Can anyone tell me if the Australian 998 Cooper engine was the same spec as the English version. i.e. D top pistons, cam etc.

I have a 998 motor that I believe is a Cooper motor but has OEM Mowog dished pistons and STD bore. Engine number of no help because it has a Vic Pol number. This engine came assembled with a Cooper close ratio gearbox, a Cooper harmonic balancer (ala 997 Cooper and S) and the very distinctive Cooper breather on the tappet cover. Has a single ring on the camshaft.
Got me thinking that the Oz version may not have used D tops to achieve the lower compression ratio.

Ok seems that the low compression version of the 998 Cooper did in fact use dishes pistons to achieve the 8.3:1 compression ratio. The part number for these pistons were 12A593 and the hi comp D top pistons were 12A674.
The AEA630 camshaft was used for both versions and is quite different to the 998CC deluxe.

Thanks, I will add that info to my files.

Just glancing through Leyland Fast Moving Parts on another matter and came across the following which may be of interest. No date on the publication but appears to be late 1970's.

Morris Mini 998cc 4 ring piston 12A673/03, ring set 86745

Morris Cooper 998 (HC) piston 12A647/03, ring set 86745, same as above
Morris Cooper 998 (LC) piston 12A593/03, ring set not listed

Does not answer your question directly but indicates a difference between the two pistons.

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John Sneddon
0408 431 807
1963 Morris Cooper
1965 Morris 850
1968 Morris Cooper S

Thanks John. I'm not sure quite what happened here in Australia when they introduced the 998 Cooper in 1964. Unsure if BMC Australia used their Australian version of the 998 engine (unlikely) or were importing LC 998 Cooper engines from UK as they did for the 997 Coopers and later the "S". Can't really see BMC Australia building an engine specifically for the Cooper (Using different pistons, head and valve gear, not to mention a close ratio gearbox).

Anyway good to know that the LC 998 Cooper most likely had different pistons to the D tops of the HC Coopers. Explains why the 998 Cooper engine I have has dished pistons fitted.

Do you think the LC engine was a very short term measure? Before the HC came in?

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

When BMC Australia was making the 998 Cooper with a locally assembled engine they weren't making any other variant of the 998 locally. The Deluxe started using the 998 in 65.
They were making the 1098 for the Morris 1100 from early 64 and probably squeezed the 998 into that production run. (and the local 850 as well)

My question is, does the local 998 Cooper have a hole for an external fuel pump?

The low compression (LC) engine was used due to the poor quality of the fuel available at that time. The octane rating was not high enough to run HC engines.

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John Sneddon
0408 431 807
1963 Morris Cooper
1965 Morris 850
1968 Morris Cooper S

Also remember, an Australian High Compression engine is not the same as a UK High Compression engine.

Did they continue with using the 12G295 head and Sa close ratio gearbox? Surely those items weren't locally made as well? The 998 Cooper block I have here has a factory fitted cover over the fuel pump hole. This engine was fitted to a close ratio gearbox and had a Cooper style harmonic balancer and Cooper breather arrangement to clear the twin SUs.

As far as I know all Cooper and Cooper S engines for our market were designated as low compression versions.

All 1275S sold here were 9.75:1. High compression, there was no LC version.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

I would imagine that they would have fitted all the usual Cooper stuff.
The ID plate for a Cooper with an Australian assembled engine lists the engine prefix of 9Y/Sa/H
The Sa shows the close ratio box and the H shows High Compression.
How high the compression was I don't know.

Local assembly of the engine was pretty much a trick to increase local content. Instead of importing a complete power unit they could import the parts and assemble it here. The local content was the labour involved in assembling the imported components. Some items were machined here which also adds to the local content.
No A-series heads and blocks were cast here, they were all imported.

Thanks for the interesting background. So it is entirely possible that the 998 Cooper engine was assembled here using a combination of local (parts and machining and assembly) and imported bits.

At that stage I would doubt if there was any local parts apart from gaskets and paint.