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MG TD TF 1500 - MG TD MK II air intake 1 1/2'


All knowing experts- We have been having trouble with this MK II TD since the day we got it and could not figure out why, something just wasn't right. Well we found the problem this weekend, it had an 1 1/4' intake on the carbs and should be 1 1/2", correct? Also, on the cast iron intake, there was a PO petcock added on the bottom center, what would that have or could be used for? I can not imagine wanting to add unfiltered air to the mixture !! Thank you sara D.
sara D

Certainly not an all-knowing expert, but just some thoughts: Petcock: perhaps for one of the old "top cylinder oiler" type deals (Marvel Mystery Oil, etc.) A vacuum gauge? Nitrous injection (just kidding)? Trick vacuum advance distributor? Do you mean the cast iron manifold or the air cleaner manifold is 1-1/4"? I think both were different. The air cleaner manifold is fatter extenally, with the canister different as well. The cast intake would obviously need to be 1/4" bigger. My CD with the factory parts list is at home-I'll look at it in the next couple days. George
George Butz

sara, is the engine a TD3? A lot of MKIIs have had their engines replaced by non-MKIIs. What is stamped onto the brass tag on the side of the engine? Are the carburetors 1.25" or 1.5"? Either manifold will bolt onto the head.
Bud Krueger


George & Bud - Thanks for your notes. Maybe I should have been a little clearer. The carbs are 1 1/2" (based on the opening, my TC's are 1 1/4" again based on the opening. The cast iron intake that the carbs mount onto has a 1 1/4" opening (same as my TC, actually they are identical except for the cast 'fork' that mounts the TD air cleaner). The cast intake, I think should also therefor be 1 1/2". As I see it I have 2 choices, try to find the correct one or have a machine shop make the hole larger, but is the intake the same for a MK II and a non-MK II. Any suggestions as to where I could get one? thank you sara D
sara D.

The factory parts list shows part # SA2440 for a regular TD, and SA2440/1 for the "TD/C", definitely different. The TF part # is SA2240/1, which would be 1-1/2", but I am not sure what else is different (air cleaner support? Length?) I would think a machine shop that does porting work could match up the openings nicely, presuming the metal was thick enough. There should be no step, ledge, under- or overhang. Any of these cause turbulance, and possibly droplets of gas to collect. I would check the manifold to head interface while you are at it, and definitly check the gaskets. Question: do the carbs you have have two, or four holes on the air cleaner side? George
George Butz

Hey Sara -
I would contact O'Conner MG Classics and see if he has a TF intake manifold. You could probably buy that for less than the machine shop would charge for the modification. Also - Are you a member of the Southeastern MGT Register there in Atlanta... Hope you are as that is a good bunch...

Jeff
Jeff



Bud & George - I forgot to answer Bud's question, yes it is a TD3 motor. The carbs have two obround mounting holes not 4, otherwise that would be MGA, correct? sara d
sara d

sara, I have a MKII intake manifold that I will not be using. If you want to contact me off of the BB I'd be happy to discuss it with you. Bud
Bud Krueger


Jeff - No we are not members of any clubs, including NEMGTR, sometime I will tell you a story about that. And no, we quit buying from Mike & Moss years ago. Most of what we have needed we have bought from Mick at Keystone in Penna. mmmgtcars@yahoo.com . He only sells NOS/reconditioned/restored parts. Most people don't know much about him as he does not advertise or do any swap meets and really prefers to sell to the trade (restoration shop). His parts are dead on and exactly as he says. He is not the cheapest (his prices are very fair we think) but he only has the 'real Mc Coy' and goes out of his way to help. We got a part a few weeks ago that we asked for on our TC two years ago (NOS dash light) and he sent it N/C for inspection before we sent him a check, who does business like THAT anymore. thanks for you note sara d
sara d

Check your 'ports' on the head when you pull the smaller intake... They should be larger to accept the larger intake... someone could have put a 'non' MKII head on it?
gordon lawson - TD 27667


Thanks Gordon- We did check that, this motor smokes a bit but is original and has never been apart. THAT is what is so confusing about the 1 1/4" intake, Is it possible that it was put on wrong at the factory, I say no, but who knows? We are also still not sure about the fitting (petcock) that was installed on the bottom of the cast iron intake as to it's function, that is not from the factory. I have read all of the articals (not many) and nowhere does it show or mention this, could it be in a service bullitin somewhere or does anyone else have an idea? sara D.
sara d

