Emissions for pre-cat cars

[Louie Lungbubble 0]

(Yes I've used the search)

 

MOT time soon. Wanna check if my ropey valve seals are gonna spew the emissions test for me.

Just borrowed a Gassy Sniffy Box Thing ™ off a mate, and am gonna ram its probe up my cars fundament when I get in.

 

Dumb questions for today are......

A) What Co2 % is allowed on a pre-cat motor?

B) What % should an unmodded 1.8 normally be putting out?

C) I'm assuming burnt oil will result in higher hydrocarbons. If so, what's the upper limit for those bad-boys?

 

Cheers in advance.

[davidwort 0]

valver should run at about 1% at idle(0.5-1.5), 2% tends to make them run a bit better at the top end, I think you can go up to 5% on a pre cat car for the MOT though (nope - make that 3.5% see PDF), e.g KR 16v.

 

1200ppm for HC's

 

PDF from VOSA:

non cat test

 

pre '75 is visual only :) if the car doesn't dissappear in a cloud of smoke you get through!