Let me start this with a link to my build “journal†started March 2011 —- http://www.motoringalliance.com/forums/member-garages/15303-2007-mini-mcs.html It gets updated about every six months. It’s currently located in General MINI Stuff under Member Garages as “2007 Mini MCSâ€. I started wanting “the baddest Mini in northern Nevada†and finished with possibly the baddest street-able R56 in the country. I gotta admit, the claim is for dyno numbers only (charts are in the journal), not practical use on the strip, track or street. Some of the mods are not compatible with each other, and would cause grief with many other drivers. It was built to be a “sleeper†—- all kinds of fun on the streets. It’s something I can get away with being located in northern NV —- rural, small town living (2 traffic lights), ½ hour from the nearest big city, and ¼ mile from U.S. 50, the loneliest hiway in the country. Not sure which was the biggest problem, probably too high a CR (10.5:1) for the 30PSI boost limit. I hoped the CP Carrillo pistons and rods could handle it. They did for awhile —- I got over two years of 28 - 30 PSI max with no issues. However, this boost level was seldom used. Most of my driving is close to speed limits, and very little hard acceleration. With 360 WHP available, you don’t need a lot of gas pedal to get around. Plus, a long time ago, I did 3 days in L.A. county jail for “speed contest†—- not gonna happen again! When the engine “let goâ€, I was at the Sacramento, CA drag strip, half way thru my 2nd run. I was expecting better numbers for the 1st run. Hopefully they’re low because part failure had already started. I was hoping for a couple good runs at a sea-level strip to compare with my local strip at 4K’. Not gonna happen for awhile. I have terrible reaction time —- that’s me, not the car. The ET is low because there’s also terrible launch capability —- a light flywheel and slow-spooling turbo results in not enough inertia to get moving quickly. Even slipping the clutch and an unlimited launch RPM doesn’t help. This was a good combination for keeping me out of jail, and saved a bunch on tires and axels, but lousy for the drag strip. Here’s a copy of the time slips. http://www.motoringalliance.com/forums/attachments/cooper-s-clubman-s-engine-and-drivetrain/10365d1471903690-baddest-deadest-sacto-time-slips.pdf One interesting discovery —- the 3†exhaust pipe doesn’t clear the frame under hard acceleration. Notice the pipe kink where it hits the frame during “engine rollâ€, or torque. Gotta fix that when installing the next turbo. http://www.motoringalliance.com/forums/attachments/cooper-s-clubman-s-engine-and-drivetrain/10366d1471903942-baddest-deadest-exhaust.jpg Here’s a pic of the damaged block at #2 piston. Another block w/crank “is in the mailâ€. http://www.motoringalliance.com/forums/attachments/cooper-s-clubman-s-engine-and-drivetrain/10367d1471904001-baddest-deadest-block-piston-2.jpg Then #2 piston. There was also aluminum “residue†on top of rod #2 —- apparently from the blown-out piston. Didn’t get a pic before I cleaned up most of it. Wrist pin and rod bushing also took a hit. http://www.motoringalliance.com/forums/attachments/cooper-s-clubman-s-engine-and-drivetrain/10368d1471904201-baddest-deadest-piston.jpg During engine teardown, I found these in the oil pan and oil pump screen. Apparently from the Garrett turbo. http://www.motoringalliance.com/forums/attachments/cooper-s-clubman-s-engine-and-drivetrain/10369d1471904317-baddest-deadest-loose-bearings.jpg All 5 of the intake cam journals, cam, and caps are scored. Plus the cam has one of the two interlocking rings broken —- the rings that fit inside the vanos unit. The ring might be replaceable but the journals need to be machined. If machined, they wouldn’t fit the head without building up the 5 journals, then line-boring it to accept the machined cam. Not practical! No damage to the exhaust cam or its journals. Did a partial tear-down on the Garrett and convinced myself that the bearings found in the oil pan came from the turbo. Turbo also has a slight amount of end-to-end shaft play, so it’s on the “replace†list, not repair. Have no clue how / why the bearing failed. It was performing nice up until the engine blew. So, now to rebuild. All 4 rods are out for new bushings, #2 clean-up, then all 4 to be balanced. Looking at Schrick and Cat cams, Borg Warner EFR 6258 or 6758 turbo, 9.5:1CR and 77.5mm CP pistons (notched for a hi-lift cam), working with a local indy shop to machine the next block, and working with Thumper again for a replacement head. I’m posting all this in the hopes that someone will learn from my mistakes, and not make the same ones. I purposely went with the 10.5:1CR pistons, even tho popular opinion was “that’s too high for 30PSI boostâ€. My “heyday†was before turbos were common, and lowering CR was unthinkable. An expensive lesson learned! And 5 years ago, when I got the Garrett, there were only a couple JCW hybrids available (that I could find) —- nowhere near the capability I wanted.
