8 replies to this topic

[cal844]

Hiya folks. Needing some advice for the refreshed (rings, shells and relapsed valves) 998 in my Clubman Estate, I'd also had the gear cluster changed as the old unit was jumping out of second gear, engine wasnt smokey but was breathing a fair bit (not the worst I've seen, but definitely not as good as it should have been.)

I know this has been asked a million times

What needle choice is best for a 998A+
Totally standard except stage one kit and the commercial version of the RC40?

I use 20/50 engine oil in the dash pot, the car runs good but stalls at idle and I know it is running well above the 3.0% CO currently, recently changed from a 1275 engine from a late carb car.

I've still to check what needle I have fitted and I cant access the Minty lamb files for some reason.

Thanks and kind regards

Cal

[Daz1968]

20/50 probably a little thick and piston not raising quick enough. 

[luismx123]

ive used an AAA and AAU and both worked well. I did some vizards mods on my carb and some small inlet porting and used the AAA which went really well. The AAU was installed before - just with a standard stage 1 kit so Id go with that first, and if you feel you need more AAA

[cal844]

20/50 probably a little thick and piston not raising quick enough.

If I go to any other oils the car doesn't like running right, currently it's just the stalling at idle, I'd also like to get the emissions down a bit too

[cal844]

ive used an AAA and AAU and both worked well. I did some vizards mods on my carb and some small inlet porting and used the AAA which went really well. The AAU was installed before - just with a standard stage 1 kit so Id go with that first, and if you feel you need more AAA

I've heard that AAA will be way too rich but at the moment it's worth a try, I'm going to remove the current needle and see what it is, I just need to know whether to go richer needle then lean the mixture screw off or just fit a lean needle.

I think it needs to be slightly richer at idle and leaner for cruise.

[cal844]

I currently have an AEM needle fitted

I have a choice of
AAC
AAU
ABS

Plugs have grey electrodes but sooty outer area

I can't access the Minty Lamb data and there doesn't seem to be a comparison or selection database

Edited by cal844, 20 May 2020 - 10:03 PM.

[timmy850]

Try this site which uses the minty lamb database
https://www.classicm...chnical/needles

Mine was perfect with the AAU in the minispares stage one kit

AEM is about the same as the AAC down low but then is much leaner at the top end
AAC & ABS are leaner than both AEM & AAU

[cal844]

Perfect, thanks!

I will have an experiment on the road today, I have a 3 or 4 mile long stretch of 60mph road near me, so I should be able to do a few stops, to simulate rolling up to a set of traffic lights, as that's where the issue is.

[sonscar]

I always thought that the first few sections of all needles around idle were the same?I found erratic return to idle was throttle spindle wear,poor butterfly fit,or too weak at idle.Just my thoughts,Steve..