the overflow(there's significant blow-back at lower rpm too) and I'm back to blaming vibration(even though it doesn't feel that severe). Both float and needle/seat are in good condition, and I've tried different float heights and made shure it doesn't hang up on the overflow tube(common pwk issue).
My whole inlet tract is 112mm if I remember correctly, and the carb venturi is 24mm.
There are currently 18 users browsing this thread. (0 members and 18 guests)
Bookmarks