Sara ,
I could be wrong (have been before!) but believe you might be refering to the "bolt" on underside of intake manifold.
I have this on my TF as well. (Oct built 1954 XPEG 1500 w/1 1/2" SU's) To the best of my knowledge it is used to adjust an equlizing rod that is internall to the intake manifold. I found mine years ago when the bolt fell out and car started sucking too much air! I have some pic's posted on Bud's "T-Talk" site where I believe you can see it. http://www.ttalk.info/picture_this.htm#JetHot%20coated%20manifold
Look closely at last 2 pic's for "JetHot" coating ...(you may have to "save" the pic's and blow them up to get a better view ...but is this what you are inquiring about?
Cheers,
David 55 TF1500 #7427
David Sheward


Dear Experts - I think it might be time to start this thread over and get things correct. Let me start by saying I have given you some wrong info to start this subject. I stated that the fitting/petcock (and it is actually a petcock/bleeder valve not a bolt) is on the TOP of the cast iron intake (I had it upside down, dumb). With the help of George Butz and Mick's two hour phone conversation last night(sorry mick, if you are reading this you talk too much) I am now ready to state some facts. Also,Mick does have an extensive collection of these intake manifolds in his collection and I think we should get him to take photos and submit them to Bud K. for the Ttalk files. The following information was sent to this thread by George and then expanded on by Mick all based on his collection and past experiences.

1) TC-ONLY intake manifold factory # SA-2408 *casting #24062 'V' - 1 1/4" w/no cast fingers for mounting the oil bath air filter, TC's used a different style air filter system, bolts to mount carbs.

2) TD 1 1/4" (several styles were used-possibly by more than one mfg'r) factory #SA-2440 *casting #24280
R/1 & R/2, both look identical, except for the R # part. Used cast fingers on the intake to mount oil bath air cleaner and bolts. Also used 2 different styles of 'fingers', narrow & wide.

3) TD MK II 1 1/2" factory #SA-2440/1 *casting #168434 w/'W' (Wolsley mark) cast in and 'fingers', bolts for carb mounting

4) 54 TF & 55 TF 1500 factory #SA-2440/1 *casting #168434 w/o 'fingers' (as you all know TF's used dry element style on each carb) and 'studs' instead of bolts to mount the carbs.

Several things should also be noted here. There were some other slight variations in the TD 1 1/4' SA-2440 intakes which means they could be maybe early/late or maybe different suppliers were used, who knows. It should also be noted, that in my case with the 1 1/4" intake it was probably switched/swapped at the dealer by mistake (yeh) or a wrench turner that put the wrong one on. It should also be pointed out here that #168434's with fingers could have been used on 54 TF's to use up inventory but there was no need for the fingers of course.

Which gets us back to the original question, any idea why the petcock was used? sara d

David S. OHIO - Your note mentioned an internal equalizing rod inside the manifold, what is that all about?

If anyone has anything additional to add to help clear this up please feel free to help

sara D

In the center of the intake manifold there is a balancing washer that is held in location by that stud and nut on the bottom of the intake manifold.It ,in my case was approximately 1/2" thick with if I remember a 1/4" hole in the middle. If this stud or bolt is loosened and the spacer is allowed to move you may never get the car to run right. I had this happen to my TF 20 some years ago. It was my fault that the bolt was removed.
Sandy sanders
Sandy Sanders

I have also heard of the bolt (on the bottom of the intake) and the equalizing rod...never seen one/it but there it is.
If a valve/petcock/opening is in the top of the intake, it was added later...could have been for anything that runs using vacuum...hmmmm.... not the wipers (like old U.S. cars).....not the covertible top/hood raising mechanism (like some convertibles)... not for extra power braking....
Maybe a vaccuum gauge?
gordon lawson - TD 27667


Hi Sandy- I guess I don't follow this, remember you are talking with a girl, ha. On what manifold are you speaking, all of them ? On the bottom side there IS a bolt, looks like 1/4" and directly above that (opposed) is the petcock. It(petcock) does not look factory and is not on the other TD/TC or the TF, so I have to believe it was added there for some unknown reason.


