cus i have seen those exact marks first hand
and i do mean exact and i know how/why they got there.
i'll pm ya

 

nope ive checked that today, definitely wasnt

 

were they new (bigger) pistons?
if the tolerances were too tight when it all got hot.. that might of done that??

im assuming the block is scrap now too

 

There are no det marks at all on the piston.
It is a HEAT SEIZURE, this could have been caused by an air lock, or insuffecinet beddingbin before full power run.
I had this on a xr4i, that was caused by a air lock in the cooling system.
The rear pistons run hotter and leaner than the fronts which will aggravate this as well.
tabetha

 

yes mate they were new bigger pistons but seemed to move freely enough when they were fitted and block is fooked

 

the engine had done about 3.5k miles bedding in. The power runs on rollers were the firts time it had been given any stick since being built

 

who built it mate?

 

me

 

dicko, that looks to me like the piston/bore clearance was wrong, and it's nipped up as it got hot,

steve

 

go back and have a word then

 

ive had several

 

I have often thought about building an engine myself but it when things like this happen that you realise it not as easy as it looks.

Shame you couldnt have fixed it mate

 

i could have had it fixed but only so much you can continue to plough in

 

would have been good to get her up and running

what power did it make before the probs?

 

just before the engine cut out it made 345ATW @ 1.2 bar

but then it seemed to lose loadsa power then cut out

 

thats good going can u remember what rpm it went tits up?

 

erm just under 6k

 

was a quick car rip

 

People...

How the hell can oil stravation kill a piston but not kill the crank - think about it!!

Alex

 

I meant from poor circulation thus causing the piston to overheat

 

345bhp @wheels would of been a quick car mate

spec was similer to mine

gutted for you


fuk it buy another

 

345 ATW at only 18 psi ish?

you sure? not sure mine would make that power at such low boost?

 

will see eh

hes thinking of buying another one and if he has enough money, keeping the t4

 

In which case your thinking of coolant.

Oil doesn't "circulate" its pumped. If its not pumped the first thing to be effected are the bearings.

Alex

 

not if a spray nosle on the bar blocked but i cleaned that out for him so i doubt it unless sealer got into it

 

jacko you got a spare exhaust housing sitting about in ya little garage......ive fucked another,,,

 

yeh mate 48 t3 and its a minter

 

yeah defo keep the t4

 

the bearings have wear marks on em but no score marks, but not the full bearing only in certain places

 

just pollish em and put em back in lol whats the inside of the block like

 

they look over heated to me too...what do people think ?

 

wasnt blocked i checked

 

fucked

 

thank foook for that its not my fault then lol

 

If the oil pump was was producing a lower pressure due to the score marks would it still reach the spray bar?

 

By spray bar are you talking about piston cooling jets? (spray bar to me is a device that lubricates camshafts, but like most car things that just the name I use/prefer/know).

Alex

 

From the numbers on the top I can see they were Wossners, top notch pistons those too

Do you have to break it ?

Z

 

yeah they were wossners, ive got 3 left though

already broken it in many many pieces now

 

Even if the spray bar was blocked, bores are only splash lubricated anyway. Not all engine has under piston cooling jets.

That is a heat related seizure. Reason why is nobody knows.

Wossner recommend a 4thou clearance on their pistons. It could be that the tolerance was too tight and it just expanded and gripped on number 3 as that is the leanest pot.

 

That would make sence Daz....