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MG TD TF 1500 - Carb Overflow tubes...
|Can anyone describe or provide pics of the proper routing for the carburetor overflow tubes on a TF-1500. I recently purchased new ones to replace a broken one and before I go out to the garage and start messing around, I decided it might be wise to check with the experts.|
Cheers - Dennis
|D L Rainey|
Hope the attached photo helps. I got it from this same BBS last year to help me refit my tubes.
|Try this page:|
|Remeber there was a ton of discussion about this, and the result was that this is common, but wrong. That said, unless I was going for total concouse originality, I would do it this way. Feeding through the hole in the bearer plate with the clip on the front (as was decided to be original) was very difficult with the engine sitting in just the frame. George
|George, just out of curiosity, why did you route the pipes through the hole? Seems a lot more difficult and I can see nothing to be gained.|
|To get it as far away from the hot exhaust pipes as possible!|
Bowl overflow will miss the exhaust, even at speed as the air flow sends it towards the rear.
The whole point is do all you can to prevent fire when a float valve sticks open and the chamber fllods.
Beware of the engineering goof with the tickler pins venting overflow rather than the overflow tubes!
|dennis, right or wrong, mine go OVER the plate down through the same bracket. the hole sits empty. regards, tom|
|Thank you gentlemen,|
I would not have had a clue without your help. Seems that the PO just let them hang straight down before and thats probably why one (the front one) eventually broke off at the banjo bolt, most likely due to vibration.
Thanks again - Dennis
|D L Rainey|
|Jim, yes it was a pain. I did it because of doing my restoration that was as close to original as possible. Otherwise, forget about it! George|
|Dennis, could you tell me how long the new overflow pipes are that you got. Right now I have mine going straight down. They are 19" which is not long enough for the one closest to the firewall to reach the bearer plate. Also, one of mine is steel and the other copper. I understand that steel overflow pipes were used on the TF's which I have. Not sure how easy steel tubing bends. I will be changing these before I get it on the road because I don't see how they could last with the vibration as you pointed out.. John|
Sorry for having taken so long to reply. Believe it or not, I couldn't find a tape measure around the house until just this AM. My overflow tubes are 31 inches long. They came from Moss Motors. I now have the problem of how to bend them so that they windup looking like those in some of the pics posted here. Anybody help with that one???
Cheers - Dennis
|D L Rainey|
either bend them very slowly and carefully using your thumb as a bending form, or better, take a glass beer bottle bend the tubing around it. When you are done you can drink the beer, so don't drop the bottle while working... it's your reward.
You may also want to view all the tube pictures on my website, under MG TD15470 Restoration » Engine XPAG TD2 15613 » Carburetors
|John, and Dennis - here is another photo of the tubes going straight down the engine plate, with a clamp on the bulkhead side. I tried to find a definitive answer on this when I restored my car, and didn't find an exact method, or consistency going through the hole in the engine plate - which didn't make much since to me. Actually the ones I remember from the 50s and 60s all looked like spaghetti, and rambled all over. |
Most were soon cut off, although they shouldn't have been.
Anyway the tubes can be bent with a tubing bender, or just around a small diameter can, especially the copper which is not drawn and soft.
Straighten them first by hand and then measure twice - bend once ;^)
|D C Congleton|
Very nide job on the tubes,,, but I do have one comment,,, when I first did the overflow tubes on my TD, I soldered them together as you did where they both join. After a few thousand miles, the tube from the front carb fractured at the banjo fitting. I am assuming that by soldering them togehter there wasn't enough flexability from vibrations, and thus caused the fracture. I have since joined them together with a piece of rubber hose (spiral cut and then wrapped around both tubes) has they turn down in front of the plate. This allows for flexability.
|Seems we've been here before. I'd suggest that you go the archives for "overflow". Look for 'Carb Overflow pipes' in the list that comes up. IMHO, the answer is 'Yes, the did go through the hole in the bearer plate.', the clamp belongs on the front surface.|
|Steve, the tubes aren't soldered together - that is a strap made from copper and bent around them like a clamp, loosely holding them together.|
Bud, I really don't know how they were as I couldn't find a factory photo or drawing that showed them clearly. I actually saw some drawings that showed them sorta rambling down.
Sorry, but I don't use the archives of an anecdotal forum as an authoritative source, or do I offer my method as such.