Gordon- Again, on what manifold and is it internal placed inside the casting, what does it do?

sara D
sara D.

does the MKII intake manifold (1 1/2")look the same externally as the standard TD manifold (1 1/4")? thanks, tom
tm peterson

Sara,
Yea ..like Sandy said..he and I are on same page, said 2 different ways, but the same thing and same results! Any sign of different dizzy being on the car at some point? From what Gordon said, I'm wondering if some PO had devised some kind of vacume advance for that? I have seen a design for,(and toyed with the idea of building) a manual advance for timming. If the car has been out west in it's history maybe a chance somebody took this a step further for mountain crusing? Just a guess ...whadda' you think? Not a big change in elevation here in the mid-west but might have an advantage on the left coast! My 1500 came from NJ and at some point the PO (or one of his mechanics) had added a PCV valve to it. (it was done via a rubber hose sticking out of a aftermarket valve cover that should have been on a TD!) I sold that cover to a TD owner as it had the correct fitting for that type of oil bath filter...on top instead out out the side as the TF is done to forward Volks type.
hmmmmmmmmmm
Cheers,
David 55 TF1500 #7427
David Sheward

See http://www.ttalk.info/Tech/intake_manifolds.htm for some images of early and late MKII manifolds. Thanks to Sara, Mick and George for their input.
Bud Krueger

Is the petcock in the same position as the screw in the 1.5 manifold?
gordon lawson - TD 27667



Gordon, No, it is about 1/4 across from the end, as you are looking at the carbs from left to right closer to the firewall. This is really driving me crazy, it does not make and sense to me. sara D.
sara D.

Sara,
The petcock is an add-on by the dreaded previous owner, no TD or TF had such originally.
The screw on the TF manifold is likewise the same.

Externally, the manifolds look the same.

Sara, we wish you would join us as we have 6 or 7 TD Mk II's in our club and a lot of local experts to help.
( The Southeastern MG T Register)

Vist with us at the 2006 British Motor Car Day at Barry College in Rome on May 13 and look at TD & TF manifolds to be sure.
Don Harmer

Sara and Bud,

If you look carefully at Bud's picture of the 168464 manifold the "W" you speak of is an "M" in a diamond.
I think you were reading it upside down. If it is in the same orientation as the casting number it's an "M"

This could be for MOWOG ??? or for MG??? or for whoever cast it.

I have 3 TF manifolds, the latest one from TF 8986, Jan 15, 1955, all have the "fingers" although not needed as Sara points out.
Don Harmer


Hi Don, Thanks for the invite to Rome, I'll mark it down. I read somewhere,I thought,that the diamond 'W' was for Wolsley as they were an old company and had been a major supplier to the war effort. MG contracted them to make motors and gear box housings but not the rear ends as the were already making motors. They later then had the castings with the MG mark. It is not important but always nice to know. I guess it's kindda like 'MG' which means nothing except MG not Morris Garages like everyone thinks. NOW, once again, back to the original question, and that was 'what the heck was(could) the petcock/screw/bolt in the top have been used for? With all these experts out there SURELY someone can answer this $64,000.00 dollar question (deal or no deal). sara D.

Oh yes, the finger & no-finger manifolds, I wonder if any of the #168434 you have (you say yours is #168464) have the fingers, could you look for me ? thanks
sara D.

Sara,
Oops!!! I misread it, they all are 168434. (not 168464)
and all have "fingers"
The one pictured on Bud's site looks more like a 5 (or even a 6) than a 3.
Look at this picture also to see the "M" vrs "W"
I have seen this "logo" on some other casting somewhere but I can't rember where.

My guess is the petcock was added to yours by the DPO to allow use of a vacuum gauge to aid in tuning the carbs or to monitor the engine while driving.

See you at BMCD at Berry College
Don Harmer

Don,
I've got to dissagree with this: "The screw on the TF manifold is likewise the same." .....I've seen it on too many cars in exactly the same spot (bottom side of manifold)...and talked to quite a few people that have had the bolt come out as I did! Just looking at any "mods" that were made by my 2 PO's ...this one would have been very "unlike" anything else they did.....it's too "neat" and "well-done"!
(Everything else my PO's did was more along the lines of "lummpy-the exhaust manifold fix" as seen on pics @ "T-talk"!)
Hard to believe same person that did that could tap such a nice thread into the underside of the intake manifold!
Sandy is "dead on" about trying to get the car to run correctly if the spacer is allowed to move! In fact...mine did not "move" untill I bead blasted the inside of the manifold before I did the JetHot treatment to the exhaust. (I was considering having both done...but the rep at JetHot was honest enough to inform me there was really no advantage to doing the intake and that simply painting that one would be be fine.

