8 replies to this topic

[bennivory]

hi, i rebuilding my 1275gt engine and i want some new rings, the engine has been rebored and on top of the pistons it says, "21251" and "+060" if somebody could give me a link to the set of rings i need on minispares it would be greatly appreciated, thanks a lot, benn

[icklemini]

21251 pistons are dirt cheap, so it may be better to get a whole new set of pistons (as rings are included), as depending on age (a) your piston ring grooves could be stuffed (they need to be measured), and (b) the current rings available may not be suitable anyway for older 21251 pistons...

rings are about £40
http://www.minispare....aspx?pid=37813

or a complete set of new pistons and rings are about £80
http://www.minispare....aspx?pid=37942

hth,
Dave

[bennivory]

if im buying new pistons, do you think i should go for a different more expensive brand, the car is going to be used on the road every day.

[icklemini]

if im buying new pistons, do you think i should go for a different more expensive brand, the car is going to be used on the road every day.

i would imagine its to late for that i am afraid...

the 21251 piston is very low compression, and to get the compression back up a wedge is often taken off the top of the block. this then means you cant (for example) fit a 21253 (a high compression piston) as it'll hang out the top of the block far to much...

ttfn,
Dave

Edited by icklemini, 20 May 2007 - 09:10 PM.

[jonny d]

Is 21251 pistons standard on factory 1275s, and what would happen if you put them in a high compression
engine?

[icklemini]

Is 21251 pistons standard on factory 1275s

not in a mini - they are replacement however for low compression engines - marina vans vor example!

and what would happen if you put them in a high compression
engine?

would lower the compression.

[jonny d]

WERE THEY SLIPPER PISTONS OR JUST STANDARD (DON'T KNOW MUCH ON THIS SUBJECT) I BOUGHT SOME PISTONS YEARS AGO
FROM BROWN BROTHERS THEY WERE 1.6MM SHORTER THAN THE MG METRO PISTONS I WAS REPLACING SO I TOOK 1.6MM OFF THE
BLOCK, DID I DO THE WRONG THING? THEY WERE THE SAME OTHER THAN THE 1.6MM IN HEIGHT I WAS TOLD. HEAD WAS SKIMMED
60THOU AFTER WORK ON THE HEARTS AND POLISHING AS WELL ( MG HEAD )

[icklemini]

no they are a diferent design completly compared to say a 21253, have big fat rigs, massive oil groove... i did a brief post about them before..

[jonny d]

Thanks how does my spec sound to you?