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MG TD TF 1500 - TF Carb Body Numbers


Hi,

Can someone please tell me, if there are two different numbers for the throttle bodies? AUC 6020 and AUC 6021? If that is so, which one is the front and which one is the rear? I have a pair of dismantled carbs but both bodies are showing AUC 6020?

Thanks

Maurie P
R M Prior

Hi Maurie
The correct number cast into the TF 1500 carburetor bodies is AUC 6020, Then on the 'rear' carburetor, usually directly under the cast in number there should be 6021 written with an electric pencil
This number is hand written onto the carb body after machining to identify it as different to the front one, What's different---not sure ,maybe throttle stop or vac. advance drilling--?---but 6021 is the rear carb
Cheers
willy
William Revit

From My car
Rick


Willy,

I had a closer look at both my carbs (which are AUC 6020 bodies)and one is clearly etched as 6033, and the other mostly indecipherable looks like it might be something,31?

I saw somewhere that these could be from an MGA? I was hoping to rebuild these, so would they still be use-able for a mgtf 1500?
R M Prior

Maurie
MGA carbs
6031 is the front 6033 is the rear
I can't see why you can't use them, there'd be a slight difference there somewhere in the machining, That's what the etched numbers are about, different numbers for different machining to the basic 6020 casting-I think the front carb has extra machining for the choke setup and the rear has the vac advance drilling but not real sure.
Something to be aware of and doesn't really matter is that MGA's have their carbs on the left side so if fitting them to a T type they will be round the other way 6031 on the rear and 6033 to the front
Just out of interest, right on top of the mounting flange of your carbs, just above the top stud hole there should be a code stamped there, what have you got there--
William Revit


Hi Willy,

Thanks again. On the 6033 carb is a number - R12, and while there might have been once, there doesn't appear to be anything on xx31

Cheers,

Maurie (freezing in the New England Highlands of NSW)
R M Prior

Maurie
If they were sold/fitted up as a pair, which they would have been, it's possible that only one carb was stamped, you're lucky to be able to read it and that some overenthusiastic enthusiast hadn't polished it away
I'm doing a pair for an XK120 at the moment and had to get the cracktesting kit out to read it and only one carb was marked

The answer-
99% sure 1500MGA ,your stamping indicates Nov/early Dec 1958 with 1600MGA's not released 'till later 1959
There would have been a slight delay in the dating between SU manufacturing to when the carbs actually got used on a car, but only days/weeks I'd think
The only reason I asked about that was to determine if they had 1500 or 1600 needles but I guess you'd be replacing them anyway so no big deal
But yeah, late 58 MGA carburetors-
When you do get around to needle choice I'd be going the std. GS MGA needles, they're 'just slightly' richer than MGTF needles and would be better suited to current fuel
William Revit


Thanks Willy - a great source of information,

Cheers,

Maurie
R M Prior

On my 55 with numbers matching engine, the rear carb is a 6020 the front is a 6021! Gave them to a rebuilder, (Bob Johnson) as a set and they came back the same way. Perfect carbs that perform like new. ?? PJ
PJ Jennings


Great information as always. Being a "should have a spare set" type of fellow, I am attempting to source a set of the exact and correct H4 carbs for this car. While the ones I have will be reconditioned by myself, I will use them if I cannot obtain the "correct" set.

A faint hope, but here goes - does anyone know of a set I could purchase?

Cheers,

Maurie
R M Prior

Wouldn't get too pedantic about it Maurie, there'll be hardly any difference between what you have and what TF carbs are--possibly a screw hole or some minor machining somewhere--The basic housing will be identical----I'd be finding someone with a 1500TF and have a good look at theirs and making yours the same, unless you're a concours buff, but even then most people won't pick the difference---Which raises a question, what's on your car now, if this is a spare engine you could swap them over when you fit it up then you'd have the carbs that came with your car originally.

willy
William Revit

Maurie - I have a set of genuione TF carbs. Shipping from the US to Australia might be a killer, tho.

Please contact me off-line if you are interested: tlange@acada.net

Tom Lange
MGT Repair
t lange


Willy,

The carbies on the car at present are H2's, and the engine was a Ray Skewes,superbly reconditioned XPAW. This was how I bought this TF1500, some 2 and 1/2 years back. This TF1500, is a beautifully restored example, but the "educated" person who spent squillions in restoring it, was extraordinarily foolish in not attempting to engine match the car. I have now done this and this is why, I am looking at "maybe" fitting the correct SU H4's to my newly reconditioned XPEG engine.

You are quite correct in suggesting that the differences in the MGA carbs I will most likely fit are miniscule, and I would be happy with that, but......I am "terrified" of the "purists" and the wrath they would inflict on me, if I dared to waver from the path of exactitude! (smiles)

I must admit though, to anticipating with lots of enjoyment to that encounter, at some time in the not too distant future!

Maurie



R M Prior

Maurie,
Burlen will sell you a brand new set, generally a lot better than what an original set plus refurbishment will cost you.

Bernie
B W Wood


Hi Bernie, thank you, and yes, I have looked into getting new ones, however, there is just a question of what the final cost would be, by getting them from Burlens, and with not knowing whether there would be GST and import duty attached it is an unknown at this point. If these costs were to be added, then I would guestimate the landed cost at anything up to $2600 AUD or more. One local supplier wants $3600 for a set!

