"OldSchool" <OldSchool@here.com> wrote in message
news:tee6bvs2bj8la50oua1ccgdgs1uqb71t14@4ax.com...
>

You have to set the length correctly to get the optimum performance fromyour
engine. This is done by adjusting the length of the gap between the end of
the manifold and the start of the pipe using a plastic (teflon) joiner or
something similar. If you cannot get the pipe short enough then you cut
some length off the manifold or the pipe.
A lot of engines have a recommended pipe length which you can set as a
starting point. If this is the case, then the distance is measured from the
face of the piston in the exhaust port to the first baffle in the pipe.

Carps

"Andy Carpenter" <andy@REMOVEcarpsTHE.coUPPER.ukCASE> wrote in message
news:b8vmag$o6q$1@titan.btinternet.com...
>
> "OldSchool" <OldSchool@here.com> wrote in message
> news:tee6bvs2bj8la50oua1ccgdgs1uqb71t14@4ax.com...
> >
>
> You have to set the length correctly to get the optimum performance
fromyour
> engine. This is done by adjusting the length of the gap between the end
of
> the manifold and the start of the pipe using a plastic (teflon) joiner or
> something similar. If you cannot get the pipe short enough then you cut
> some length off the manifold or the pipe.
> A lot of engines have a recommended pipe length which you can set as a
> starting point. If this is the case, then the distance is measured from
the
> face of the piston in the exhaust port to the first baffle in the pipe.

And the recommended lengths are always WAAAYYY too long, but for good
reason.

The "standard" length as supplied will give a boost to power, as opposed to
silencers/mufflers, which ALL strangle the engine to some degree causing a
LOSS of power, yet still retain a lot of flexibility with carb settings and
allow a pretty wide rev range where the power is produced.. The shorter we
go with a pipe, the more power it'll let the engine produce, but always at
higher revs and always within a "shortening" rev range. This is why people
associate pipes with "peakiness", and the TRULY well tunes pipe/engine
combination will have a VERY VERY narrow power band (rev range) but give
HUGE amounts of power when compared to the same engine running a muffler.

What we have to decide is.....do we want the absolute max power from the
engine, at the expense of tractability, or do we accept a small sacrifice
drop in peak power for an easy to use system. Us heli blokes usually opt for
the 2nd option because we have a varying rev requirement, whereas the ducted
fan blokes will go with the 1st because all the want is a screaming demon in
their machines.

Like the old saying goes, there're no free lunches, but the pipes today are
FAR better than a muffler, even if they've not been tuned to perfection.

I personally wouldn't entertain a heli with a muffler when they're are pipes
like the NovaRossi and Rossi pipes out there just waiting to be bought.


--
Beav


Please note my E-mail address is "beavis dot original at ntlworld dot com"
(with the obvious changes)

Beavisland now lives at
www.beavisoriginal.co.uk