6 replies to this topic

[cal844]

Hiya folks

Car is a 1980 Clubman Estate with a 998 A+, HS4 carb and stage one kit, currently fitted with an AEM needle (ideally I need a leaner needle at idle but richer throughout the range as the engine, whilst not stuttering like a fuel issue, struggles slightly to gain speed, pulling the choke doesn't help either.) Air filter is a KnN element type, fitted in a late carb car air filter box.

Current set up has the CCV port and timing cover breather to atmosphere.

My question is in relation to the CCV port. Will there be a difference in emissions if I reconnect the breather to the ccv port will the emissions of the engine drop or increase? The engine was rebuilt 200 miles ago, doesn't smoke at all BUT stinks of fuel (plugs are a grey soot colour, which tells me they're slightly rich). Car runs really well just slightly flat then pulls well.

The issue I have is if I do change to the recommendation of an AAU (as supplied in the stage one kit) then I will need to raise the jet towards the bridge of the carb but I can only get 2 full turns until the bridge and jet is level.

Apologies for the long post, trying to get as much information in one go!


What do you all recommend I do?

Thanks in advance

Cal

Edited by cal844, 19 June 2020 - 07:40 PM.

[sonscar]

Not any help but I thought 2 turns down from level with the bridge was the standard start point for carb tuning.Steve..

[Spider]

I'd suggest you connect the Oil Seperator to the CCV Port of the Carb. and be sure you have a vented Oil Filler Cap.

 

The arrangement isn't only for blow-by and crankcase fumes, but also to continually ventilate the crankcase, so you don't end up with a load of moisture in the Oil.

[timmy850]

And if you have the system hooked up as Moke suggests, a smaller amount of air will go through the carb port (as the oil cap has a small hole) and this can reduce the idle rpm

[cal844]

And if you have the system hooked up as Moke suggests, a smaller amount of air will go through the carb port (as the oil cap has a small hole) and this can reduce the idle rpm

Thanks all, as you say Timmy850 I did have to lift the idle slightly.

Will I need to lean the mixture off at all as the engine will now theoretically be richer due to the CCV being connected to the breather instead of open to atmosphere?

Am I overthinking this?

Regards and thanks

Cal

Edited by cal844, 20 June 2020 - 10:12 AM.

[timmy850]

I don’t think that’ll cause any mixture issues. Theoretically it should all just be air with a very small amount of water and oil vapour.

[cal844]

I don’t think that’ll cause any mixture issues. Theoretically it should all just be air with a very small amount of water and oil vapour.

Perfect buddy, thanks.

Road test and perhaps a change of needle from AEM to AAU, I'll see how it goes