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MG TD TF 1500 - Weber Heresy

OK I am ready for the outrage, but I am going to ask. Is there any standard Weber Carb conversion package or plan for a 50 TD with SU-2s . I am about to embark on a fuel overhaul, SU vs. Judson Supercharger vs Something else, and just want to have any info available before I decide/start any info appreciated even threats and warnings. I had seen a weber listed on ebay for a TD just don't see any info in the archives or on Weber sites
Jon L

Jon,

A worthy question. I get the impression you are tired of slogging along on a 54HP TD engine and that you are seeking more umph!!

There are several routes you can take, but remember that a Weber sidedraught is a thirsty beast. I have also seen a Delorto sidedraught on a TD and I expect that is a more economical route. But if I were going to go that route, I would probably opt for the Weber 37IDA, a downdraught option available for the MGB - Irrespective of which you chose, expect to be fabricating an inlet manifold and linkage. I would suggest you contact one of the racer boys who are running Weber/Delorto set-ups, like Bob Grunau at grunau.garage@sympatico.ca.

The nice thing about a supercharger, is that you have infinite torque available at 0 RPM. So this will provide a nice power increase while doing so throughout the entire power band. You really only have one choice of a new s/c and that is from Moss, but occasionally a re-buildable one pops us like a Marshall Nordec or a Judson, but rebuilding these requires access to a good machine shop. I suggest you contact Jim Mertz at STLQB@earthlink.net, as he has good knowledge about rebuilding the Marshall Nordec.

I too sought more power, but I chose a more conservative route. I simply used 2002 technology and adapted it to a 50-year old engine. To do this I have the following:-
A cyl head that looks like a jewel. Everything matched and polished. Stainless valve seat inserts
Polished and lightened valve gear (Note: TF valves are larger than the TD valves)
. + .040" o/size pistons - balanced to a gnat's ass
Polished, matched and balanced rods rods
Dynamically balanced crank pulley, crankshaft, flywheel and clutch assembly
Freshly re-built 1" SU carbs (note:- TD standard is 1")
A modern, spin-on oil filter
Electronic ignition
Electronic fuel pump
. Replaced the "hand-chopper" fan with a thermostically-controlled 10" fan

I've topped this off with a 4.3 cwp and - voila! A modern cruiser with gobs of smooth power.

Ya pays yer money, and ya takes yer choice!

Gord Clark
Rockburn, Qu.
Gordon A. Clark

Gord,
IMHO, I think you have done your homework,,, rather than just trying to bolt on more power to a posibly tired engine, start from the begining, and bring every thing fresh and up to date,,, there is no sence in adding more fuel pushing carbs if the rest of the engine can not handle the increase,,,
SPW
Steve Wincze

Don Harmer, Atlanta, GA, mgnut@mindspring.com
I agree with Gordon, above.

However, I think the Factory Special tuning manual is the best source of "How TO" for the XPAG/XPEG. As above, port and polish the head, increase compression ratio,
TF valves, TD Mk II or TF 1-1/2 Carbs, overbore, etc and/or the supercharger, (as do the racers, but not the extreme).

I have a "Stage II" XPEG (TF 1500) and I can out pull most MGB's (9.5 to 1 Comp. Ratio) 4.1 rear end.

Putting a Weber on, that was designed for a 1500 cc Ford engine, on a 1250 cc engine is a bad mismatch ( even though lots put it on an 1800 cc MGB).
Buckets of gas wasted!

Somehow I posted this to the wrong thread
Don Harmer

Jon,
Before you perform such a heretical act I'd like to make a couple of suggestions:
1) Take my TD for a spin. It's set up just about as Gord Clark described, except that I'm still using 1.25" carburetors, the standard fuel pump and fan. I think you'll find that it provides quite spirited performance. Just let me know when we can get together.

2) Reinstall the Judson that came with the car and put a set of 4.3 gears in the rear end.
Bud Krueger

Jon,
I have a TD with a shorrock, and sold earlier this year, a MGA with a judson. I would agree with the boys on their comments about rebuilding the engine correctly and then adding a supercharger. George Folchi is the judson guru and can rebuild them so they look better than they came from the factory. He charges about $500-700 depending on wehat you want done. But it comes back better than new using modern bearings and vane material. I liked the judson, but it does makes a flapping noise at idle that is a bit weird to my ears. The shorrock on the other hand has an air whining noise ( kinda like my wife made when she sees my TD parts bills!!). There is a huge difference with a blower of any variety. I drove my car both ways and was impressed with the fact that I actually had a first and second gear that meant something instead of being a way to get into 3rd as fast as possible. Double clutching does help of course. Good luck with your decision.
Cheers, Rob
Rob Silverman

The above people are very knowledgeable and right on! Years ago we would put bigger carbs on two-stroke dirt bikes- unless you totally made a hot race motor (lots of internal/external mods), they always ran worse. The often maligned SU's are actually well ahead of there time in some ways with the continually (and accurately)varied mixture.
George Butz

This thread was discussed between 28/11/2003 and 01/12/2003

MG TD TF 1500 index

This thread is from the archive. The Live MG TD TF 1500 BBS is active now.