Vintage Thing No.37.1 - MAE head (Modified Anglia Engine)

Following my recent amazement at discovering Ford Modified Anglia Engine head at Adrian Booth's workshop, not only have I been in contact with the owner of such a device (more on that later) but I also stumbled across this illustration of one in a most unexpected place.

This is a scan of a black-and-white illustration from Dave Vizard's book, How to modify your Mini. This work was subsequently expanded to embrace all A series engines, whether fitted to a Mini or not, but whereas the later book concentrates purely on the engines, this volume also covers suspension and braking. In terms of modifying Minis, bigger engines have always been popular and in the chapter that I find most appealing a number of big for long stroke Mini engines are proposed. But right at the end of this chapter is an engine transplant involving a kit produced by Richard Longman allowed the fitting of a Ford cross flow engine.

A series engines can be enlarged up to 1600cc but this is a very time-consuming and expensive business. Dave Vizard pointed out that the resulting engine, whilst not lacking in power and more importantly torque, was something of a brute. It was quite a harsh unit and suffered from vibration that did not really make it suitable for a road car. A far more practical proposition was to use the Ford engine on the Mini gearbox, even though this was, in itself, quite uninvolved operation.

And what sort of head did they use on this hybrid? An MAE head. If you look closely you can see the inlet passages onto which would be bolted onto the curved elbows that allowed the figment of the much coveted twin Webers.

Of course, nowadays there are much more sophisticated and powerful engines to put in your Mini but I really like this idea. It shows the ingenuity of the competitive engineer to good effect and I can understand the thought processes that they went through as they weighed up the pros and cons of the highly modified but still long stroke A series engine compared to the relatively unmodified short stroke Ford engine. Due to the bigger bore that short stroke engines inevitably determine, the Ford cylinder block is longer than the BMC A series block so various adapters and gearbox extension parts had to be developed. It was still felt to be worthwhile, though, and allowed engine capacities of up to 2000cc and the use of not only with the downdraught MAE head but also Lotus and BDA twin cam heads.

The example of an MAE pictured was produced by Holbay at the arrow in the bottom left-hand corner points to a Holbay dry sump oil pump.

It's unlikely that anyone would go down this route today but there are probably conversion parts still out there somewhere may be whole powertrains.

Ford MAE downdraught heads are just as rare because beyond the historical racing formulae there is very little real need for them to be used. Like grafting Ford engines onto Mini gearboxes, they have been overtaken by more modern tuning options.

But there is a classic simplicity about them both and they are a tribute to the craftsmanship and skill of racing engineers and in some circles period tuning parts have taken on an appeal all of their own, despite being outclassed in sheer power terms by more modern developments.

A series valves

Adrian is sorting out the reconditioned cylinder head for my Austin Allegro. He's made up a mandrel that fits inside the new silicon bronze valve guides and drifted them into the head but when I dropped in the other day he told me that the old valves weren't quite as good as they might be. If we looked closely at the end of the valve, the area where it meets the rocker was slightly warn. I could actually see fine lines running across the surface and if I ran a finger across the valve I could feel them too.

Adrian didn’t like the look of these. He said that these imperfections could lead to the valve being pushed over sideways, as the rocker levers it against the valve guide whilst the valve is off its valve seat. This would have increased wear on the valve guides and before long oil would be seeping passed and the engine would start smoking again.

One solution would have been to clean up the end of the valve but when I saw that valves were only a few pounds each from Minispares, I opted for new ones.

I asked Adrian if the rockers themselves would have a similar problem on their contact pads but he said he would have a look and dress them up on a stone if necessary.

I also bought some new valve springs because they're only £1.60 a go.

Now that we have the valves, the valve seats themselves might have to be re-cut because British Leyland valve guides were notorious for being so eccentric. Aftermarket valve guides are made to much closer tolerances than the rubbish the factory turned out but, once fitted, new valve guides can cause the valves to no longer fit properly on the valve seats.

When I arrived with the new parts, Adrian was involved in some displacement activity. This wasn't surfing the Internet when he should have been doing something more practical. He was boring out the block for another A series engine, this particular one having originated in a Metro Turbo. He was doing it with a boring bar and I found the operation quite fascinating. Once setup on alignment of the cylinder bore and switched on, the boring bar moves the cutting bit down the cylinder at a predetermined rate.

I asked him if he was going to do a really big bore but he said no, it was just a 20 thou over bore.

We had a brief discussion about doing a big valve head for the Allegro but, when we remembered what car is going into, we thought better of it. One day, it might be fun to do a really fast Allegro, but that day has not yet arrived. I just want my standard Allegro not to smoke like a two-stroke on start-up.

I quite fancy my own boring bar, though. Apparently, they come up on eBay fairly frequently.