VIDEO: How to Identify various A-Series engines
In this video we identify the various A-Series engines found in the Austin Healey Sprite and MG Midgets through 1974.
Below is listing of the various Engine ID Prefixes and other associated information.


Hi gang its Brendan from Spridget Mania! Today we're going to do a real quick video here for you to help you identify which engine is in your sprite or midget and today, we have an example here of an engine core that we purchased recently this one we're going to do a rebuild on but while it's in this state I wanted to show it to you because this one is basically an untouched motor from 1967 or early 1968.

Now, how do I know that? Well the first and best way of course is to check your engine identification plate. The engine ID plate is going to sit on the engine block itself. It's going to sit on the horizontal Cylinder block here and you're going to notice that it's actually riveted on you have an engine where this is missing. It could have been that it was taken off and put on another engine. It could have been that it was just lost over time the most likely cause however is going to be because the engine was rebuilt and when the head is removed obviously when you get an engine rebuilt.  And if you have it board over or what-have-you they surfaced the top of the block in order to do that since this is on the same plane as the cylinders, this invariably gets removed and taken off and oftentimes the machine shop, you know isn't careful doing it, they just sort of tear it off and then they machine it and this gets destroyed and you never see it again.

When we see an engine like this usually means that the engine hasn't been touched and it's probably still standard bore. So that's something that we actually like to see this particular engine is out of a midget and we know that it was made sometime after November 1967. The reason that we know that is because it has a 12 C as in Charlie, D as in David engine prefix here and we know that the 12 C D blocks were made for the North American market. We also know there's other clues on this engine that would give that away. You see these bosses here, these threaded areas here on the head are actually designed for a rail that would come across here that would inject fresh air into the head and that was part of the emission control system that ended up on these engines for the North American market the Gulp valve that used to sit over here on the engines previous to that was done away with at that time and so this was part of the Emission control stuff that you would see so this is actually everything we're seeing on this engine is really consistent with a 12 CD motor. Notice the color, both sprites and midgets had this sort of light metallic green color for a certain amount of time. If you read the Terry Horler book the original sprite midget book he says that this color coincided with the thick flange block you can't really see it because it’s really dirty but this block here has actually got the thick lower flange here where it mates with the oil pan. Earlier engines, they had a thinner flange here this one's a thick flange even though it's just covered in in muck at that current time. You can also see the color on the oil pan down there some other things that you can look at on this motor to tell about originality. If you look over here the thermostat housing thermostat housing actually will face towards the left of the engine and this is because by this time they had switched over to a cross-flow radiator vertical flow radiators have the thermostat that faces out on the generator or alternator side of the engine and ones that face this direction actually are for the cross flow radiator. Some other bits of originality on this engine, it still has although it's missing, its distributor cap it has the 25 D distributor which was original on this engine it still has the bracket for the generator which this one would have come with it even still has the original dipstick. So this is a great example of a 12 CD motor and you know all indications.

At this point without taking the engine apart show that this is an all original 12 CD motor from that time period so this is a great candidate for rebuilding. Maybe another thing to mention is the balancer here BMC had created different balancers for different cars Sprite midgets, they had this style balancer. It was a thicker style, there's also a thinner style, but I believe all of these actually came with the thicker style balancer. You've got the original oil pickup system. These engines at that time they were they still used the canister type with the paper filter. That would go in here and it also still has the adapter piece here, which actually lifts this slightly up as you mounted on the block so that you clear your frame pieces in front of the engine and when they went to the different style head that used the screw on filters this wasn't necessary because the screw on filters are a lot shorter and they won't impact the frame.

 What we're going to show you next we're going to show you an engine that I built for my 67. Which is actually a thin flange block and mine is actually missing the identification plate,  I have my heritage certificate. So I know the number that it was supposed to be and so we'll go through that one next and I'll show you what a slightly earlier engine would look like.

 Alright what you're looking at here is actually a 12 CC Charlie Charlie designated Sprite engine. The first way that you can tell that it is a 12 CC engine, as you can see that it has the very thin flange on the bottom of the casting. You can see that normally the later thick flange blocks are about this thick on the bottom here and this one's much much thinner and this particular casting number is a 12 G 949. So this was the very first of the 1275 engines this is the very earliest of the 1275 s that were available on the sprites and midgets.

Okay, I wanted to show you guys what the earliest sprite engines look like. This one obviously is not all together, but this will give you a good idea of what the first 948 looked like. I believe this particular one, is that of a Morris Minor because they also had the 948 inline. But of course the biggest difference that you're going to see for the early what they call small bores the 948 and 1098 engines is the fact that they had tappet covers. Of course. These are not on this block currently, but the 948 would have just two solid covers that would go over these. The 1098 would have a solid one here and then it would have the front one here would actually have the breather on it that would then go up to the manifold carburetor manifold so that after  the 1098 was introduced in October of 1962 for the sprite mark 2 and the midget mark 1 they got rid of the valve cover on the cylinder head that actually had the stub pipe on it and they vented it from this particular place right here.

And of course later with the 1275 s they vented it from the timing cover so of course that's this is the easiest and quickest way to tell whether or not you've got a small bore in your car is if it has the tappet covers on it, you know 1275 didn't have to have the covers under 948 the 1098 did Of course. This one's also got the designation right there actually cast into the side of the block it says 950.  Another thing about the 948s is that they did use a mechanical fuel pump. And that's what this hole here is for This hole didn't return until the very latest of the 1275 s but it but even then it actually wasn't used. It still had an electric fuel pump at that point so it was just blanked off with a plate. You can see that there is actually no engine plate here if there were it would have a 9c number for 948 if it were a 1098 it would have a 10c. The engine plates on the 948 were different from the later cars, you can see that this is actually this was just hanging on a dowel pin here and can take this off but it's actually a piece of stamped metal and it has the oil cover here actually welded in place the later 1098 in 1275 units had a much heavier solid steel piece, this is the style that would have been on the later cars.

