302 Non CAT Emissions for IVA

Hi Guys looking at 302 Blocks and IVA emissions requirements.....
Hope you guys might help with some advise on whether engine Block age really matters re emissions.....?
I understand that a Pre 1st August 1986 engine has to have less than 4.5% CO and 1200 HC at idle with anything Post 1986 having 1.0% less tolerance at 3.5% CO with same 1200 HC ppm.
I am thinking of using fuel injection and am just wondering if anyone had any stories out there re their personal difficulties or not passing the IVA emissions with the different engine Blocks..... i.e. is it possible/impossible with a V8 non CAT block to meet the IVA emission standards....?.
If anyone has a personal tale to tell that would be really most kind.
Cheers All

Ian Anderson

Lifetime Supporter
Hi Marcus
i did SVA and have a 1990 Morgan Block same as Range Rover.
The first builder took the brand new engine and sent it away to be tuned so it is Full Race TVR spec. Radical cam head and valve work.
it does not have Cats
the Lucas EFI system just about copes but it does kangaroo at 1200 to 1800 rpm so I try not to drive in that range other than acceleration.
MOT time and it does pass but has to get really hot to do so and it does so at fast idle for one of the readings (2000 rpm)

So it is,possible to get it to work.

Now if I had a standard cam etc it could pass with a carburettor! The valve overlap is the killer!


Andy Sheldon

Tornado Sports Cars
GT40s Sponsor

You would need an engine block dating certificate to prove the year the engine was manufactured.

Failing that you would need to pass a 2020 emissions test.


i suspect with good tuning a new set of modern shaped alloy heads, new modern injectors in a new intake and a good exhaust system, you could get the old Windsors to approach the performance of the current LS series of engines. There have been a fair bit of work in the shape of the combustion chamber over the years that have improved the combustion process and the completeness of the fuel burn. Making sure that the rest of the system (engine sealing/venting/emissions control gear/Fuel tanks and vents) is all up to snuff as well will be critical. this will mean using hoses and connections that don't allow vapors to pass through them as well.

I am not sure what the regulations are in relation to IVA requirements in the UK

Hi Marcus,

I hope you saw the reply from Andy Sheldon at Tornado. There are a number of engine rebuilding companies who can issue an engine dating certificate. HOWEVER, before rushing ahead I strongly advise you talk to Andy at Tornado or Mick Solis at Southern GT. They regularly put customers cars through the IVA test and therefore are right up to date with the current requirements. Since the days of the SVA test the game has changed a great deal and the requirements of the current IVA test has introduced a mountain of detail that wasn't required 5 - 10 years ago.
Talk to the experts and listen to their every word. Both Andy and Mick have had cars fail on tiny bits of detail and therefore these guys really do have a huge (factual) level of knowledge.
Steve (MDA MK1 with Ford 302 running 4 barrel Holley)
Hi All... very much appreciate all the feedback on this... Paul good to hear you managed to get a 1985 through with a 750 holley that is very encouraging news... I dont object to going fuel injection route as I drove one recently and power delivery smooth no flat spots.... I appreciate everyone's help and will defo discuss more with the IVA experts..... I guesss its like most things you gotta roll up your sleeves and get involved to really understand but sounds like things are possible....