13 replies to this topic

[Mark506]

I’ve just had my 1275 rebuilt but gone up to stage 2.

I’ve got a HIF44 for fitment on assembly, any suggestions on what needle to fit?

Cheers

[KTS]

ultimately you'll need a specialist to get the correct fueling set, but as a starting point you could do worse than have a read of the following

 

https://www.calverst...edle-selection/

[StefanMini]

I have a modified BDL needle on my 1293 stage 3 with kent 266 cam and runs very nice and have good AFR readings. I also tested a non modified BCE needle but is too rich on lower RPM.
Best thing if you want the right fueling is too book a tuning sesion with ACdodd.

[Readers14]

Each engine is different and needs setting up individually.

As mentioned previously, book it in with a specialist to get it setup correctly.

I have tried 3 different needles in my HIF44 & none of them run perfectly. 
Mine is booked in with Ron Harper Classic Sports next week to have it set up with the modifications I have (essentially a Stage 1).

Edited by Readers14, 20 June 2023 - 08:04 PM.

[Speedymad]

Contact AC Dodd via Facebook and watch some of his videos on YouTube.  He’s not a million miles from you and will get the car running spot on. 
 

I’ve got him coming up next month as can’t get ours running right. 

Edited by Speedymad, 20 June 2023 - 09:07 PM.

[alex-95]

If it's a newly rebuilt engine then stick a BDL needle in, it's a leaner needle so good for the running in stage and then get AC Dodd to tune it after 500 miles. AC Dodd recommends using a BEJ needle for the initial start up and bedding in the Cam, then swap to BDL, Bed the rings in and get 500 miles on it ready for tuning.

[Mark506]

Thanks for that.

Plan on getting it set up properly, just want a starting point more than anything.

[Lplus]

Thanks for that.

Plan on getting it set up properly, just want a starting point more than anything.

Does your carb have a needle in it already?  If so what is it?

[Carter61667]

Hi,

I’ve got a newly built 1380 A series engine with twin HS4 SU carbs. Unfortunately I have no clue what components are in the engine (believe it to be a 275/285 cam) and I’m not mechanically minded. It’s running pretty well but not perfect (Orange on colour chart) - what carb needles would you recommend? In a rush as need it to work before I take it away for Classic Le Mans next week!

[timmy850]

Do you know how the carb is set up now? Needle/spring/oil? Is it running rich or lean at idle/load/cruising?

You really need some air fuel ratio measurements to make anything other than a complete guess

[Mark506]

The carb going on it was good running happy when it was a standard 1275.

It’s as standard I think, so BFY needle I think.

[StefanMini]

The carb going on it was good running happy when it was a standard 1275.

It’s as standard I think, so BFY needle I think.

Try first a BDL or a BBW, I think a good starting point.

[Lplus]

The carb going on it was good running happy when it was a standard 1275.

It’s as standard I think, so BFY needle I think.

It might be ok on that. I can lend you a BDK and BDR needle to try but if the BFY is too weak low down those may also be too weak.  I'll try to remember to bring them to Ropley tomorrow.

[Lplus]

Hi,

I’ve got a newly built 1380 A series engine with twin HS4 SU carbs. Unfortunately I have no clue what components are in the engine (believe it to be a 275/285 cam) and I’m not mechanically minded. It’s running pretty well but not perfect (Orange on colour chart) - what carb needles would you recommend? In a rush as need it to work before I take it away for Classic Le Mans next week!

Orange on the colour chart suggests you are using a colourtune?  That only gives mixture at idle and just above in which case weakening the mixture using the adjustment nuts should produce the correct colour.  As to the higher throttle openings, does it run smootly without black smoke above idle/light cruise?  and if not what needles are in the carbs.

 

Gettiing needles right is a protracted process.