i have done floats ,changed plugs
you name it.
i can't get the mixture to get of 11or 12 to one.
i have used 45 through to 80 idles
mains 135mains to 210 airs
180main 220airs
135 main 120 airs
at the moment i have had it idling for about 1/2 hourwith the following set up
45 idles
135mains 200air
and the mixtures are 13 to 1 and it is starting to sound crisp,but from all the info i have read the car should be running lean with this set up.does anyone think the same.
it has taken 1/2 to get the oil temp to 140f is this normal.
please help as i am running out of idea's.
down sharon.
Can't help with the jets (the saying among the bike racing boys was "jet it down and rev it" - but I'm sure that wasn't meant to help anyone)...
As for oil temp. One of my cars has both oil and water temp gauges. Water temp comes up to spec in about 500 metres of driving - but it takes a good 10 km at 60 - 80 kph before the oil gets up to 80C. Same car takes about 10 minutes at idle to get to the same oil temp.
Just a thought from the bike racing days - why not try a "plug chop"? Take it for a run at a constant throttle opening then kill the engine, coast it to a stop in neutral and check the state of a plug. (beware the steering lock trap when you kill the engine)
fuel pressure?
testing 1 2 3...
what fuel should it be,48 ida's
down sharon.
around 4psi from memory? not too sure. What is it running now?
testing 1 2 3...
was at 6 yesterday,now 3.5
down sharon.
plugs are still fat
just ordered another box.
down sharon.
plugs 1mm
plugs .5
btoh still charcoaled
down sharon.
Westi, what heads (valves and ports) and eng size?
Matt
Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
OFF-ROAD,CIRCUIT,DRAG,STREET,ENDURANCE
2386-87
044 44inlet 38 ex
11.1
big ports
down sharon.
557 lift at valve
down sharon.
I set up a 2332 with 9.7 comp and 42 x 38 valves in scat ported 040 heads. we ran this at Warwick and jetting feels great but no a/f meter yet.
37 venturi (40 better for hp)
180 air
f7 emul
155 main
60 idle
CB book start point with 40 venturi
210 air
f7
185 main
60 idle
These combo's will be close for your setup I would expect.
3.5 psi should be perfect and 1/2 hr for temp on workshop floor sounds right.
80 deg C = 176 deg F
Cheers
Matt
Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
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60 idles are fat as hell
i am going for a drive will report what i find.
down sharon.
60 idle shouldn't be obviously too fat. Are the carbs new or proven?
I had a set of new webers where the jet stacks weren't seating properly... any thing is possible.
Sorry to ask, but you are resetting idle mixtures on each jet change, and have you checked float level?
Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
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new carb's
yes ,to the resetting of jets.float levels have been rechecked and are great.
the idle srews are set at 1 to 1 1/2 turns which tells me they are still rich.
there is agood settting ring around the jets
down sharon.
I haven't heaps of expierence on IDA's but more than many, and I would have thought 1-1,1/2 turns with good response is about right. 60 idles seemed too rich with what main/airs combo? As you no doubt know, you change mains or airs, even idle jet and idle mixture circuit feel the change.
Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
OFF-ROAD,CIRCUIT,DRAG,STREET,ENDURANCE
i had a lot of trouble with the idles so i started with the mains
this has helped alot.but it feel weird going to small jets.
but it seems to be working.
i am going to go allitle less on the mains
which will take them down to 130.220air
down sharon.
130/220 does seem a bit light on, maybe its the baby cam? What grind & rocker ratio r u running?
Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
OFF-ROAD,CIRCUIT,DRAG,STREET,ENDURANCE
You also mentioned plug gap. what gap now and what ign system/timing?
Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
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msd,blaster coil and 6al.
gap is 1mm
timming just got changed from 7btdc to 15
it is sounding alittle better
down sharon.
msd recommends between 1 to 1.25mm for the plug gap
down sharon.
cam is 2248 cb
557 at valve
318 duration
276 @ 50'
1.4 rockers
it is starting to sound pretty angry.
but mixtures at idle are good 13.5 to 1
but rich in mid and high.
down sharon.
better off being rich 4 a while
vw54 wrote:better off being rich 4 a while
👍 Yeah what Dave says. Within reason, but as engine frees up you can bring it closer to 14:1.
Cheers mate
Matt
Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
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Just noticed on Pimp'n thread your running f11 emulsions
Have you any f7's to try, with the cb setup 60/185/210?
Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
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i have no where near the experience of Matt and others but two things from my ricer experience: I like to shoot for 12:1 a WOT and i like to set my timing on bugs at full advance rather than base line. That is to say I shoot for 28~32deg full advance and let idle fall wherever as I've always had issues getting 009's running sweet. Anyway possibly all crap but still keen to see so video of the bug.
Stephen
555bug wrote:i have no where near the experience of Matt and others but two things from my ricer experience: I like to shoot for 12:1 a WOT and i like to set my timing on bugs at full advance rather than base line. That is to say I shoot for 28~32deg full advance and let idle fall wherever as I've always had issues getting 009's running sweet. Anyway possibly all crap but still keen to see so video of the bug.
Stephen
i'll second the motion for total advance............should be going advanced by the 1500rpm mark..........?
The F11 is the odd man out, but....
I have heard some guys prefer this for smoother drivability but will throw out most 'rules of thumb', but.....
"10:1 to 11:1 idling mixture strength with allowance for partial condensation of fuel and less efficient distrobution."
"12:1 Rich mixture giving maximum power"
Remember also that the sensor in you exhaust is an OXYGEN sensor.
It converts the exhaust oxygen content to a voltage, which tells you a ball-park equivalent a/f ratio.
Don't depend on it entirely.
If you can't find F7s find some F2s.
Then take it for a drive.
Provided you carbs are synched,
try an idle jet that has no flat spots(especially when warm), and then using the 4 x veturi 'rule of thumb',
adjust the air corrector till the engine doen not nose over up high.
All the while use your a/f ratio as a reference tool, not a bible.
And remember the mixture reading is only a calculation based on the voltage .
Until you make some HP and load, the heat will remain low, especially with larger duration cams.
westi wrote:That's mad Alan.
cheer's dave ,
i will try the f7's
down sharon.
