Gas Mileage in the AC Vanagon, 1980

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wcfvw69
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Re: Gas Mileage in the AC Vanagon, 1980

Post by wcfvw69 » Sat Jul 11, 2015 11:36 am

asiab3 wrote:I didn't mean to say it was impossible; I simply do not feel like trying to squeeze one or two MPG out of an air-cooled engine would be a smart decision if you're approaching factory estimates. Yes, if the fuel consumption is noticeably worse, then by all means go for a better state of tune.

RobbieLongevityForMe
What MPG are you getting Robbie out of your stock motor in your bus?
1970 Westfalia bus. Stock 1776 dual port type 1 engine. Restored German Solex 34-3. Restored 205Q distributor, restored to factory appearance engine.

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Randy in Maine
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Re: Gas Mileage in the AC Vanagon, 1980

Post by Randy in Maine » Sat Jul 11, 2015 4:45 pm

Why have you not upgraded to correct tires?
79 VW Bus

cegammel
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Re: Gas Mileage in the AC Vanagon, 1980

Post by cegammel » Sat Jul 11, 2015 5:15 pm

Me? Price tag. The ones on it are only 4 or 5 years old, with less than 8000 miles. The only thing wrong with them is the load rating...which is only about a thousand pounds too low...

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Randy in Maine
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Re: Gas Mileage in the AC Vanagon, 1980

Post by Randy in Maine » Sun Jul 12, 2015 6:01 am

Are they about the correct size? Correct air pressure?
79 VW Bus

cegammel
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Re: Gas Mileage in the AC Vanagon, 1980

Post by cegammel » Sun Jul 12, 2015 8:11 am

They are correct size, and close to the correct pressure. However, the pressure required for the Vanagon rears exceeds the safe fill level.

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asiab3
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Re: Gas Mileage in the AC Vanagon, 1980

Post by asiab3 » Sun Jul 12, 2015 9:06 pm

wcfvw69 wrote:
asiab3 wrote:I didn't mean to say it was impossible; I simply do not feel like trying to squeeze one or two MPG out of an air-cooled engine would be a smart decision if you're approaching factory estimates. Yes, if the fuel consumption is noticeably worse, then by all means go for a better state of tune.

RobbieLongevityForMe
What MPG are you getting Robbie out of your stock motor in your bus?
It wildly varies by driving style. 15.5 is the lowest I've seen, which was all balls-meet-wall hill climbing and driving at a steady 65. I held another tank at a meager 50-55 and got 23. I average 18-19 on my frequent trips from San Diego to LOs Angeles and back. That's about 60mph, depending on grade and condition of road. The 5 is such a mess I'm usually down to 50-55 to save my suspension. 405 is significantly smoother, so I can cruise at 60. Of course, I fly by night so I'm not a sitting duck pile of scrap!


This weekend I've been in the convertible which sees 28mpg on every fill up I've ever logged. Go figure....
Robbie
1969 bus, "Buddy."
145k miles with me.
322k miles on Earth.

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SlowLane
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Re: Gas Mileage in the AC Vanagon, 1980

Post by SlowLane » Thu Jul 30, 2015 7:06 am

On my just-completed 1208-mile journey north from California to BC, I averaged 20.0026 mpg, which is better than I had expected. This is with me varying between cautiously staying around 55 to keep the head temps below 400, or throwing caution to the winds and flooring it just to keep from being shoved off the road, trying to avert my eyes from the climbing CHTs (which of course I couldn't so I just cringed while seeing #3 cylinder go as high as 440 at some points.)

I did "cheat" a few times by drafting behind a large truck that I could comfortably keep up with. I managed to get 20.46 mpg on the stretch from Klamath Falls to La Pine, Oregon by drafting behind a truck that was doing a perfectly locked-in 60 MPH for most of the way.

This is in a van that has been converted to a California-spec L-jet system (mit Lambda), so it was running neither rich nor lean, but juuuuussssssst right, at least as far as the catalytic converter was concerned. Except for when I engaged the WOT switch above 3000 RPM, then the AFR dropped to 12.3 or so. Which didn't lower the CHTs at all, since I was still asking the engine to work even harder.

