mk1-forum.net

Hi,

Looking for a set of 1380 pistons for my engine build. There seems to be a huge difference in price accross the manufacturers that I have found so far.

Powertune seem to be about the cheapest, omega the most expensive and powermax somewhere in between.

The engine is an a plus unit and I plan to use an SW5 cam for a warmish motor. I am not into rallying or racing as I don't have the cash, but I do want a reliable (for a tuned mini!) engine.

Is it worth splashing the cash on the expensive stuff? or would the money be better spent on getting the engine balanced?

Any links to pistons at reasonable prices would be appreciated!

Cheers

Mark

Personally I'm using the pistons from Keith Calver. They've suffered abuse from machining, hard driving and detonation due to a distributor mistake
. Best of all I didn't go to 73.5 so have material left in the block should the worst happen.

I'll not go to 73.5 again while there are good smaller pistons available. I feel there is advantage to be had because the bore walls are thicker, less distortion and more compression saved.

I ought to have said you can have 1342cc and 1360cc.

The block is already at 73mm plus about a thou and would need a hone. Piston to bore gap is likely to be greater than ideal if I stick with 1360 pistons. The pistons seem to be about the same sort of price for either 73mm or 73.5mm I dont want to shell out 2 or 3 hundred quid and end up with a set of pistons I cant use in my block. I would like to keep as much meat as I can in the block, but I don't want to spend money on a should be alright kind of build rather than a spot on kind of build.

Hypertecs are also a very good piston, I've used lot and lots of these and have had zero problems.

I'll add that I was put off for many years using these as I thought them too cheap, however they really are a high quality item, way better than any AE Piston and there's a better variety of rings available for them too.

http://precisionintl.com/Engine.aspx?ID=1279&EID=3399

https://www.somerfordmini.co.uk/eshop/i ... chapter=20

Different compression heights are confusing.

Thanks @Spider for the information on the hypatec pistons. I think I am going to go ahead and order some of the 73,5mm size. I may get stuffed with inport duty but they seem about the best bet for my build. The difference in price between these and the Omega options is pretty significant and I am not building a screamer. Reliable is more important. Thanks Again

Have had Auz Hypatec 73.5mm pistons in mine for the last 8 years.

Bullet proof, no slot behind the oil groove, little holes like the old GTS / Cooper S pistons.

I must have done over 50,000kms in it already

Mega Pistons from Minispares are the ones which AC Dodd used in teh past and I had them in my 1330 RSP.