anybody know how to use an old sun machine? (and other ??'s)

[omaha]

   OK, I ve been gone a while. In the mean time I've finally got the engine done in the dodge Pickemup.
specs 318 +.030, magnum pistons (a bit more C.H.) shaved deck .025 '84 360 heads shaved .007, chevy valves +.100 long , 1.94 int, 1.60 ex 11/32 stems , 5.0 ford springs and retainers melling cam  dual pattern .429 intake .440 ex . stock rockers and pushrods. The intake is also a stock 1984 360 intake and yes the carb is the original MOPAR Q-jet used on the same intake. (very nice unit for something that comes out of the mid eighties)  Did a somewhat basic rebuild with Cliffs kit. The only thing I wanted to do but did not was to change it over to a front pulloff. But I am not complaining as the rear pulloff seems to work quite well, (its a truck with a seriously heavy flywheel and a NP 435 trans). I think I did manage to get the compression up to 9 to 1 (or just barely under) if my calculations are right. BTW, the valves were a great deal (bulldog brand, stainless) and got me some extra compression because of the non tulip design. I was gonna experiment with the jet/rod combo and maybe the apt spring but seriously, I dont think it could run much better. Seems just a tiny bit soft during medium aceleration and I think I should have notched the flaps (I forgot). Any way it idles great and starts great and when you hit the secondaries in second gear (granny tranny right?) it tries to slam your head through the rear window and wants to lift the dana 44 front axle off the ground. I guess it should have a more "even" progression into the secondaries but oh well. I thought the mains would be too rich  but they seem to be right on. I will try tip in test though and may experiment with apt adjustments. Would a cheap 02 gauge work for tuning the jet/rod at cruise?
     Anyway, my bud aquired and old sun tuneup machine, for like 200$ and it actually has a HC and CO meters built in to it. I'm wondering how I could utilize this for the tuning of carburetors?

[Schurkey]

Sun made a lot of machines that would now be considered "old".

I was expecting this thread to be about the distributor advance testers.

Seems like what you've got is an exhaust zzzzyzer perhaps in combination with a 'scope.  God, I love automotive oscilloscopes.

It's been so long since I've played with an exhaust zzzzyzer, I hardly know what to tell you.
High HC is misfire--raw fuel going out the tailpipe.  You've got to have an EXTREMELY rich mixture to show on the HC meter.  Like the float sunk, and the engine is gargling on gasoline.  Just being "off" on the tune won't make much difference to the HC meter.  This means that a high HC often means a LEAN mixture to one or more cylinders, the mixture is so lean it won't burn, and the raw fuel goes out the tailpipe.

 If you pop the cap off the radiator while holding the exhaust probe nearby,and get a HC reading on the meter:  you've found combustion gas getting into the cooling system via a cracked casting or past the head gasket.

High CO is rich mixture.  Enough oxygen to break apart the HC, but not enough to reduce the CO to CO2.  Whack the throttle open, and you'll get a bump in the CO from the accelerator pump.

High NOx is hot combustion chamber.  Typically EGR is used to cool combustion, so high NOx often points to defective EGR.

O2 is used as the basis to determine rich/lean on any "closed loop" feedback system, so the O2 sensor in the zzzzyzer is used the same way.

[Schurkey]

Oh, for funny.

I can't post "zzzzyzer" because somebody's software has decided that's a naughty word.

Maybe I can spell it out this way:  A  N  A  L y  z  e  r.

That's like saying "my baSEMENt contains s e m e n".

Cliff???  Oh, Cliff??

[Schurkey]

If all you have is a meter for HC and a meter for CO, you've got the basis of a rich-lean assessment.

High HC can also be a fouled plug or open plug wire.  Anything that prevents the air/fuel from burning.  The trick is, (if you're testing at idle) you'll probably hear the engine stumble, and you'll smell stinky, eye-watering exhaust.  If the fuel mixture burns AT ALL, your CO gauge will be telling you the important story.

Do you have a 'scope to go with the exhaust ana lyzer?

[jamesF]

OK.... analyzer will be allowed in your case Schurkey ;-)

[omaha]

    THX for all responses.  Its crazy how BIG this old sun machine is. I=ll bet it weighs at least 200 lbs.
Anyway were still playing around with it. Its got a built in timing advance knob and the test lead for the
 timing is the old Magnetic pickup that stuck down in the little round tube so im guessin that its a mid eighties somewhere built. the big ossciliscope is cool. EVen if you never used it, its kinda like a garage memorabilia piece. Its got a giigamtis light on top that has full lenth flourscent bulbs and the signage is sweet. it has other stuff on it but were missin a few of the leads.   (missing stuff is avail. on ebay of course).  would also like to find an operating manual/book.

[Schurkey]

Spent some time with the Sun model 1010 (I think!) prior to about '83 or so.  Spent very little time with the REALLY BIG Sun diagnostic unit, but I forget the model number.  THAT was a real monster.   My next employer had even older Allen 'scopes.  I'm thinking yours may be newer.  I don't remember the 1010 having a magnetic probe for timing.  The magnetic timing probe is REALLY COOL; I've got the Snap-On version of the magnetic timing probe; its a separate deal from the Snap-On Counselor, Counselor XL, or Counselor II scopes.  IF (big IF) there is a holder/positioner for the magnetic probe on the timing cover...you're set.  Of course, not so many engines have the probe holder.

I don't know how the Sun machine is set up for magnetic timing, but if there's an adjustment for "offset" or something similar, you'd want to enter 9.5 degrees for GM vehicles.  Other makes will have a different amount of offset.












analyzer analyzer analyzer ANALyzer analyzer.  Nyah, nyah, nyah, nyah, NYAH!

[Goat and Chicken Farmer]

Back in the day, I used to work for a local tune-up franchise and the shops were set-up with the big Sun machines mounted on an overhead I beam and they could slide from one bay to another. As I recall, calibrated properly the gas analyzer was quite sensitive and accurate. The magnetic probe was handy on cars that had the hole/bracket thingy. I really liked the cylinder cut buttons to observe RPM drop. These were great until everything got all sophisticated. I remember guys used to get the leads caught up in the fan and pullies all the time, and back out of the shop with the gas probe still in the exaust pipe.  :)One of the guys that I worked with there bought a few of those franchise stores years ago. I was at one of his shops recently and I don’t think they use those buggers anymore. I did spy a pile of Quadrajets in the bottom of a cabinet though.   

[Too Fast]

Good information in this thread.   I work at Firestone now, and the I beams are still there, in the middle of the shop ceiling between the bays.

[429bbf]

omaha. my buddy marty has a couple of old sun machines and still uses them.if you let me know the model ill see if thats what he has and put you guys in touch.dean