looking for tips to pass emissions testing

[bach4660]

my flathead failed emissions so it got pulled off the road, ( actually failed it three times so it is a Triple X), after the first failure I noticed that there was a hole just above the heat riser, leading into the base of the intake manifold, after I plugged it, the temperature dropped from 200 down to 180, but then the emissions went up. So firstly I am thinking of drilling out my plug and running it hotter, but apart from that I am out of ideas, ( I am about ready to make a fake tail pipe) any ideas?

[Norm's Coupe]

You've got to be kidding. Here they don't test cars over 20 years old. How in the world could one of our flatheads pass emissions anyway? There are no emission controls on it to begin with. Do they test lawnmowers for emissions up there too?

[Normspeed]

When they failed it did they give you a printout or a list of exactly what items failed? like CO emissions, or HC emissions, or oil leaks, excessive smoke, etc.?

[James_Douglas]

I took a quick look here: http://www.aircare.ca/

I found this:

The AirCare standards for a pre-1960 passenger car with a curb weight of 1800 kg., and an engine displacement of 4.2 litres are as follows:

Driving Mode HC Standard: 473 parts per million

Driving Mode CO Standard: 4.49 percent

Driving Mode NOx Standard: 3520 parts per million

Idle Mode HC Standard: 948 parts per million

Idle Mode CO Standard: 4.70 percent

I have no idea if this is high or low for our engines...

James

[builtfercomfort]

General advice:

1. Tuneup first - good spark is important

2. Try setting your carb leaner if possible, and advance the timing.

3. I once got an old smokey Corvair with a bad cylinder to pass CA smog, they tested the 'good' side not the 'bad' side of the flat-six engine. So if you've been thinking of splitting the exhaust, maybe now's the time?

Like the others asked, what were your numbers - why did it fail?

[bob westphal]

The hole in the manifold is sucking air giving you a leaner mixture and causing higher engine heat. If the engine runs OK this way, which it shouldn't with a vaccuum leak like that, you possibly have an over fueling problem. Over fueling will cause a cooler engine temp because the excess fuel actually cool the engine. Check out your carb and plug that hole. A fuel/air mixture that is too lean will cause your valves to burn. I can't believe that they actually test your old truck for emissions.

[PatS....]

Wouldn't a more detailed interpretation of your results tell you which area of the system is causing the excess emissions?

Driving Mode HC Standard: 473 parts per million

Driving Mode CO Standard: 4.49 percent

Driving Mode NOx Standard: 3520 parts per million

Idle Mode HC Standard: 948 parts per million

Idle Mode CO Standard: 4.70 percent

[bach4660]

thanks for the tips, here are the test results

first test pass all but one

Driving Mode HC Standard: 473 parts per million

Driving Mode CO Standard: 4.49 percent

Driving Mode NOx Standard: 3520 parts per million

Idle Mode HC Standard: 948 parts per million 2000 fail

Idle Mode CO Standard: 4.70 percent

second test

Driving Mode HC Standard: 473 parts per million

Driving Mode CO Standard: 4.49 percent 6.33

Driving Mode NOx Standard: 3520 parts per million

Idle Mode HC Standard: 948 parts per million 967 fail

Idle Mode CO Standard: 4.70 percent

f8.34 fail last test fail on all but NOx

[Gary Manes]

The U.S. established EPA standards applicable for vehicles sold in the U.S. which were built on or after January 1, 1970.

As noted before, there were no standards nor equipment to buy or adjust for our cars. This sounds a little bizarre.

[Normspeed]

As far as the first two tests, if all that failed was idle hydrocarbons, you should make sure the air filter is thoroughly cleaned in solvent and dried if it's an oil bath type. warm up the engine and adjust the idle mixture by turning in the mixture screw til the engine idle speed drops then back off just enough for a smooth idle. Make sure the spark plugs are fresh and properly gapped. Drive the car to really warm it up well before the test.

If it failed everything on the third test after passing all but one item the first two tests, maybe the problem is with the technician running the test machine.

[Don Coatney]

How can they establish standards for this car with no baseline? When the car was built there were no emission regulations in place to establish a baseline? How do the other Caniadians with old cars get them to pass?

[40phil41]

How can they establish standards for this car with no baseline? When the car was built there were no emission regulations in place to establish a baseline? How do the other Caniadians with old cars get them to pass?

In Ontario, antique cars do not have to pass an emissions test. The only requirement is for a mechanical safety inspection when a title changes hands.

Phil in sunny Ontario