Give that slant some more MPG

[SixBanger]

Two studs have been made for attaching the sensor. These are mounted on the block at the timing gear cover. A steel profile is welded to the existing sensor mount.
After testing, it is a robust fitting of the sensor.

The top studs I will mount another set of bearings. This acts as the support for the alternator belt.

 

[SixBanger]

I currently have the intake manifold and air filter connection gas-tight.
So I have changed the ignition again. And he runs fine on this unit. The switch between petrol and LPG is now smoother. However, I do notice that driving on petrol is not that much better (acceleration). However, he runs nice and quiet.
With LPG I notice the biggest difference myself. This would also have to do with the fact that the manifold is also gas-tight (which I also notice with the brakes). I have roughly adjusted the mapping for both fuels. With the data found from forums.
In addition, the car now switches more smoothly at part load.

Below the current mapping. Today the car starts and drives fine to work. Although it was cold.

Petrol

LPG

 

[BudW]

I like this a lot better, than the version mounted to the torsion bars. Your setup looks nice!
By any chance, did you record any measurements (so someone else could duplicate your work)?


I’m no expert about fuel type and ignition timing – but I can see different fuel types needing different timing curves.
Even different grades of gasoline burn fuel at different rates.
BudW

 

[SixBanger]

No problem. The total length of the studs is 140 mm, diameter around 12-15 mm. On one side I have tapped 17 mm 5/16 "and for the other side 23 mm M8 (I have more nuts for this).

At the moment I have not done any measurements concerning temperature or acceleration. In addition, it is possible to route an analog sensor to the ECU as an AUX input. For pure measurement, or for adjusting the ignition curve.

At the moment I have tune it with regular Super E5 gasoline in Germany (old Euro 95).

Another question, should there be another main nozzle in the carburetor? Given that the current E5 or E10 fuel yields less energy (?) In relation to the older euro 95 (AFR ethanol)?

 

[SixBanger]

Today heavy snow on way back to home.

 

[SixBanger]

First test the engine ran a bit restless on LPG. The stationary screw (air filter) what adjusted. It is better in recent days. Maybe once along an LPG specialist not to adjust it with co meter.

Engine has probably(compensation by tuning power mixture)
always run rich because of a intake leak.

 

[BudW]

I can’t comment on European fuels, but I can comment on what fuel we have in USA.
Our E10 is 10% Ethanol/90% gasoline, and it requires about 10% more fuel overall over using 100% gasoline. Electronic fuel injection (speaking about modern cars) is great about compensating for fuel types, automatically.

Here, any FMJ vehicle should AVOID using any E10 fuel because the carburetor (even the factory computer-controlled carburetors) can’t compensate for the additional fuel usage (I recall Chrysler saying it can work with about a 5% (or so) change on fuel usage). Also, the ethanol is very hard on the metal/rubber parts.
If you do not have access to 100% gasoline – then you may need to get/find some jet(s) and some small drill bits to play with.

In US (also applies to Canada?), I can instantly tell if I get a tankful of E10 – for car will start to run like crap.
BudW

 

[Oldiron440]

I had a friend who had a gas station in the 90s, the e-10 he received was anywhere from 10 to 30 percent alcohol.

 

[Charrlie_S]

By law, E-10 = 0-10 % ethanol
E-15 = 0-15% ethanol
E-85 = 0-85% ethanol
The "E" rating is the MAX percentage of ethanol allowed. Can be any amount less.
That is why racers don't buy E-85 at the Local gas station, the percentage is not is not reliable/consistant. They buy in sealed drums.

 

[Oldiron440]

That may be the law but often not what is delivered.
I know of two racers that run LS turbo Firebirds, both make north of 1100 hp at the wheel who run pump e-85. They say that as low as 65 percent alcohol will still work for them.

 

[SixBanger]

I have look for some information, and euro 98 and 102 fuels contain little ethanol. It would not matter much for its older type of engine. Maybe you could give a little more for ignition.. The only advantage would be that the fuel would become outdated less quickly.
In my older two-stroke motorcycle I do not notice a difference between all fuels.
In the coming spring, use the current tank capacity for the motorcycle and then euro 98 in the car.

 

[SixBanger]

Back on mpg project.

Get some more data. Still driving with the above shown ignition mapping.

After work did some 0-100 'performance' test.

I use an great tool on this site to calculate wheel horsepower instead of early used simplified tool:
Acceleration simulator

Also checkt the estimated Cd of 0.47, result 0.447 (with window closed, I did 0-100 with window open so 0.494 :
Vehicle aerodynamics

Test 1. Previous result 0-100 back in 27 December.
Note:
- with old ignition system.
- With some some airleak by intake/carb (Compensated with richer mixture)
- Less weight, 10 L ish gasoline. -> Curb weight rounded to 1500 kg

Results:
lpg 23 sec -> 56 hp at wheels
gasoline 16 sec -> 73 hp



Test 2. 27 February
Note:
- With new ignition system with shown map
- More weight 50 L ish gasoline, -> Curb weight rounded to 1530 kg
- Hotter air intake temperature but should be the same engine bay temp after 20 km driving(?)

Results (best):

lpg 18 sec -> 67 hp at wheels
gasoline 17 sec -> 70 hp

I think I can give a difference between new and old ignition, I will also do another 0-100 measurement with the old ignition. But you could say that it now gives an increase in power of roughly 20%.

Beside trying to get an idea what the engine putting out. I did some tests with adjusting the rich settings of the main lpg adjustment valve. You can turn the valve easily from rich to lean in an 180 deg rotation.
Numbers are based on estimates. 0 degrees I have defined as half open, as being between rich and poor. Rich CW Lean CCW

I don't have an oxygen sensor but might the fastest 0-100 measurement, with some adjustment to the rich side give an good adjustment of the main lpg mixture.

 

[SixBanger]

Fuel usage data. Running with new ignition since 17 January.

I have driven the car not very often. And with short and long runs mix together. Double tank stops at one day are not shown.
Biggest difference is the highway usage with old one in December (avg 12 mpg). And an 150 km highway drive in February (avg 14 mpg).

 

[BudW]

1500 KG (3,307 Pounds) seems a bit too light.
Have you weighted the car to get an exact figure on weight?

I love the data you are providing!

 

[SixBanger]

Hi Bud. I didn't have weighted the car jet. For base car reference specs I use the info on the site Automobile Catalog.
Detailed specs review of 1979 Plymouth Volare 4-Door Sedan 225-2 TorqueFlite offered since October 1978 for North America
Here the Curb weight shows 1454 kg without driver. So rounded up and add 30 kg for lpg. But do you know the weight of the a volare? An lpg system should add also some extra weight + liquid.

 

[SixBanger]

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