Sara:
Back to that $64k question...never did see anybody's opinion on my "theroy" of this maybe being for a PO's attempt at making an vacume advance for a different dizzy! What say thee experts? hmmmmmmmmm?
Cheers,
David 55 TF1500 #7427
David Sheward

David,
The screw I was talking about is the one in the top of the 168434 manifold pictured in Bud's note above, not the bolt in the bottom you mentioned that they all have to locate the "restrictor" plug in the manifold.
The top screw was added, not original.
Don Harmer

Sara D. ---- I put 1 1/2" carbs on my TD manifold by grinding them out to match the diameter of the carbs. There was plenty of meat there. Opened up the cyl. head side to match the enlarged intake ports also. Also found the exhaust manifold did not match the exhaust pipe so had to open that up too. Seems the early TD's had a smaller exhaust pipe than the TF's. Don't know about MK11's though. I beleive that the major suppliers are now only providing the TF size exhaust systems.

Don't know about your fitting on the intake manifold might have been for a upper cylinder lubrication device like Marvel Mystery Oil. Distributors probably would have been connected to a carburator as the MGA was.
Cheers,
Bob
R. K. (Bob) Jeffers

I remember as a kid back in the 50's, one of my uncles, who was deaf and dumb, installed a vacuum gauge to aid in determining when to shift gears in his '54 Ford. Just food for thought. Marvin
Marvin Stuart

Don...I got you now "The screw on the TF manifold is likewise the same"....meaning the one "Sara" has....hey, at least I'm still singing "patrotic" songs in English!
LOL......."restrictor" plug was the term I was looking for ..thanks could not for the life of me remember what theu called it and keep forgeting to look in the book whilst in the garage. The more I read these post over the years the more I become convinced the "rarest" of all M.G.'s would be 2 idendical cars...part of the fun!
Cheers,
David 55 TF1500 $7427
David Sheward


David S. OHIO - I see you have your 1500 for sale at $7427, I'll take it {smile}. UPDATES: We got the mainfold bored out over the weekend to 1 1/2", that worked out fine and Bob J. was right, enough 'meat' there to do the job, but still not the 'correct' intake. Also, I think the 'petcock' mystery is now solved or at least put to bed. We took the petcock off and sure enough, there was the restricter, down below being held on by that 1/4" 'BOLT'. WE think somebody took the bolt out(PO) and then could not get the restricter to line back up and drilled the hole to relocate or align it. I honestly don't think anything else makes much sense. Also, there are end plugs in the manifold (that I did not pay any attention to before) and I think THAT is how the FACTORY located and set the restrictor, HUMMMMMMMM !!! sara D.
sara D.

#7427 for $7427.

What a deal! :)
Carl Floyd

You lost me here : "David S. OHIO - I see you have your 1500 for sale at $7427,".....
Where did you see that?
Cheers,
David 55 TF1500 #7427
David Sheward

Nevermind ...I see it now!
Whoa ...freaked me out!
I just "trashed" one of those "somebody is accessing your ebay account from the UK" phoney letters. Normally forward them to ebay "spoof" (but all I ever get back is their "form letter" telling how they will invesagate)...so I just deleted the one this am.
You had me going for a minute there till I saw my typo!
"Izzy" is here to stay...my will states my ashes are to be used as "oil-dry" for her!
I have some children that have entered the "felony years" however that I might consider some offer in that price range for! (you take over all legal expenses!)
Cheers,
David 55 TF1500 #7427
David Sheward

I've added a couple of images sent to me by Marv Stuart. They're of the intake manifold on his MKII, TDC/12828. It's a 24820 casting with the R2 designation. I've also reshot the 168434 image after removing some paint to show that it's definitely a '3', not a '6'.
http://www.ttalk.info/Tech/intake_manifolds.htm
Bud Krueger

This thread was discussed between 24/04/2006 and 02/05/2006

MG TD TF 1500 index

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