Engine Rebuild on TD13030

MNE 4 at Brooklands

MNE 4 is quite a well known MG TD having completed the 1952 RAC Rally in atrocious weather in late March/early April 1952 driven by Reg Harris, better known for his exploits on 2 wheels rather than 4. After 3 further owners, MNE 4 was purchased by Harry Crutchley in 1969, the year ”H” formed the MG Octagon Car Club.

I purchased MNE 4, in September 2009 from a dealer. He assured me that the engine had just undergone an extensive refurbishment including new liners and unleaded head conversion. Just over 1000 miles later, in April last year, the engine failed, losing power and making a very “expensive” sounding internal mechanical noise.

After extensive research I approached Iain Rooney (now one of TT2’s listed suppliers) to repair or rebuild MNE 4’s engine to period Stage 2 tune as that was the car’s state of tune when it competed in the RAC Rally. I trailered MNE 4 to Iain’s premises, near Selby in Yorkshire in May (see photo below taken on departure from home).

Iain dismantled the engine that day so we could understand the nature of the failure and decide a way forward. As the engine was dismantled, the full extent of its problems became apparent. The list of issues is too long to record here but to give you a flavour, we noted that it had the wrong cylinder head gasket, no liners or unleaded head, impact marks on all pistons from contact with the cylinder head, failed small end bearing on number 3 cylinder etc etc etc!

Engine strip down (above) and rebuild (below)

Iain and I agreed that the engine would have to be completely rebuilt using the block and cylinder head as the basis of the rebuild. All the internal moving parts of the engine would have to be replaced apart from the flywheel. Over the following few months Iain and I exchanged many e mails and telephone calls, verifying correct period parts were to be used. I sourced a period NOS dynamo and starter motor from Charles Russell of The Electrical Parts Company Ltd. I also found Andrew Turner to rebuild the carburettors to MG TD Mark II specification 578 SU H4 standard.

The rebuild proceeded through the summer months with Iain cleaning, checking, machining and fabricating all the parts required and using his extensive network of contacts, built up through many years in the business. The flywheel was lightened, the cylinder head gas flowed and a camshaft of Iain’s specification fitted. At a late stage it became apparent that the sump would need to be replaced. As had proved typical throughout the rebuild, Iain could find many examples of the larger capacity finned sump but could not, initially, find the smooth sump that would have been fitted to MNE 4’s TD2 (8 inch clutch) specification engine in January 1952. Fortunately, Ian found a “mint” example of the 9 pint sump and the build continued.

By November, having had numerous frustrations with period parts, the unbelievably poor workmanship previously inflicted on the engine and my insistence that originality should be the guiding principle, the rebuild was complete. Originality was sacrificed in one specific area. The original oil bath air cleaner and air inlet manifold were not refitted. I have seen virtually no period photographs of TD Mark IIs with those components fitted. Iain convinced me that the poor breathing caused by the air cleaner/inlet manifold combination would undo most of his efforts to produce the “fast” road car torque and power profiles of the rebuilt engine.

MNE 4’s rebuilt engine ready for installation (above) and installed (below) showing rebuilt carburettors

I am still running in the “new” engine but what a transformation! It is flexible and is raring to go with a delightful throaty roar from the exhaust. I would like to thank Charles Russell and Andrew Turner for their part in the process but particularly to Iain for his patience, professionalism and brilliant workmanship.

Paul Critchley

Editor’s Note: You can learn much about MNE 4’s history and National and Internationally renowned racing cyclist, Reg Harris, by going to the following website: http://www.oldclassiccar.co.uk/mg-td.htm

By the way, you’ll notice from the photo of the rebuilt engine that it has the TB/TC/early TD oil filter arrangement. This is quite correct as the engine fitted at the Factory to MNE 4 was XPAG/TD2/13087. This engine number falls between XPAG/TD2/9408 (the first TD engine with the 8 inch clutch) and XPAG/TD2/14224 (the first TD engine with the later oil filter arrangement).

I am indebted to Paul for his article (and useful endorsement of Iain Rooney’s services) and also for the photographs of the rear bumper TD MK II plinth arrangement and badge as featured in the TD Mk II badge article in this issue.