I picked up a 2008 MCS Auto with a busted engine (dropped plug that chewed up a piston and possible scored the wall), but a perfect body. I purchased the car as a project, so it’s not my DD. I’m taking the engine all the way down, but would like to build it back more powerful. Not looking to make a drag strip type car, but I plan to take the next year or so to rebuild not just the engine, but the whole car.

I’m looking for input on the engine rebuild. Piston size, valves, cam, etc. For those that have done it, or do it, what things have you experienced that provide great results?
I understand there is a balance between making it fun and creating a never ending tinkering nightmare. I would like to have something fun when I’m done.

I would appreciate any input.

I’ve had 2 MCS before and very familiar with the engine and car.

 

There are numerous thread covering this, but since you asked.....

In my last engine build, I went with a set of Mahle pistons. CP can be had cheaper, but I wanted a stock sounding engine. The 77.5mm overbore should clean up the cyl wall enough. Unless, it's got some deep scoring. Machine shop should be able to guide you on that.
In conjunction with those, I went with the JCW head gasket (.3mm thicker), to get just a tick lower compression.
No matter how many miles are on the car, get the head rebuilt. Guides and seals are most important. If you have the $, a ported one will help you make the best power. So will cams. It really comes down to how big your piggy bank is.

When you go to refresh the bottom end, it's a crap shoot. Rod bearings will probably need to be replaced. Main bearings, well, it depends. On the ones that I have experience with, some were in good condition and didn't need to be replaced. Some did.

In the turbo dept, get a JCW one if you can find it. This, really, is the only way to make better, more efficient power. You can push the smaller stock unit, but if you are going for moar powr, then why?
Lastly, a tune. Your choice, but let me say this. Unless other ones can lower the engine coolant temp, go with Manic. This will, will, will help keep oil from cooking in the engine. Put a catch can on for extra oil build-up reduction.
Edit: obviously, a larger intercooler.
Now, it being an automatic gearbox, you are not going to be able to get stupid with the power. I mean if you are a gambling man, have at it.

another edit: you said it yourself; you don't want a tinkering nightmare. keep it tried and true, with some simple mixed in and you'll have a nice driving, reliable, fun MINI.

 

John, thanks for the input, that is very valuable. I spent the last few days going through the search and found good info, but it was on a wide range of topics and power expectations.
I appreciate the the hands-on advise.

 

I’m on engine #4 in my car, and I think this one is the right combo... working now on tweaking the tune and anticipating adding a WMI kit in the new year. Know that you’re in for a rolling series of things that break/things replaced/repaired/adjusted. Build the block and head as solid as your wallet can afford.

See my Sig for details and ask away.

 

Good advice so far. If you get into high boost / compression, be aware that high exhaust temps will destroy OEM valves. If you rebuild the head (which is a good idea), Inconel sodium filled exhaust valves will be good protection from heat damage. Lotsa WMI will also help with chamber cooling, as long as it's in use soon enough --- not too late in the RPM range.

For the block, consider a Cylinder Support System --- something to keep the combustion chamber out of the water jacket.

Neither of these suggestions (except WMI) will add HP, just a bit more reliability and protection for your investment. Lotsa details in my "Phoenix" thread.

 

Wow, I can’t thank you enough for the info. This was exactly what I was hoping for. I’ll be bouncing questions off all of you.