7 replies to this topic

[Neil7744]

Hi,

Been looking into buying a full piston & ring set to replace my originals from a 1275cc metro block. Just want the standard dished pistons, same compression ratio etc as my current ones are damaged.

Ive seen Mini Sport & Minispares do the Hepolite ones, just wondering where is the cheapest place to get some new ones from is?

Plus does anyone know how long it takes when buying from Mini Sport and parts arent in stock? Waiting for some bits to come through as i cant progress with my rebuild until i get them!

[Cooperman]

The best standard replacement pistons now available are the Hepolite 21253 which give a decent compression ratio. The cheaper ones are the 21251, but they are not as good in performance terms and give a lower compression ratio. In this case you can have cheap and not-so-cheap, but as usual you get what you pay for.

[minimender]

I have some 1275 pistons marked 21968 G8 R45

Any idea what they are please Cooperman

[Cooperman]

I think they are original factory fitted late 1275 pistons. They are NLA although ring sets are available from F.W. Thornton of Shrewsbury.
I just fitted a set of the 21253 to a 1971 Clubman GT engine at 1293 cc this afternoon. The dish is 8.4 cc and they give about 9.5:1 C.R. when fitted as a replacement for standard original pistons.
The 21251 is a low comp piston, but a higher CR can be achieved by machining the block deck a bit. I did one at 10:1 CR with 21251 and had to skim 0.055" off the deck of the block. The strength of the 21251 is not as good as the 21253, but it is OK up to around 10:1 and 6000 rpm so long as the engine does not run with the ignition too far advanced and 'pinking'.

[minimender]

Thanks for that.

I had them on the shelf for a 1275 which had bad pistons in it but sold the block etc a few weeks ago as it was never going to get done.
May as well put them on ebay as there isn't much call for standard pistons I suppose.
Could make four ashtrays out of them

[Cooperman]

Thanks for that.

I had them on the shelf for a 1275 which had bad pistons in it but sold the block etc a few weeks ago as it was never going to get done.
May as well put them on ebay as there isn't much call for standard pistons I suppose.
Could make four ashtrays out of them

Have they been previously used. If not they could be in some demand as the quality of those was very good.

[minimender]

Thanks for that.

I had them on the shelf for a 1275 which had bad pistons in it but sold the block etc a few weeks ago as it was never going to get done.
May as well put them on ebay as there isn't much call for standard pistons I suppose.
Could make four ashtrays out of them

Have they been previously used. If not they could be in some demand as the quality of those was very good.

Taken out of a used 1275 engine that was being upgraded. Been on the shelf for a few years and I found them whilst clearing stuff out as I have retired.
I'll get the micrometer on them and see if they are ok, cant see why they wouldn't be ok with new rings though, at least they are proven to be up to a good threshing so wont fail.
I am not used to working with new parts anyway unless it's gaskets and the like, (once got the wife to iron an old copper head gasket and I put it back on...no problem) my life has been spent making power on a limited budget (nowt) with scrapyard parts that have to be mended or modified. Still beaten some very expensive machinery with my budget racers though, and taught the younger generation that you cant just throw cash at a motor and expect it to work at its best.
The younger generation now have rolling roads and mappable ignition which feels like cheating but I suppose that's progress if you can afford it, I never could and never will have the money to do that.

[Cooperman]

Thanks for that.

I had them on the shelf for a 1275 which had bad pistons in it but sold the block etc a few weeks ago as it was never going to get done.
May as well put them on ebay as there isn't much call for standard pistons I suppose.
Could make four ashtrays out of them

Have they been previously used. If not they could be in some demand as the quality of those was very good.

Taken out of a used 1275 engine that was being upgraded. Been on the shelf for a few years and I found them whilst clearing stuff out as I have retired.
I'll get the micrometer on them and see if they are ok, cant see why they wouldn't be ok with new rings though, at least they are proven to be up to a good threshing so wont fail.
I am not used to working with new parts anyway unless it's gaskets and the like, (once got the wife to iron an old copper head gasket and I put it back on...no problem) my life has been spent making power on a limited budget (nowt) with scrapyard parts that have to be mended or modified. Still beaten some very expensive machinery with my budget racers though, and taught the younger generation that you cant just throw cash at a motor and expect it to work at its best.
The younger generation now have rolling roads and mappable ignition which feels like cheating but I suppose that's progress if you can afford it, I never could and never will have the money to do that.

You and me both. I started on 850's back when I was an engineering apprentice and the Mini was just introduced.
Now retired I just play about with the 'little dears' and am currently building a nice engine for a 1275GT for a good friend. Like you, didn't have rolling roads and tuning consisted of fiddling with the ignition and mixture, then testing against the stopwatch and adjusting again until it was as good as we could get it.
Ah, happy days!