Baby steps

[Charlie Chops 1940]

Wayne,

I never anticipated the possible desire or need for an A/F mixture gauge and an 02 sensor, The header and exhaust pipe is now complete and black ceramic coated. Not thinking I'd like to insert a sensor now.

I have a lot of Weber tech data which includes a road map of sorts to work through the tune up. I think I have the idle circuit pretty close now...in that the carbs are synchronized and the idle is good. The transition to the main circuit will be the next bit. I never got the engine to settle down and idle cleanly until this current effort. As a result I was never able to spend time checking the timing - hard to see the tab, and the engine wouldn't keep running. When I get back to it today or tomorrow I hope to get that checked and see how much total I have.  Since there seems to be no way to run Vacuum advance I am relying on what is in the dizzy from the factory. Not the best but it's what I have. As I move along and verify each step I will probably hook up the vac. advance to a bung I put in the intake manifold. There are no vac. taps on the carb. Anecdotal evidence says that the vac. is so strong in the intake with these carbs that the vac. advance never lets go. I don't know if that's true or not. I will prove or disprove it as I go along.

The Weber guys, Redline, and others have a lot of good printed data. I have talked to some of them but before I do again I want to make sure I have carried the process as far as I can and know that I haven't missed something elementary.

Thanks,

Charlie

[wayne petty]

one last thought....  what sort of collector flange did you build into the headers..  is there room to temporarly put in a custom made collector spacer with a bung for an o2 sensor .....


header===| spacer |======exhaust system...

that is if there is room to push it back an inch and a quarter...


there is one last idea... how about a tube.. several feet long that has a bung in it.. that fastens tight to the tip of the exhaust system... maybe even use flexable exhaust tubing... (the bendy stuff make out of coiled materials..)  since the o2 sensor is self heated...  if there are not any leaks between the tube and the flexy part it should give you an accurate but late signal... the tube will have to extend several feet  to prevent reversion pulses of fresh air in to mess up stuff...

and ........     most parts stores  and northern.com sells garage exhaust tubing... to divert exhaust out of garages for working on cars in cold locations...  with the doors closed...    might work....

again this is just a thought... i know that you have it under control...

i will try not to make any more FUELISH remarks..


wayne, out....

[Charlie Chops 1940]

Wayne,

There is maybe one place I could put a sensor. Between the lakes header turnout there is a removable block off plate. Would the exhaust buffeting against it while seeking the down tube to the mufflet have any bearing on its function? A thought

Make all the "fuelish" comments you want, no offense taken.

Charlie

[Dave]

I find it kinda funny that I remember when i used to scoff at these new fangled o2 sensors but then i started learning more and more about why they are used and what they do. Interesting that even the new harleys have em but although they do help the computer adjust the fuel mixture to the needs of the engine they still haven come up with a full blown closed loop system and i dont know if the are running 1 or 2 o2 sensors.. There is a company out there that makes an add on closed loop system for the harleys with 2 bungs to install and 2 sensors for a true closed loop system      Good stuff but really expensive.. I gotta agree  though if you can find a place for the bung and get the right analyzer you can sure learn alot ..
Dave

[1FATGMC]

Wayne,

There is maybe one place I could put a sensor. Between the lakes header turnout there is a removable block off plate. Would the exhaust buffeting against it while seeking the down tube to the mufflet have any bearing on its function? A thought

Make all the "fuelish" comments you want, no offense taken.

Charlie

Charlie you could take that turnout and block off plate off.  Then put a small pipe just big enough to weld a bung in on a flange and bolt it temporarily where the turnout is.  It could turnout/turndown also.  Make sure that it is long enough that the O2 is at least 16-18 inches from the end of it. You could weld up the end of it so that there was just a 1/2 inch or so outlet.  You just need to divert some of the exhaust flow down this pipe and past the O2 sensor.  The majority of the exhaust can still go out the main pipe.

Now you are all set to go.  You just need the wire from the LM-1 to hang outside the car to the O2 sensor and you need 12 volts to the LM-1.  If you have a cigarette lighter outlet you won't even have to wire anything.

Don't cheap out and get one of the narrow band sensors if you want to get some good data.  I have one that is suppose to be accurate from 12:1 to 17:1, but comparing it to the LM-1 at the same time it starts getting way off below 14:1 and above 15:1.  If you and Jack and Ken all chipped in you would each only have about $100 into it and you could move it to any of your cars.

Then make a TPS that you can move from vehicle to vehicle and with that and the data logging you will really be able to see what is going on.  I have a page.................

http://purplesagetradingpost.com/sumner/techinfo/LM-1%20TPS.htm

.............. on my site showing how you could make a TPS for cheap that could be moved from vehicle to vehicle using a small cable or one of the cruise control type chains to hook it to your throttle linkage.

Call me or let me know if you need any help.  Believe me once you get a "wide band" sensor, controller, data logger you will see how far off all the methods we have used for years are.

I have a connection on buying the LM-1 where you might save some money.

c ya,

Sum

[wayne petty]

sum... thats a great idea... i was thinking of a custom plate and tube assy that fits into the cutout with an sensor bung in it... with the end of the tube at an angle to divert the exhaust flow downword at the opening... that would stop the pulse reflection off the dead end...

that might even make it run better...


i was working on a drawing of it...  but i got called away....

i will post it a bit later...

edit
this fits inside where the block off is... and not only has a place for a sensor.. but has the angled plate to divert flow downward to end the reflection off the dead end...   you might get creative and make it a curved  surface...   think of a old style port plate...
\===|


oh... and when you finish tuning...  take it out and unscrew the sensor and put an easily available plug in it...  or build a matching one without a bung...


wayne.... sometimes i wish i had a pc so i could run fluid dynamics patterns...   but i run an old hot rodded mac...

[Charlie Chops 1940]

Thanks Wayne. Actually I had thought of carving out a deflector in there some time ago but the need for such never arose.

I wrapped up a couple little things yesterday. Moved the foot feed a couple inches closer to the firewall and Installed a cable to operate the starting enrichment circuit. It opens a dribble well in each throat of the two carbs. Works quite well
This morning I warmed it up and set the timing and with just centrifugal advance I only had about 30 degrees total. I hooked up the vac, advance and it pulls about another 10/11 degrees of advance and backs out under WOT as it is supposed to. I put a little more initial in and reset the carbs for best idle. It now idles at about 750 at operating temp. And, starting at operating temp is almost immediate.

Will be taking it out this afternoon for some miles.

Charlie

[river1]

Will be taking it out this afternoon for some Smiles.Charlie

you forgot an S i added it in

later jim

[Charlie Chops 1940]

Miles - Smiles. Same deal, huh Jimmy?

Charlie