i borrowed a piston ring compressor from a mate but it turns out it doesnt compress the rings enough , do i need a mini specific compressor ? wot piston ring compressors do you recommend and where did you get them from ?

cheers Jarrad

Stear clear of the cheap made in China ring compressors. I broke a set of oil rings using one of those that I bought from Supercheap.
I ended up borrowing the same style of compressor but made in the USA it worked fine.

Sometimes it is easier to pull apart a cheap one and just use the sheet metal band and a big hose clamp.

The ratchets are just too coarse in the cheap ones...you can get by,but barely and you have to be super careful using them (which is not the point of the excercise really...)

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

The best type of ring compressor is the tapered cone type.
The pistons just fall in.
Downside is you need a different one for every bore size!
Easy to make with a reasonable lathe.
You would have seen them in use if you have ever watched a top fuel tear down and rebuild.
Dave

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cheers i might try and improve the one i have then

If it is designed for big pistons they don't close up for a Mini piston very well, there is too much friction as it tries to tighten up. But if you oil the sheet metal it may slide a bit easier. (let it right off so that the oil can get between the layers.)
As you tighten it up you can try to squeeze it by hand on each side as you turn the key it may help.

Or you can pull it apart and slice the steel so that it is the right size and use a hose clamp.

I have a Meco (it's about 30 or 40 years old)- no ratchet, instead it has a friction adjustment. Way better idea.
But as Matt said the tapered tube ones are best, I made a 90.0mm one when I rebored my 115HP outboard years ago. Bit big for the Mini...

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

I have a "blue point" one for 1275 + has a steel band and work just like multi grips
.............and a "ratchet type" one for small bores as i cant get a band small enough for the blue point grips but i may try and see if i can get some one to make one for me as it is so much easier to use.

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http://www.youtube.com/watch?v=nDMkVq1jRGU

I use a REPCO rachet type thats 20 years old. The bore, piston rings & ring compressor must be oiled when you assemble for you will break rings.

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