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MG TD TF 1500 - SU Carb 4468?

What can you tell me about the SU 4468 carbs on my wife's TF681 (1250)? Trying to learn about them before I remove and start a minor rebuild next week.

The casting number on the body is 4468. The casting number on my TF7211 (1500) is 6020. I assume that the 4468 carbs are not original to the car. The suction chambers have dampers. Early TFs had caps, but no dampers until TF3495. The 4468 dampers have a vented round brass knurled top.

One obvious difference is the number holes on the top of the throttle body. SU4468 has three holes. SU6020 has four holes, but only three are used.

Thanks for any help that you can give to me.

Lonnie
TF7211
TF681

Top photo: Rear carb 4460 on TF681
Bottom photo: Rear carb 6020 on TF7211





LM Cook

I do not know what the original application is for the 4468 carbs. The original carbs for all TF's is 6020 and 6021 (rear carb) The first picture shows a carb that is internally vented and yet has a vented cap which is incorrect. I haven't got a clue as to what you are saying when you say the early TF carbs did not have dampers. I have rebuilt early TF carbs and late TF carbs and they were all the same.
L E D LaVerne

I think the original brass caps were hexagonal, and non-vented. Wasn’t it the early TC carbs that had no dampers? George
George Butz III

I noted the damper info for early TFs as a side note to give more info about the carbs/replacement carbs on TF681.

Still looking for info on SU throttle body #4468. Especially looking to know if the rebuilding and set up is that same as later TF carbs.

Here is why I said that early TF carbs did not have a damper:

> TD-TF Workshop Manual Section B.13, "No damper is used in earlier units."
> TD-TF Workshop Manual Section P.5, "There is no damper in the carburetters of early Series "TF" models, but later models are fitted with carburetters of this type."
https://drive.google.com/file/d/0BxisXBEpc-IWdHBJQmhEYkRZLWc/view?usp=sharing&resourcekey=0-OsIlkz-OLJA6VFPf9yfMmw

> BMC AKD804 TF & TF-1500 Service Parts List page J.2,"Cap and damper assembly AUC8102 Com. at Chassis No. 3495." (1954-02-24) The oil cap without damper is not listed.
Neither oil cap nor oil cap & damper are listed in the Nuffield TF Service Parts List pre TF-1500, May 1954.
https://drive.google.com/file/d/0BxisXBEpc-IWbzBTM1RpTDB1ZEk/view?usp=sharing&resourcekey=0-Nc2p1iXW5hZvNJAaic3NPg

> Anders Ditlev Clausager, 'Original MG T Series' page 97, Production Changes TF: "TF3495 Piston Dampers added to carburettor dashpots."
No link.

> WKF Wood 'The XPAG Engine Data, Service, Supertuning', diagram of TF carb without damper on page # 44 of the 54 page PDF. Parts list on page #45 of 54 shows the oil cap part number AUC 4602. The diagram shows a hexagonal oil cap. See image below.
http://www.ttalk.info/WKF-Wood-XPAG-Engine-Book.pdf

> WKF Wood The XPAG Engine Data, Service, Supertuning (This OCR version edited 11/98 by Jerry Austin, Vintage MG Club of Southern California, changed the earlier TF carb diagram to the later model with damper, page 49, and changes oil cap/damper in the parts list on page 50 to part number AUC8102)
http://www.tcmotoringguild.org/techinfo/the-xpag-engine-wfk-wood-rewrite.pdf

Regarding vented or non-vinted cap - I don't know if the ramp on top of each suction chamber is drilled. Won't know until I remove the carbs and chambers. I have heard that some ramp were not drilled and therefore required a vented damper or vented oil cap(?)

Lonnie
TF7211
TF681


LM Cook

TF1414 has round non vented caps with dampers.

Frank
Frank Cronin

Ok Lonnie. Just have never seen it myself
L E D LaVerne

You are right! Interesting that the TC also started without dampers. To paraphrase The T-Series handbook:" Dampers were added to retard piston movement....The factory recommended that earlier TFs be retrofitted, so undamped TFs are rare." This is interesting, because a TD or TF with no dampers, a broken one, or no oil is barely drivable. I don't know the source, but the hex damper was original in the article I'm recalling- maybe Doug Pelton wrote it? If carb is double vented, it won't matter. However, an unvented and sealed (it no air leak at threads) carb with an unvented cap will run super rich and lousy. As we know, many times something "non-standard" was used here and there on these cars, perhaps as stocks ran out? Suggest email Joe Curto with the carb ? George
George Butz III

Hmm - interesting - I have a pair of carbs that I 99% believe came off a TD2 several years ago, they have 4031 on them and are the longer(5 1/4")square body design- I believe they are original -they have the 3 screw hole fitting for the piston cover, are internally vented with a brass hex headed non vented damper--The damper assy has one of those retainer setups that jams into the top of the piston tube to stop you being able to easily remove it from the carb.
My question is to Lonnie---are your 4468 early TF carbs long body like the TD2(4031) carbs or short like the 6020 and do you think my 4031's would have had dampers originally or do you think they've been fitted later
With my carbs among other bits and pieces there were 2 round knurled vented caps with bare shafts but no damper pistons which I doubt were fitted to these carbs originally because of the internal venting

willy
William Revit

I found a couple of 4468 carbs in a Google search. No usable info. Must not be common. I'll know more about mine when I disassemble. They work pretty well. Just leak a little. Cleaning and new gaskets, and Teflon/Viton seals should help, and is cheaper than a $2,000 set of proper 6020 TF carbs!

Willy: Hmmmmm - short vs. long carb body. I'll measure my 4468 carbs and 6020 carbs that are on a TF-1500 to see if they are the same size. I hope that the 4468s aren't longer ... not much space for air cleaners.

Page 59 in Clausager's book says, "TC/3856 (Aug 1947) Hydraulic piston dampers added to carburettors." I don't have a TC Service Parts Manual, so I can't confirm.

The TD Workshop Manual and the TD-TF Workshop Manual did not mention carburetors without dampers in TDs. I didn't check the TD Service Parts List. Here is a link to one that is stored on my Google Drive. Click the link. When the image appears, click the "download" icon to save it to your computer. Must save to use the bookmarks, which make navigation much easier.
https://drive.google.com/file/d/0BxisXBEpc-IWQkR0ZVdpRmVsSU0/view?usp=sharing&resourcekey=0-nt7Zg5MYxNeneugPgu0U9A

Lonnie
TF7211
TF681
LM Cook

Willy- 4031 carbs are only found on the Mark II or TD/C cars.

Tom Lange
MGT Repair
t lange

Thanks,Lonnie/Tom - It's interesting that TD2 run these longer carburettors when bonnet space is limited, that was the only doubt I had that they came from a TD but I'm happy now that that's where they came from.
They were with my MGY when I got it(deceased estate) and had been in storage along with the car since 1959 so had a strong chance of being what they told me they were. Apparently the old fella was going to fit them up to the Y-
Cheers
willy
William Revit

This thread was discussed between 27/05/2022 and 29/05/2022

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