MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MG Y Type - Thermostat

Curiously, a previous owner removed the bypass hose and blocked off the little inlet in the thermostat compartment.

I wanted to fit a water temperature gauge. So I decided to use this inlet to insert the sender unit. When I removed the thermostat housing, I discovered that the thermostat was absent. So I made my modifications and reinstalled everything.

As I suspected, without the thermostat, the engine takes a good 15 minutes to warm up and even then remains only at around 160 degrees.

Since I live in a cold country and plan to use the car until it snows, I would like to fit a proper thermostat before October.

However, I can't find one in Moss or NTG catalogs.

Is this such a rare part? Is the only solution to find and adapt a modern thermostat?
Gilles Bachand

Gilles

In NTGs catalog you have a choice of 3:
1) B349A 74 degrees C(165F) HOT £5.72*
2) B349B 82 degrees C (180F) STANDARD £4.68*
3) B349C 88 degrees C (190F) COLD £5.72*
*=last price I know of and are shown as for the TF.

Closer to home for you though, and more appropriately for the Y, Moss Motors have:
434-200 Thermostat (no temp range) $12.85* which fits into
434-178 Housing - specially modified $149.95*,
OR you can go for:
434-168 Housing - original with Non-removable thermostat $149.95*
*=last price I know of.
Clearly if you go with Non-removable, if it fails, it is a replacement housing and thermostat, but there doesnt appear to be a price penalty.

If you go the Moss route with 434-200 & 434-178 and order from Shadetree Motors (see Links page, Suppliers, General)in the next couple of days you will get a minimum of 15% off as they are closing out ALL of their inventory - see my seperate posting on Shadetree Motors on this BBS. They have inventory of both of these parts, but not the non-removable 434-168.

Paul


Paul Barrow

Hello Paul

So in your experience, the TF thermostats can be adapted to fit in the YA housing?

In the NTG diagrams, my thermostat housing is the B308 type and not the B309 «TF-Type».

Thank you!
Gilles Bachand

The original equipment thermostats were very cleverly designed. When closed (cold) the passage to the bypass hose was open allowing the water to circulate by the pump, but closing all flow through the radiator - warming the engine quickly.

As the engine warmed and the water started to flow through the radiator, the bypass passage was gradually blocked until all the flow went via the radiator and none via the bypass.

The modern replacement thermostats work well to cut off the flow to the radiator, but the flow through the bypass is maintained at all times.

A question for the XPAG guru's - what is the original thermostat operating temperature ? - does anyone know.

I have a 74C thermostat in my YA which seems to cope well with summer temps in the mid 30C range here in Brisbane. What do others run in Australia ?.

An wise old mechanic once told me that an engine thermostat is the hardest working yet least understood part in an engine. It controls the operating temperature of the engine and therefore its energy, efficieny and performance under varying load, speed and ambient temperature - clever indeed.
Tony Slattery

Fitting a modern Waxstat is easy. All the data required is in the booklet sold by the MG Octagon CC or the MGCC Y Register, 'Living With The XPAG Engine'. All profits go to the relevant club/register.

NC.
Neil Cairns

Thanks Neil, I will order a booklet then.

Will it tell me what temp Waxstat I should be running ?.

How do you decide to run a 74C (hot), 82C (standard) or 88C (cold) thermostat ?.

Are these the temperatures at the thermostat starts to open (or fully open), and how do these relate to the actual operating temperature of the engine.

I have fitted a temperature sender below the thermostat in the head elbow, and this indicates an operating temp around 170F with a 165F waxstat thermostat fitted. Of course neither the guage or thermostat are "calibrated".
Tont Slattery

This thread was discussed between 08/06/2007 and 09/06/2007

MG MG Y Type index

This thread is from the archives. Join the live MG MG Y Type BBS now