That's what I'm talking about! Very shallow bowl but essentially a copy of the Mahle piston crown.

What kind of numbers have the ABF guys been seeing with these pistons in higher boost applications?

 

The only set I know of in use is in mrrjm car and I've yet to see numbers from his car. Hubie may have sold more, but I can't be certain. TBH they should be just as reliable as the ones he had made for the R53 that saw 600+ whp.

The CP piston is probably decent strength wise and very comparable to the JE, but there is the matter of that missing cup.

 

Contaminated cylinder heads when pistons broke

 

Pics of combustion chamber and intake port

 

Have to agree ^^^ but without the wall guide, there is no way to control the injected fuel, nor to place the fuel charge mix in the precise position of the pent roof chamber, and the central position of the piston crown, to optimise the ignition charge!

Furthermore without the exhaust valve relief step, you are going to encounter valve/piston contact, from what I can see from your image of the pistons you have selected, unless the centre – centre height has been re-calculated to take into consideration of the known valve lift (9.5mm) and subsequently engineered into the piston/connecting rod package.

But I doubt this is the case, and those pistons in the image are wrong, for the intended use.

 

Rod and Piston comparison. Stock vs Carillo

 

What did Carillo say about those piston crowns?

 

The intakes reliefs are very visible on the new pistons. We decided to choose a lower compression piston, there for the dish is larger. That is how lower compression is accomplished, by a deeper "dished" piston. Since the original exhaust valve reliefs were very small to start with, the additional new deeper cut dish removes the need/sign of the exhaust relief. This missing exhaust reliefs are very common with lower compression pistons and exactly signifies the piston is indeed lower compression as spec'd.

 

Thank you for your explanation, however a few of us, are quite familiar with the concept, so you've selected dished crowns a static CR of 9.5:1 what is your solution to controlling the air/fuel tumbling mix, from not having a combustion wall guide ? And with a lower than desirable volume charge pressure, how will that effect the ignition control ?

 

Why would you lower the compression? Do you plan on cranking the boost up?

 

Subscribed. I love this stuff

 

This is one of the most interesting threads I've read in a long time. I'm curious though about all the failures some of you have experienced with your,stage three tunes. I'm assuming stage three entails the upgrading the fmic, exhaust/intake and engine tune. This has me a little nervous as these are all the same mods that I've performed on my 2007 MCS.

How did u all perform these upgrades without upgrading the fuel delivery systems (i.e. injectors, high pressure pump, etc...).

Thanks for posting the details on your build. Will be watching with great anticipation!

 

I agree! This has to be the best thread in a long time. I'm very interested in the bottom line cost to rebuild to this level. I was just telling a friend this week that it would be fun to build a high HP and reliable Mini engine.
Can't wait for the updates.

 

time to sit and watch!

 

Lower compression combined with a larger turbo = huge lag.

 

Yeah but, you destroke it and rev it up higher means more boost. Yes less tq though.

 

What's the noise maker and which part of the firewall is it? Thx.

 

destroking means having a one off crank built for build then you need to
come up with new valvetrain components and cylinder head mods to handle the higher rpm.

For a street/trackrat tq is king.

 

You don't have to worry about it they took it out in the 2011 Cooper S and Countrymans.

 

Good. After researching what it is...I'm glad it doesn't exist on my vehicles.

 

Any more info on this build? Just curious how things have been going.

 

Sorry haven't update you guys for a while. I just got the car back. The car feels strong for not running any tune. Once I break in the motor will upload the stage 4 tune. Will dyno the car and post results.

 

WOOOOOOO HOOOOOOOO! Keep us posted :-)

 

Im also about to start to rebuilt my engine and I have a quick question... Would it be bad to just change the pistons and not the rods? From what I have read, the pistons are the weak point not the rods.

Thanks.

 

Yes that is correct. You can just change the pistons and not the rods.