15 replies to this topic

[Moshtaraq]

Hi again,

So here is my shameful story: today I fitted my rebuilt engine, followed the procedures like squirting a bit of oil in the cylinders a bit before. Well the tip of my squirt bottle fell of in my cylinder without me knowing it and when I started the engine I heard a loud rattle... Removed the head to inspect the damage: my piston is pitted, no damage to the head or valves. Can I just clean things up and reuse the piston even though it has small pits in it? I'm worried about carbon building up in the pits, heating up and causing detonation.

Thanks
Jens

[steeley]

Have you got pics of damage

[Moshtaraq]

Here is a picture, it looks rougher than it feels though.

Attached Files

•  DSC_0466 (1).jpg   47.47K   26 downloads

Edited by Moshtaraq, 09 April 2021 - 10:04 PM.

[Homersimpson]

What sort of engine is it?  Standard or high performance?

 

Personally I would change that piston but if you don't then I would still remove it and check all the rings are free, years ago when I was about 12 I changed the plugs in my dads Sierra 2.0 Pinto engine and broke the top of the plug off one and dropped it into one of the cylinders, I didn't realise and when we started it up there was a lot of rattling, we fished the broken bit out but the engine wasn't right and made a loud tapping noise, when we stripped it we found the piston had been squashed at the edges slightly which pinched the rings and held them in, we fitted a new piston and all was well.

[austinseven]

Turn the engine over by hand till the piston is at the bottom of the cylinder and check the cylinder walls for scoring, you could also remove the valves from the head and check that they are straight and that the valve seats aren’t damaged.

[Spider]

It doesn't look like the peripheral of the Piston has been hammered down that could cause a Ring to Pinch.

You can check this, with the engine cold, you can move the piston about in the bore, move it around in a circular motion and look down the bore at the ring. If it maintains contact, then happy days, put the head on and enjoy it.

[Moshtaraq]

The cylinder walls are spotless, no scratches or anything. The only damage is on the top of the piston, the edges weren't bent or deformed. Today I'll inspect the head and remove those valves.

by the way it's a fast road as some would call it. 1330

Edited by Moshtaraq, 10 April 2021 - 07:09 AM.

[Quinlan minor]

If it were me, I'd replace the piston and check the conrod, very closely, for deformation.

 

Otherwise I'd be clenched, waiting for the bang, every time I drove it.

 

Cost of new piston vs. cost of rebuilding a grenaded engine?                   Minor

 

Cost of not being able to relax and enjoy that 1330 motor?                       Priceless

[PoolGuy]

I'm sure it'll be fine, BUT I'd change it for peace of mind. I've respect for you admitting what you did though, many wouldn't.

[floormanager]

I feel your pain.  We've all done stupid things with a bit of hindsight, we could of avoided.  Hang in there.

[Moshtaraq]

@quinlan minor I get it and I'm going to get it fixed eventually. It was a copper tip so it wouldn't have given a lot of resistance so I'm not really worried about the conrod.

[austinseven]

If the bores are ok and the valves are ok, if it was mine I’d put it back together and run it, but it’s up to you, good luck  

[Maccmike8]

Change it.

[steeley]

I’d at least take out the piston and check it ,
I know but a lot more hassle and expense to have to rebuild if it’s more serious

There is always something stopping it getting finished

Mine is pretty much done and rr session booked for three weeks time

Was cleaning up engine bay and dropped throttle pivot pin down the back of the engine bay, spent about two hours on and off searching for it with mirror torch magnets and still couldnt find it

While looking I found a puddle under the car, turns out the rear brake line has a small split and has taken off paint and gravitex off

So time to run new front to back brake line (it was a lot easier to do when the car was on a spit than it will be now )

Ho hum

[62S]

If everything else looks good I would put it back together and give it a compression test. If that is OK I would run it as is.