I reckon I might have found out why I got a misfire on the way to Le Mans.

I thought the tappets were a bit noisy!!

I guess it didn't like running over 7K for a fair time along the payage.

I have seen a few broken pistons in my time but never come across one that was completely gone. The bad news is the head has taken some abuse as well and may be scrap. The good news is the cams are OK.

I just need to work out what caused it now. I guess either the big end bolts let go (but I am not sure as the rod is still attached to the crank journal) or the rod stretched to the point of the piston hitting the head or the piston just broke up from the abuse. I reckon I will go for stronger ARP bolts in the new engine.

Just a guess but that would probably cause a missfire Have had a piston snap in 2 before but dont think i've seen 1 that bad Enjoy the rebuild

Ronnie

Rebuild ?........................Its scrap


Still £250 will sort that...cheaper than a bike engine

and shotblast the piston to death but not as drastic as that.

Wow!

Excellent work!!

I dont suppose you want a 1.8 Zetec block and head do you?

Free to a good home but no idea whether its sweet or sour?!

Geoff

That should have run............

brothers ford ka had piston gone at 50000 miles it stopped on him and when engine was stripped the piston was missin and it was the same one !! just completely gone not even markings on the other chambers from bits of metal in oil.

I did run.

I drove it into the workshop when the breakdown truck brought it back.

I have another 2.0 engine lined up for sensible money. Well OK £175 which is a bit steep but it comes with a guarantee.
Just need to swap all the bits over and strip the head to have a better look.

Was the piston teleported out?

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TextStill £250 will sort that...cheaper than a bike engine

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Originally posted by big_wasa
Rebuild ?........................Its scrap


Still £250 will sort that...cheaper than a bike engine

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I is a bit past a rebuild as the bore is scored about 2mm deep.

But at least it stayed together which saved me loads of grief. French law doesn't allow my breakdown service to work from French motorways so I needed to drive off the payage and onto an N road.

A bike engine would have been spread all over the road whereas I could still drive, albeit very slowly, through the paystation and onto an N road.

And it wouldn't be easy to replace a BEC for under £200.

Sorry but that is good, I like it, put a hole now meaning to running on three.

i had a guy come into the place i used to work with a misfire and heavy rattle on a vectra gsi v6 i ended up taking the head off the faulty bank and found a piston had turned to dust and i mean dust no large chunks just a metal powder covering the sump and no score marks except from where the gudgeon pinon had hit the bore had me and the other mechanis scratching our heads

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Originally posted by TGR-ECOSSE

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Originally posted by big_wasa
Rebuild ?........................Its scrap


Still £250 will sort that...cheaper than a bike engine

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Thats not scrap remember its a real engine

[Edited on 25/6/07 by TGR-ECOSSE]

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Thats not scrap remember its a real engine = Sarcasm

Simalar happened to me, but I new there was more than a misfire, throttle stuck open on a pug Mi16 engine with twin dellorto 45s. Turns out the little end on piston no2 let go, the piston got mashed to bit taking the valves with it. The conrod still on the crank took the front and rear of the block out. Found bits of piston on the recovery truck when I got home. Bits of engine all over the engine bay.

7000rpm?

For your next engine build I suggest some forged steel pistons, although its a modern engine, cast pistons are not really made for anything 7000+ for an extended period of time.

What cams do you have? I know its a popular thing to cam up an engine and get alot more power from it, but before you do so you should probably think about the other engine internals that will get stressed from the extra rpm. Although most engines are understressed for reliability, so uprating your cams a little bit really won't hurt.



Im amazed this is the first piston failure I have seen on here

But seriousely, get some forged pistons next time and all should be well

This was a still running ZZR 1100 engine which had a bit of a miss. When removed had run number 3 big end allowwing the piston to hit the cylinder head until it disintegrated!

Description

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However it also got home without dropping it guts everywhere

1500cc zetec, thats a rare engine

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Originally posted by CaptainJosh
7000rpm?

For your next engine build I suggest some forged steel pistons, although its a modern engine, cast pistons are not really made for anything 7000+ for an extended period of time.

What cams do you have? I know its a popular thing to cam up an engine and get alot more power from it, but before you do so you should probably think about the other engine internals that will get stressed from the extra rpm. Although most engines are understressed for reliability, so uprating your cams a little bit really won't hurt.



Im amazed this is the first piston failure I have seen on here

But seriousely, get some forged pistons next time and all should be well

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