17 replies to this topic

[Shooter63]

At the moment the mini is in the workshop getting ready for the refit after a bare metal re-spray, so it's time to think about the lump ( highly technical term I know ) it came with a 998 engine but will get changed to a 1275, as I need to source a unit,I seem to remember that due to core shift problems bl ( as it was) had to liner the blocks, can anybody tell me the years/ numbers to avoid? I seem to think it was in the early days of the A+ but could well be wrong.

Shooter

[Spider]

There were some early A+ Blocks that had porosity and so were sleeved in the factory. I've not heard of any that suffered core shift though.

 

Unless you are looking to bore the block beyond the size of the sleeve, there is nothing in the world at all wrong with these Blocks.

[ACDodd]

The sleeves were fitted throughout the production run. There are no pointer as to which to avoid. I would say 20% were lined. These blocks should present no problems when use at 0.020" over size. Liners can also be replaced.

 

This is an A+ block being sleeved back from 1380cc 73.5mm bore in my workshop to STD size. The sleeve will actually benefit the block structurally and wear resistance.

 

 

 

AC

Edited by ACDodd, 21 June 2015 - 09:04 AM.

[axnutty]

Interesting, I came on here today to ask pretty similar question, I'll hi jack this thread if I may, as you my find some of the info useful.

I've just dropped 2 pre A+ 1275 engines off for machine work and the engine builders finally got back to me on Friday. One of my blocks has been retro fitted with liners. The other is a standard casting. They both however need re bores. This is what I was told:

" the liners are all made by hepolite, because of the way they are made they are of superior quality spun steel with less air bubbles and denser quality and as such have a much better seal than the standard block wall with the piston ring, as such BL fitted liners to the last engines in the days of increasing emission regulations...."

"They have never known a liner to break up, even under race spec conditions, nor when it has been over bored 020, in fact they could take them out 030 but that is technically beyond the safety margin given...."

"You can't run liners on big bore conversions as there isn't enough space..."



I'm not sure if any of that reassures you? I came on here to see what other people opinions are on these liner'd engines are as well? Because if anything the engine builder was sort of making out that they were better?!?!? Certainly in my scenario he was saying use the liner'd block and make it a 1293... Rather than use the other block with an offset 060 over bore. What's other people's thoughts?

Edited by axnutty, 21 June 2015 - 09:15 AM.

[Spider]

It's always been my experience with linered blocks that the rings last and seal much better than un-linered and that's not just A Series Blocks either.

 

<Edit: I'm fairly sure though that the sleeves are CI and not Steel >

Edited by Moke Spider, 21 June 2015 - 09:29 AM.

[ACDodd]

No, not all later block were lined. Certainly the material is a better quality and does make for an excellent sealing surface. However this is as much to do with finishing and accuracy as it is with the material itself. It is also true that some racers are actually lining there blocks before use. This may because the blocks are scarce and/or they believe there is an advantage. It is not true that you can't sleeve a big bore converted block. The picture above is me actually pushing the liners in just such a block. OE liners were probably made by hepolite. However those produced by westwood liners are usualy of better quality in terms of finish and size accuracy. Those shown above are the 2.925" repair liners (part no. WCL 13A) as produced by Westwood liners. They are a very well made liner and certainly better than the genuine rover ones ones I also have on the shelf, factory liners are nominally 2.8775" in diameter.

 

I have also bored factory liners to +0.040" with success, but have limited the engine use to standard applications.

 

Using a properly linered block should be considered a bonus!

 

AC

Edited by ACDodd, 21 June 2015 - 09:43 AM.

[ACDodd]

http://www.westwoodc...o.uk/technical/

 

 

As to liner material. Liners are not steel!

 

AC

Edited by ACDodd, 21 June 2015 - 09:43 AM.

[axnutty]

Right so some of what I've been told is accurate and some isn't. But in terms of reliability, longevity and possibly some sealing attributes the liner is a better option than a standard block re grind. Or at least, there is no disadvantage what so ever?

[ACDodd]

Liner is better if correctly installed. Liners can be fitted in a number of ways some of which are: Pressed in, pressed into honed bores or glued in to seated bores.

 

I use the pressed into honed bores method. After fitting the sleeves need to be bored and honed to finished size. It is not cheap to have a block sleeved. But it is better in the long run for the block.

 

AC

Edited by ACDodd, 21 June 2015 - 10:05 AM.

