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MG MGB Technical - Engine numbers for 18G/18GAs

The engine whose oil pressure I have been talking about in a separate thread came to me without an engine number.

Hence I would like to invent one but I don't want to use one that exists. Does anyone know the range of numbers used on 18G and 18GA series so I can invent an 'out of range' one?

Paul
Paul Dean

According to Clausager...

18G 101 to 31121
18GA 101 to 17500
Dave O'Neill 2

Thanks Dave.

As an A owner, hence have wrong Clausager for this info, I presume this means Gs and GAs were produced in parallel. I always thought Gs came firt and then they went to GAs. I presume for they were for different markets?

Paul
Paul Dean

I believe they were consecutive.
It seems that all engine series start with serial no 101
Dave O'Neill 2

G'day Paul,

Dave is correct that 101 is the start point and they were consecutive, so don't pick something like 99 because it will be a dead giveaway.

Reading from your other thread, are you sure this engine is a genuine MGB engine? - there have been mariner/landcrab engines converted to in-line drive!

In that case things like the oil stick are a giveaway among others.

Assuming you have the genuine item, perhaps consider linking to an overseas market, eg Oz, engine number sequence. That way you avoid the possibility registration bodies may pick up and investigate a duplicated engine number in their records - which would really p**s me off if I were the owner of the legitimate numbered car.

I don't have the web address but there is a site here that lists Oz car details of MGBs from 1962 on, so covers the 18G and 18GA series. You might adopt one of those in the UK with a degree of safety.

Someone may have that address or you could try Google.

This message will self-destruct in 5 seconds and I don't exist if you st**f this up!

Regards
Roger
R Taylor

"so don't pick something like 99 because it will be a dead giveaway"

Anything 'out of range' is going to be a giveaway, if the purpose is to fool a potential punter. If it's just to register it with the DVLA then it doesn't matter.

The 18G, GA and GB were consecutive and common to all markets. It wasn't until the USA started demanding emissions controls that North America had their own versions with the 18GF in November 67.
Paul Hunt

No I am not trying to fool anyone. I just want one that correctly reflects the spec hence I will probably go for one beyond the G/GA range. I bought the engine from Andy Jenning who is a well known breaker of MGs in the UK. The reason I wanted this spec is that it has the mechanical rev counter drive hence is an easy fit in to an A. I do have another option of using a Gold Star number.

I did find one slight problem in that the casting around the water pump is slightly different as is the pump itself hence I had to space the A radiator forward by about 5 mm. Out of interest I attached picture of the 2 pumps, with used A one on left. As you can see the B one has more of the impeller exposed and probably more effective.

Paul

Paul Dean

The B pump also seems to have an extra bolt hole, or is it a hole for a locating pin?
Andrew Dear

You do have to be careful with pumps, there seem to be two that will fit, but one combination gives inadequate cooling. Judging by the different impellers it could be when the A type is used in the later B engine. This is in addition to the long nose and short nose variants of later B pumps.
Paul Hunt

Yes their is a lug the B block as attached photo shows. I will also send photo of A block in separate email. As well as lug the B casting has a wide open hole where A has a sort of cast in flange. I tried various options before settling for pure B and accepting I would have to move the radiator a bit.

Paul

Paul Dean

Here is A photo. Paul

Paul Dean

That would seem to preclude the A pump (shallower impeller) from being fitted to a B block unless that peg is removed.

However this 18V pump doesn't have that hole, and the block doesn't have the peg of course. This is a short-nose pump GWP117, and the later GWP123 is almost certainly compatible. These pumps need a spacer between the pulley and the fan to prevent the fan hitting the block. This pump would probably avoid you having to move the rad.
Paul Hunt

Dang, hit the wrong button to add the image.

Paul Hunt

Paul,

On the assumption the B block photo is of the rebuilt engine, are you now replacing the water pump? Also, why is the block/pump mating surface painted? I would think that may compromise the gasket seal.

Roger
R Taylor

This has reminded me of a problem when I installed a 5 -bearing engine in my Magnette. The new water pump resulted in the fan being too close to the radiator.
The boss on the pump shaft protruded past the end of the shaft - simply pressing it further on gave sufficient clearance.
(Check alignment with pullies.)

A long shot, but it might be worth checking before you move the radiator.
David Overington

I did actually manage to fit the A pump to the B block by a bit of filing of the A pump body to avoid the pin. I then changed my mind and went pure B including using a B pulley to get fan belt back in right plane, but I kept the A fan. My reason for going pure B is that there is clearly a conscious design change as you don't change a casting design without a reason hence presumably it was regarded as an improvement.

By the way changing from 72bhp 1500 to 95bhp 1800 improves the driving pleasure immensely. The torque improvement is even better and even when you are not using the power the better low down pull means you can be lazier about gear changes. It also masks the issue of big ration gap between 2nd and 3rd. And externally only a B series engine expert can tell the difference, cast 1800 on block and 18 on head.

Paul
Paul Dean

"Reading from your other thread, are you sure this engine is a genuine MGB engine? - there have been mariner/landcrab engines converted to in-line drive!"

Except that the 3 main MGB was never used in either of those models, so the difference will be pretty obvious.
Bill Spohn

G'day Bill,

In asking re "a genuine MGB engine" I was seeking to establish the fact, not the model. Confirmation came with Paul's "...cast 1800 on block and 18 on head."

Regards
Roger
R Taylor

This thread was discussed between 18/08/2014 and 25/08/2014

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