Miraculously, the valves don't seem any worse for wear after having been subjected to this abuse. I've been checking for valve recsession at stops along the way and haven't noted any, even on the most-terrribly abused #3 cylinder.
'81 Canadian Westfalia (2.0L, manual), now Californiated

"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
- Terry Pratchett

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Happyfolk
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Re: Gas Mileage in the AC Vanagon, 1980

Post by Happyfolk » Mon Aug 10, 2015 7:51 pm

Our '79 California FI Westy Deluxe has been getting about 19-20 mpg driving around locally. We recently took a trip about 250 miles away and got about 24 mpg there and back. I kept highway speed at about 60 mph to keep CHTs in check. CHTs averaged about 385 ranging from 365 to 405 with outside temperature at about 90-92* and HUMID. This was on a 4-lane non-interstate highway with a speed limit of 65 but without the traffic or necessity to do 65 that an interstate has. Fewer stops and starts than a 2-lane highway going through towns. People seemed to understand why we were going under the speed limit.
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79 CA FI Westy
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SlowLane
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Re: Gas Mileage in the AC Vanagon, 1980

Post by SlowLane » Mon Aug 17, 2015 1:58 pm

SlowLane wrote:On my just-completed 1208-mile journey north from California to BC, I averaged 20.0026 mpg, which is better than I had expected.
Update: just completed the rest of my vacation adventure. 3428 miles through California, Oregon, Washington, British Columbia and back again. Averaged 20.11 mpg for the whole trip.

Between fill-ups I saw averages ranging from 15.5 to 23.9 mpg. Wish I knew how I managed to get that last one. It's not like I gassed up at the top of a mountain summit and coasted downhill to the next gas station.
'81 Canadian Westfalia (2.0L, manual), now Californiated

"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
- Terry Pratchett

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Amskeptic
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Re: Gas Mileage in the AC Vanagon, 1980

Post by Amskeptic » Tue Aug 18, 2015 6:32 pm

SlowLane wrote:I've been checking for valve recsession at stops along the way and haven't noted any, even on the most-terrribly abused #3 cylinder.
Number 3 is not a problem child on Type 4 engines.
Number 2 is.
a) it 's piston cooling is at the end of the oil supply tree
b) it is standing under Niagara Falls as far as cooling air spooling past it to the favored #1

Every seized Type 4 engine I have happened across has a killed #2 cylinder wall.
Colin
(now, on the Type engine, heck yes #3 is the abused cylinder with our oil cooler dumping hot air into its cooling path)
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

luftvagon
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Re: Gas Mileage in the AC Vanagon, 1980

Post by luftvagon » Mon Aug 24, 2015 1:04 pm

On the "leaners" comment, with my very limited experience, and my own account {and other DIY EFI tuners}, you can lean the engine past stoich as much as you want, as long as its not under load, pinging, surging or slowing down.... the flame is cooler the further away from stoich it is, except you start to loose power, so it gets to be a loosing proposition.

The problem is being able to do this safely with L-Jetronic (or carb) and not affect the overall system.

I can safely cruise at 16.5 AFR @ 55-65 mph without straining the engine (; interstate cruising at steady state), and immediately adjust the mixture for load.

Hi Colin :)
1981 Volkswagen Vanagon Westfalia - air-cooled Type4 1970cc CV (hydraulic lifters, 42x36 valves, stock cam, microSquirt FI with wasted spark ignition)
1993 Ford F-250 XL LWB Extended Cab 7.3L IDI

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SlowLane
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Re: Gas Mileage in the AC Vanagon, 1980

Post by SlowLane » Mon Aug 24, 2015 5:03 pm

Amskeptic wrote:
SlowLane wrote:I've been checking for valve recession at stops along the way and haven't noted any, even on the most-terrribly abused #3 cylinder.
Number 3 is not a problem child on Type 4 engines.
Number 2 is.
a) it 's piston cooling is at the end of the oil supply tree
b) it is standing under Niagara Falls as far as cooling air spooling past it to the favored #1

Every seized Type 4 engine I have happened across has a killed #2 cylinder wall.
With deference to your vastly greater experience, Colin, I was more concerned with valve seats losing their grip in the head pockets, which I've had happen on two engines previous to this one, on cylinders 1 & 3 respectively. I'm not as troubled by the prospect of a seized engine.

