MPJG Engines

[Roger Muir]

Roger Furneaux's note about an MPJG engine for sale brings me back to my quest. If anyone out there finds MPJG 2774 I would like to know, but it's not the engine so much that I am interested in, but the TA the engine was once in!! Reward to the finder!!!!!!!! Roger Muir (Bromsgrove UK)

[Robert F. Butson]

Some while ago before I was removed from the list by yahoo, someone sent an article about the MPJG engine. I sent a copy to the guys who were machining my engine parts and the following is their reply. If anyone has a copy of the original article, I would be grateful for a copy off list, my copy was lost in the ya hooha...Bob. Subject: Re: [mg-tabc] MG TA cylinder head. Robert thanks for the e-mail. The torque figures will certainly be useful when you are reassembling. It is always good to learn from other peoples experiences and for that reason the document is good. The other side of the coin is that it can be too tempting to believe - and even be frightened by - the printed word. These MG and Morris heads are prone to cracking around the exhaust ports, yes. But this is true of many other pre-war cars too and is a result of the limitations of the casting technology of the time. You head was cracked in 4 places. To the uninitiated (like the originator of the discussion thread) this may sound catastrophic but for those in my field it is just routine. The cracks can be gas fusion welded but the process is rather out of favour now for such small cracks because the need to heat the entire head to "glowing red" makes it costly and some degree of distortion is inevitable. We prefer (where possible) to use cold stitching -a mechanical method of crack repair. We, in fact, use the American "Castmaster" stitching system which employs patented threaded pins to seal the crack and draw the 2 sides together. It is more expensive than traditional stitching but provides much better and neater repairs. The main problem with the exhaust side of the block will be frost cracks - this is a large flat section of unsupported cast iron and will distort easily with a little frost expansion in the water jacket. Your block is crack-free however. "Irontite" is a good product but is for professional use and I would not recommend that all MPJG owners start swilling it into their water systems - it is designed to be used with the "Irontite" metal stitching system for crack repair. I do not agree with the comment about not refacing cylinder blocks - this is probably the most overlooked area of any engine repair. Block faces of this age are often distorted by as much as 0.010" and this will lead to head gasket failure. Furthermore fitting a refaced head to a distorted block will create uneven stresses in both components and is much more likely to lead to cracking and thread failure. I find the comment about valve seat inserts depressing - these engines, together with just about all engines from the late 1920s onwards, were designed with enough material in the casting to allow valve seats to be fitted. Indeed in the days before more modern fuels appeared in the 1950s fitting valve seat inserts was a common reconditioning job and is mentioned in many period publications. When someone says that a machine shop "cut through to the water jacket" it just means they are rubbish at their job and have chosen the wrong insert for the head.