I ended up doing what seemed logical, neat, and practical for an assembly line worker. The routing of the tubes over and/or through the hole in the plate was also counter to all my Air Force training to avoid wear points and sharp bends in routing tubing.
Having said that the tubes may have been run and bent over the top of plate, run down the front side for an inch or so, then bent back through the hole, then bent back down, then clamped, the continued down. ?
|D C Congleton|
|You're absolutely right, Dallas. Baring the discovery of some long lost factory document, we don't really know how they were formed. I do find it interesting to note that the 'through the hole' configuration has been found in a number of cars. It's not a simple configuration, but would be easy to do using a jig to prebend the tubing.|
|Dallas, your tubes look better than mine, and would be very easy to remove to service or polish. Very difficult to remove them routed through the plate hole. After re-reading all of the threads, studying pictures, who knows? There seems to be a more of a concensus about TF tube routing, but very little on the TD. Interesting comment about the definitivness of the archive-since we weren't there we can't really say for sure. But it is a good body of knowledge and you do have to give consideration to people like Don Harmer who dealt with T-series since new, etc. I personally think that as these cars were sort of hand-made that there are a lot of variations- thank goodness we aren't doing older Corvettes. George|
|I think I could commission Gordon Lawson to make a definitive period photo of the correct routing in photoshop. (wink)|
Besides, as Gordon demonstrated, I worked on the line when they built TDs (wink)
|On my TF the overflow tubes start wit a right angle and go vertically downward clearing the bowls by abut 1/2 inch.|
The rear goes about 2 inches below the bowl and then angles down and forward at about 30 degrees ( directly towards the hole in the front plate) until it reaches the front tube. togeher they both then follow the same angle thru the hole and then bend vertically downward thru the clamp on the front of the plate, About a 60 deg. bend, ( 1 90, 1 30, and i 60 degree bend in each tube)
Note that the rear tube goes directly thru the hole after the bend from verticle (minimum distance) and the front tube then parallels it,
The plane of the tubes is parallel to the engine and perpendicular to the front plate so it looks reasonable.
This is the most logical requiring the minimum of bends and tubing length.
This looks neat and clean and the easiest to install.
I don't know if this is the original in all cases but it makes sense with the fewest bends and the most direct route to the end point. ( and the easiest to install).
When I can get to Jim's Original TF I will check further.
|Interesting picture Dave,|
Looks like you were having a good time at the factory (he he)
I think Don has the correct info on the tubes.
I digress a little.
Interesting picture. Gives you some kind of idea of the original order of assembly regarding tub and chassis. The chassis looks much more complete than I would have expected including radiator chrome and steering wheel installed. Also windshield and rear fenders are installed prior to tub attachment. Also noticeabe are various lines comming thru the fire wall. Makes you wonder if the dash and instruments or how much are also installed at this point.
|Hi Don, It would be great if you could phtograph the car in detail and somehow make the pictures available- maybe Bud could post them, you could sell CD copies, or whatever? George|
|Darn it Dave,|
If I had known you had experience on the line, I would have asked for your help installing the tub on the frame a few years back!
Great picture Gordon!
|I'm not trying to add any "fuel" to the fire but thought that I'd put the question of overflow tube routing to someone who is considered an expert on T-series cars. Some of you may know him either by reputation or by name or personally as I do. Anyway, here is his take. I might add that Lawrie Alexander has resorted many T-types over the years and is an Englishman himself who has been involved most of his life with our hobby. |
Knowledgeable folk do have varying ideas about the correct placement of the two overflow pipes! There is, however, to my mind only one correct answer (the "several pints" theory notwithstanding!) - the pipes make a 90 degree bend about 5/8" away from the float bowls, then parallel the bowls downwards. The front one sits at about 4:30 relative to the brass nut, the rear one at 7:30, viewed from standing at the side of the car. The front one then bends inwards about 2" below the float bowl, heads back towards the engine until it is in line with the bottom of the intake manifold, then heads forward and downward towards the top of the front bearer plate. Once there, it bends sharply down and passes through a flat, 2-pipe-wide brass clip that is held under the bolt adjacent to the bulge in the timing cover which covers the chain tensioner. The rear pipe also bends about 2" below the float bowl, angling inwards and forwards, clearing the choke and throttle linkage and passing in front of the exhaust manifold, until it meets and parallels the front pipe. It also bends over the top of the bearer plate and goes through the brass clip. Both pipes run side-by side down the bearer plate and are cut off just below the bottom of the oil pan flange. I hope this is clear! The reason that so many pipes were cut off, or left long and routed straight down, is that when bent correctly they are a pain to remove when you are servicing the float bowls. However, the factory must have had a reason for doing it the way they did so I always install them correctly. When making the first bend at the banjo end, remember that the larger hole in the banjo goes downwards, the aluminum washer goes on top and the odd-shaped fiber washer goes underneath. If the holes are the other way around, the float bowl cannot breather through the slots in the fiber washer.
