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Discussion Starter #1
Hey Fellow Montifisti,
I have been driving the red Monti a lot lately, and the gas mileage is atrocious.
I think it is getting 10 miles per gallon, at best.
It does seem to run a bit rich, but not enough to cause this gas guzzling.
What miles-per do you folks get with yours?
 

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Glenn,

When I first put together the car, I was getting as little as 8 - 10 MPG around town, and the plugs would become very black. Obviously rich. I had Wes overhaul one of my TAs for the car, installed it, and adjusted the warm-gap to .019".

I can't say that these changes did anything obvious, but figured it couldn't hurt.

The drive over to Concorso this year was mostly all high-speed highway work. I clocked around 16 - 20 MPG for the trip to APE in Tracy, where I pulled the plugs and found them to be nice and white. In fact, they appeared just a little hot, so I replaced them (BPR6EIX) with plain old BP7ES. I have not yet pulled them to check, but the highway running was fine.

I'm chasing worn cam, questionable distributor function, and idle issues at the moment. Nevertheless, it appears that these cars just aren't happy loafing around town. No surprise there.

I'll report more after I've swapped the cams and overhauled the distributor, which I'm doing right now.
 

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Back in May I put about 700 miles on mine doing a wine tour with an Alfa club. About 70’ish miles were in the mountains the rest were highway. I averaged 19 to 20 MPG.
 

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Discussion Starter #5
I'll have to check the TA again. It does seem to "load" a bit when I'm off the gas pedal, maybe it is running richer than I think.
All my miles have been backroads, with aggressive throttling.
I just can't get enough of that sound!!
 

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Hi HeavyMetalAlfa,
Wes told me that gas slips by the 8 little plungers in the Spica even a short time after leaving the Alfa factory when new. He overhauls them with very tight- fitting sleeves. He did this to mine and I get 19MPG.
We tuned it with a gas analyser and the plugs (BP7ES ) are a light grey colour. ( I take out plugs every 3 months to check). We balanced the throttle bodies with a carby balancer to stop hunting at idle.

Steve
 

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If my current Spica pump is in the same condition as the cams in the engine, it's slap worn out. That's why I'm looking forward to the fresh overhaul from Wes arriving soon. However, even with the suspect pump clearances, I was getting 16 - 20 in highway driving at 70 - 90 MPH. I'm guessing the basic curve of the 3D cams just feeds a rich mixture at low power settings.

BTW - plug color after extended highway driving is a very good indicator of both mixture and any possible inlet air leaks giving lean conditions. It might not dial it in to .3 - .5 mixture ratios like an analyzer, but it'll keep you out of trouble.

The TA that was in my car when I got it showed zero extension both hot and cold. DOA. The gap appears to have been reset a little to make it a bit more lean in the absence of the TA doing its job, and the fuel cutoff needed to be slightly enrichened after the new TA was installed as well. Lotsa loose ends. Starting over now that the rebuilt TA is installed.
 

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Any gas mileage will make me happy!

I just hope that when the Montreal is back on the ground with its new speedometer sending unit, the speedometer and odometer work.

We already know the fuel mileage will not be that good based on refueling frequency and black plugs (BPR6ES, don't know why the 'R' plugs (resister), car has no radio). The Montreal could have used a larger fuel tank.

HeavyMetal All my miles have been backroads, with aggressive throttling.
I just can't get enough of that sound!!
I think we both have the same problem with our cars; it is caused by our right foot!

Mark
 

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About 20 mpg US on highway trip to a show last fall. I've invested much time with a Gunston CO analyzer on this car, mainly because I had to richen beyond book spec to keep from stalling (during mid warm up) with AC on. Monti is challenging to troubleshoot with analyzer because each bank / exhaust pipe is influenced by 2 point sets, 2 coils, 2 different rotor phasings, different vacuum feeds, and of course those individual fuel plungers. My remaining mystery is that CO falls at upper rpms when air temp is cool, but rises from idle 3% level when air is summer hot.
 

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Hi Glenn, I drive with a very heavy foot and get 16mpg. Once I checked the mileage do 60mph, very boring and putting me to sleep but got 20mpg. Pete.
 

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Discussion Starter #12
Well Guys, I guess my heavy foot is gonna make driving it expensive.
Not that that will stop me!
Just, instead of a 2+1/2 hour drive in my Blue Meanie GTV6, I get a 1 hour drive in the Montreal for the same fuel cost.
Actually, the Meanie out performs the Monti in a big way, but the sound of that 2.6 V8 is even better than the GTV6 2.5 or 3.0 . And THAT'S saying something!
I still need to dial in the SPICA a bit more for sure. A bit hard, doing it by ear. But we are getting there.
 

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Glenn.... My lady and I are hooking up an electric/Roland guitar and bassoon duo for local pub work. Opening tune will be "Money" (Pink Floyd) with bass line on bassoon, followed by "Larks tongues in aspic".

Reckon that'll be on a par with Monty V8?
 

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Discussion Starter #14
Wow Don ! I would love to hear that !!
Just totally weird and interesting enough to get a head nod from the V8 ! :-}
 

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Maybe a little late to the party (again), but I got 10,2 mpg or 23l/100km the time everything was dialed in nicely but the SPICA had a completely inactive TA. The popping and backfiring was cool, the fuel bills were not.

After Wes Ingram fixed the TA, it consistently did between 14 and 15 mpg (15-16 l/100km).
 

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Also a little late to the party, but my results are consistent with the group as well: I have gotten 19.5 MPG consistently when being careful (i.e. under 70 MPH highway driving); more realistic real world conditions (and some slightly extra-legal speeds in mixed driving) give me mileage more in line with what TorW is getting.

It ain't cheap, but boy does it sound great over 4k rpm!
 

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Very late to the party, but thought I'd chime in.
I've got aftermarket efi on mine and I averaged 29mpg to Melbourne from Adelaide and back in 2012. That's about 780km each way.

I was in company with a '74 Spider with two on board and a S1 1750GTV with one and it was a but odd that we had to keep stopping so the Spider driver could fill up, but I was only needing to refill every second stop.

Steve
Adelaide
Australia
 

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Discussion Starter #19
Hey Steve, I would like to see more on your EFI conversion. I want to able to drive my Monti a lot more and even 15 mpg would make a huge difference, let alone 29 !!
 

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Glenn,

I'm not even remotely a Spica expert, but am slowly learning. When I first starting driving my car the mileage was staggeringly bad. This last trip involved a variety of changes, including mixture adjustment, ignition timing fix, TA replacement, gap adjustment, etc. The mileage on the trip was, as I posted earlier, 16 - 20+ mpg.

Bottom line, I think small changes really add up, and putting one's right foot down hard blows dinosaurs out the tailpipe in a way that makes this oil-well owning Texan proud.
 
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