10 replies to this topic

[Jammy]

I often see people saying I have such and such and then someone else says well you can't get a 1370 or something, so could someone just post up a list or something of all the different capacities that are capable with the A/A+ engine?

[Pavel]

To be honest you can have almost any figure you want by using offset ground cranks which is how most long strokers are made from a standard crank.

Most usual sizes are 1275, 1293, 1312, 1340,1380 (std, +20thou, +40, +60 and 73.5mm respectively).

After that stroking cranks come into the game and as said before almost any figure can be achieved. (i.e. 1399 engines to be under 1400cc for racing classes)

[Dan]

Oh my god, there's hundreds!

Starting way back in the mists of time the A series engine was invented for the Austin A30 and was originally supplied as 803cc. This was using the original small bore block which also gives us standard sizes of:
848cc
948cc
997cc
998cc and
1098cc.

Then there's the big bore block which gives us standard sizes of:
970cc
1071cc and
1275cc.

Then you get in to the oversizes. Bearing in mind that all of the various standard pistons are available in four oversizes you can see that there are many different capacities available. Then of course there's also non standard pistons.

In the large bore engine by using different stroke and bore combinations you can get over 20 different sizes just using the standard crank casting. Use one of the 2 short stroke Cooper S crank castings and you have even more options.

Basically if someone quotes a figure to you between 803cc and 1480cc you can probably make it with an A series engine.

There's also the possibility of sleeving various parts of the block to get bores over 74mm and making a custom billet crank. I think the largest ever made was around the 1560cc mark but I can't remember for sure.

[Mini_resto]

i heard it was about 1556 cc,

if Rover made a 155+ cc cooper it would have sold i think?

[TimS]

that sounds about right dan, the gear box had to be ground out to alow the crank to clear!

[miniman5]

qwite a few most miglia racers are 1440 in the ultimate mini dvd there a 1460!

[duds100]

I read u can get u can get a 1598cc in th david vizard book but u have to chop bits of the crank and cam!!!+ 1340cc can only be achieved with a short stroke crank, just like 1299cc. What people call 1340cc (+60 bore i think) is actually 1330!

[duds100]

so how do u get 1425cc? is that what people call 1430 and uses a standar crank just re-sized? +is your "1425cc Bill Richards engine" 130bhp @ wheels or engine?

[Prawn]

a 1425 is a 73.5mm bore with an 84.3mm stroked crank.

i think 84.3mm is the largest a std crank can be ground to, after that billet cranks are needed i THINK.

in a 73.5mm bore, you can have
1340 (really short stroke-around 79.6mm i THINK)
1380-std 81mms troke
1399-82.3mm stroke
1420- 83.5mm stroke (largest an A+ crank can be stroked to due to fillet radius)
and 1425-84.3mm stroke

after that i think an 86mm stroke gets you 1460cc, an 85mm stroke gives 1442 i think.
of course if you use a 74mm bore you can add 20cc to all those sizes....

the list is endless

personally, ive bought a 1380 short motor, with a set of S rods, but in need of a new crank, so im going to take teh opportunity to have the crank stroked to 83.5mm (ive only got A+ cranks around) to give me 1420, which should give me a good bled of a nice torquey road car, yet still be able to rev reasonably well....


basicly, do the maths and you can get ANY cc you want, its simply a case of surface area of all 4 boresXstroke to give cc

[Jammy]

Ahhh, I see. The one thing that was confusing me was the 1330/1340 thing!

And in answer to duds100s question. Bill said it should be about 130 at the wheels, but I've since swapped over from a webber carb to HIFF44, so it will probably be about 110-120 now. Gonna stick the webbers back on for Combe though, if I still have it.

[Dom]

if I still have it.

:erm: