Moss Motors, Ltd

OK, I've installed the Ford 5 speed in my TD and now the car is running  10 to 15 degrees hotter than before (measured with a good quality sensor on the header tank). Apart from the engine being 3/8 inch closer to the rad and slightly lower everything else is as it was. My first thought was that I had an air lock in the cooling system so I raised the front of the  car as high as possible and refilled the system. No change. Any comments or suggestions?

 

Thanks, Trevor in Canada

Congrats on the new transmission.  I installed the same kit into my '51 TD, and have not noticed any cooling issues to date.  The "drivability" of the car is so much improved and better than before - worth every penny!

Having said that, the XPAG's temperature will indeed increase 10-20F with "spirited" driving and WOT running from a stop - which is now fun to do with the new transmission.  If you've been racing around with your hair on fire while running the gears, that could be a source of the extra temperature.

Assuming you pulled the engine during the conversion and dismantled the cooling hoses, I'd first check that you have the same coolant mixture ratio as before.  Too much anti-freeze actually reduces the coolant's ability to transfer heat.  Another very remote possibility could be the original-style thermostat stuck closed.  That could be monitored with one of those inflared style temp readers.  Monitor the top hose temp from a cold start to normal temp - you should spot when the thermostat opens and heats the hose.

Enjoy that new trannie - makes a much more "drivable" car out of the TD!   

Trevor, As Dick pointed out there's a number of posibilities for the perceived? problem. Many moons ago, after an engine-out on my original YA, I did manage to put the fan back on back-to-front but [alas] I was young and foolish then!! However it did produce the effect that you have observed.

Enjoy the drive     Cheers     --  steve

 

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To a man equipped with only a hammer, most problems look like nails

Thanks for your reply Dick, as you say the drive ability of the car is much improved with the 5 speed.

I have checked that the thermostat is opening and it is working fine and I reused the original coolant so I know that nothing has changed there. There is a very sharp offset in the large hose from the cylinder head to the header tank (due to the engine being moved forward) and I tend to think that the coolant flow may be slowed down due to turbulence at this point.

When you say that you haven't noticed any cooling issues is this because you do not have a temp gauge? Perhaps I should put a piece of tape over my gauge and solve the problem  ;-)  

 

Trevor in Canada

Trevor-

I like the tape idea. Similar to how I solve increasingly bad engine noises in my Mustang...

I install a louder sound system.

LCJUTILA 

Abingdon apparently wasn't too concerned about the XPAG running hot, as they didn't bother to install a real temp gauge until halfway thru the TD production run - Feb '52.  My '51 acquired an aftermarket temp gauge mounted left of the speedo sometime in the distant past.   Malcolm Greene in his MG history books indicates that a temp gauge was a common dealer-installed option.  I guess the philosophy back then is that if the front of your car hasn't disappeared in a cloud of steam, there's nothing to worry about!

Another thought - check your ignition timing.  If the distributor was removed or bumped during the trannie work, it could be off and a retarded timing will cause the engine to run hot.  Motorbill66 and other restoration experts recommend setting the timing at 2 degrees BTDC vice TDC, plus an additional degree for every 1000' above sealevel.

 Steve, thanks for your suggestion. Installing the fan backwards was my first thought but after looking at it I saw that it has a symmetrical twist to the blades so it does not matter which way it is installed. Here's a photo of my rad hose which I think may be causing a slower coolant flow   http://picasaweb.google.ca/lh/photo/m2cqpMjA3Ha8ZBRErV5A8w?feat=directlink 

As the paint is not blistering off the engine block I guess I may just have to live with it and if all else fails I can always improve the airflow through the engine bay by removeing all the plugs from the holes in the firewall that I've just painstakingly filled in  ;-)

 

Trevor

Trevor, a thought, what have you done with respect to the old thermostat by-pass arrangement? Fitting a modern thermostat and not restricting the flow thru the by-pass pipe will lead to overheating as the water will take this easier route rather than thru the restriction of the radiator core. Some people block this by-pass route completely, however I put a plate in with a1/8 hole in it on my old YA! Hope this helps!  Cheers  steve

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To a man equipped with only a hammer, most problems look like nails

Steve, I installed a new water pump and a modern (modified to fit in the original location) thermostat last summer and all was well, the original by-pass functioning as it was designed. As I mentioned in my first post, everything is as it was before the 5 speed installation but now it runs hotter.

I'm using a spin-on oil filter and for a bit more clearance I did change to a different size but that's the only thing that is different and I really can't see how that would affect the cooling system.

Meanwhile it's back to scratching my head.

Cheers, Trevor