Since I already have a decent pair,I might also go down the rebuild route. I have rebuilt several pairs of HS4's over the years so these older ones, won't faze me. (Images attached of my rebuilt HS4's)

Cheers,

Maurie



R M Prior

Hi Maurie,

I understand, here in NZ we don't get charged customs duties for vintage car parts. We do get charged GST but some times shipments get through without it. About 10 years ago I paid an expert to rebuild a set of 1250 TF carbs, it cost NZ$1080, a year later I bought a new set for mty TD at NZ$1250 delivered, so since then I have never had any rebuilt, just bought new. I then sell the old ones which brings the cost down. The problem here is labour rates kill us, maybe Aus is cheaper and a lot cheaper if you can do it yourself. I just don't have the skills when it comes to things like throttle shaft bushings.

Regards Bernie
TD, TF1250, MGA 1500, TF120, 4.2 E-type coupe
B W Wood

Conversation with Burlen a couple of weeks ago. They currently have no new 1 1/2 SU carbs but will recondition mine for around £1000 !!! After problems I stripped mine (car imported from the US to the UK about 5 years ago) and discovered that the needles for example had a number 226 on the shaft. Burlem did not recognise this number. So the correct ones and new jets were ordered. One assumes that during previous work what sort of worked- was used. I must state that the car was always running to rich and the only way I could previously correct it was to have the needles adjusted so that the shaft was actually protruding below the piston base.
JK Mazgaj

Terrified of the purists--? -Just ignore them, most of them just like shiny cars so they can see their own reflection, poke em in the eye with a blunt stick, they'll go away.
I might have something stashed away, or not, What's your chassis number, it's on the lh front chassis iron just in front of where the steering rack protrudes.
willy
William Revit

JK,

The H4 carbs on TF681 also have “226” jet needles in .090” jets. The carb casting is 4468 so not original TF carbs. I can’t find info about the needles or the carbs.

Like you, I lowered the needles .050” in the pistons. Don’t know if rich running was caused by the 226 needles or by the damage on them and on the jets.

Joe Curto is sending new GJ needles and .090 jets.

Lonnie
TF7211
TF681
LM Cook

#226 is a Beck-Arnley needle--it's the equal to a GJ

I'd be going a GS needle-90 jet and red springs, specially if you have any of the dreaded ethanol in your fuel
GS is just slightly richer than GJ and suits these modern fuels quite well

willy
William Revit

Willy, Will contact Burlen and have a chat with them Monday to see what their opinion/experience is. Having ordered the replacements GJ needles and new jets Friday they may not yet have posted yet. My castings are both AUC6020
JK Mazgaj

Cheers JK---I'd be most interested to hear their opinion of using the GS needle---
William Revit

Willy, Spoke to Burlen yesterday when ordering replacement needles and jets regarding the point about ethanol fuels and jets. They said they were unaware of any advantage of using a particular needle in the world of ethanol fuels other than that most are aware of namely the detrimental effect on gaskets/hoses etc.
JK Mazgaj

JK
We didn't learn much there then, they'll need to get on top of things if you're going to get forced onto E10
What fuel are you running----
You can get away with E5 ok ,just, but E10 needs a tiddle extra fuel
Modern cars with O2 sensors automatically adjust the mixture to Lambda 1 (Stoich) which results in 14.7:1 mixture for normal petrol and is at 14.1:1 for E10 and would be approx.14.4 for E5
cars 'without O2 feedback' will need a bit extra fuel poured in to run right as well
With an SU you can go a flat or two richer on the adjuster to get a bit more but that in turn richens the idle so not ideal----slightly richer needles are the go if you are stuck with E10 and if you are running E10 regularly as your fuel you need an additive, fuel stabilizer to stop the fuel attacking your aluminium bits-carbs,pump--ethanol loves aluminium and forms a creamy paste if the car's left sitting for any extended length of time
William Revit

Trying to stick to Esso I quote
"Although our pumps have E5 labels on them, our Synergy Supreme+ 99 is actually ethanol free (except, due to technical supply reasons, in Devon, Cornwall, North Wales, North England and Scotland). Legislation requires us to place these E5 labels on pumps that dispense unleaded petrol with ‘up to 5% ethanol’, including those that contain no ethanol, which is why we display them on our Synergy Supreme+ 99 pumps."
This of course doesn't help me living in Cornwall. So it's E5 with an additive. Regards to Burlen whilst claiming to be the sole manufacturer of S.U. carbs I can only assume that their avoidance of comments on Ethanol could possibly be commercially driven-don't highlight knowledge detrimental to their product, just my opinion.
JK Mazgaj

Sounds about the same as here--We go to the petrol station and it's multiple choice
Straight unleaded(can be up to 5% ethanol) in 3 octane ratings 91-95-98 then E10 and E85

Sorry if I've put the frighteners into you but if your fuel is the up to 5% E then you should still be ok

but my personal choice would be go for the GS needles, they're only just a tiny bit richer than the std. GJ and the slight richness is more at higher cruise speed and at wider throttle openings ---but if you've already got your new GJ needles and your car has been going ok and doing what it's supposed to do with the GJ (226) needles it should still go ok with new ones of those as well I guess

I was really hoping that Berlin would come back to you with heaps of info on mixtures etc for us to get into but there you go-

willy
William Revit

Maurie - have you found that chassis number---
William Revit

Hi Willy,

I hope by entering a new post it might reactivate the thread I was after -

My chassis number is TF9612

Cheers, Maurie
R M Prior

Well' there's a thing, I tried reactivating this and there was nothing there just the title-It says this thread has been removed--My guess is that you must have got in and reactivated it before I tried-interesting
but still-
same as-
GS needles -red damper springs is the go and don't drop the needles, flush with the piston is where they go

William Revit

This thread was discussed between 04/06/2022 and 10/08/2022

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