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 Something interesting for the Q-jet lovers... 
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Joined: Wed May 29, 2013 6:12 pm
Posts: 34 ... 4d&vxp=mtr

Wed Nov 12, 2014 11:15 am

Joined: Sat Jun 21, 2014 5:38 pm
Posts: 17
Would be cool to pick the brain of the guy that developed it to see exactly what he was trying to accomplish.

Fri Nov 14, 2014 2:31 pm

Joined: Sat Aug 24, 2013 7:57 pm
Posts: 155
Location: Frostburg, MD
I wonder if it came from a GM lab, or maybe a contractor working for GM?

Sat Nov 15, 2014 8:33 pm

Joined: Sat Jun 21, 2014 5:38 pm
Posts: 17
Yes, more info would be interesting.

Sun Nov 16, 2014 11:16 am
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Joined: Fri Feb 08, 2013 2:37 pm
Posts: 1744
My thanks to TommyK for this gizmo. No one else bid so the price was only $89. I got the thing a month ago and sure enough, the smoke had leaked out of a transformer because some klutz left a booger of solder between the pins the output wires were soldered to so the short let the smoke out. Ebay provided the exact same transformer new in the box for $23.09 freight prepaid.

So, the happy ending is it works and I got it working on Christmas Day so Santa was good to me.

From the look of the film of carbon in the bores it has been used on running engines a lot. It has been banged around some, has a slightly bent shaft and lever on the air door servo motor but the Heim end doesn’t bind. The zero and span adjustments for the meters work, the switches work, the cable pinout tests are good but the cables need some attention to strain relief where insulation has deteriorated at the AN connectors.

Now what? I would sure like to talk to somebody who used this deal to get a better understanding of what procedure they employed to use it. I can see what to do with it but I would like to talk to someone who used it when it was new and in service.

Some clues in the box with it were a new Mercruiser spark plug wire and a folded cardboard box imprinted “Genuine Quicksilver Parts” and “Mercury Marine, Fond du Lac, Wisconsin", some T-shirts, one of which is embossed “City of Lake City” and another “Stewart Memorial Community Hospital”. Lake City Iowa has a Stewart Memorial Community Hospital. The blue cloth background in the pictures is what appears to be the remains of a hospital scrub shirt that was in the box. Don’t know what to make of it.

The carburetor itself, the body casting is about as close to perfect in the molding alignment I have ever seen. The core shift is zip, nada. My guess is the dies used for the ’70 to ‘72 era. The body is such an accurate part it had to be made when the die was essentially brand new and the die maker or his apprentice was on hand to set up the machine. Makes sense that a prototype carb for dyno development would need to be as close to the blueprint as possible.

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Sun Dec 28, 2014 9:10 pm

Joined: Wed May 29, 2013 6:12 pm
Posts: 34
I actually had you in mind when I posted it. I'm glad it worked out.

Please let us know what you are able to determine with regard to its operation.

I'm starting to get the Q jet bug again. Maybe I'll pull one off the shelf and post up a thread to see if I can correct the drill bit savagery I committed on it a few years ago.

Mon Dec 29, 2014 8:36 am

Joined: Sat Mar 29, 2014 10:27 am
Posts: 45
Cool! Definitely early 70's vintage electronics. Wonder if it was used by Merc Marine to calibrate marine Qjets?

Tue Dec 30, 2014 2:48 pm
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Joined: Sun Nov 02, 2014 2:32 pm
Posts: 24
Wow, and I thought my NOS, never had fuel through it 950 3bbl was cool carb junkie stuff, but this trumps it by a long shot! Nice score!

Tue Dec 30, 2014 6:08 pm

Joined: Sat Jun 21, 2014 5:38 pm
Posts: 17
I thought about bidding on it but didn't have a clue what to do with it. Its cool it went to someone who understands and loves Q-jets. Please keep us informed if you find out any other info you find on this setup. Just out of curiosity, does it have the factory carb number on it?

Tue Dec 30, 2014 7:17 pm
Site Admin

Joined: Fri Feb 08, 2013 2:37 pm
Posts: 1744
I'm glad nobody bid on it. I expected a mob clamoring for it with big bucks. LOL I guess people really don't understand just how good a carb the QJet is. It is amazing how well they can be tuned to make crazy radical engines run so smooth and get such good mileage. If Rochester had engineered an aftermarket performance QJet, Holleys would be called the double-puker and double-toilet, and have center-puker bowls.

I'll keep updating this thread about this as information comes my way or if I put it to use. I need to figure out a translation of the meter reading to metering rod depth and make a chart or graph. I'm pretty sure the position sensors' signal voltages will be recordable with the analog input channels of an Innovate LM-2, or it can be interfaced with an AuxBox or SSI-4 with LC-2 or MTX-L WBO2, so there the whole shebang can be data logged.

There are no numbers stamped in the usual locations like the boss by the secondary throttle lever or on the back where inspection marks are sometimes. It is just a blank raw casting with no marks I noticed yet in any of the usual places. I think the casting has always been what it is, a prototype or calibration tool. I should have taken a picture of the inside of the box so you can see the prototype nature of the construction and wiring, it is almost a field expediency sort of thing. I doubt many were made or they would have made some printed circuits instead of using a breadboard sort of fixtures. On the other hand, it may have been repaired or modified. Definitely, whoever worked on it last was a klutz with a soldering tool or couldn't see well. Some of the solder connections are poke and booger, because that was what shorted the transformer.

Tue Dec 30, 2014 9:57 pm
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