Getting a Dart SBC through an emmissions test

[Davrianman]

Hi all,

With the imminent arrival of my engine from Peter Knight, I need to start thinking about setting it up to get through an SVA. Here is my setup:
434 (7.1L) Dart Little M Steel Block
Brodix heads (330's)
Kinsler 2.5" Stack injection
Motec M8 ECU
Cam TBD, but probably mild road with little or no overlap

I want to set the exhaust up with Cats, lambda sensors and a cross over pipe. I will be using a closed loop lamba control on top of the base maps.

Questions: -
What are the criteria for passing the SVA emmission test? Is there a startup sequence etc that needs to be followed?

There seem to be lots of different Cats that you can buy from Summitt etc. Are some more effective than others? Is there a way to differentiate between them?

How high an AFR reading can you safely fun at for the purposes of an SVA / MOT?

Also what exactly is tested? Is it the amount of unburnt fuel in the exhaust?

Cheers,
Mart

[BogBeast]

I belive that its "visible smoke" only.. Is for my SBC..

[Slinky]

Visible smoke for this BBC Dart too..

[Steve_D]

It is all based on the age of the engine which I'm told SVA are getting very hot on these days and are not easily convinced that your new ali block is pre 1973 which would result in the 'Visual smoke only' type test.

The words they will use are 'Vehicle effective date' which in your case is the 1st Jan before the date your engine was made.

If I assume this is post 1st Aug 1995 the test will be....
Engine hot, oil >60C
Fast idle 2500-3000...CO <=0.3%..HC <=200ppm...Lambda 0.97 to 1.03
Idle 450-1500...CO <=0.5%.

All this should be possible with efi, mild cam and cats.

Steve

[eliot]

Steve_D said:

If I assume this is post 1st Aug 1995 the test will be....
Engine hot, oil >60C
Fast idle 2500-3000...CO <=0.3%..HC <=200ppm...Lambda 0.97 to 1.03
Idle 450-1500...CO <=0.5%.

All this should be possible with efi, mild cam and cats.

Steve

I assume thats as bad as it gets. In other words, putting a brand new block in - doesn't require euro4 & obd2 etc.
I'm sure the car above doing a wheelie (not naming specifically) hasn't actually declared that its running a new block - if you know what I mean. Which would therefore require cats etc.

[738 driver]

So has this recently changed Steve? when I last presented for SVA test the local station stated 'our test is based on the 'original' engine design spec, therefore if the engine was designed in the early seventies it does not matter that this is a much later version designed to run on efi, cat etc as you are stating the original design date of xxxxx and its before 1985 then thats how we will regulate it'

[Davrianman]

Steve_D said:

It is all based on the age of the engine which I'm told SVA are getting very hot on these days and are not easily convinced that your new ali block is pre 1973 which would result in the 'Visual smoke only' type test.

The words they will use are 'Vehicle effective date' which in your case is the 1st Jan before the date your engine was made.

If I assume this is post 1st Aug 1995 the test will be....
Engine hot, oil >60C
Fast idle 2500-3000...CO <=0.3%..HC <=200ppm...Lambda 0.97 to 1.03
Idle 450-1500...CO <=0.5%.

All this should be possible with efi, mild cam and cats.

Steve

Thanks Steve,

That's really useful info. You obviously have your Summitt thinking cap on today! :-)

Back to my other question, do you know if some cats are more effective than others? For example, if you run a physically larger cat, is it more effective than a smaller 'competition' cat? I can't seem to find any information quantifying how effective they are.

My setup will indeed be post 1995. As you mentioned, the SVA testers are taking these tests very seriously now. If you want a lot of horsepower then using genuine old blocks is quite a risk when compared to using new stronger Dart blocks...

Thanks,
Martin

[Steve_D]

738 driver said:

So has this recently changed Steve? ......

