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Discussion Starter #1
I've read several threads about engines that don't run as expected and what to do to make them run. Usually the discussions center around cam timing, ignition timing, ignition advance curve and carb jetting. That's a lot of variables to juggle. Shade tree mechanics, myself included, can make educated guesses all day and occasionally get lucky.

A vacuum gauge ($10-$20) can provide diagnostic info on ignition and cam timing and, possibly, advance curve.

When adjusting the AFR the suggested approach is to put the car on a dyno and attach an AFR to the exhaust. Expensive. An alternative to using a dyno to determine if a carb is jetted properly is to install a wideband O2 sensor connected pto an AFR meter ($200-$250). Drive the car and have a passenger record AFR data. Depending on budget, you get a data logger that can record AFR, EGT, rpm, etc.

Has anyone tried this approach to tuning?

John
 

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When adjusting the AFR the suggested approach is to put the car on a dyno and attach an AFR to the exhaust. Expensive. An alternative to using a dyno to determine if a carb is jetted properly is to install a wideband O2 sensor connected pto an AFR meter ($200-$250). Drive the car and have a passenger record AFR data. Depending on budget, you get a data logger that can record AFR, EGT, rpm, etc.

Has anyone tried this approach to tuning?

John
Yes and it works!! I was working on an engine on an engine stand, engine sounded good but after installing an O2 sensor to the ex pipe I could see it was running to lean (14,5 AFR) after a few changes in jetting AFR was between 12,5 and 13,2 in all the rpm range so my experience is good about it
 

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Discussion Starter #4
Thanks for the link to to thread on lambda sensor tuning

The thread on tuning Weber carbs using a lambda sensor is very interesting. From the difficulty tuning Webers and variation in AFR I'm surprised that more Alfa owners haven't switched to EFI. Is EFI too expensive or difficult to install and tune?
 

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I'm surprised that more Alfa owners haven't switched to EFI.
I and a few others have Megasquirt EFI (and ignition control) on Alfa V6's. It is a straightforward conversion because it is more about replacing things that re-engineering. Jarrington has a thread about converting his S3 Spider to Megasquirt but again, that was replacing Bosch FI with programmable. I know one member of the ABB who is converting his SPICA Spider to Megasquirt using the original throttle bodies. Hopefully he will post details when it is complete. I too have thought about it but I don't know of a GOOD ITB setup that will locate the injectors in a good position.
Bianchi1 has programmable FI in his Alfa but it is with a GM engine!
 

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Discussion Starter #6
3D printed plenum

I don't know of a GOOD ITB setup that will locate the injectors in a good position.
Has anyone considered designing a plenum and intake runners for Nord engines that can be 3D printed? That would solve the ITB injector location problem.
 

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Has anyone considered designing a plenum and intake runners for Nord engines that can be 3D printed? That would solve the ITB injector location problem.
Maybe that is a business opportunity. I would be interested in a well designed ITB manifold with 45 mm throttle plates that accepts Bosch injectors, but anyone going in this direction should consult with an engine builder with a proven record of getting the most out of these engines.

I recently saw the dyno sheet for a 2L Nord motor that made 230 HP at 7000 rpm with 45DCOE Webers. It has distracted me from pursuing EFI on my motor, at least for a while.
 

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Torque curve is fairly flat. Peak is 194 ft-lb @ 5500. It is 175 [email protected] 3800.
 
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