Cracked pistons

[DW]

Running Hepolite pistons (with deepened valve pockets) in a 1700 135bhp Xflow, and am in the process of replacing the piston rings, but on taking out the pistons all 4 of them have cracked between the top and middle rings - the cracked bits actually drop out

 

Is this a common problem - engines only 6,000 miles old, and at 135bhp it shouldn't need forged pistons surely?

 

Looking on the vulcan web site they're nearly £200 - is that likely to be each or for a set (they're not open)?

 

 

 

David

1700XF

 

Edited by - DW on 30 Apr 2005 17:41:51

[Myles]

It ain't bhp that kills pistons in this way - it's revs and/or unsympathetic use before the engine has warmed properly, AFAIK.

 

On the latter-point, I'm lucky in that my car came with an OT gauge - so I was aware from the outset that the oil doesn't get up to temp for a good 10ish miles further down the road than the point at which the coolant is up to spec - and certain metallic bits will take longer still.

 

I suspect a fair-bit of damage is done by people who just rely on the WT reading before giving it beanz.

 

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[DW]

I always thought that I was sympathetic Myles - clearly I'm not ☹️. Looking at other threads I think I'll drill a hole in, and thread the sump bolt for an OT guage. Nothing like learning from experience eh 🤔

 

The idea was that I'd hire the engine crane for the weekend and get the engine out and back in. I've now got an engine crane doing nothing for the weekend - I'm on the Evesham side of Bredon Hill if anyone wants to take a lend tomorrow or Monday

[Roger King]

Ever so, ever so common I'm afraid. The piston is designed for a 55bhp 1300ccm engine and simply isn't up to the job. If you've had any detonation in the past this will only have speeded things up.

 

The longest I've known these pistons in this application last is 60,000 miles and the shortest is 300 miles with 20,000 being about average.

 

It's not the piston's fault, it isn't designed for this type of use. This is the reason that anyone with experience will spec forged pistons.

[clive powell]

cracked 2 of mine 5 miles after putting 2* (long time ago)in by mistake and didnt hear the pinking till to late.As the man said "detonation"

[Paul Formston]

God what have you been doing to the poor old Ford motor this Engine was the Back bone of English Raceing and Ralleying it is unbrakeable yet you have manage to kill it ,have you no respect all I can say is its A dam good job you have'nt A standard Rover Cocloate Engine, you would Kill it on your way to the shops, best Try going Zetec the Raceline one may take your right foot but done ever use A Rover unless you get into big money £35,000 to make A good Rover Engine (MINSTER )Best Regards Paul PS I dont Like Fords I Drive A BMW its A shame we carn't A bema Engine in A Caterham