1984 n/a with 13b 6port swap, running rb intake, header and 48 side draft dellorto and rb exhaust. This my first time tuning a rotary with an innovate, running a digital read out gauge on dash.

I have tuned many dells before by trial and error and egt readings, so I am ok with tuning to run correctly. my numbers after he final tune are 13 to 13.5 idle at 1k. cruise at12.2 to 12.8 at 3500 and 11.5 at wide open.

so by my calculations i am at 2.6% co at idle and very smooth.
at 4.5% co at cruise and 8% co at full pull.

feel I am still a little lean at full pull, runs hard right to the buzzer and no smoke reported from a friend following me. running the biggest main jets I have at 280 and did want to buy more if not needed, already have a bag full of jets, e tubes air correctors and low speed jets.

all you carb tuners out there what are your thoughts.

thanks for the replys, only owned the car for a week and trying to work through the issues.

Joe

 

I havent been tuning rotarys for a while but from my experiance when i was tuning my friend's mustang we had it tuned to be 12.3 at WOT and it was fine.

 

12.2 is pretty damned rich at cruise.

What I would want to see int a carbed n/a is
14-15 idle (if it will do that, some big ports wont, and you need to make sure your timing will work with the leaner idle)
13.5 or maybe a little richer under light accel
14.5 or leaner light load cruise
12.9 or leaner WOT full pull. No leaner than 14 though, and I would expect to start to lose power and get a bit warm above 13.5 WOT

It can be hard to get a carb/dizzy to idle lean and still have full advance at higher rpm, so its a balancing act.

 

still working on it, got the idle number up to 13.5, some times when stopping hard will got to 15 or 16 and idle low at aroung 500 then come back to 900 and 14 then go back to 13.5, when I jetted down to lean the wot, it really seemed to strugle to make rpms over 6k and was all over the map, but cruise was good at high 12's. Don't know, sure seems to like the fuel on a hard pull. could be ported, don't know, but with a free flow exhaust and lots of fuel it sure pulls hard. still testing..........more to follow

 

I run mine at 16.5 or so cruising with no ill effects. I ran the engine around for quite some time like that, and after my tear down last fall the rotors look perfectly normal. And gas mileage is nicer At 5 dollars a gallon!!!!

As far as idle every car is different and it is all a matter of making it run smooth. If your shooting for a benchmark AFR you will need to mess with your injector and spark timing.

 

what are you running for ignition/timing, particularly at idle?

i like Mr Walkers targets, and he's right, at idle you just wanna tune for the best quality. they are just targets too, you want to err on the side where the engine is happy

 

timing is at 27 degrees at 4k rpm . never checked at idle

 

Well lets take a step back here a sec-

I have not even seen a Dell in probably 10 years, so your own your own picking exact components. However, if it were me I would be looking not at my main jets but the emulsion tubes, idle jets, etc. The reason for this is during light load cruise and even light accel your running on the idle jets with the emulsion tubes playing thier part as well. My tuning technique back when we ran Dells, Webers, and Mikuni side or downdrafts on the Porsches was always the same: Get the idle jet close enough the car would drive relatively cleanly, then dial in the main jet for hard accel, back up and work with the main jet and emulsion tube until the light load, light accel, etc. was good so that we could get good clean pulls out of a corner. Never cared about fuel milage really, so no help at all there beyond the obvious.

Glad to be of any help that I can be, but realize its been a looooong time since carbs were something I dealt with.

 

thanks don for the replys,
well with my exhaust and intake set up I think I have found a happy medium the engine likes. Idle is at 14 plus cruise light throttle is 13.5 ish and wot is at 12.5 tried many things to change the numbers as suggested, went back to old school. how does it run? is it smooth? does it pull hard at wot? got it where i am happy with performance, took plug reading at various stages and looks good. every car and engine combo is different.....we all know this. I am done tuning at this stage and looking forward to a few dyno pulls to see what I got

 

i'd be happy with those numbers. when you dyno it, you might wanna try a little leaner and a little richer

 

ya my thought also....got a bag of jets and e tubes. gonna try to lean the low speed side a little more this week end before i leave for california for a week and the car sits.
Thanks all for the input, getting better by the day. I really get a kick out of out pulling v8 cars on the freeway, just in search of a little more, as always.
Joe