spridgets
[Top] [All Lists]

An emissions test result- 75 Midget(long)

To: spridgets@autox.team.net
Subject: An emissions test result- 75 Midget(long)
From: Thecarguru@aol.com
Date: Tue, 13 Jul 1999 22:38:41 EDT
Reply-to: Thecarguru@aol.com
Sender: owner-spridgets@autox.team.net
Hi everyone.
This is my exhaust emission test results taken this afternoon. 
I live in Washington State, your test area may have different requirements.
For a '75 MG Midget 1500, no catalytic converter, no egr, no smog pump (air 
pump) no vacuum retard (a 1500 particular it seems) Flat top pistons from VB, 
stock cam and gears, and 12-15 degrees base timing, with a Weber DGV ,exhaust 
header and an Allison electronic ignition.
In this area, if your car is an '80 or older and passes they dont care what 
is under the hood. (Case in point my 74 Vega wagon has a .040 over 3.8 even 
fire Buick V6 where a 4 cyl once sat- obviously never an option in those 
years) Its only when you dont pass and are looking for a "waiver" that they 
require all original emissions devices, engines etc.And that you spend 100 
dollars at an emissions certified shop in an attempt to pass.
Maximum CO 3.00 Maximum HC 0600 ppm Minimum CO2 >6.00 Idle must be below 1100 
rpm
my results
CO at cruise (on dyno rollers at about 23 mph in third gear) 2.29
HC at cruise 0085 ppm
CO at idle   (740 rpm) 1.34
HC at idle  0161

And yes, I did lean the idle mixture out a bit before the test, but the 
results tell me I could have leaned her out a LOT more before the HC would 
ever have failed. 
Pretty cool, huh? As long as your engine burns all the fuel you put into it, 
and you arent putting way too much fuel in, it should pass the test.
Two years ago, I leaned her out-  WAAAY out, and this is what resulted
CO at cruise 0.29
HC at cruise 0025
CO at idle 0.99
HC at idle 0120

CO2 readings are there to determine if you have an exhaust leak, which will 
dilute the readings. If your exhaust has too many holes it will be under 6 
percent. Mine has always been above 13 percent.

At one point a few years back I worked in an emissions certified shop. I was 
"department of ecology emissions certified" to make emissions diagnosis and 
repairs. Your test results say a lot about the condition of your engine, 
ignition, and fuel system adjustments and calibration.

Thanks for reading!
Gary
75 Midget daily driver
75 Midget project car     

<Prev in Thread] Current Thread [Next in Thread>
  • An emissions test result- 75 Midget(long), Thecarguru <=