Engine Drivetrain 2nd Gen S Most liked posts in thread: From the “Baddest†to the “Deadestâ€

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.

 

Good to see you are choosing Thumper again for different results.

 

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.

 

YUP we see this time and time again with the same results but people never learn.

 

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:

 

TFTFY.

 

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.

 

As long as you flow test them. But if you don't....

 

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.

 

Your right, it doesn't make sense to skip that step. But guess what....

 

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...

 

#2 splodes off manic tunes or just in general?

Maybe these motors just suck

 

manic tunes or not-- S model or JCW #2 ALWAYS is the one with detonation and broken/melted ring lands and crown. We have replaced over 25 N14 engines with this exact issue when new engines from MINI were 4300 or so- now we take them apart and attempt to fix them. I am as yet unsure why it is #2 every time, but it is.