One Piston Is In The Wrong Way Round

[Dan Ingram 1]

I'm changing the headgasket and on removal of the head I've found that the No4 piston is in the other way round to all the others. Is this normal? If not is it ok like this? The engine seemed to run ok before the gasket went so its not fouling the valves or anything.

 

 

Thanks in advance

 

Dan

Edited December 20, 2008 by Dan Ingram

[Goliath 94]

Lol! No its not normal, they should all be the same way round. I thought because otherwise they foulf the valves but obviously not if yours is fine. Do you know any history on your engine? like when it was last rebuilt/ any work its had done?

Very odd

[Dan Ingram 1]

I know nothing about it at all, no service history or anything. Am I ok to leave it? really cant be arsed taking pistons out.

[welshpug 1,657]

I'd drop the sump off, take that cap off the crank, push it up turn it 180 and bolt it back on.

[Miles 331 1 Cars]

The piston's should all have 'Dist' on them and the arrow point towards the Cambelt end, The nick's which hold the bearing's should also be on the exhuast side but unless you drop the sump you won;t know.

[pug_ham 244 3 Cars]

In line with what Miles has said, is it that one is the wrong way round or three?

 

Graham.

[Dan Ingram 1]

If dist is supposed to point towards the cambelt end then its just one the wrong way around. And what are the nicks that hold the bearings that you talk about?

[welshpug 1,657]

in the conrod, there is a nick and a corresponding tab on the bearings.

[pug_ham 244 3 Cars]

Thats not to bad then if its just one that wrong & not the other three.

What are the nicks that hold the bearings that you talk about?

When you remove the sump & big end cap you will see a nick in the cap & conrod for the bearing location tab.

 

See attached images.

 

Graham.

[Dan Ingram 1]

Excellent thanks. How do I get the chain off the oil pump sprocket?

[Dan Ingram 1]

Scrap that, done it. Helps if you take the spacer plate off

[pug_ham 244 3 Cars]

Make sure you mark the cap for orientation on the rod or you might wonder why the crank doesn't turn when you tighten it back down.

 

Graham.

[Alfie 6]

I'd drop the sump off, take that cap off the crank, push it up turn it 180 and bolt it back on.

Amazing that it would run really. Not wanting to raise any alarm, but would there be any worries about the Rings if this were done?

[Matteo 17 1 Cars]

Every time a piston is removed from its sleeve, its piston rings should be renewed as they settled in a defined position. Otherwise lack of compression could occour. Piston rings should be renewed in each pistons at the same time.

I hope you can understand my words, and I apologise for my poor English.

[CosKev 16]

Amazing that it would run really. Not wanting to raise any alarm, but would there be any worries about the Rings if this were done?

 

In my experience the rings will stay in the same position,and JUST the piston will turn round,leaving the rings in there settled/bedded in position

[CosKev 16]

Every time a piston is removed from its sleeve, its piston rings should be renewed as they settled in a defined position. Otherwise lack of compression could occour. Piston rings should be renewed in each pistons at the same time.

I hope you can understand my words, and I apologise for my poor English.

 

Your correct,but the above reply was not talking about removing the piston from the liner/bore,just taking the rod off the crank and turning the rod and piston threw 180 degrees

[Dan Ingram 1]

The shells are on the wrong way around aswell but on the 3 other pistons they're fine. Bit of an odd one really.

[pug_ham 244 3 Cars]

The shells are on the wrong way around aswell but on the 3 other pistons they're fine. Bit of an odd one really.

How do you mean?

 

Graham.

[Alfie 6]

How do you mean?

 

Graham.

Beginning to think that the con=rod is ass about face as well, lol Is there aright and wrong way to fit 'em Graham?

[Dan Ingram 1]

The nicks are supposed to be on the exhaust side but as the piston was in the wrong way round that meant they were on the inlet side. So I turned the con rod and piston through 180deg and did the same with the shells and the big end cap.

[Alfie 6]

The nicks are supposed to be on the exhaust side but as the piston was in the wrong way round that meant they were on the inlet side. So I turned the con rod and piston through 180deg and did the same with the shells and the big end cap.

In my limited experience, that would appear to be all ok then.

[Dan Ingram 1]

Well it all went back together ok and I've timed it all up and everything seems to be moving freely. Fingers crossed there aren't any problems when I fire it up.

[SeanO'Connor 0]

Hmmm curious, I think you got a Friday engine there mate. Let us know how she goes, although I find it quite amusing.

[mattbenselin 0]

How did it go with rotating a piston? I'm in half minds whether to do this too, though I have all four to do...see recent topic.

[Dan Ingram 1]

I don't know mate. I sold the engine to Gti-si. I don't know if he fitted it in his car or not.