My 4-channel CHT gauge was showing #3 cylinder to be consistently about 50 degrees hotter than #2 and #4, as it has done since I installed it in 2005. What is new to me and my Westy is the CA L-Jet setup which adamantly insists on doing its rich-lean-rich-lean dance around stoichiometric under all conditions except for high-RPM WOT. This is essential to keep the 3-way cat happy, and the van runs pretty smoothly, so I'm not going to mess with fooling the ECU into running leaner or richer. Well, maybe I'll see if I can jigger the OXS relay to close its circuit at 2500 RPM instead of 3000 RPM.

With the CA setup it takes very little in terms of headwind or grade for the #3 cylinder to shoot up to 400 degrees and beyond. The hottest that I saw was 447 degrees, which does have me worried, but not so much as it used to, because the van just keeps on running great. Compression clocked in at 135 - 150 psi across all cylinders. Valve adjustments were fine: the largest deviation from adjustment was 1/4 turn on the #4 exhaust. I need to do another valve adjustment now that I'm home, but I'm not expecting any surprises.

This is running with out-of-the-box AMC heads, valves, guides, seats, springs and retainers. The same ones which The Perceived Wisdom has been telling us are pure crap that will self-destruct if subjected to temperatures over 400 degrees. I dunno, maybe I got lucky and got a pair of heads with "good" hardware, but I doubt I have that much karma banked up. I will continue to monitor my engine health and baby it up the hills, but I don't think I'll be sweating the high temps so much as I used to. Of course, if things go pear-shaped, I guess I'll pack my heads of to Len Hoffman for his special treatment.

Oh, BTW, I've been running with Amsoil 20W50 "Z-Rod" oil the whole trip. This stuff has extra ZDPP which is supposed to make our flat-tappet engines happier. The Westy seemed to like it. #4 cylinder stopped burning oil (by the spark plug colour), and my oil consumption was just over a quart for the 3500-mile journey. I'm going to keep using this stuff.
'81 Canadian Westfalia (2.0L, manual), now Californiated

"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
- Terry Pratchett

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Amskeptic
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Re: Gas Mileage in the AC Vanagon, 1980

Post by Amskeptic » Thu Aug 27, 2015 9:23 pm

luftvagon wrote:On the "leaners" comment, with my very limited experience, and my own account {and other DIY EFI tuners}, you can lean the engine past stoich as much as you want, as long as its not under load, pinging, surging or slowing down.... the flame is cooler the further away from stoich it is, except you start to lose power, so it gets to be a losing proposition.

The problem is being able to do this safely with L-Jetronic (or carb) and not affect the overall system.

I can safely cruise at 16.5 AFR @ 55-65 mph without straining the engine (; interstate cruising at steady state), and immediately adjust the mixture for load.

Hi Colin :)
Hi, I wish I wish I wish I could get L-Jet to flick from lean to rich.
16.5 at 65, what are your head temps and vacuum signal?
When you then hit a hill at 65, what is your AF ratio, head temps, and vacuum signal then?
I swear I am going to find a simple full throttle switch and wire it to the TS 2.
Colin :geek:
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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asiab3
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Re: Gas Mileage in the AC Vanagon, 1980

Post by asiab3 » Thu Aug 27, 2015 10:45 pm

Amskeptic wrote: I swear I am going to find a simple full throttle switch and wire it to the TS 2.
How would this differ from the "full throttle enrichment switch" on some FI models?
1969 bus, "Buddy."
145k miles with me.
322k miles on Earth.

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Amskeptic
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Re: Gas Mileage in the AC Vanagon, 1980

Post by Amskeptic » Fri Aug 28, 2015 12:37 pm

asiab3 wrote:
Amskeptic wrote: I swear I am going to find a simple full throttle switch and wire it to the TS 2.
How would this differ from the "full throttle enrichment switch" on some FI models?
Because the full throttle enrichment switch only does its little injector pulse time extension according to Bosch engineers. MY switch will bypass the TS 2 and substitute a nice 3,000 ohm path to ground, engine will think it is cold, and that enrichment is not only more enriching, but we'll make it adjustable with a rheostat.
ColinOrSumpin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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