I'll let the pictures do the talking...








Was driving the car, brought it on boost "full throttle" in 4th after cruising and it started to come on boost and then just cut out... No bang, no drama. It had slightly mis-fired earlier on the journey, i thought but im not 100% sure. Left a small dent and split in the sump. So i pulled the engine apart to find that little lot!

 

Bloody hell!

If your going to break something then break it well!

 

thats some mess! what caused it? are they orginal parts? Full rebuild needed?

 

:O Nicely done!

 

Standard rods?

 

100% Standard Bottom end... Heavily flowed head, stage 3 t3. Ofam 480cc injectors mapped to 19psi of boost! Rev limit 6400rpm.
I dunno what caused it, ideas welcome?

 

wow what other damage has it caused?

Turbo and head pick up much?

 

Piston contacted the head and bent a valve, pulled a valve guide out and left a slight mark. All repairable, luckily i run a turbo pre-filter and that caught afew bits but tbh once i died i didnt try starting it etc...
Bottom on the piston is completely broken up too! I was gonna salvage the oil pump from the block but i guess thats picked up alot of the bits

 

Nice that you done that full on

 

Sorry to see that bud. I ordered a pre-filter oil feed to my t38 for that exact reason.

 

Sorry to see this mate, Whats the plans now though?

Sticking with the cvh, go zvh with your ported head, or full Zetec?

 

Wow that doesn't look good, is it me or does it look like one of the con rod bolts has snapped?

 

Almost looks like the piston heated up alot and not enough piston to wall clearance left.
Piston starts to sieze in the bore and then piston breaks in two - lets go and destroys the rod as it bangs around.

If the connecting rod broke first the piston would be much more intact.

Do any of the cylinder walls show scuffing?

 

Hmm... you mention a slight misfire earlier in the drive, I'm going to put it out there and say detonation? Any marks on top of the pistons?

Really hard to say mate.

 

Roger, its time for more valves in the onion,

 

Seen similar before, and that was big end bolts

 

Whag a mess lol. Ive never seen that before.

 

Rod went in my yb! Chucked the gudgeon out the sump lol I've not striped the bottom end yet but the head has been removed and there's no sign of the piston having got hot and picked up or started to melt so I'm guessing big or small end fault in mine

 

hear hear lol.bloody hell roger that's let go in a big waytime for the zetec me thinks

 

Ah yes that could do it, rod just sitting there waiting for the crank to hit it.

 

No, det... I had been out with det cans the night before and it was all clear and i'd just filled up with higher octane fuel, so ive kinda ruled that out... Piston crowns are mint and unmarked too!
Piston getting hot, hmm sounds possible. Id just solved the running hot issues tho?
Head is salvagable so i'm thinking 1.9cvh...?

 

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Ah that's a shit, what a mess, My mate Laren has an Orion turbo that was having heat issues, he took your advice on the choice of rad and it seams to have solved the issue.

As for thinking about going 1.9cvh, have you thought about an 1.8 cvh, I have a Ferriday engineer one, wicked engine despite everyone saying the 1.8's are rubbish. From what I research they are basically the same block as the 1.9 but with smaller bores equalling thicker bore walls (not gospel). Mike at Ferriday is a very helpful man and has loads of advice.


Ginger


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Feel ya pain mate. I had a rod go in my fezz turbo but was a great excuse to go forged bottom end

You were only mapping it the other week wernt ya ? I dont want to slag your mapping skills off or knowledge but.............................

 

Thanks Ben... Yeh i was but i dont think mapping is to blame for a conrod breaking or a rod bolt snapping...So i wont slag your knowledge either! Unless youre implying i mapped it to produce too much power
Both rod bolts have broken their heads off, but i dont know if they were the cause or the result of the rod breaking.

Its def onwards and upwards from here... Either a forged 1600cc or a us tall block. Dont really want to mess about with a zetec yet tbh!

 

If your going to do break something. Do it properly! That is some epic destruction.

Good excuse to make it bigger and better though!

 

Ouch! I wouldnt like to see the puddle that left behind, There's me thinking you couldn't kill the old cvh

 

It only dribbled a bit of oil out of the sump, left a small split right at the top of the sump...
Trouble is it was the first time i'd given it beans that evening n it wasnt even on song when it stalled n this happed, poor old engine lol

 

Roger you say zetec yet? If eventually you plan to you might aswell do it now, cheaper in the long run.

 

Glad to hear that you will stick with a CVH!

If you decided to switch engine to a 16 valve, there are options that are far, far better than a zetec. A ported cvh head outflows a standard zetec head. One can certainly make big power zetecs, but they cost $$$ too - dry sump, better cylinder head (st170), steel rods, etc... and then you need to think about a gearbox change.

The newer duratec 16 valve engines are a far better starting point than the old zetec (nearly same block as old cvh).

 

Did u have ARP's on the rods ?

Ben

 

was gonna ask same thing, did it have arp's on? looks like the increase power/loads has seen the std rod bolts off and erm mullered it proper.

 

No standard rod bolts... Embaressingly

 

Just "wow"

 

Has the engine been over rev'd previously or have you been sitting on the rev limiter too much? Exhaust valve bent?

 

The top part of the piston looks like heavy scuffing with the cylinder wall.
This scuffing would not happen after the piston broke at the pin boss.

Engines that have connecting rod failure (or bolt failure)have the piston and half of the rod on one end, and the bottom half of the rod thrashing around.

With a piston pin pulled from the top half of the piston it indicates piston to cylinder wall seizing.

This can happen with any type of engine - if piston becomes too hot and not enough clearance to cylinder walls. Not uncommon with turbocharged deals.

 

So how does the rod bolt manage to snap after the rod snapped? The bottom end of the rod wouldn't have any strain put on it if the rod had snapped first surely?

 

Perry, i understand what you are saying but what would cause the rod to then break up so much and indeed strip the bolt heads off?
Engine was from an unknown car, cost me Ł50 a couple years back and i was pushing 20psi with quite a good spec of add on's through it, so im not suprised it broke! Rev limit 6400rpm and i rarely hit it, talking once or twice ever! I change around 6k!

 

For it to shatter rather than bend and snap (too much power, piston seizing) surely it must have been 'hit' so to speak? I think snapped bolts is a good shout and then the crank journal effectively 'hit' the bottom of the rod sending a nice shock wave through it, or bolts snapped and combustion pressure forced it down and it hit the crank?

Perry, this is an old engine so if anything the piston to bore clearance would be way bigger than it should be, would had to of expanded a lot!

 

I did that once, mine came through the front of the block on number one cylinder... 😕

That is well and truly shattered! 😯

 

did they snapp or get ripped out or were they still bolted in after the "explosion " ?


Ben