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Engine emmissions
rcx718 - 30/12/15 at 08:26 PM

I'm reading the IVA manual. Am I right that the engines emissions are measured against whatever limit was current when the engine was produced?

I.e. if I'm using a low mileage 1997 EFI engine will it be subject to current emissions (which it could fail), or the limits that were current in 1997?

Thanks up front for help!

chillis - 30/12/15 at 08:32 PM

Assuming you are building a kit using non-new parts then you will be going through the BIVA. Thus from 1st August 1995 you will require cat emissions.
You only need to worry about current emissions standards (Euro 5) if you are building a kit using all new parts as a new car IVA where you are required to meet the current emissions legislation.

theprisioner - 30/12/15 at 08:53 PM

They print the emission limits on the bottom of your V5. Basically it is difficult to pass the limits without a modern ECU that takes feedback from a Lambda sensor. The Lambda limit of 0.97 to 1.03 is very difficult, the slightest anomaly and you are struggling.

rcx718 - 30/12/15 at 08:55 PM

quote:
Originally posted by theprisioner
They print the emission limits on the bottom of your V5. Basically it is difficult to pass the limits without a modern ECU that takes feedback from a Lambda sensor. The Lambda limit of 0.97 to 1.03 is very difficult, the slightest anomaly and you are struggling.


There's no V5 because the vehicle hasn't had it's IVA test yet though!

big-vee-twin - 30/12/15 at 09:25 PM

You will need to go through the bet test, 0.2 CO, 200ppm HC at lambda 0.97 to 1.03 which is done at idle and fast idle. I been been through this and its extremely tough.

You will need fuel injection and cat.

If you fail the bet you can opt to try the cat test but this puts the engine under extreme stress.

sdh2903 - 30/12/15 at 09:44 PM

quote:
Originally posted by big-vee-twin

You will need fuel injection and cat.


Not strictly true. My last iva was on a 1999 carbed R1 engine, no lambda, no fancy ecu. Just a 400 cell cat and some tweaking of the carbs on an emissions machine before IVA.

[Edited on 30/12/15 by sdh2903]

theprisioner - 30/12/15 at 10:41 PM

quote:
Originally posted by sdh2903
quote:
Originally posted by big-vee-twin

You will need fuel injection and cat.


Not strictly true. My last iva was on a 1999 carbed R1 engine, no lambda, no fancy ecu. Just a 400 cell cat and some tweaking of the carbs on an emissions machine before IVA.

[Edited on 30/12/15 by sdh2903]


This is also true, I have heard of this many times. The reference cat has to be removed after the IVA test otherwise it rapidly become useless or worse choked. The ECU keeps the lambda at 1.00 at therefore ensures the cat is running at the correct temperature (600 deg C) at all revs and throttle openings. It (the cat) has then to be fitted for each MoT with exactly the same carb settings that are absolutely useless for track use let alone road use. However the world is a changing place after the now famous VW scandal, to what I don't know, but you can bet it will not help us. It is well known that cheating takes place and exactly how it is done. The diesel word is full of it.

rcx718 - 31/12/15 at 09:39 AM

I've got the exact same engine installed in my runaround car, I'll check my last MOT and see what the readings were.

The IVA manual flowcharts use the vehicles "effective date" to determine which test to use for emissions but I haven't found what this means yet. Still reading the IVA manual.

ian locostzx9rc2 - 31/12/15 at 10:00 AM

I got a zx9r engine on carbs through Sva just with a cat on it ,bit of a struggle but it went through had more problems with noise .

britishtrident - 31/12/15 at 07:22 PM

Yes the way it works on production cars is cats need stoichiometric air/fuel mixtures to clean up the exhausts but the lean mixture when throttle is lifted off and injection cut-off cleans the catalyst and allows the catalyst matrix to store reserve oxygen.

The text books will tell you if a catalyst is working properly the exhaust gas temperature at exit should be at least 75c higher than at entry, in practice this is difficult to measure.

MikeRJ - 31/12/15 at 11:50 PM

quote:
Originally posted by britishtrident
Yes the way it works on production cars is cats need stoichiometric air/fuel mixtures to clean up the exhausts but the lean mixture when throttle is lifted off and injection cut-off cleans the catalyst and allows the catalyst matrix to store reserve oxygen.


I was under the impression that it was the constant rich-lean cycling when under closed loop control that allowed cats to work correctly?

[Edited on 31/12/15 by MikeRJ]

britishtrident - 2/1/16 at 08:31 PM

quote:
Originally posted by MikeRJ
quote:
Originally posted by britishtrident
Yes the way it works on production cars is cats need stoichiometric air/fuel mixtures to clean up the exhausts but the lean mixture when throttle is lifted off and injection cut-off cleans the catalyst and allows the catalyst matrix to store reserve oxygen.


I was under the impression that it was the constant rich-lean cycling when under closed loop control that allowed cats to work correctly?

[Edited on 31/12/15 by MikeRJ]


Yes that was what I thought until the first time I looked at the scanner output of B1S1 on a Toyota with a wide band sensor, control was so tight there was no oscillation. It still went rich when the throttle is blipped open and closed but recovers quickly but stays slightly lean for a second or two afterwards.

jumping jack - 16/2/16 at 10:49 AM

When the special I built using a Mazda 1.6 fitted with an HSK turbo kit failed IVA on emissions as it had to satisfy a CAT 1 due to the age of engine not being verifiable.
I took the car down to Mitsi Art in Cosham Portsmouth who kept testing the car after I fitted a CAT and we plugged and unplugged the piggy back ECU that HSK supplied until it passed the required levels which left the tickover high.
Once home I could adjust the tickover emissions using a Gunsons gauge (kindly lent by Mitsi Art) until I got the required levels.
This was achieved and I finally got my IVA pass.
Looking at my V5 there is no mention of emission requirement and I have one year to go before it's first MOT.
However I elected to have a "Q" registration because an age related may have meant more emissions hassle.