9 replies to this topic

[wile e coyote]

no doubt.... as a notorious neighbourhood scrounger with only a moderate amount of scruples and a keen nose for what may be lurking unused in sheds & garages - and the cheek to ask - I'm quite often given things...just been out of my way walking the mutt - chat to an old boy with a metro I've had my beady eye on for ages...and hey presto......

These came my way for nothing.... - in plus 0.030" - a size I'm very familiar with - but not used any more it seems..... BHB split skirt 4 ring'ers.... reference SA196 - now I know BHB made bike pistons but have never seen any for cars - let alone an unused set so.... with a tired 1275 lurking in the garage in need of rebore and these to hand I'm considering using them but......... need some views here (and budget minimal for this exercise) anyone able to shed any light on these - suitability? - never used a split skirt piston so pro's /con's???.......

Better anyone know the CR these are likely to give before I get into measuring wrist pin heights & dish volumes???

http://i1300.photobu...zps8ee321a4.jpg

[Cooperman]

Split-skirt pistons are not really suitable for high revving engines as the attachment of skirt to crown will be poor.

The 850 Mini had split skirt pistons and for competition it was usual to replace them with solid skirt flat top ones.

I have never seen the ones in your photos and if I had any I would certainly not fit them to a Mini. To ascertain C.R. you will have to measure & calculate.

[Tamworthbay]

Split-skirt pistons are not really suitable for high revving engines as the attachment of skirt to crown will be poor.
The 850 Mini had split skirt pistons and for competition it was usual to replace them with solid skirt flat top ones.
I have never seen the ones in your photos and if I had any I would certainly not fit them to a Mini. To ascertain C.R. you will have to measure & calculate.

What do you think they would have been made for originally in that size Cooperman?

[Cooperman]

Hi Clive, I was wondering that too. It seems strange.

[Tamworthbay]

Hi Clive, I was wondering that too. It seems strange.

Could it be for something like the allegro?

[Cooperman]

That might be the case. It used to be claimed that a split skirt made the engine run smoother, although I never noticed the 850 being smoother than the later 998.

 

I don't think I would fit them, especially if they were for the All-agro  .

[blacktulip]

austin All-agro lol

[wile e coyote]

Lol! - not that I run high revving anyway - strictly road use only these days..and in all likelihood these will end up as paperweights (if only on the basis that if I'm going to spec an overbore then I'd like it to be on measurements for something I can get spares for!)... I think these predate the allegro - hang on a mo - good god the allegro came out in '73.... and are designated as for "BMC/LEY" on the printed label...

By 5 mins of confusion have just deciphered the worst writing known to man from the top of the box ..."Healey Sprite 67 on" - aha yep the spridget got 1275 from 67.....

On reflection I'll chuck them on fleabay and whatever they fetch wll go towards yet another set of '253's.......

Have no idea why +30 is seemingly abandoned - it was the max BMC "factory" overbore....

Cheers all...

[blacktulip]

i have +.30 pistons in my engine. 21253s. makes 1301cc

[wile e coyote]

so do I!