Hope this is of some help.
Cheers - Dennis
|D L Rainey|
Are we now saying that the pipes,on TF's at least,do not travel through the hole in the Bearer Plate but go over the top then through the Brass Clip ?
Cheers for now.
Well, that seems to be what my friend is saying and he does know a lot about the T-series MGs. He has restored several T-series cars over the years and even ran a successful business repairing and restoring MGs for several years.
Hope this is helpful - Dennis
|D L Rainey|
I'll go on record as saying that I believe they take the covuluted trip through the hole in the bearer plate before fastening to the front of the bearer plate with a clip. Just the way almost all of my research as pointed.
|Let me check with my friend, Lawrie, and see if that's what he's really saying re: originality. Actually, I'm dealing with Lawrie right now for engine parts for 'the53'.|
|I am trying to reach Chris Holcombe who now has his Dad's TF 1500.|
Jim Holcombe bought the TF from an estate and it had never had any work done on it. It still had the tags showing the original antifreeze filling in 1955 when he aquired it. It was ALL original!
I think it went thru the plate as this is shorter than over the top.
We shall see
See photo of mine
|not that the MG assembly line was state of the art...even for the '50's, but the extra work to install pipes through that hole doesn't make sense to me. on the assembly line, what is the advantage? regards, tom|
|Here's Lawrie's response to the direct question:|
I, too, have heard that the pipes are supposed to go through the hole in the front bearer plate, though I have never seen a car done like that. When I was restoring my first TF back in 1976, I was told that was the way to do it and I tried. The problem is that the tight bend that has to be made in the pipe after it goes through the hole makes it very difficult to get the pipes through the clip. Unless one removes the clip, that is. Then consider servicing the carbs once the pipes are routed that way - to remove the pipes, first the clip has to be undone, then a very tight angle has to be passed through the hole, and how do you maneuver the pipe behind the plate, with the exhaust manifold and carb choke linkage in the way, to allow the pipes to clear the plate? Remember, on a TF the side panels are fixed and access to the bolt that holds the clip is extremely difficult! If the pipes just go over the top of the plate, removal is simple; they can even usually be slid up through the clip without removing it. My belief is that in a production-line environment (even at 1950s speeds!) no-one would have taken the time to make those tight bends and fiddle with the bolt and clip to pass the pipes through the hole, especially as there is absolutely no benefit that I can see to the routing through the hole.
Could it be something that might have been done on TDs, but not on TFs? --Bud
|Slightly off the subject of overflow pipe routing but I was wondering if these pipes ever did route raw gas out it would seem to me that the gas/vapors could end up on the exhaust pipe if you were tooling along. Does anyone know what the temperature of the exhaust pipe might get to? The spontaneous ignition temperature of gas vapors is around 500 degrees F I think. Just curious... John |
|My TD melted silver solder on the exhaust pipe which I think melts at about 1000F after an extended run on the New York Thruway.|
I let the pipes extend much lower than the photo's in this thread seem to show. Don't know if that helps or not but I felt better about it anyway.
|R. K. Jeffers|
If the pipes didn't route through the hole in the bearer plate, then what is that hole for? Kind of curious that they would put a hole like that where they did otherwise...
Can any one do anything with the pictures of this "Unrestored TD" to see where the carbie overflow tubes go??? I can't enlarge the photos... Seems like carb #1 tube does not follow the tube from carb #2 !
It is a little hard to tell from these pics but to me it appears the front carb, in pic #1, overflow tube is cut off just below the flow bowl and in pic #9, the overflow tube seems to go over the bearing plate.
