Megajolt Ignition Upgrade
Valve Guide Seal

Passing Aircare - a Willys challenge?

Background:

The Provincial Government, in its wisdom, brought in AirCare for all vehicles regularly used on public roads in the "Lower Mainland" of BC. This area, Vancouver and hinterland, holds the lion's share of the vehicles - being urban or quasi-urban has the biggest incomes. Vehicles 1991 and newer are dinged $45 for a bi-annual inspection, while older vehicles pay $23 annually. Reinspections cost $23 each. The reinspection fee isn't too bad since any repair shop exhaust gas analysis would cost more.

Vehicles under six years old, "Vintage", "Collector", Electric or Hybrid are exempt along with Farm vehicles and big Motorhomes. So-called "Collector" vehicles must pass the test once.

There are five types of tests:

• ASM 25/25 for 1991 and older in which the vehicle is driven at 40km/hr for 90 seconds (our Willys)
• IM240 for 1992 and newer vehicles in which many "real world" conditions are simulated for 240 seconds (best test)
• OBD for 1998 and newer vehicles in which stored onboard info is used from the vehicle's computer(s)
• D147 for diesels in which "real world" conditions are simulated for 147 seconds
• Pressurized Gas Cap Test for 1975-1997 vehicles

The maximum pollutants (HC, CO and NOx) allowed in our Willys' exhaust have decreased over the years. For example the maximum allowable carbon monoxide in 1996 was 1500 ppm, while in 2011, 15 years later, the value was 964.

According to the government and logic, older vehicles pollute much more than newer ones due to the superior computer controlled systems onboard all newer vehicles. The Government estimates that the average older vehicle that fails the test, is repaired and later passes the test, has an average 35% decrease in the three pollutants. If these numbers are true, Aircare makes sense. It is interesting to note that in general, a larger proportion of older cars/trucks can be found in rural areas, not in the city - there is reason therefore to compel 'country vehicles' to pass the test also. However, this sentiment may not be politically feasible.

In 1996, our newly acquired 31 year old Willys wagon failed Aircare miserably but since we were using the vehicle on a remote rural island only, we were not required to achieve a pass to get insurance. 15 years slipped by until we wanted to insure the vehicle for recreational use in Vancouver - it was time to try again.

How to (hopefully) do it

After consulting numerous sources of information, I decided to attempt the following improvements to the old and pretty worn Willys Tornado engine:

• Replace worn out valve guide seals that were allowing too much oil into the combustions chambers (blue smoke).
• Update to a fully programmable electronic ignition from the ancient points and condenser OEM design. Make sure the timing is not too advanced at idle. I set the timing to stay at 4 degrees BTDC until 1500 rpm(the original setting was 12 degrees BTDC). This reset may be extreme, but many tuners say certain older engines will not pass without setting the idle advance back.
• Make sure the air cleaner is more than large enough for the engine and change the "element". Note: our Tornado engine had a reusable/cleanable style air cleaner which was much too restrictive. Remove the aircleaner before the test if you suspect it is restrictive.
• Clean or replace the PCV.
• Set your idle up to about 1000 rpm. Some people say a low idle (500rpm) will cause chronically high hydrocarbon (HC) and carbon monoxide (CO) readings.
• Make sure the carb 'Idle Mixture' is correct with the air cleaner removed. The Idle Mixture screw is on the primary metering block which is the 3/4 inch thick 'spacer' between the float bowl and the main body of the carb. The mixture screw turns in (CW) to lean the basic setting and outward (CCW) to enrich the mixture. The Tornado engine has a dual throat Holley carb (model 2300) which has an idle mixture screw for each throat. It is critical that both mixture screws are turned exactly the same amount! I found that 1/8 of a turn made an enormous difference to the emission readings. Once you have the best/highest idle speed setting, turn the idle mixture CW (leaner) 1/8 turn - this slight leaness should be offset by a new air cleaner.
• Change your oil and oil filter just before the test.
• Fill up with fresh fuel (make sure there isn't 1/2 a tank of year old fuel in there!). Some advise putting in some alcohol to cuts down on unburnt hydrocarbon emissions - I did not because routinely we would not do that...
• Before entering the Testing Station, take the vehicle for a good drive and while waiting in line hold the revs up a bit - perhaps 1500 rpms so she's good and hot.

Here are the values from our three attempts to get the Willys to pass Aircare - two Fails and finally, a Pass. At right are comparative values from a somewhat 'modern' multiport injected aluminum V8 representing a mid-90s technology.

On October 14, 2011 (4:45pm) we took the Willys and the LandRover through the Aircare testing station literally side by side, so environmental factors should not have too many variables to skew the comparative results...

The good news:

The Willys DRIVING Dyno test values for the October 14 Passing test were amazingly better than the Failing August 16 values:

50% improvement for unburnt Hydrocarbons (41% + 9%)

42% improvement for Carbon Monoxide emissions (12% + 30%)

9% improvement in Oxides of Nitrogen (28% decrease followed by 19% increase)

The Willys IDLING test values are even better:

75% improvement for HC (59% + 16%)

88% improvement for CO (26% + 62%)

So, the average improvement according to the Government for tuning an old engine (up to a passing test standard) is 35%. We achieved: (50 + 42 + 9)/3 which averages to 33.5% for DRIVING and (75 + 88)/2 which averages to 82% for IDLING. Wow, not bad for an amateur playing mechanic in his back yard!

The bad news:

When you compare the 1965 Willys Driving values to the values from the 1996 Land Rover, the difference between a carburatored engine and a computer controlled engine become glaringly apparent!