TO TWIN CARB OR NOT

[FORREST]

DEAR SINGER OWNERS;

MY NAME IS FORREST JOHNSON I HAVE MET SOME OF YOU AT STOWE THIS PAST YEAR. YOU WILL RECALL THAT I HAD A FINE 1954 4AD BARN FIND, THAT I HAD BOUGHT FOR A PARTS CAR BUT SEEMED TO NICE TO PART OUT. THE 1952 4AD PROJECT IS COMMING ALONG WITH THE ENGINE GOING TOGETHER NOW. I SHOULD HAVE A RUNNING CHASSIS IN APRIL. I WILL TRY TO POST SOME PICTURES IF I FIGURE OUT HOW TO DO IT. NOW FOR THE REAL QUESTION. I HAVE PURCHACED ANOTHER PILE OF SINGER FOR MORE PARTS (THESE THINGS BREED LIKE RATS) AND I NOW HAVE A TWIN CARB ENGINE. I WOULD LIKE SOME ADVICE AS TO WEATHER TO KEEP THE 54 ORIGINAL OR UPGRADE TO THE TWIN CARB. AS I HAVE NOT DRIVEN A TWIN CARB I DO NOT KNOW HOW MUCH BETTER THE PERFORMANCE IS. SO IF YOU ALL COULD WEIGH IN ON MY PROBLEM I WOULD THANK YOU.

IF I CHOOSE TO REMAIN ORIGINAL I MAY HAVE A 1955 TWIN CARB COMPLETE CHASSIS FOR SALE IF I CAN FIND A REAR END FOR IT.

THANK YOU

FORREST

[Paul Bouchard]

Hi Forrest,

Beauty is in the eye of the beholder. In the end, the choice is yours. We have seen many cars saved only through mixing and matching. There are "cars" that are that by name only. More a collection of parts than a car really. Those restoring these into cars have their work cut out for them. Years could be spent finding everything needed. Robert Morreau is an example. A collection of body parts were hardly a car until he cobbled them together with an MGB engine and drive train giving us the "FrankenSinger". My A series had, at one time in its history, an engine and gearbox change. A Roadster none the less, but original, no.

There are those who will look for every single nut and bolt to make their car original, while others think nothing of doing things their way. Who is right? Well, both of course. If the desire is to keep originality then keep as much of the car together as is possible.

The performance difference between the 4AD and 4ADT are below. There is a difference. Not earth shattering, but a difference none the less otherwise why produce the car?. If the goal is to make a rarer car by swapping engines, then you may do so, however the engine would be a transplant and the car would still be a 4AD. Keep in mind that there were other parts differences between the cars... rear axles and gearbox (ratios) are examples. As for value, swapping the engines may make some difference, however to someone wanting originality a car with matching numbers is much more desirable.

Not really an answer, but more to think about.

Paul

[Peter McKercher]

Forrest
Good to see things are coming along nicely with your restoration.

There has been an extended debate by members of the UK Singer Owners Club about this very issue with each side claiming they are correct in that there is either enhanced performance or it makes no difference. One would assume the extra aspiration would make a difference and certainly when the cars were raced in the Fifties by the Singer Owners Club of America (a vigorous racing club at the time), they were separated into two different classes - single carb vs twin carb. The race times for hill climbs, for example, were consistently better with the twin carb models.

I owned a twin carb and found the performance to be vigorous as compared to my MG TD. I have never driven a Single carb Singer to make the comparison though. I can tell you that the Twin Carb sounds better, however. And that could make all the difference.

With respect to originality and impact on your investment (if that is a concern), I can say with certainty that the upgrade will not have a negative impact, but indeed will likely make it a more desirable car when it comes to resale.

[mikeyr]

You are not swapping engines when you make it twin carb, just swapping the head. I have been lucky to own and drive both twin and single carb cars, I will never again own a single.

The difference in power is noticeable, the difference in drive ability is noticeable, it may only be a few horses on the charts but you can immediately tell the difference when you give it gas. I have never broken a single carb car rear axle, how many broken twin-carb rear axles would you like, free ? There is a reason why Singer put the Salsbury axle in the twins, the Moss BREAKS when you put a twin carb head on. I know because I only had one Salsbury axle so I kept putting twin carb heads on Moss rear ends and breaking them, until I had brand new axles with modern metallurgy made for my 4AD driver.

But the real most important part is driving around town, its just smoother and better.

You could swap out the entire motor if you wanted to and then you would not have a matching numbers car anymore and that is important to some people, less important to others but it will make a difference when you go to sell the car. But unless the current motor is shot (you said its near being finished so its not shot) why swap it ? just swap the head, you can keep the original single carb head and swap back and forth very quickly...gee I think today I will drive slower than my grandpa ever did ! ok put the single carb head on go do it...gee I think today I will drive a safe car in todays modern traffic, ok put the twin carb head on, its that easy and almost that quick, hardest part is finding the head gaskets you will from swapping every weekend

[Phillip]

Hey Forrest,

Welcome to the world of the Singer enthusiast! They do seem to multiply, don’t they!! LOL!