Cheers - Dennis
|D L Rainey|
|Steve I tried this a couple of years ago and could only detimine they went toward the plate. |
It is also reduntant in that these photos were traken in the early seventies of this "unrestored car", not exactly an untouched factory photo.
|D C Congleton|
|I intended to attach the photo...
|D C Congleton|
|scott, there are a few possible manufacturing reasons the hole could have been there...original drawings for another purpose and not deleted, used during the assembly process, etc...just can't see the guys on the line doing the extra bends to install tubes this way. regards, tom|
|i agree a photo taken in the seventies may no be factory correct. it appears to me that both pipes go over the bearer plate. the front carb tube is more visible in one photo than the next..the shadow of the front carb tube is easier for me to follow. regards, tp|
|I have a copy of the Brooklands Books "MG TD 1949-1953" (ISBN 0 946 489 017) It is a compliation of articles taken from such magazines as "Motor" "Autocar" and "Road & Track".|
On page 14 is a black and white photo reproduced from a February 22, 1950 article in "Motor". It clearly shows that the overflow pipes went OVER not THROUGH the front bearer plate. In fact, the front pipe is routed straight down from the 4:30 position, as Laurie says.
I might have to say I stand corrected?
|Interesting- seems most likely they came both ways- a Feb. 1950 photo would likely be a very early production car- ,maybe changed later? Whatever, I have to re-do mine, since the rear one doesn't angle down. Good spot on the photo- I think I have that book and will look it up tonight. George|
|See also page 103 upper picture in "MG The Immortal T Series" by Chris Harvey ISBN 0 902280 46 5. It is very clear in that photo that the pipes go over the engine mounting plate not through the hole.|
I had a bit of trouble with the "Gold Portfolio" picture mentioned above because my copy is not very clear in the area in question.
My pipes run over the plate also.
|R. K. Jeffers|
|Hi guys: From this very long thread and discussion, I can only reach one conclusion: nobody really knows how the gasoline overflow tubes were routed!|
|Stuart J. Ramos|
I don't want to claim one photo is better than another, but the shaping of the tubes in the "MG The Immortal T Series" is fairly haphazard, and the photo in question is from a series of photos that show other 'changes' such as the coiling of the water temp sense line under the bonnet, which we pretty much know was a straight shot to the radiator stay, with the coiled material being behind the dash instead.
As the book was first published in 1977 we really don't know when the photo was taken, but with the Motor article, we know that photo predates Feb 22, 1950! That's why I went to my compliation books to try to discover the answer.
It's always fun to sort these details out, but one has to recognize that on any given TD we may never know everything the factory may have done! I applaud your sharp eyes. Let's keep looking!
|Who would have this thread would have lasted this long?|
What a great BBS!
|The scan is grainy compared to the photo in the book. With direct magnification of the photo in the book ( of factory original TF engine), I can clearly see the overflow pipes going forward through the hole, then one emerge below the bearer plate. Another picture shows what is likely about 1/2" of the overflow (from the other side/front angle) below the water pump pulley going behind the plate, definitely not over. The Dave B picture shows the rear pipe running rather horizontally, and definitely has them going over the plate, while the shot on pg. 10 of the same book of the early production TD chassis(solid wheels) appears to show the rear pipe angling down steeply behind the plate toward the area of the hole (which is itself not visible), with the pipes almost forming a "V" (as in the TD chassis picture). In light of this, it would seem that either way may be correct. Anyone know how to contact Al Moss or Dick Knudson? They may have knowledge/opinions or photos. George
|George, here is your photo in negative- shows fairly well. This is how I remember many of the tubes, just sorta gathered together and "jammed" through the hole.|
|D C Congleton|
I considered mentioning the picture you displayed of the factory TF engine in the T Series Handbook published by the NEMGTR (I have the golden aniversary issue) but I am suspect of pictures of engines as display items as the factory may or may not have done the same details. I was hoping to site a contemporary picture of an installed engine. However, now I'm beginning to think it depended on who was on the production line at the time!
|Finally got around to seeing how the scanner works in the 'All in one' printer. Here is a scan of the page 14 showing the overflow pipes from the Motor, Feb 22, 1950. It seems to show that someone made at least one car with the pipes going over the bearer plate, not through.|
This thread was discussed between 02/01/2009 and 16/01/2009
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