QuestionQUESTION: On TR4,TR6,and Stag. We have 3 different size engines.
2138cc,2496cc,and the 3 litre.
Each of these cars are fitted with 1.75 Strombergs.
Is it just the needles that are different?
Are the carbs interchangable with their 'fixed' jets,or would these jet have to be changed as well?
And can you tell me what the jet and needle sizes should be for the TR6,if I have to change the insides from a carb off say a Stag for instance?
Hope you understand and can oblige,many thanks,Nick.
ANSWER: Hi Nick,
The jets are fixed and can not be changed. The size and taper of the needles will be different.
The Stromberg, like the SU is a constant velocity carburetor that controls mixture by the volume of air going through it. You may find that any one of the carburetors will work on any of the engines but for fine tuning you should use the needles applicable to the particular engine. The needles are usually marked with a letter/number ID. The TR-6 used a "B1AF" needle where as the TR-4 used a "2A" needle and the TR-4A used a "2H" needle and the stag used a "B1AQ" or a "B1BF" depending on the model. The carburetors on these cars did have minor differences again depending on models.
If you are familiar with the process of tuning a carburetor for mixture at different RPMs you can use just about any carburetor on any engine if you can mount it. I have just mounted four 2 brl. Weber carbs from a 308 Ferrari on a Olds 215 engine (predecessor to the Rover 3.5). If you can modify throttle linkage, you should be able to fit most any one of the 175 Strombergs to a TR-6. They may each have a different choke assemblies so that also will need attention. You will need to look at the throttle shafts to see if they need to be changed also.
But that brings up a question. Why are you changing carbs?
Howard
---------- FOLLOW-UP ----------
QUESTION: I see jets for sale on ebay right now,hence my question about changing them? see mg-automotive item 180108251395,How are they not changeable?
Comments please.
Reasons why carb change is that I need to use a proper 1.75" inlet under the lid of my gt6,and on to my 2.5 eng'.In order to do this,I need to use 'stubbier' carbs and or the 'sloped' manifolds from 'English Parts' if I decide to go triple. Cheers for your help.
AnswerI never seen a jet replaced maybe they press or drive them out. I thought they were cast in. Unless the jets you see are for the Strombergs that have adjustable jets. I don't know what cars they came on. Have some statements in a Stromberg book but I have never worked on one. If you have adjustable jets it may be what you need.
Howard