Of course the first 1098 that came out, it wasn't, you really couldn't tell much other than the like I said the fact that they were venting from the first tappet cover and from the engine number outwardly, they were pretty similar to the 948 and the first 1098 from October I believe of 1962 they had the same crank mains size. They were a 1 and 3/4 and then later for I think it was from October of or March of 1964 on they were a 2 inch main. So in the 1098 first came out, it was a one-in-three quarter main and then it went to a 2 inch main. So that's what the basic identification is of the small worse.
They've got to have covers on them and in a second, we'll go over and do a quick little video showing you the difference between the heads on a 1275 and the earlier small bore engines.

Ok, well here we got a couple cylinder heads. I wanted to show you real quickly the difference that you can tell between a small bore either a 948 or a 1098 cylinder head versus a later 1275 cylinder head this one right here. That's a 12-8 1456 that's one that might have been pretty common on like a 948 and one of the things that you can tell when you put it up against this 1275 head right here you'll notice that at the front it's a different orientation for the thermostat housing here and you can see that this one kind of comes out to a point on the small bore, whereas it's a little bit more flat up here. This is a 12 G 940.

So this is a pretty common 1275 cylinder head. That's one way you can tell if you ever see the one stud for the thermostat housing pointing straight towards the radiator you know that that's a small bore even if you even if you don't look on the other side of the engine and see that it's got tap recovers you see this and you know that it's just that it's a small bore engine automatically. You can also tell actually by looking back here if you notice the heater valve tap is sort of perpendicular this way and on the 1275 it comes off at a slight angle you can also tell that that way by looking at it so that's a that's a couple different ways of being able to tell just by looking at a cylinder head if it's either 4998 1098 or a 1275 there's one other way if you had these sitting in a shop and you needed to you needed to find one to recondition for an engine. You'll notice that the combustion chambers on the bottom of the small bore ones actually, they've got kind of a real heart kind of a shape to them and you'll notice that on a 1275. It's not quite as defined. It's a little bit more open see like that versus that that's the difference in the way that the combustion chambers look. So you have 948 and you've got 1275 over here.

Okay, I'm just going to do this last engine really quickly. This is another of the 12 CD Charlie David engines for the sprites you can see that this one also has little holes in the head where the rail would have gone for the emissions control type stuff the equipment on that. This one also has a later screw on oil filter head. This one does have something a little unusual on it, that's probably not original to this motor and that's this valve cover which actually has this little stub tube on it. I believe that that's off of a later 12 CJ as in Jackson engine which was one of the evaporative loss engines and that's part of the evaporative loss setup which actually wasn't present on the 12 CD engine. Those engines first started. I think the CJS first started in you know in 1969 but then I think that they went to all of the North American engines went to that after 1971 even though the system's painted black. From the 12 v as in victory engines all of the 1275 engines were painted black that was up until the introduction of the 1500 Spitfire engine that was in all of the later midgets from 1974 on.

So if you have an engine that has a 12 V for victory designation it should be painted black this particular one has  been repainted obviously. This one's too early to be painted black. It would have been one of the one of the kind of greens. Either the olive green or actually this is a thick flange block. So this one probably would have been, this one could have been the other more austin-healey colored green you can see the thick flange here, this one's less dirty than the other one.

If you have any other questions about engine identification, you can email me. I'll put my email down in the description of the video.

I'll also put a list of the engine designations and years and colors and all that kind of stuff. So if you don't

Click the show more button on the description for this video and there should be a list there. You can always give me an email or give us a call if you have any engine questions. What part fits your engine or if you want to do an engine overhaul or buy a new engine or if you're looking for a used runner Give us a ring. We're here to help

Factory Engine ID Prefixes:

  • 9C - Austin Healey Sprite Mk I (Bugeye/Frogeye), 1958-1961, 948CC - MOWOG/"Engine" Green
  • 9CG - Austin Healey Sprite Mk II/MG Midget Mk I, 1961-1962, 948CC - MOWOG/"Engine" Green
  • 10CG - Austin Healey Sprite Mk II/MG Midget Mk I, 1962-1964, 1098CC - MOWOG/"Engine" Green (1.75" Crankshaft main journal size)
  • 10CC - Austin Healey Sprite Mk III/MG Midget Mk II, 1964-1966, 1098CC - MOWOG/"Engine" Green (2.00" Crankshaft main journal size)
  • 12CC - Austin Healey Sprite Mk IV/MG Midget Mk III, 1967, 1275CC - MOWOG/"Engine" Green/possibly also the Light Green hammer finish (all "Thin Flange" blocks)
  • 12CD/12CE (home market)/12CJ - Austin Healey Sprite Mk IV/MG Midget Mk III, 1968-1971, 1275CC - Light Green hammer finish - All emission controlled/evaporative loss engines (except 12CE)
  • 12V - MG Midget Mk III, 1971-1974, 1275CC - Black
Got a question about your engine? Email us at [email protected].

Sprite and Midget Light Green Metallic Engine Paint:

Sprite and Midget MOWOG Green Engine Paint: I

f you've got a Classic Mini Cooper, here's a very comprehensive list of engine ID's from Mini Mania:

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