Well, as Paul says, at the end of the day, it is your car. That said, I tend to be a preservationist and a historian of the original. I well recall the red ’54 4ADT you brought to Stowe and was amazed at how original that car was. It is a rare one by any standard and to get one in such original and unmolested shape is a miracle. I remember seeing the steering center, for example, which has the ‘SM’ logo button on it. Only the last 200 cars were so fitted. Everything down to the mirror was there and all original. Lovely!

History tells us that the twin carb Roadster engine was first offered in the fall of 1952 as a ’53 model and benefited from a 10HP increase in power due, in part, to a an increase in compression ratio as well as the extra carb. It also incorporated a number of other refinements such as a thermostat, vacuum advance distributor and a higher rear axle ratio was fitted. Road tests of the day claimed an increase in top speed of 6mph from 74 to 80mph.

It all looks good on paper, but Ashley Crossland, one of the world’s foremost experts on the Roadster, reviewed the topic of one vs two carbs and reasoned there was not much really in it overall. I’ve owned and/ or driven every Roadster, except the R type; so that’s A. 4A, 4AB, 4AC (yes, Ashley’s car) 4AD (single and twin carb) and the SMX and agree that the 4AD is the most flexible and practical version of the model for modern-day motoring, but beyond a feeling of more torque, which gave the impression of it being a bit more ‘lively.’ I have to agree with Ashley that I personally didn’t feel a huge difference. With the additional tuning that the cars received for racing, I bet they went really well with the dual carbs.

The second-generation ‘universal’ head used on the 1500 has the provision to allow either a single carb or twin units to be fitted, so a basic conversion can be done to any engine so equipped. Not impossible – the Solex FAI carbs are reasonably easy to get and I’ve seen manifolds for sale. However, if you want to benefit from the whole 6HP, you’re better swapping the whole thing out if you have a complete spare engine to get the compression ratio improvement and other mods. Singer knew what they were doing when they introduced all the improvements as a ‘package’ on the 4ADT and combined they amount to the full benefit. Paul’s performance chart gives a good indication of this.

Somewhere in the region of 12,000 Roadsters of all types were made and Ashley reckons there are no more than perhaps 600 remaining world-wide. You have two of those survivors and one is probably the most desirable model: a REAL, original 4ADT with all the right details. I say just be sure to bring that one back to life as Singers intended. Any 4AD, original or not, with twin carbs is going to appeal more to the sports car enthusiast. A real Singer enthusiast would prefer an original car, but the wider market won’t be so fussy I guess.

Forrest, at the end of the day, it’s great to see you collecting these cars and saving them and thanks for considering the question in the first place…it shows you care about the result.

Motor On!
Cheers,
Phillip

[BRG]

Forrest,

Like most have said it is really up to you on the engine swap. The only note I have is that the ID number on the twin carb will be 4ADT***** anfd the transmission ID number will be T4AD*****. If you want to be a speed demon go for it!!!
BRG

[FORREST]

THANKS TO ALL WHO LOOKED AND AND GAVE THERE VALUED OPINIONS;

AFTER A WEEK OF THOUGHT I THINK THAT I HAVE COME UP WITH A PLAN. I WILL RESTORE THE THE 4ADT CHASSIS, ENGINE AND TRANSMISSION. THOSE NUMBERS MATCH TO A CAR THAT WAS DISPATCHED TO VAUGAN MOTORS IN 1955. THE CHASSIS NUMBER IS 4AD2900 BUT I DO NOT HAVE THE BRASS PLATE FOR THIS CAR, I ALSO DO NOT HAVE THE REAR END FOR THE CAR. I DO HAVE A FEW BITS OF THE ORIGINAL BODY BUT THAT IS THE WEEK PART OF THIS PROJECT. THE CAR HAD A SALISBURY NO. 2 BACK AXLE WHEN SHIPPED AND I WILL NEED TO FILL IN THAT HOLE IN MY COLLECTION OF SINGER. WITH WHAT I HAVE OF THE 2900 CHASSIS I WILL DROP THE BODY AND REAR END FROM MY 1954 ON TO THAT CHASSIS AND GIVE THE TWIN CARB A TRY. I HOPE THAT I DO NOT TEAR UP THAT REAR END WITH ALL THAT MASSIVE POWER. THIS HOWEVER DOES NOT MEAN THAT I WILL BREAK UP MY ORIGINAL 1954 I JUST CAN'T AFFORD TO DO BOTH ENGINES AND CHASSIS AT ONCE.

I WOULD LIKE TO HAVE AN ORIGINAL REAR END IF SOMEONE KNOWS WHERE ONE IS HIDING. IN THE MEANTIME OLD 2900 IS OFF TO SAND BLASTING AND THE ENGINE IS ROLLED UP TO THE WORK BENCH. I HAVE TO GET THE NUTS AND BOLTS OFF TO PLATING, BECAUSE DRIVING TIME IS COMMING AND IT TENDS TO EAT UP MY RESTORATION TIME.

THANKS AGAIN

FORREST

[Phillip]

Hey Forrest,

You said it, my friend...driving time is coming and...yes...Stowe edges closer every day!!!

We got a replica plate via Robert Moreau for John Lewis' Coronation Blue 4ADT and I stamped it. If you really want one for the car we can see if Bobby could get a few more made.

Good luck with the resto!

Cheers,
Phillip

[William Howerth]

I have a very nice 4AD engine block that is not cracked if you would like to trade it for the twin carb set-up?