Piston Part II!

I'm all set to replace my pistons and rebuild the top my engine (2.5D
N/A) over the weekend, a couple of queries to anyone who can help:

a) Piston ring 'gaps' - any particular way of arranging these?
b) Any tips or things to watch for when restarting?

Thanks

Smudge

In message <[email protected]>
"Smudge" <[email protected]> wrote:

> I'm all set to replace my pistons and rebuild the top my engine (2.5D
> N/A) over the weekend, a couple of queries to anyone who can help:
>
> a) Piston ring 'gaps' - any particular way of arranging these?

Yes! They method varies a bit from engine to engine, and of course
I can't find the TD engine manual at the moment, but for Tdi's the
gaps are arranged as follows with the arrow on the piston crown
pointing towards the front of the engine :-

Top compression ring gap is at 11 o'clock
Lower compression ring gap is at 5 o'clock
Oil ring gap at 7 0'clock

looking at the top of the piston.

I'd recommend checking this before assembly as the position of the
gaps is crucial in preventing the piston slapping in service.

> b) Any tips or things to watch for when restarting?

Turn the engine over by hand (with the glow plugs out) and be sure
that everything is nice and smooth before starting - some oil
down the bores while hand truning won't do any harm.

Crossing fingers and having a bucket of language to hand may
help...... ;-)

>
> Thanks
>
> Smudge

Richard

--
www.beamends-lrspares.co.uk [email protected]
RISC-OS - Where have all the good guys gone?
Boycott the Yorkshire Dales - No Play, No Pay

"beamendsltd" <[email protected]> wrote in message
news:2665ae304e%[email protected]...
> In message <[email protected]>
> "Smudge" <[email protected]> wrote:
>
> > I'm all set to replace my pistons and rebuild the top my engine (2.5D
> > N/A) over the weekend, a couple of queries to anyone who can help:
> >
> > a) Piston ring 'gaps' - any particular way of arranging these?
>
> Yes! They method varies a bit from engine to engine, and of course
> I can't find the TD engine manual at the moment, but for Tdi's the
> gaps are arranged as follows with the arrow on the piston crown
> pointing towards the front of the engine :-
>
> Top compression ring gap is at 11 o'clock
> Lower compression ring gap is at 5 o'clock
> Oil ring gap at 7 0'clock
>
> looking at the top of the piston.
>

Not that important so long as each alternate ring gap is on roughly opposite
sides, they don't stay in the same position when running.

> I'd recommend checking this before assembly as the position of the
> gaps is crucial in preventing the piston slapping in service.
>

The position of the ring gaps is nothing to do with piston slap, piston slap
is caused by incorrect piston to bore clearances which may include wear.

> > b) Any tips or things to watch for when restarting?
>
> Turn the engine over by hand (with the glow plugs out) and be sure
> that everything is nice and smooth before starting - some oil
> down the bores while hand truning won't do any harm.
>

Oil on assembly would be better. Oh, and 0.003" per inch of bore for the
gaps as a general rule if you are checking them in the bore which relates to
about 0.012" for the Landrover to be safe.

Martin.

> Crossing fingers and having a bucket of language to hand may
> help...... ;-)
>
> >
> > Thanks
> >
> > Smudge
>
> Richard
>
> --
> www.beamends-lrspares.co.uk [email protected]
> RISC-OS - Where have all the good guys gone?
> Boycott the Yorkshire Dales - No Play, No Pay

In message <[email protected]>
"Oily" <[email protected]> wrote:

>
> "beamendsltd" <[email protected]> wrote in message
> news:2665ae304e%[email protected]...
> > In message <[email protected]>
> > "Smudge" <[email protected]> wrote:
> >
> > > I'm all set to replace my pistons and rebuild the top my engine (2.5D
> > > N/A) over the weekend, a couple of queries to anyone who can help:
> > >
> > > a) Piston ring 'gaps' - any particular way of arranging these?
> >
> > Yes! They method varies a bit from engine to engine, and of course
> > I can't find the TD engine manual at the moment, but for Tdi's the
> > gaps are arranged as follows with the arrow on the piston crown
> > pointing towards the front of the engine :-
> >
> > Top compression ring gap is at 11 o'clock
> > Lower compression ring gap is at 5 o'clock
> > Oil ring gap at 7 0'clock
> >
> > looking at the top of the piston.
> >
>
> Not that important so long as each alternate ring gap is on roughly opposite
> sides, they don't stay in the same position when running.
>
> > I'd recommend checking this before assembly as the position of the
> > gaps is crucial in preventing the piston slapping in service.
> >
>
> The position of the ring gaps is nothing to do with piston slap, piston slap
> is caused by incorrect piston to bore clearances which may include wear.

We'll just have to disagree on that :-0 !

<snip OP>

Richard
--
www.beamends-lrspares.co.uk [email protected]
RISC-OS - Where have all the good guys gone?
Boycott the Yorkshire Dales - No Play, No Pay

> > "beamendsltd" <[email protected]> wrote in message
> > news:2665ae304e%[email protected]...
> > > In message <[email protected]>
> > > "Smudge" <[email protected]> wrote:
> > >
> > > > I'm all set to replace my pistons and rebuild the top my engine
(2.5D
> > > > N/A) over the weekend, a couple of queries to anyone who can help:
> > > >
> > > > a) Piston ring 'gaps' - any particular way of arranging these?
> > >
> > > Yes! They method varies a bit from engine to engine, and of course
> > > I can't find the TD engine manual at the moment, but for Tdi's the
> > > gaps are arranged as follows with the arrow on the piston crown
> > > pointing towards the front of the engine :-
> > >
> > > Top compression ring gap is at 11 o'clock
> > > Lower compression ring gap is at 5 o'clock
> > > Oil ring gap at 7 0'clock
> > >
> > > looking at the top of the piston.
> > >
> >
> > Not that important so long as each alternate ring gap is on roughly
opposite
> > sides, they don't stay in the same position when running.
> >
> > > I'd recommend checking this before assembly as the position of the
> > > gaps is crucial in preventing the piston slapping in service.
> > >
> >
> > The position of the ring gaps is nothing to do with piston slap, piston
slap
> > is caused by incorrect piston to bore clearances which may include wear.
>
> We'll just have to disagree on that :-0 !
>
> <snip OP>
>
> Richard
>
It's not a question of disagreement, what you said was wrong and I was
only trying to put you right for the benefit of the OP. You are usually
right 99% of the time and also very informative and helpful but no one can
be right *all* of the time!

Martin.