10 cc

[stuupnorth]

Hi all
I have managed to find a 1098 engine (complete with carbs)
with the code prefix 10CC
which with my basic info is from a midget
looks like the engine will need a re-build etc
and what are the differences between the standard 1098 minor engine I've heard the bottom end journals are bigger
and is it worth doing and fitting to my minor

[philthehill]

The 10CC engine was fitted to the MG Midget Mk 11 and the Sprite Mk 111.
The main difference between the 1098 CG engine and the 10CC engine is the size of the main bearings.
The 10CG engine main bearings are 1.75" nominal.
The 10CC engine main bearings are 2" nominal.
The PCD of the flywheel mounting bolts is also increased on a 10CC engine.
All interchangeable as a unit.
The 10CC engine is a much better engine and will stand being revved longer without failing.
Is it worth it - depends on how much work you have to do to get it running well.
The head is good being the 12G295 which has good shaped combustion chambers and ports; also fitted with decent sized valves.
Phil

[bmcecosse]

It won't 'go' any better than the earlier 1098 Spridget engine - but it is as Phil points out stronger - it was to give BMC a 'Production Block' to use on Formula Junior racing - and indeed is the pre-cursor of the Coooper S engine. Since there seems to be a lot of classic Formula J racing still going on (Goodwood etc) you may find it would fetch a good price if marketed carefully -with much emphasis on the larger crank mains and possible FJ use. They must get their engines somewhere - although not all were BMC engines of course .

[ManyMinors]

- it was to give BMC a 'Production Block' to use on Formula Junior racing - and indeed is the pre-cursor of the Coooper S engine.

I'm not sure that is true. The later 2" main bearing MG Midget engine (1964) was not introduced for a year or so AFTER the Cooper S was introduced in 1963. It is a worthwhile basis to work on. They're becoming harder to get hold of now. I have one in one of my cars and it runs very well. Power output for the two different engines was:
Early 1098: 56bhp @ 5500rpm and 62 lb/ft
Later 1098: 59bhp @ 5750rpm and 65 lb/ft

[bmcecosse]

Ah but I bet they had developed the block well before that - and then had to put it in a Production car to qualify. There may even be some non 'CC' engines out there that actually have the larger bearings. Also - it's development may have been forced along by breakages of the 'normal' engine in FJ racing. Certainly mentioned regularly in old Mini books that it was the source of the S engine design - which first came out in 1070 capacity (could rev to 9000). The 1098 is the longest stroke (and therefore slowest 'wise' max revs) version of the A series engines. It still think it would be worth a go at marketing it wisely. I had no idea there was so much classic FJ racing still going on till seeing a recent well supported Goodwood 'members' race meeting on TV. These were the days - no wings/light cars and much sliding about!

[philthehill]

Formula Junior is alive and well world wide - my neighbour has just returned from South Africa after competing in several of the FJ Diamond Jubilee races staged there.
His car is mid engine and has a Fiat engine mated to a VW transaxle if I remember right.
Lots of photos and details of FJ cars within the attached link.
http://www.formulajunior.com/

[bmcecosse]

Ahh - but is it the classic FJ using engines etc of the period? the S engine is often described as having been developed from the FJ engine - usually by Cooper, although I'm not so sure if that's so - probably a Works Co-operation with Cooper.

[philthehill]

bmc
The Fiat engine, VW transmission etc. are of the correct period and the car has FIA historic papers so all proper and correct.
A very nice car too.
Looking at the FJ web site you will see that there are a multitude of engines used - S/H cars are not cheap either.
Phil

[philthehill]

Whilst on the subject of FJ
These may be of interest:

http://www.ebay.co.uk/itm/O-S-N-Formula ... SwU0RXHe2q

Pity that there is not a view of the con rods AEA623 DE
They must be special as they do not appear on my list of production con rods.
The nearest production rod is AEA624 Cooper S with forging number AEA625.

Phil

[bmcecosse]

With what look like the Teflon buttons - which I thought was a reasonably recent innovation.

[andypocock]

I stuck one in a Minor last year, or was it the year before? Time flys. The topic was cover in some detail in my post of the time:
http://www.mmoc.org.uk/viewtopic.php?f=4&t=56808