While it sucks that the motor is trashed, i think its really good that you are being open about it. and explaining what all you know so we can all learn from it. thanks for that. Hope to see you on the road again soon. So it also looks like i need to get to work on a upper R56 mount. This is the second car ive seen that seems to need it. I wonder how it would sell.
A tad bit beyond my mechanical experience but very interesting. Will you rebuild another "Sleeper" or something with a dedicated purpose like the drag strip?
WOW-that #2 piston shows the results of the cr/boost issue, that is some heavy detonation damage. When we have seen these with stock pistons detonated and broken ring lands (several times) it is always #2 cylinder. I agree the cr may have been too high but there is something more in the engine design this happens to cyl 2 first no matter the situation.
Dayum sorry to hear that... Many factors could be at play here besides just compression. This proves my theory that powering through detonation can splode any piston, "fully" forged or not... It's the pressure in the cylinder during detonation that splodes things in my experience... I've said before that I've blown up fully forged Pistons in low hp applications due to powering through pings.. Have you spoken to manic? If the engine knock settings are turned off because of loud Pistons it defeats the purpose of having a strong piston to begin with IMO. Any reason your going with cp Pistons again? Same tune? What exactly are you changing this time? Just lower compression? I'm not sure it's a compression issue prolly detonation/tune problems maybe... How many miles did the motor last on that tune?
Dave, Dave, Dave... There are two things I know are true from reading the interweb: 1. Thumper heads never ever cause a single problem and make more power than your average nuclear power plant, and often times just as much heat. 2. Manic Tunes never ever cause an engine to blow up, even when it does. But I hope the OP gets his car up and running, and hopefully with no other issues. I'd go in a different direction, but at least he's putting things together and trying.
Ported heads run cooler not hotter. I blame manic, I'm sure ppl do fine with their wimpy stage 2 but I've been told veery bad things about upper level manic jobs...
CNC ported heads run cooler not Old Man hand ported heads with no flow testing done. Cough THUMPER Cough :ihih:
It's not difficult to build a flow bench and hand port and polish cylinder heads, just take your time. A CNC machine is not necessary unless you want to port a lot of heads commercially.
If you port heads and sell them to customers you need to flow test them and make sure everyone them is the same. :idea:
I agree, I said that it is easy to build a flow bench to port heads on. It is so easy to flow test heads that it doesn't make sense to skip that step. A flow testing bench is basically a fan and a box with a U tube manometer on it.
My main interest in this build is seeing what level of power these engine will make and I love that the op was/is willing to find out. That said, there is STILL an inherent flaw in the #2 cyl, whether is it the timing maps or the fuel injector, #2 is ALWAYS the one that detonates and melts the piston/breaks the ring lands.
How do u know thumper doesn't flow test? Port work isn't rocket science. I've never seen CNC port work in anything... As long as the machinist isn't a ham fisted monkey I'm sure it would be fine... I don't see why the head has anything to do with this motor fragging...