I don't believe so. The wording in the SVA manual is pretty much as I said re Effective date.
I do know they are getting more stringent on the engine age so even if you have a genuine 73 block you will still have to work hard convincing them.

In your case you are saying your engine is after their youngest cut-off date so there is no more stringent criteria and therefore no reason for them to challenge it further.

The only emissions level tighter than the ones I stated will be for vehicles that are on their 2001 and on type approval list which cannot apply to you as your car is not type approved.

Steve

[738 driver]

Hmm, not sure if I explained it too well........ basically, the example I presented was in 1999,... a 1991 1800cvh block, fitted with a different Ford head,internals, race cam,sidedraughts, water pump, ignition etc but originally EFI/CAT motor. If it were considered a current engine at the time it would have needed to meet a certain set of exhaust emissions. However, as the CVH engine was first produced in 1982, with a carb, then the original 1982 carb emissions level would be all that was required (less than 2.5% idle CO if I remember correctly), according to the local ministry testing facility. Thus suggesting that it did not matter what actual date the individual engine was manufactured (even if it left the factory the day before SVA) it only had to meet the 'ORIGINAL production design' exhaust emission spec.
So if you have an engine originally 'produced' in the late 50's then late 50's emissions standards (smoke tests)are how it should be tested??

[Steve_D]

Not sure how they interpreted it that way.

More extracts from the wording in the SVA manual…
If an engine has been modified it still has to meet the figures for the ‘Effective date’. The ‘Effective date’ is Jan 1st immediately before the date of engine manufacture.

It then goes on to say
Evidence of the date of manufacture could be…
• A copy of the donor V5 where the engine was original.
• A letter from the manufacturer confirming manf. date or the production period.
o If the period spans a critical emission boundary the later standard will apply.
• If the ‘Effective date’ cannot be determined then Aug 1st 1997 will be used.

Steve

[738 driver]

I think perhaps the SVA may have undergone some refinement since 1999 as there was definitely no mention of the terms you have listed back then.
Otherwise, I wonder if there exists a clear definition of the word 'engine' within SVA, its certainly more than just a block. Perhaps that was how the testers favoured my past efforts, as the numbers had been machined off the block (part of the re-machine process) it was a non matching cylinder head and most of the ancilliaries were new but of old design. Yet it just appeared to be a sidedraught equipped CVH!
It'll certainly be a very interesting exercise with this new project,as in principle its very similar.

[Davrianman]

As far as I am aware, for SVA, the age of the engine is defined by the block age. This is determined during the test by verifying the block casting number against a data base to find it's manufacturing date.
If you use a new dart block, I am not sure how it will be age dated, as there are no visable casting numbers like you see on the old SBC engines. I guess in this case it is classed as a post 1995 (or is it 1997?) engine and then subject to the emmissions that Steve has stated. As Steve said, as the Ultima is not type approved, it does not have to meet the latest post 2001 standards (Phew)...

Interestingly, I have heard that to get the latest new cars through the new emmissions tests, ECU's sense when a test condition is being made (i.e. the engine held at 3000rpm without the car moving) and automatically lean out the engine... Don't know if it's true, but it's a good idea!!

So.... anyone know anything about different types cats? Need to buy some soon.... (not tabbys or persians before someone thinks of it.... :-))

Edited by Davrianman on Tuesday 5th August 23:00

[Steve_D]

Local to me is a company Eurocats.co.uk who manufacture cats and seem to offer a custom type range.
I would start by contacting them as I'm sure the cat size and type will be related to both engine cc and power and they should be able to offer something.

Steve

[ringram]

No point leaning the engine out as you will then fail on Lambda, the limit is 15.1:1 AFR
So yes there is a small variation from 14.7 allowed, but not much.

You "could" throw a stock small cam in and pass then put a proper cam in for a while and swap back after your experimenting... which may, or may not coincide with your annual MOT test. 2 piece timing covers are useful for such experimentation.
Also you might want to consider bypass pipes etc.