Another possibility

 

You said that piston 4 was not traveling the same distance as the rest. But it was still traveling non the less so i doubt it is the rod. If it was a Rod bolt stretching then it would actually travel a greater distance then the rest so i doubt it is that. And as stated above the stock ecu controls knock very well so im pretty sure it wasnt detination specially with the minor mods and stock boost levels you are running. I would have to agree with the rest that it was somthing to do with your cam install. It is very easy to get a tooth or more off with a install. The TDC lines on the crank dont always align perfect with the TDC marks on the cover. I would definetly keep a close eye on what they are doing to the car and if possible be there when they take it apart to see what it is. Also allign all your marks agian before they do anything else to see how it looks and take a picture if possible (if needed in court) GOOD LUCK!

Chris

 

imagine if the installer forgot a socket in there... be there and look for any small parts in the oil or in the head. Trust me I forget tools on my car myself.

 

right...big mechanical damage would be kinda odd for the timing belt setting of a tooth. that would just cause a few bent valves and a non running engine.

bottom end damage (broken rod, broken piston) is more likely to be SEVERE interferance. IE peice of hardware or a tool, socket ect...getting into the combustion chamber and smashing stuff.

The spark plug insulator coming apart is also a possiblilty. As I said before it only takes a little tiny bit to get between the valve and seat to snap the head off the valve. then you have a 1" diameter steel part bouncing around.

GEt the head off the car...you need to see what happened up there, not only what's busted in the oil pan.

you don't want them to pull the pan...see a messed up rod..and just say "you need a new motor" and start working on the car. What happens if it was a socket or bolt in the cyl (might now be in the turbo too..look there for additional damage).
would you want those guys taking the car apart AGAIN?

 

Oh yeah...you should be there when they are taking this stuff apart. Funny how a socket could fall out and noone would notice

 

Sounds like the shops fault. It either was put in time wrong, wrong cams were installed, they overrevved it, something was left in the engine etc. etc.

I would watch closely as it comes apart.

David Buschur
www.buschurracing.com

 

I have had the fun with an engine swallowing a bolt. I could hear it rattle and the piston had dents. If your mechanic let somthing drop into your open cylinder you will have ample and obvious evidence of it when the head is removed. I concure that detonation would have caused piston failure first on a stock rolling assembly. I would not discount a rod bolt faliure being the culprit here as the stock bolts have been known to fail before the shot peened rods do. Hope your crank and block are ok. My sympathies.

 

Any updates? Based on everything i've read I think it can be a combinations of things...

1. Cams installed incorrectly would cause bent valves..no bottom end damage..

2. Spun Bearing, Broken rod, Detonation - pushing the car to hard, over reving the motor or missing a gear during a shift and the RPM flies ways up causing the bottom end damage

3. Detonation - ECU programming could be off and needed to be recalibrated for new mods or the mechanic could have tampered with the boost pressure and pushed the car to hard and leaned out a cylinder.

4. If you have ever changed Cams yourself, you will know that it's highly unlikely that any socket fallen into the valvetrain area could make it's way in a cylinder..don't get me wrong a small nut or bolt can fall inside of the valvetrain area but to makes it's way down into a cylinder is highly unlikely but NOT impossible. Were the spark plugs removed during the cam install? A tiny nut or bolt can fall into a cylinder thru the spark plug hole. If you were present when the car started up the first time you should have heard a rattling noise right away.

Overall..I agree with everyone on the board, you will have take the engine apart and determine what caused the damage and experienced mechanic will know exactly what happend. Hopefully, your dealing with an honest mechanic who will tell you exactly what happened and will work together with you to have the car repaired.

 

I was under the impression that the EVO's 4G63 is a 'non-interference'engine. If this is the case, you could almost certainly have the HKS cams at full lift with the piston at TDC and not have valves hitting pistons.

 

but the compression is so low that even if you drop a nut or whatever into the cylendar, it should clear and just bounce around or at worse case senario nick the piston top. it shouldnt have anything to do with the crank/rods. i would almost be willing to be there was a factory flaw. a small imperfection in the rod that made it weak, and with the increased boost and the more agressive lift and duration from the cam stuffing even more air in it finnaly went. it sounds to me like overboosting!

from the description given, it has to be somthing in the crank/rod/piston combonation. the damage to the rod/crank would have to be due to way high cylendar pressure, otherwise the piston would show severe wear marks or even cracked - especially before the rod broke, the piston would! i blew my SRT4 (before you all laugh - my wastegate broke pussing unlimited boost into the combustion camber) head, all i did was bend a valve - mind you it was at a darn near 45 degree angle. it did not once come in contact with the piston. now i have 8.1:1 compression, not sure what the evo is, but if its even close i highly doubt its a nut or bolt that caused this problem. it sounds like weak rod/crank snapped by an overboost/detonation/too high cylendar pressure issue to me. i know the headgasket would go before a rod, thats why i think there was an issue with the stock piece.

 

to date i've had to rebuild 2 EVO 8 motors and just got in my 3rd at my shop.

1 - Spun a Bearing at 22k miles - over revving and abuse

2. - Blew the #4 Rod thru the block at 3k miles - over revving and abuse

3.- Detonated at 6k - as of lastnight it looks like detonation on the #1 cly - were still doing the autosy, but it looks like a lean conditon on #1 that could have been caused by a improper install or tuning of an E-manange system.

 

so far...they havent taken it apart yet...i've decided since it already deals with the motor to just have ams build me a motor. the shop is working with me on this in terms of $$$...so its all good. Next time i go to the shop ill get the pictures of the spark plug and show you guys.

 

Ted the evo, like all 4G63 engines is an interference engine.

AL

 

SAME HERE. I DON'T THINK THE CAMS WERE INSTALLED RIGHT. DID YOU DO ADJUSTABLE CAM GEARS? IF SO THE ADJUSTING BOLTS ARE LOOSE WHEN SENT. THEY HAVE TO BE TIGHTENED. JUST AN IDEA. GOOD LUCK GETTING IT FIXED.

 

IT IS AN INTERFERENCE TYPE ENGINE. PISTON AND VALVES OCCUPY THE SAME SPACE.