help piston damage (pics)


it had been under heavy load but only for 2 miles at a time, with idling whilst waiting for the stage
 
Sorry to hear about this Dave.

If it does turn out to be too tight a clearance causing the damage will you be able to claim any losses from the machinist?
 
When checking plugs the engine needs to be put under load and switched off. If the engine is allowed to idle then plug reading is worthless. If this engine was running lean and the piston didnt have enough clearence expand then it would cause this. The thing is the AFR's could of been fine on the dyno and the piston to wall clearence could of been within JE's range. Thats just half the battle, the AFR's could of took a big swing when put in real world conditions. Thats why people install wideband gauges... I recommend that when you get this engine up and running again you do that. Did your tuner and engine builder know what you was doing with this car ? If they did they should of advised you on this.

I feel your pain by the way and i hope things work out well in the end. :) I bet your completely gutted.
 
Looking like too tight piston to wall clearance. How do the other cylinders look?
 
Sorry to hear about it this and hope you get it sorted! Defo claim losses from the machinest. Who done the machine work?
 
the car is running jenvy throttle bodies and an omex 500 ecu, the guy who mapped it, maps rally cars and omex ecu's all the time and was recommended to me, and the machinest knows his stuff, supose the dial gauge will tell.

the mapper was raving about the engine, a kept winding me up that it was an 1800 or 2 litre as it pulled so well ! and was also telling other people, one of my friends had his 205 done there

it is gutting after a 2year build, i've took an 6 month back step when i should be smashing it up lol :win:

i have a spare block so guess its just a set of pistons

going to do the master cylinder on my dads mg now then off to machine shop with the piston and see if he will bring his dial gauge to my garage before i take the engine out

then off to work for a rest !!!!!

cheers guys
 
Whats the expansion rate of these pistons though? did the machinist have the specs when he carried out the work?
 
right went to machine shop and jed who works there(boss is away) is going to measure the engine, check the clearances and see if it will hone out, he thinks it might, so need to take the engine out weds/thur.

iain who sponsors me and has raced cars for 30 years and has his own garage, thinks the damage might of happened before the car was even started, as there was a small brass plug missing from the head.

he ported and welded the head up to optimise the combustion chambers a few years earlier but never used the engine/cams/throttle bodies etc as the car they were for wouldn't work and never got finished. i bought all the gear off him and built the engine, but the small brass oil way blanks in the head hadn't been replaced and he'd forgot they were missing. he told me head was finished, so when the engine was built it had no oil pressure on the starter until i found this eruption of oil inside the head, whilst cranking. the shells were damaged and were replaced, and he thinks this may have caused the piston damage as well

will get it all measured, i may get away with a re-ring + re-hone but need to wait and see

bad mistake but with the timelapse and different people doing different things over three years an easy one to make

cheers
 
I'd be looking for my gun :p

At least you know what caused it so that the second time around it won't reoccur and you can have faith in the engine again.
 
Hmmmmmm, i'm not sure. Was the engine actually fired up ? If the damage was caused then you would of had problems from the start. I can tell you now your rings would not have seated properly and you would of been down on power if your bores looked like that.
 
wasn't run until it had oil pressure, and didnt smoke on idle until the second rally, which would suggest it happened after initial running.

will get it out and measured and let you all know

thanks

and produced 209 bhp est. flywheel on rolling road
 
my friend had the same problem with his k24/k20 the cylinder walls look exactly the same on his motor and believe or not it was clutch problem. the twin disc wasn't disengaging all the way and it was putting so much pressure on the crank that the pistons got off balance by a tiny bit.
 
oscarsayco said:
my friend had the same problem with his k24/k20 the cylinder walls look exactly the same on his motor and believe or not it was clutch problem. the twin disc wasn't disengaging all the way and it was putting so much pressure on the crank that the pistons got off balance by a tiny bit.
Click to expand...

Crank walk usually occurs from thrust washer issues maybe found on your friends engine?

The oil idea doesnt seem to tally with the bore marks though, is it me or are they on opposite sides of the bore and piston respectively?
 
If the piston is ever going to rub the walls it will be at the thrust sides , perpendicular to the crank.
 
You must log in or register to reply here.
Back
Top