emissions question

[VC]

My car has recently passed its SVA. I am doing a mod to the fueling which would probably fail it on emissions if it were theoretically re-SVA'd. Know I'll have to get the emissions right for an MOT in 3 years time but is the car legal in the meantime with its high emissions?

[excess baggage]

VC

 

Your car will probably be illegal but I doubt if you will have a problem for the next 3 years (unless it belches smoke like buses or black cabs) In 3 years time find a garage owned by two brothers. One must own a 7 that he sprints every weekend, and the other a bike engined single seater for racing and a 7 for fun. I did, and my Supersprint has passed both times they have MOT'd it. The emmisions testing machine gave such outrageous readings that it was decided that it must be broke. Carbs were balanced, mixture adjusted, readings still silly. Machine declared dead and MOT issued. No probs.

[Peter Carmichael]

Just has my pre-SVA ('97) car MOT'd for the first time. The amateur builtness of the car meant it was treated as though it had a pre '75 engine for emissions purposes. i.e. visual smoke test.

 

This even though the engine was less than a month old.

 

Not sure if whether the car has been through SVA is an issue. I would go to a garage and ask to look through the MOT manual.

[CHRIS CLARK]

Did it pass on the 'spewing oil onto face' test Peter?

 

I assume that's all fixed now?

[Peter Carmichael]

A new scavenge pump belt went on the morning before the test.

 

When it falls off the same thing will happen again and maybe I won't be so lucky and maybe I'll kill the engine.

 

Not particularly happy at the prospect and I am working out a less messy early warning system.

[StewartG]

Welcome back Peter we've missed you. It must have taken ages to get all that oil off your hands so you can type again.

[Peter Carmichael]

My hands were oil-free.

 

My nose was not.

 

I don't type with my nose, so the delay is unexplained.

[Roger King]

The law is very grey in this emissions area.

 

At present, amateur built cars are exempt from emissions test with the exception of the visible smoke test. Note that the wording is 'amateur built', not Q reg.

 

Many MOT stations are unaware of this fact and should be reminded.

 

To pass SVA, you need to pass a test, but then don't need to worry for MOT! God knows what you will have to pass if you get stopped for a roadside test.

 

I wouldn't mind betting that the MOT gets changed in future so that cars that have been SVA tested then have to pass emissions after 3 years.

[Simos]

Does anyone know what the various emmissions regs are ?

 

I recall you Roger saying that for my car (way before SVA and a kit to boot) it was done at idle revs and was something like 1500ppm for hydrocarbons and 10 somethings for carbon (di/mon)oxide.

 

On the actual RR my emmissions at idle were about a tenth of the limit because my idle jets are pretty lean. Which is a joke really 'cos at 5,000+ on main jets I think it spits raw fuel and no doubt every poisonous gas known to man out of the exhaust.

 

Does this apparent loop hole extend to SVA assessed cars where you can tune for the test revs and then go banannas through the rest of the rev range ?

 

Or am I talking bollox again ?

[Roger King]

The MOT limits for non-cat cars are 1200 ppm for hydrocarbons (unburnt fuel) and either 3.5% or 4.5% carbon monoxide (CO) depending on vehicle age. Pre '75 cars are checked for visible smoke only as should amateur built cars be.

 

Even a well set up full-race Crossflow should be able to pass these tests easily.

 

The standards for catalytic cars (generally post '92) are much tighter and are individually specified for the specific model of vehicle. The lambda figure (fuel/air ratio) is also checked. Lambda 1 is a theoretically perfect fuel/air ratio of 14.7:1 and it needs to be very close to this figure to pass. A lower figure indicates richness and a higher figure indicates weakness. The catalytic converter needs a figure of 1 to work properly.