Exhaust and higher revs

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Guest

Guest
I mentioned a short while ago that I recently fitted a new OEM front
downpipe on my 80. As soon as this was fitted I noticed that the
tickover revs were higher. I don't have a rev counter but I guess
there may be 100-150 or so more revs.
The old downpipe and its predecessor was one single length of pipe
with no flex section, which went from the manifold down to the
bracket under the RHS front footwell. The new pipe however, has a
flex section fitted where it nears the firewall which is then
followed by a short fat silencer (or at least an expansion box)
before the support bracket. I have seen this type of pipe on other 1
HZ powered 80's in an office fleet; but the last time I needed a
downpipe (the other one sheared at the manifold flange - no guesses
why!) I went to the local super scrapman in Sarajevo and picked over
his ex UN wrecks for one.
I assume that the silencer is responsible for some back pressure thus
causing the extra revs, strange as I would have thought this might
affect a turbo engine and not the more 'numb' characteristics of my
basic naturally aspirated 1HZ engine.
Does anyone have any thoughts on that, or even, should I turn the
limit screw down to reduce the revs, though they seem harmless enough. TIA.
Cheers
Jon
Linslade, Beds
'92 HZJ80 ex UN Bosnia surplus
 
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Guest

Guest
I think if your moteur speed goes up then may be there is less
restriction. One time I replace the pipe on my Peugeot 605 and find
inside that it was split open to block the gas leaving! But that new
pipe you talk describe sounds like the pipe on my HDJ80. That box is
to arrest flames they say.
2008/1/14, toyj80 <[Email address removed]>:
 
G

Guest

Guest
Not strictly Landcruisers ...
... but I once read W O Bentley's autobiography, and part of it is about
his time designing aero engines in the First World War.
Someone was working on an engine, I forget what, and accidentally
drilled a 2mm hole in the exhaust manifold, with the result that the
power suddenly increased by 15%. They hadn't a clue why this should be
so, but they went round airfields in France with a drill.
In fact (isn't Google amazing?) here it is:
http://www.theaerodrome.com/forum/356079-post4.html
it turns out that my memory is at fault: it was the induction pipe, not
the exhaust - but even so, a small change in breathing caused a big
change in performance.
CB
|
| I think if your moteur speed goes up then may be there is less
| restriction. One time I replace the pipe on my Peugeot 605 and find
| inside that it was split open to block the gas leaving! But that new
| pipe you talk describe sounds like the pipe on my HDJ80. That box is
| to arrest flames they say.
|
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G

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Guest
Benoit wrote....
I think if your moteur speed goes up then may be there is less
restriction. One time I replace the pipe on my Peugeot 605 and find
inside that it was split open to block the gas leaving! But that new
pipe you talk describe sounds like the pipe on my HDJ80. That box is
to arrest flames they say.
SNIP
THEN Chris wrote...
it turns out that my memory is at fault: it was the induction pipe, not
the exhaust - but even so, a small change in breathing caused a big
change in performance.
SNIP
Gentlemen thank you, I was beginning to think no one read my post !
That there is a change in 'breathing' is of no doubt. Benoit, your
remark that the box is a flame arrester is interesting and would fit
with the turbo engine, though overall there is no less restriction in
the total length of the system. I wonder if Toy just shave costs by
making virtually the same pipe assembly except that in the case of
the 1HZ they have the slightly longer rigid section up to the
manifold flange. Not only have I seen the same pipe on fleet 80's but
when I picked up the pipe from the dealer they had a turbo engine
pipe beside mine and they appear identical save for the extra 15cms
of pipe on mine before the flex section.
So as it is breathing differently, no matter how slightly, its seems
that turning the idle rev screw down on the pump will be in order.
Believe it or not, although it's LHD someone literally stopped me on
the street in the UK this week and asked if he could buy it for cash,
wanting to bargain on the spot - he gave me his phone number and I
haven't called him back - yet.........
Thanks for your help.
Cheers
Jon
Linslade, Beds
'92 HZJ80 ex UN Bosnia surplus
 
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G

Guest

Guest
Oh yours is some of the best posts I read.! But we have new bebe in
home and extra hours in my work so I not get to be here on the list so
much.
Yes I agreed do use the idling screw.
 
G

Guest

Guest
Congratulations Benoit and hope everyone is well
Jeremy
On 20/1/08 20:47, "Benoit Bernard" <[Email address removed]> wrote:
Jeremy Llewellyn-Jones
Mob: 07831 458 793
--
 
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Guest

Guest
Benoit-congratulations!!!!!!Salute !!!
for the newborn baby-wish you a lot of luck to the whole family
cheers
Lubo
On Jan 20, 2008 11:24 PM, Jeremy Llewellyn-Jones <[Email address removed]>
wrote:
> Congratulations Benoit and hope everyone is well
>
> Jeremy
>
>
> On 20/1/08 20:47, "Benoit Bernard" <[Email address removed]> wrote:
>
> >> Gentlemen thank you, I was beginning to think no one read my post !
> >
> > Oh yours is some of the best posts I read.! But we have new bebe in
> > home and extra hours in my work so I not get to be here on the list so
> > much.
> >
> > Yes I agreed do use the idling screw.
> > --
> > European Land Cruiser Owners Mailing List
> > Further Info: http://www.landcruisers.info/lists/
>
> Jeremy Llewellyn-Jones
>
> Mob: 07831 458 793
> --
>
>
>
> --
> European Land Cruiser Owners Mailing List
> Further Info: http://www.landcruisers.info/lists/
>
 
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Guest

Guest
You the guys are so nice! I use my ear plugs to sleep when bebe
cries. My wife she is very understandinge.
2008/1/21, Lubomir Kolev <[Email address removed]>:
 
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