11 replies to this topic

[Carlos W]

I bought a job lot of parts the other day, and I've been sorting through what I'm going to keep for my project and what I'm going to sell on.

 

There are a set of 4 pistons in there, but 2 of them have got hair line cracks in them, I don't want to use or sell them if the heat they're exposed to causes them to split in half

 

Any thoughts? Are these scrap?

The crack is right in the middle

Edited by Carlos W, 30 April 2013 - 01:09 PM.

[Fast Ivan]

scrap imo

[Carlos W]

scrap imo

 

That was certainly my gut feeling I can only see this getting worse with heat cycles

[Tommyboy12]

Ill take one for a pencil pot?

[johnnyblaze]

yeh scrap mate, thats what happens when the valve hits them

[Carlos W]

not much value in the 2 good ones either

[mini13]

dosent look like a valve mark to me.... as its dead centre.... looks more like a machining mark.

 

how far down the piston is the top ring, it looks to me like a shed load has been machined from the top of the piston, to the point where its become too thin and weak, and started to crack.

[Tamworthbay]

not much value in the 2 good ones either

Not much but some, it may be that someone is after a single to replace a damaged one. I am sure I remember Cooperman mentioning he had done that on his grandsons car (apologies Cooperman if I am wrong)

Edited by Tamworthbay, 01 May 2013 - 04:51 PM.

[Carlos W]

Thanks for everyone's comments! I think I'll list the good ones on eBay

[johnnyblaze]

dosent look like a valve mark to me.... as its dead centre.... looks more like a machining mark.

 

how far down the piston is the top ring, it looks to me like a shed load has been machined from the top of the piston, to the point where its become too thin and weak, and started to crack.

 

ahh yeh i only had a quick look at it, id be guessing  your correct on your machining to much off theory

[Cooperman]

 

not much value in the 2 good ones either

Not much but some, it may be that someone is after a single to replace a damaged one. I am sure I remember Cooperman mentioning he had done that on his grandsons car (apologies Cooperman if I am wrong)

 

We changed one piston as the other 3 were in perfect condition and one was 'broken' (is that the correct engineering term? I thought the correct term began with an 'F'?) so one new piston was fitted and all is well again. The broken one was damaged by an unleaded valve seat breaking away from the head.

Edited by Cooperman, 03 May 2013 - 09:18 PM.

[Carlos W]

I'll measure them, photograph them and chuck them up for sale then!

They'll be nice and cheap, see if I can do someone a favour