Piston sets
Turbo Mini Forums

Chamber size in BMW K series head is already 28cc

& for anyone interested, the Hypertecs from Tony & Andrew from Minisport Aus are great, i use em & they won`t give you curry, they`ve been designed & tested & developed over a very long period of time taking into account all the problems associated with lots of other piston designs & materials over the years.

simply put--> they`ve been tried & tested & proven well worthy & have been for a very long time over here, just that you guys have been a little slow off the mark

I remember some years ago there was a mad rush from people on Mini Mania site for them but funny enough at that time there suddenly became a shortage & new batches of them were slow in the making, not so anymore tho, there seems to be a constant flow of them (well ok, maybe 1275+ 20thou pistons were a bit hard to get but are avaliable thru other stockists i`ve since found

for years & years i`ve been using pistons that were designed by my dad (Jack Read ala ReadSpeed Mini mecca in Brisbane) & they were made by JP in Adelaide exclusively for us & they proved absolutely indestructable (altho a little heavy, but we did lighten them for race engines without any strength issues so all was good) But the cost was twice as much as these hypertecs, so i use hypertecs now, simple as that

but anyways,,, have faith, these pistons are great & Tony & Andrew from Minisport Australia are tops & they don`t beat around the bush, a spade is a spade with them... no mucking around.

so there is my 2 cents worrth if anyone is interested

& sorry but i can`t coment on the MiniSpares mega pistons as i havn`t used them.... never really needed too

www.miniman.com.au

"""LazyGoodForNothingSmartArseKnowItAllBackYardMiniMechanic"""

Glad i bought 2 sets hehe! The rings that come with the pistons are chrome, are these ok for turbo use?

1/4 Mile 14.3secs 96Mph Terminal 10psi of boost.


Fibreglass Parts? - http://www.tdkracing.co.uk/
Split Rims? - http://www.force-racing.co.uk/

Woo hoo! Arrived today after the UK post office balls up

Look great, no slots in sight. These are for a temporary engine while I save for a 16v, hope to get them in for machining next week.

Check out the (slow) progress at.......
http://www.turbominis.co.uk/dn89mini

Woo hoo! Arrived today after the UK post office balls up

Look great, no slots in sight. These are for a temporary engine while I save for a 16v, hope to get them in for machining next week.

Check out the (slow) progress at.......
http://www.turbominis.co.uk/dn89mini

what size are they?

+114 on their site 73.5mm

Check out the (slow) progress at.......
http://www.turbominis.co.uk/dn89mini

After a few emails with Andy I've also ordered a set, BUT, he tells me only the +094 and +114 have the oil drain holes as shown in dn98mini's photo - the std/020/040/060 apparently have the dreaded "slots" shown much earlier in the thread.
I've gone up 2 sizes on what I could have got away with on a rebore to get the better ones (094 in my case).

Rod.

Schrödinger's cat - so which one am I ???

Is that the 1360 size?

From my maths, +094 imperial (73.0mm) is 1360 and +114 (73.5mm) is 1380.

But I stand to be corrected... (it's getting too late for me to think straight !!!)

In my case it was a choice of the lowest size I could get in these pistons, so I've wasted one or two potential rebores and run the risk of a porous block...

Schrödinger's cat - so which one am I ???

The 1275 +094 and 114 sets look like this:


Please note unlike the 1275 STD/020/040/060 these have holes behind the oil ring not a slot.

Thought I may bring this to your attention.

Andrew@Minisport, South Australia
Ph: 08-8177-1275
Skype: minisport.au

www.minisport.com.au
sales@minisport.com.au

Maybe a daft question, but why cant you manufacture the smaller sizes with the holes rather than the slots, would make for a better piston?

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"

Joey

Paul only refers to the 998 +0.080/100/120

Ill be delighted if the std and +0.020 have holes to, delighted enough to buy some anyway :)

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"

I think you will find that the 'normal' over sizes are slots, and the aftermarket over sizes are holes, thats what Paul S was getting at too

ah, arse

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"

Well mine arrived today (1275 +094", ie, 73.0mm) and is the better design (I confirmed this with Andy for the 1275s before buying)
Whether the smaller ones (normal oversizes) COULD be made to the same design is a good question, I've sacrificed one (maybe two) rebores to get this design.
I'm now going to do some detailed measurements to see how much the dish can be safely enlarged by.

Anyway, Andy - well done, that was 5 1/2 days from our last email and me placing the order to them arriving first thing this morning !!!

Rod.

Schrödinger's cat - so which one am I ???

do you think there is enough meat in the tops for valve cutouts and such?.

what was the final amount o beertokens?

That sir, is not rust, it is the progressive mass reduction system

http://aseriesmodifications.wordpress.com/

Today I did some measurements on the set I received (73.0mm, the better design).
There is a little raised circle in the middle of the crown so I took the thickness measurement just off this raised bit and got 6.1mm
The depth of the dish is 5.5mm (again just off centre and the dish is 57.5mm dia so, approximating the radius of the dish curvature, the dish volume should have been 7.2 - 7.5 cc
Using a burette, I measured an average of 7.3 cc over four tries.
Using very simplistic maths (ie, ignoring the fact that the diameter of the dish will change) for a 1mm increase in depth of the dish I should see another 2.6cc
I think 1.0 - 1.5mm would be the furthest I would be prepared to go overall, but, for valve cut-outs, these would be nearer the edge so more might be acceptable and the thickness at the edge is probably a lot more than the thickness I measured just off centre.

What I don't know yet is how far up/down the bores these pistons will end up...
I've measured 28.42mm (average) from top of gudgeaon pin hole to top of piston but haven't yet compared this to a standard Leyland one.

Hope that helps - once I have more measurements, I'll post them (block going into shop next week).

Oh, and they were £ (UK sterling) 106.14 for the set of four including everything (I upgraded to chrome top rings, postage included, everything) - Now I may have got lucky, no being held up by customs for duty, VAT, Parcelforce "handling" fees, they just arrived 5 days after I ordered them !!!

Rod.

Schrödinger's cat - so which one am I ???

£106.14 for 4 pistons, thats an effing steal!

As below, UK figure in the middle....

No extras this side (although I probably got lucky this time).

Schrödinger's cat - so which one am I ???

Hi, wondering if anyone can help... starting to confuse myself with this.

Just contacted minisport aus and they dont do a 020 1275 piston with oil holes only slots..

so whats my next best option using these pistons? what size block should i go to to get a correct set?

and if these are only dished to 7cc with a 29cc head whats the max psi of boost i should run?

cheers.

Im running the +0.60 Pistons with the slots, 28cc head, Cossie intercooler and iventually MJLJ. I hope to run a max of about 10psi.

After discussing this with steve (benross) I recon that should be a safe amount of boost and should be well fun.

1/4 Mile 14.3secs 96Mph Terminal 10psi of boost.


Fibreglass Parts? - http://www.tdkracing.co.uk/
Split Rims? - http://www.force-racing.co.uk/

thought slots were a big no-no??

what does +0.60 give you.. 1380?

and i wanted to run 10psi min, with the ocasional 15+ psi