11 replies to this topic

[MK1russ]

I'm in the process of fitting a stage 1 kit to my 1970 998 mini and have now realised that its fitted with an early fixed jet HS4 SU carb.

 

Which needle would be the correct one to fit? 

 

Thanks in advance 

[carbon]

Are you sure it's a HS4?

 

Most 998s were running HS2s in 1970. But may well have been changed at a later date.

[MK1russ]

Yep definitely a HS4, it's an Automatic.

[cal844]

AAU needle

[Dusky]

You can knock the needle out of the collar to use a swinging needle in a fixed carb. I've done that before with good results. In that case Of start by using a AAU needle.
I knock them out by putting the needle through a very small ring spanner, small punch and a vice. It's all easier than it sounds!

[MK1russ]

I've already got an AAU needle and compared the two side by side and the swinging needle was a fair bit longer than the fixed one. Would it still work though?

[Dusky]

It should, they work in the swinging carbs as well. And they always worked for me too

[carbon]

1970 998 Automatic - excellent. I've got a '69 and it's a really great car about town.

 

I would suggest using AH2 needle together with a new red spring from Minispares. And Shell V-Power, not supermarket fuel with lots of ethanol in it.

[MK1russ]

Thanks for the advice. I've been comparing needles on here : http://www.mintylamb.co.uk/suneedle/

 

The AAU needle as recommended previously, is very similar to a No.6 fixed jet needle. Just compared a AH2 needle to the stock AC one and it is richer but not as rich as a AAU/No.6, not sure which one to try?

 

I've made up my stage 1 kit using a cooper freeflow manifold, single box RC40, Oselli torquemaster inlet manifold and a pancake air filter.

[carbon]

I think you will find AAU behaves quite differently to number 6 needle, look closely at the first half of the profiles. This section affects low speed pick-up and acceleration - particularly important to get this bit right for an automatic.

 

Spring selection also makes a very big difference in my experience with getting early 998 auto to work well.

[MK1russ]

I'll go with your suggestion i think and see how i get on. Thanks again for the advice 

[carbon]

Thanks for the advice. I've been comparing needles on here : http://www.mintylamb.co.uk/suneedle/

 

The AAU needle as recommended previously, is very similar to a No.6 fixed jet needle. Just compared a AH2 needle to the stock AC one and it is richer but not as rich as a AAU/No.6, not sure which one to try?

 

I've made up my stage 1 kit using a cooper freeflow manifold, single box RC40, Oselli torquemaster inlet manifold and a pancake air filter.

Would recommend getting smallest bore freeflow manifold to keep low speed torque, likewise use the small bore Oselli Torquemaster. For air filter I would suggest using a K&N element inside the standard air box. All of these have a lot more flow capacity than you will need for a Stage 1 998 Auto, and stick with the pressed steel rockers.

 

My final suggestion would be to go for twin box RC40.

Edited by carbon, 20 May 2017 - 09:36 AM.