11 replies to this topic

[DYO776C]

I have a mainstream Cooper, 1990 (J) which has believe it or not been dry stored since new.
It currently has 1800 miles (verified). I religiously ran the engine in when I bought the car two years ago with 100 miles only.

Now to my question: I wanted to swap the exisitng engine for a tuned lump. The block references are identical and everything seemed Ok until I came to fit the banjo pipe that goes between the block and the filter housing. The banjo bolt from the original engine does not fit. The thread in the block is larger than the bolt.

Question: I thought all were the same, although my knowledge is 40 years old (hence my handle - the original reg of my Morris Cooper 1275S I owned in 1966). Is there a chance that the replacement block has a metric thread rather than imperial? Looks as though it's 16mm root diameter x 1.25mm pitch?

Short bottom line......what do I do?

Thanks for any replies.

[Guess-Works.com]

should not be different, unless it's been re-tapped to take some metric pipes to an oil cooler.. ??

[Dan]

I think that should be a 12A engine in there right?

If it's a 12A engine then the oil feed is a nasty, olive sealed version. If you've got this, get rid of it as they leak lots and sometimes the pipe pops right out through the olive under load and sprays all the oil out of your engine really quickly. Mini Spares make a replacement pipe with special adaptors to replace the olives with threaded fittings, the pipe flows a lot better too.

Other than that they should all be the same banjo bolt which I believe is 5/8 UNF (same banjo as the vacuum servo connection to the manifold). I had a tap for it once but I think my Dad nicked it off me......

[DYO776C]

should not be different, unless it's been re-tapped to take some metric pipes to an oil cooler.. ??

Hmmm the engine originally in the car is a 12A, the new one looks the same, but the thread is I think 11/16 UNF 20 TPI (as near as I can make out). I think this new engine is built on a later block (maybe 1996 or even later).

Yeah all the older units I have played with have had the olive connecting pipe and 5/8" UNF

So I'm assuming Rover has changed from the 'old normal' one I am familiar with on later engines?

[Dan]

'96 on is the twin point block. Doesn't have an oil transfer pipe, has the filter screwed into the face of the block, doesn't have a dizzy fitting, has an extra tapping the same size as the oil PRV for an oil temp sender and some other differences.

Other than that, all blocks should have either the olive sealed port or the 5/8 banjo.


Maybe it's not a Mini block?

[Guess-Works.com]

or it's an auto block, not sure what sort of oil pipes they have

[Bigbudders]

There are two different filter heads.... they have different size connections. That engine should have the later type (with the olive), i don't know when they changed, but when i went to the scrappy they only had the old type.

[Dan]

Reading what Bigbudders said has jogged my mind a bit and looking back through your original post DYO776C I think you're getting the two types mixed up. Older blocks do not have olives, they have the banjo bolt and washers. The two types are different. The banjo uses the 5/8 UNF and seals to the banjo fitting on the pipe with copper washers. The late type (and your engine will be one of the first made like this) uses an olive inside the block and a fitting to crimp the olive onto the pipe, very much like a domestic plumbing fitting. This type as Bigbudders says uses a larger thread. When you say older units you have had have used the olive it makes me think you're getting the two confused. Older units have banjos, later units use an olive (which as I have said needs ditching ASAP).

[DYO776C]

There are two different filter heads.... they have different size connections. That engine should have the later type (with the olive), i don't know when they changed, but when i went to the scrappy they only had the old type.

OK I will try to put this a different way: I have two engines, both are 12A.

The original one uses a banjo fixing (with 5/8" UNF thread, and was the original engine in the car (registered 11/91) last of the carb Coopers with CAT. The 'new' engine block is of unknown age as it was a donor for a rebuild.

One thing is for sure though, I'm only the second owner of this car, and I know the original owner well. The car was bought new for his daughter, and she hated it, did 100 miles in the car, and then it was dry stored for 13 years, when I finally managed to get the guy to sell it to me. I have all the documentation, and the car is absolutely as new.

The thread in the 'new' block *seems* to be maybe 11/16" x 20 TPI, and does indeed have a recessed cone shape at the bottom of the thread...so that ties in with the 'olive' theory. I was confusing the other end where the pipe connects to the oil filter head and has a 'belled' end. Sorry.

My knowledge as I said in the OP goes back to 1965, and I wasn't aware that so many things had changed in 40 years )

The thing I can't fathom though is that all my other research is saying that 12A engines were not fitted until 1992 on, and people are telling me mine should have had a 12H engine ex factory. Maybe this was a changeover period.

But whatever, the blocks have the same casting number WFM1024, and seem identical otherwise.

So I'm guessing my 12A original engine for some reason had the old banjo fitting, instead of what I'm told is the olive type used on 12A engines....

Trust Rover to confuse things.

Anyway it now looks like the easiest way out of this is to fit an oil cooler kit!

Thanks to everybody who took the time to reply...I'm really grateful.

[miniboo]

could be due to the changeover period as things would have been gradual not instant which is why some things cross over

[Dan]

AFAIK 12A engines were fitted from '90 on, as you have found. Mini never had an A plus 12H, they were Metro engines.

The casting number is the same as it's the same casting, it's only the machining process that's different. The olive sealed pipe was fitted from '92 on.

The pipe uses an olive at both ends, filter head and block so the whole thing (pipe, fittings and filter head) needs to be exchanged.

You don't need to use an oil cooler kit unless you really want a cooler. The pipe I described above from Mini Spares will replace the standard olive sealed oil delivery pipe with a much more secure example, but you will still need the olive sealed type oil filter head to use with it. If you do get a cooler, make sure you get one for a '92 - '96 Mini.

Link to the pipe
Careful though, they seem to have the same product listed under two different part numbers at the same price and then a similar pipe with different ends at a different price. Presumably this last one is to replace the banjo version.

They should have the filter head as well, but I can't find it on their site. It's part number LPX10026.

[DYO776C]

AFAIK 12A engines were fitted from '90 on, as you have found. Mini never had an A plus 12H, they were Metro engines.

The casting number is the same as it's the same casting, it's only the machining process that's different. The olive sealed pipe was fitted from '92 on.

The pipe uses an olive at both ends, filter head and block so the whole thing (pipe, fittings and filter head) needs to be exchanged.

You don't need to use an oil cooler kit unless you really want a cooler. The pipe I described above from Mini Spares will replace the standard olive sealed oil delivery pipe with a much more secure example, but you will still need the olive sealed type oil filter head to use with it. If you do get a cooler, make sure you get one for a '92 - '96 Mini.

Link to the pipe
Careful though, they seem to have the same product listed under two different part numbers at the same price and then a similar pipe with different ends at a different price. Presumably this last one is to replace the banjo version.

They should have the filter head as well, but I can't find it on their site. It's part number LPX10026.

The article attached to that link says it all.......seems mine was an early 12A engine with the old banjo 5/8" fitting, and from 1992 12A engines had 11/16" fittings. So thankyou for that, you have all been very helpful to this old codger trying to relive his earlier years.

I always promised myself (for 40 years) I would sometime get another quick mini, and at 58 years old I've done (doing) it.

Do you know, I've driven countless quick cars in my motoring history - Aston Martins, Lamborghini Countach and Diablo, Porsche 996, BMW M3 to name a few. I've owned three Impreza WRX's, a Lotus Cortina MKII, and Vauxhall Lotus Carlton. My daily drivers are now a Volvo V70 T5R (310bhp) and Renault Clio 182.

But I'll tell you something.......the mini still makes me smile more....it's such good fun, and Alec Issigonis made that possible. I'm looking forward to completing the changes to my Cooper so much.

Anyway enough rambling from an old man.......Thanks again.