Engine Damage Pics

SteG40 · August 05, 2009, 06:52:52 PM

Got the head off today and this is what I found. The Inlet valve's bent like I thought but there's damage to the head as well. I'll get a new set of inlet valves put in and the head fixed but there is marks and a nick out of the piston and i'm not sure what to do. Does it need repairing, is it scrap or can I leave it what do you reckon.

Robin · August 05, 2009, 07:41:36 PM

ooo nasty

just wondering why there are those marks on the head and piston.........what exactly happened? Looks like the cylinder has eaten something like some debris or something.

you'll be best getting a replacement piston as there seems to be quite alot of damage to the piston, i don't know if you can get single 1341cc pistons...........

hayesey · August 05, 2009, 07:54:05 PM

that's been caused by detonation! It's looks like that cylinder has got seriously hot

Nick_S · August 05, 2009, 08:00:39 PM

Yep, pitting = det.

Standard pistons probably would look a lot worse if they'd been in. Holed piston results from severe detonation.

What was the compression on that cylinder after damage? -Just read the inlet valve was bent too, so no compression.

Cylider head can be repaired.

SteG40 · August 05, 2009, 08:03:52 PM

The damage is from when I bent a valve. Would that cause det? I didn't hear any pinking or is it just a coincidence that it's the same cylinder and that there's something else wrong too?

Nick_S · August 05, 2009, 08:10:42 PM

Detonation damage occurrs from explosive hammer action due to incorrect ignition timing. Will need repairing that piston because imperfection on the surface leads to a domino effect creating further damage.

Robin · August 05, 2009, 08:12:29 PM

mmmmm seems very bad for det damage considering you didn't hear any pinking going on.

what are the colour of the plugs like? is cylinder 1 running hotter than the others going by the colour of the plugs?

i wouldn't bother repairing the head, just get a another one and transfer the exhaust valve.

i am not 100% convinced its det damage, i would have thought you would have melted a valve first.

hayesey · August 05, 2009, 08:14:05 PM

not sure that head will be reusable as there's a massive pit in it at the bottom of the pic. There's only so much you can skim off the head. haynes might have the minimum head thickness in it...

is this a ported head or standard ports?

Robin · August 05, 2009, 08:15:41 PM

Quote from: SteG40 on August 05, 2009, 08:03:52 PM
The damage is from when I bent a valve. Would that cause det? I didn't hear any pinking or is it just a coincidence that it's the same cylinder and that there's something else wrong too?

det is when tiny pockets of fuel ignite before it is meant to which is mostly due to high temps caused by wrong fueling, wrong ignition timing (too advanced), too high compression ratio, shit fuel etc.

hayesey · August 05, 2009, 08:15:50 PM

also, like robin said, what does the spark plug look like? have bits broken off it?

SteG40 · August 05, 2009, 08:18:35 PM

It's a BVH i'm going too take the head to a local place and see what they reckon. Spark plugs are fine nothing broken off all the same colour too

Robin · August 05, 2009, 08:32:51 PM

this is why i don't think its det without looking at the head phyically, with the plugs being all the same colour it suggests that cyl 1 wasn't running that hot.

Also for det to damage the engine that much i think you would most certainly hear the engine pinking its arse off, i had bad det on my lader set up and ran that for about 1k miles with it detting its arse off and the head and piston showed no damage whatsoever when i changed the head gasket.

i am still wondering if something has gone through your intake system, but having said that i have just look at the picture of the head and that big hole at the bottom looks like it has melted!!!!

hayesey · August 05, 2009, 08:35:05 PM

plus to me that piston looks like it's been fecking hot, looks like the end of a spark plug from an engine thats been running lean.

yep best bet is to take it to an expert, obviously anything we say here is just guess work without having the car here.

Robin · August 05, 2009, 08:39:34 PM

mmmmmm looking at it in more detail it does look like det more than anything else.

get your injectors tested and cleaned.

Nick_S · August 05, 2009, 08:44:37 PM

That large pit on the cylinder head matches the one on the piston so i'd guess its a melt. Did you clean all the coke off the top of the cyl1 piston crown before you took the photo?