CARB ADVICE

[heralddolly]

Hello.

I managed to pick up a set of NOS Stroms 150CD's for my Vitesse Mk2.

Great   :) !!

However, these units are actually for the Triumph 2000 vehicles  :-/ .

Not a problem as I have adjusted the link rods etc.

My understanding is that the needle set-up is different for Triumph 2000 & Vitesse Mk2 carbs. That being - one is a floating needle and the other is fixed. I aplogise if I'm not describing this as spot on as  I could.

Is this correct ??

If so, what comparison needle / spring would I require ?? According to my books the Vitesse Mk2 had 6J needle + neutral coloured spring.

Finally, is there an air inlet at the side of the carbs fitted to the Triumph 2000, which I think was not on the Vitesse vehicles ??

Any help and advice would be greatly appreciated, it's my last job before getting it on the road  8)

Regards.

Richard.

[ResinRocket]

Do you have a photo of the carbs? They sound like later ones with emissions controls on them, although I'm not familiar with Triumph 2000's.

The biased needles have different part numbers, so I'm not sure if a direct equivalent to the 6J could be easily found - you can always compare profile charts though! You might find that the jets are a different size to your Vitesse carbs, which will mean you'd need different needle profiles anyway. If the carbs are like I think they are, they'll have a fixed jet and the mixture is adjusted through the top of the dashpot, whereas your Vitesse carbs adjust at the bottom. (Correct me if I'm wrong!).

I've fitted Saab 99 Stromberg 150CDSE carbs to my Vitesse 6 engine so have had lots of fun playing with needle profiles and blanking off bits of emissions parts that I don't need! In order to get the right needles I just did it by ear - bolted the carbs up and found the mixture quite weak, so took the needles to my local carb specialist and asked him for some slightly richer ones. He kindly went through all the needle charts to find them. Mine wasn't a particularly scientific method but it worked.

Of course, there could be a tried-and-tested way of putting Triumph 2000 carbs on a Vitesse that I'm unaware of, in which case things will be much simpler!

[Pete Lewis]

the jets are all the same diameter in 150cd/ cdse
think there are only 2 springs made from different wire diameters
you can fit a 150 cd air piston  with the 6j needle  in a 150cdse but you cannot adjust the needle .
if you are lucky the carb body is threaded to take the CD jet adjuster assy, press out the fixed cdse jet and remove float chamber plug and you now have a cdse body fitted with CD bottom adjuster
all a bit of a hybrid but on many its possible

just a way out of a predicament
if you remove floats make sure they fit back the right way up, some have two float needle arms and can be fitted upside down. depends which of the 2 arms you use as this messes the fuel height
Pete


Pete

[ResinRocket]

I found that with the pressed-in type jet, the orifice is smaller than that for the adjustable jet assembly. That might not go for all fixed-jet Strombergs, but the ones I have played around with wouldn't accept the adjustable assembly. You could always ream out the drilling if that is the case, I expect.
Also, the problem with using the 6J needle and piston with the fixed jet would be that you couldn't centralise the jet, so you might find it binds and doesn't rise and fall properly.

[heralddolly]

Hi.

Having checked the carbs, it would appear that I have emission units with a floating needle and a fixed jet (rather than fixed needle & floating jet)  :-/

No problem re the emission bits as they can be blanked off and that has been done  :).

The carbs are, as suspected, for a Triumph 2000. My car of course is a Mk2 Vitesse !!

The needles supplied, with these NOS carbs are B5 DG with a blue spring (medium); which makes this too lean resulting in a definate flat spot for the Vitesse.

It would appear that I need a set of B5 BT needles; although I'm not sure about the spring as I may need a neutral coloured spring (light).

It's all a bit confusing I have to say !! I presume a B5 BT is a richer needle than a B5 DG ?? Most Triumph 2000 vehicles were supplied with either a B5 BU (1970 - 71) or a B5 CB (1971 - 74) as standard fitment.

How much difference do the spring types make ?? It must be some or otherwise there would not be a choice of 3; the last being red (heavy).

Any thoughts, would be appreciated and my intention is to give Andrew Turner (Turner Carbs) a buzz to see if he can shed light on this; especially as he actually supplied the carbs in the first place !!

It's most certainly a challenge and will let you know how I get on...............................................or not !!!!!!!!!!!!!!!!

Thanks as always.

Richard.

[heralddolly]

Hi.

Well, I think I'm getting there !!!

After numerous phone calls and explanations this is the latest update on the carbs:

The tag number is 3581 which are actually Stromberg 150 CD3 carbs. This tag number / carb was assigned to the Triumph 2000 (1973), making that a Mk2  I guess ??

These carbs had the biaised needle set-up. It would appear that the correct needle to work with the Vitesse Mk2 is the B5AJ, ON THIS PARTICULAR STYLE CARB, so will be popping them in and see how it goes.

Any reference to the B5 DG / BU / CB / BT would appear to focus on the Triumph 2000 which of course had a lower bhp, hence the thinking process on the B5AJ.

Cross referencing shows that the B5AJ was the needle designed for the GT6 Mk3 (104bhp), so I'm keeping my fingers crossed.

Have to say the Carb Hospital were very very helpful in the research on this. Each needle is about £20. Hey ho !!

Any observations are always welcome.

Thanks. Richard.

[ResinRocket]

Glad you're making progress! Hope it runs nicely on the new set-up, I'm sure it will.