[MiniTim71]

Hi all. my '71 Morris 1000 has an ex Metro 1275 (low compression) and it is currently being rebuilt to "stage 2" with a Kent MD246, for road use.

I asked for it to be re-bored to +40' 1310cc.

However when I was sent photographs of the build I noticed they were using AE Nural HC +20' pistons.  A little unhappy, I questioned this and you wont be surprised to hear that the block was factory lined and +20' was as far as they could go.

The build is underway and they accept they should have told me.  They said If I get them another block they will give me what I asked for.

 

Do I stick with it or look for an unlined block?   (this is a technical question, ignore cost)

Opinions welcome ...

AC ?

[Lplus]

Hi all. my '71 Morris 1000 has an ex Metro 1275 (low compression) and it is currently being rebuilt to "stage 2" with a Kent MD246, for road use.

I asked for it to be re-bored to +40' 1310cc.

However when I was sent photographs of the build I noticed they were using AE Nural HC +20' pistons.  A little unhappy, I questioned this and you wont be surprised to hear that the block was factory lined and +20' was as far as they could go.

The build is underway and they accept they should have told me.  They said If I get them another block they will give me what I asked for.

 

Do I stick with it or look for an unlined block?   (this is a technical question, ignore cost)

Opinions welcome ...

AC ?

It depends if you're desperate for the extra 17 cc.  Performance wise you are unlikely to notice the difference.  ( I'd say you would definitely not notice the difference personally)

[Midas Mk1]

Hi all. my '71 Morris 1000 has an ex Metro 1275 (low compression) and it is currently being rebuilt to "stage 2" with a Kent MD246, for road use.
I asked for it to be re-bored to +40' 1310cc.
However when I was sent photographs of the build I noticed they were using AE Nural HC +20' pistons. A little unhappy, I questioned this and you wont be surprised to hear that the block was factory lined and +20' was as far as they could go.
The build is underway and they accept they should have told me. They said If I get them another block they will give me what I asked for.

Do I stick with it or look for an unlined block? (this is a technical question, ignore cost)
Opinions welcome ...
AC ?

Hope your not expecting much from a 246, a 266 is a very mild road cam just to compare.

[MiniTim71]

 

Hi all. my '71 Morris 1000 has an ex Metro 1275 (low compression) and it is currently being rebuilt to "stage 2" with a Kent MD246, for road use.
I asked for it to be re-bored to +40' 1310cc.
However when I was sent photographs of the build I noticed they were using AE Nural HC +20' pistons. A little unhappy, I questioned this and you wont be surprised to hear that the block was factory lined and +20' was as far as they could go.
The build is underway and they accept they should have told me. They said If I get them another block they will give me what I asked for.

Do I stick with it or look for an unlined block? (this is a technical question, ignore cost)
Opinions welcome ...
AC ?

Hope your not expecting much from a 246, a 266 is a very mild road cam just to compare.

 

 

Hi, not quite sure what point you are making here?  My question is asking for opinion on a sleeved block build.

 

Regarding the MD246 It has been recommended to me from a number of directions.  I am not looking for a weekend warrior / boy racer, more a fun torquey road engine in a cute looking Mini.

 

From Kent

"MD246 The ultimate high torque sports road touring camshaft. The combination of maximised lift with short duration makes this a superb road camshaft in all engine sizes. CNC ground in the UK for precision and reliability - often imitated, never bettered."

Edited by MiniTim71, 07 March 2024 - 11:08 AM.

[PoolGuy]

 

 My question is asking for opinion on a sleeved block build.

 

In that case, your question has already been answered in this thread.

[DeadSquare]

Hi all. my '71 Morris 1000 has an ex Metro 1275 (low compression) and it is currently being rebuilt to "stage 2" with a Kent MD246, for road use.

I asked for it to be re-bored to +40' 1310cc.

However when I was sent photographs of the build I noticed they were using AE Nural HC +20' pistons.  A little unhappy, I questioned this and you wont be surprised to hear that the block was factory lined and +20' was as far as they could go.

The build is underway and they accept they should have told me.  They said If I get them another block they will give me what I asked for.

 

Do I stick with it or look for an unlined block?   (this is a technical question, ignore cost)

Opinions welcome ...

AC ?

Stick with what you have got.

 

The liner's better ring seal and lower friction are at least equal to the increased capacity of a .020" larger bore, in an engine with your proposed state of tune.

 

Special Tuning asked Downton to put liners in the works 1300 class race engines.