Identifying engine size

[Griffer]

hi all, i'm normally in the TVR forums but popped in for some advice.
My sister is into mini's and has bought another one on a 'B' plate, supposedly fitted with a 1380 Metro lump. I'ts fitted with a Weber 45 and LCB, with the scuttle crudely hacked about to get the carb in.Since the 'installation' it's not been on the road, and was bought without hearing it run!!! Shell is good though.
This was because a late distributor was fitted and the seller did'nt know how to wire it. I have got it started with an earlier 998 dizzy, but it dies over about 2000 rpm with very rough idle.
I doubt it really is a big bore motor, no evidence of any recent assembly etc, looks like it's stock to me,and is in a bit of a state, but how can I tell it's origin without dismantling it?
Any advice much appreciated.
Steve

[pdV6]

I'm sure the experts will be along in a minute, but I seeem to recall that the first few letters/numbers of teh engine no. will shed some light on its original size (doesn't help if its been rebored, though).

[guru_1071]

if it has got the engine number still attached then is probably standard (the plate is removed when reboring).

[Cooperman]

Don't trust the engine numbers, they are sometimes changed to make a big engine seem like a small one to try to confuse the insurance co.
There is a very simple way of checking which takes just 5 minutes.
Remove a spark plug. Bring the engine to bottom dead centre on that cylinder. Put a pencil down the bore and make a mark on the side of the pencil level with some point on the head. Remove the pencil and bring that piston to TDC. Put the pencil down the bore and make another mark on it level with the same point on the head.
Measure the distance between the two points. If the distance is more than 3" it's a big engine, i.e. 1275cc or greater.If less than 3" it's a 998 cc.
The only exception to this rule is if some idiot has fitted an 1098 engine (the worst possible choice IMHO), in which case the stroke will be over 3". Then you look on the back of the block and see if there are cam chest covers. They do not exist on 1275 engines, except Cooper 'S' units (rare), but do exist on all 998 and 1098 blocks.
So, over 3" with no cam chest covers, it's a 1275,
Less than 3" it's a 998.
Over 3" with cam chest covers it's a 1098 small bore or a Cooper 'S'.
Now, how would you tell a 1098 from a Cooper 'S'? Easy again, the Cooper 'S' has 10 head studs and one head bolt, all the others have 9 studs.
I hope that helps and is not too complicated.

Peter

[Griffer]

Thanks for the super quick responses, will give it a try.I intend to remove the weber at some point, I have a 1.5" SU and minispares manifold,would that be OK if it is a 1275? I doubt she would insure it on the weber even if it were jetted OK, she isn't a speed merchant anyway.
Thanks again.

Steve

[pdV6]

Cooperman said:

The only exception to this rule is if some idiot has fitted an 1098 engine (the worst possible choice IMHO)

Genuinely interested - why is the 1098 a dog?

Also - wasn't there a 1071 Cooper engine? (although I guess they'd have made a big deal of it if it was one of those!)

[Cooperman]

pdV6 said:

Cooperman said: The only exception to this rule is if some idiot has fitted an 1098 engine (the worst possible choice IMHO) Genuinely interested - why is the 1098 a dog? Also - wasn't there a 1071 Cooper engine? (although I guess they'd have made a big deal of it if it was one of those!)

The 1098 is a small bore very long stroke engine with a crank thatb won't take much in the way of revs. I once had an 850 Mini with an MG1100 engine and standard drum brakes! 'nuff said.

The 1071 is so rare that I didn't include it in the notes. A lovely unit though, some say the best Mini engine ever and I for one wouldn't argue.

The actual stroke figures are as follows:
850cc - 2.48"
997cc - 3.2"
998cc - 3" exactly
1275cc - 3.2"
1071cc - 2.68"
1098cc - 3.30"
970cc - 2.44"

That's why it's so easy to see if it's a 1275 as if the stroke is over 3" and it has no cam chest covers then it must be.
All Cooper 'S' units have the 10 studs and one head bolt and have cam chest cover plates.
The odd ones out are the 997 Cooper, which is also 3.2" like the big engines and also has the cam chest covers like the 1275 'S'. However, it will only have 9 head studs, whilst the 1275 'S' has 10 head studs + the head bolt, and the 850 and 970, to which the same applies as all 970's are 'S' units with the 10 stud +
bolt.
Make a note of these, I shall be asking questions later!!!

Peter

[pdV6]

Cooperman said:

The 1098 is a small bore very long stroke engine with a crank thatb won't take much in the way of revs. I once had an 850 Mini with an MG1100 engine and standard drum brakes! 'nuff said.

Furry muff.
Was interested as I had a fairly fit 1098 in my old Mini 1000 that was loads better than the 2 knackered 998s that I also tried in there. Ah... student days!

