Phaxtris

Hey my new project of dual 36 mm dellortos it going to require me to install an air/fuel ratio meter

i need to know how far from the engine to mount the o2 sensor, because i know the egt gauges when to close to the motor will melt from the extreme engine temps

and givin the distance from the engine what kind of accuracy will it have, also what is the a/f ratio for rotarys, i know it piston motors it's 14.7:1 but im sure rotary its higher

input would be apperciated

Maguire

iTrader: (1)

I read that Paul Yaw reccomends 24" from the motor on the EGT Gauge. Not sure on the rest.

bill Shurvinton

A regular 02 is not a huge amount of use. I would spend the extra and get a WB kit (www.diy-wb.org or www.techedge.com.au).

As for AFR I have yet to see a concensus, and as my engine is still sitting balefully in the garage no hard measurements BUT for a ported motor, where you lose atomisation at low RPMs Paul Yaw suggests 11.5:1 for WOT going down to 13ish by the red line.

Others I have read suggest that 12.5 is good for lower RPM, so the old addage of 'give her what she wants' is probably as true here as anywhere else.

At less than wot you can of course lean out to 14 or leaner. I certainly had no problems cruising at 70 at 15.5:1 before I pulled the engine for a rebuild.

Bill

DriveFast7

iTrader: (1)

TWM Induction says mount the O2 sensor 22" from exhaust port with their a/f gauge.

12.5:1 for n/a motor ported or stock is what several rotary tuners i talk to say to shoot for.

But by all means, give her what she wants. Keep changing jets until powerband and HP is maximized

Conway

I read that too in his article on carb tuning, but I read everywhere else that much closer is better. Anyone want to clear this up for old Conway?



Conway

Maguire

iTrader: (1)

Closer is better. However, there is an issue of burning up the O2 sensor sooner.

mperformance

just get a heated O2 sensor...I bought a cheap one and sometimes the exhaust gets too cold for it to work. In either case I suggest you mount it closer to the engine...