Re: Exhaust stack

[tvallee <pwetmor@ibm.net>]

David Brown wrote:
> 
> I'm about to cut my exhaust holes in the cowling. Before I do I wanted to
> ask about the 4 into 1 exhaust.
> 
> Does the exhaust exit out the back or down the bottom?
> Do those who have it recommend it?
> Should I buy it?
> 
> Thanks very much!

The 4 into 1 exits out the bottom.  We have one, but have not installed
the engine as yet.  We bought our engine from Ly-Con at Visalia, CA and
we were there when it was run on the test stand.  After running it with
their straight exaust pipes, they mounted the 4 into 1 and reran it.  It
developed slightly less horsepower through the rev range until 2700,
when it equaled the straight pipes.  The prop on the engine was also a
tractor instead of pusher.  They had to decrease the pitch slightly in
order to attain these results.  I don't know what the result would be on
the standard 2 into 1 exhausts.  The oil line on # 4 cylinder had to be
rerouted as a result of the routing of the exhaust pipes. Only time will
tell if these 4 into 1 will work as well as the standard 2 into 1, but
the cowl work is going to be a lot simpler--just a hole in the bottom.

Pete Wetmore/Toni Vallee  
Std RG Elite