[Cooperman]

The old 1098 had loads of torque at much lower revs than the 998, but I never took mine over 6000 rpm as i thought the crank might get a bit frightened and make a hole in the block to let some daylight in!
With standard single leading shoe brakes the whole thing was frightening! That was my road car and I had a Mk 1 Cortina GT as a rally car at the time (1967-8).

[pdV6]

Ah yes - I was intimately familiar with the use of the brake spanner!

The torque is the thing, I guess... both 998s I had (although they were pretty knackered, admittedly) would have had trouble pulling the skin from a rice pudding.

[Cooperman]

pdV6 said:

Ah yes - I was intimately familiar with the use of the brake spanner! The torque is the thing, I guess... both 998s I had (although they were pretty knackered, admittedly) would have had trouble pulling the skin from a rice pudding.

I once built a 998 Cooper engine for my son who was restoring a 1967 Cooper 998 for Historic rallying.
I used a properly timed-in 286 Kent cam, slightly bigger valves in the 295 head which I opened up and gas flowed(I've still got that head), a lighter flywheel, lcb manifold and Maniflow exhaust. We stayed with 1.25" SU's on a flowed inlet manifold. Built carefully with decked block and skimmed head it gave 74 bhp at 6000 rpm - that's the same as a standard 1275 'S'. No torque, though, but still more torque than the well-modified but horrible 970 'S' lump we replaced it with, even though the 970 was giving 85 bhp at 6700.

[MR2Mike]

Griffer said:

Thanks for the super quick responses, will give it a try.I intend to remove the weber at some point, I have a 1.5" SU and minispares manifold,would that be OK if it is a 1275? I doubt she would insure it on the weber even if it were jetted OK, she isn't a speed merchant anyway. Thanks again. Steve

A 1 1/2" SU is a little on the small side for anything but a bog standard 1275. A 1 3/4" SU or preferably an HIF44 is a better sized carb for a 1275+ engine. Should be readily available from a breakers etc. You would need to check if your manifold would fit though.

[Twelve_75]

I have a 1275 standard metro engine in my mini with a HIF44 single carb and it runs marvellous. Made my own bespoke exhaust system so it sounds well.

The engine code for a 1275 starts with 12HD12

regards, Tom Tom

[guru_1071]

unless. of course its 1990 on then it starts with 12A.......

coop' agree with your 1071 thoughts, same as mine, my next little project is going to be a s.p.i rover cooper with a 1071 in it.

[ccharlie6]

if you get the moss parts catalogue for minis it has every engine number combination telling you what engine you have! it's useful to find out what you are looking at. e.g. my engine no. starts 99H997P off the top of my head which means it's a 998 A+ with high comp flat top pistons

[Griffer]

Thanks all for the advice, rang sis up (the car is 60 miles away from me)and of course the engine number plate is missing, just the rivet holes there.

So, looks like it is down to measuring the stroke as sugested to ensure it is at least 1275, it is supposed to be ex Metro taken out to 1380 but as mentioned before it has no sign of any recent disturbance to head or block, although everything is covered (poorly)in thick gold engine enamel. It was a young guy that had the engine fitted, was bought secondhand by him so no known history. May have been modded years back but I'm not so sure. Would be nice to know where to start with it though regarding timing etc.
Steve


Steve

[guru_1071]

grifer

three or four books you should buy

1) haynes manual for a mini - go for a older one as the newest one (up to 2001) is very sparse - more of a service book.

2) haynes manual for a metro - covers all the a plus 1275 stuff in good detail

3) how to power tune your 1275 (or ditto 1000) by des hamill. very good book (s) that cover sensible thru to high tuning. contains a lot of 'base' figures that can be used as a starting point for any engine. des also does a good 'how to' book on SU's

4 ) big yellow (or blue, first it was blue, then yellow - the newest reprint is far thinner than the old versions so be careful when buying!) a series bible by david vizard. very complicated book for the beginer (and most experts i guess!!)and a little out of date now. but still THE book for a series engine.

with these four books you cannot go wrong!! - cost between ebay and new i guess 40 quid? well spent IMHO.

if you really want a more tech spec (of standard stuff) get a copy of the offical rover AKD manual. it is available new and was first printed in the 1970's. you can also get the same that covers more modern s.p.i cars though this is far more 'numptiefied' for the main dealer YTS lads!!

bit of bedtime reading for you!!!

[Griffer]

Ok, all is now revealed. Compression low on 2 cylinders, so took the head off.Head gasket leaking. Its a bog standard 1275. Stroke about 3 1/4", no machining or flowing carried out. No chest covers.
Thanks for all the advice guys, and guru1071, had a bit of luck, picked up the 2 Haynes you mentioned at a car boot on Saturday for £1.00 each, allready had a copy of the blue Vizard bible from way back and dug it out the loft.So,it's head overhaul time>
Thanks again.
Steve

>> Edited by Griffer on Monday 7th March 17:10