Hi
Cracked the front on a fresh motor yesterday. Has been run in with no boost upto 3500 revs for 935 miles. Yesterday went out and started mapping with some boost. Did a few pulls in 3rd and 0.7 bar and had hesitation at around 6000 rpm. Next pull in second and screen covered in oil, pulled over and noticed the usual area on the front plate cracked.
A few pics to show you all, but need help diagnosing issue. Have searched and found a few posts saying it's detonation, the fitting used, spark plug wires (mine are all together going through bulk head), what is the problem

 

Next picture

 

Spark plug wires

 

Spark plug wires and coils

 

How advanced is your timing? Did you substract any timing as you went up in boost?

 

I honestly don't know as I was driving and my mate was on the laptop
Engine ready to pull now after 5 hours of stripping

 

That sucks. Good luck

 

Check that plug that you're using to block off the plate. if its tapered that maybe your problem,

 

Its caused by a missfire which you clearly said you have

any reason why a pro is not tuning?

 

It will be but a good mate is very good at them and has tuned Microtech on a number of occasions on 600hp motors.Timing was retarded to around 18 degree and he is running 17 degree at 1.4 bar although I'm running Motec.

What fitting is everybody using on the front plate?

Thanks Mark

 

Sounds like it was tuning related; typically that area of the motor cracking indicates detonation. If you have any tuning logs, someone better could probably chime in and help out.

 

I have sent them to the mapper so he'll hopefully come back with something

 

Nice set-up!

I think I would suspect an ignition signal crossover between the trailing coils or leads.
I try to separate those as much as possible.

 

What do you mean by that, do you mean the spark plug wires?
Are the coil positions ok? All 4 wires go through the bulk head in the same place, is that an issue?
Thanks Mark

 

Could be a couple things. Probably just Detonation. But Unlikely an ignition cross fire. Before you pull anything apart. Check the TQ specs of each of your Engine THrough bolts/studs. Make sure they're The same. If your using an ALum fitting up there on that oil feed.. that may not have helped but unless you cranked it down really hard with the wrong fitting... probably wasn't the cause. Look and see if there are rub marks on your housings.. guaranteed they tried to move. What fuel are you using?

 

The fitting isn't alloy or tapered but don't know the material to be fair.. Fueling wise using shell unleaded but not v power at the moment

 

Whats the Ocatan? It's probably not anything to do with the fitting truthfully

 

I feel you pain. Your work alot quicker then I do. I cracked a rear plate about a month ago on a 1200km motor. No idea why. 18psi at 3200 rpm 1000cc of water on a stock S4 block. Never had any issues in the past 20 years but its hard to say what did it now. Motor is pulled apart and ready to assemble with newer big casting plates, S5 high compression rotors and new aftermarket seals. There was no detonation shown on the motor.

As a few people mentioned I thought maybe you had that tapered plug installed to tight.
I hope you find out what was wrong.

Note: I believe in datalogging anything on a pull during any sort of tuning or adjusting. Better take a look at the datalogs and maybe someone might spot something. I had no datalogs. I wasn't with the car when it let go.

 

Normal unleaded over here is 95 octane.
So what are people using in this fitting then?
Just waiting to get an engine crane now as the motor is ready to pull and strip and check, I hope nothing else is found, managed to pick up some RE plates tonight so need to get the front re ported too match as well

 

generally it is best practice to have the plug wires spaced away from each other and anything metal by 10-30mm. the wires can arc to each other and to ground.

 

The coils are mounted to an ally bracket and the leads all run together through the bulkhead through one hole.
You can see in one of the pics I posted the layout. Does this need changing then?

Cheers

 

I think you have octane and ron mixed up.

USA (AKI/PON) --- Europe (RON)

87 = 91
89 = 93
91 = 95
93 = 98

you are not running 95 octane. That would 101 ron where you are from.

 

The uk so normal unleaded, wasn't running v power at the time

 

Well the engine is now stripped and pretty fucked. Front plate rotor are absolutely shot with a massive det mark on one face of the front rotor. The rotor has got that hot the corner seals had stuck down and the apex seals are all sorts of colours. We think the failure is electrical related and not tune with the coils being fired in the wrong order.
Any wiring guru's out there who know about the microtech X4 and Motec at all?

Thanks Mark