Classic cars forum & vehicle restoration.

[Phil - Nottingham]

Although none of our cars are testable on these my MOT garage did test them on my 3.5L P.5B to see just what they are like.

CO = 3.74%
HC = 184 ppm
CO2 = 12.15
O2 = 0.72
Lambda = 0.92

I know the CO level is fine but tester said HC was too high.

Anyone know what the ideal levels are? The engine is in good condition. pulls and starts well, good MPG and has low oli consumption. Air filters are new and engine breathers are clean
_________________
Rover P2
Rover P4
Rover P5 & P5B
Land Rover S2 & S3
Morris Mini Traveller Mk2

[Richard H]

On a non-cat equipped car, the limits are 3.5% CO and 1200 ppm HC. Your Rover sounds excellent for a 3.5! My Maestro needed a full carb stripdown and rebuild before it would pass the emissions test.

My dad put his Gunson Gastester on the FB Victor and it recorded 11% CO, and the A55 was about 12% I think! Neither are running particularly rich.

[Nic Jarman]

My Midget would not pass the HC emissions even witht the filters off and the jets would up as high as they would go. I got a cylinderhead of a 1974 Midget put it on and it does not need to go through emission tests now. A significant part of the engine is pre '75.
_________________
1936 Morris 8 Series 1
1973 MGB roadster
1977 MG Midget 1500
Dax Rush

[michael1703]

I M.O.T a lot of mgb's, the later ones get emmisions tested and most pass ok, the worst happened to be 5.2% though

[Phil - Nottingham]

Thanks for comments - misunderstood the tester - he said he was really surprised at how good the results were for a car that is almost 40 - modern cars even on the first MOT have worse readings
_________________
Rover P2
Rover P4
Rover P5 & P5B
Land Rover S2 & S3
Morris Mini Traveller Mk2