[NSRCA-discussion] Looking For Props & Header

Wed Nov 4 13:38:55 AKST 2009

I don't know what you mean by will it stay attached?

The new header is a wrap around style header like the previous NMP and
the Hatori 822 style headers. 

All of the 120-170 engines have the same head configuration (meaning
same angle)  and same thread size. SO the new header will fit all
120-170 engines.

There is one exception. The 120AC has the air box on the back of the
head. This prevents the use of the wrap around style headers on this
engine. Other than that they are all the same.

The NMP header was a really good header for the application. When we
were using Teflon tubing to connect the header to the pipe it was
excellent. The problem was Hatori went to the newer style pipes that the
header slides inside of the neck of the pipe with the o-ring. The
aluminum tubing used on the NMP header was not as bullet proof in this
application. Remember the Teflon when hot would flex. Now the header and
the pipe are attached to each other. The header slides inside the pipe
and the result is there is still movement but the stress on the thin
wall aluminum piping is higher. Breaking, and the header would get a
grove worn in it. Actually the o-ring would pinch the aluminum tubing to
a smaller diameter and the header-pipe combo would leak. The added
stress of vibration and the direct connection many folks would break the
header tubing.

The new header is similar to the Hatori in terms of connection to the
pipe. So that swedging ( shrinking of the dia at the o-ring)  problem
and the leaking should be solved. In my setup its working well on the
proto-type headers. Next issue is the tubing being stronger to take the
stress of the direct connection. The solution is kind of unique and is
working well. Some more testing and maybe a few tweaks and its going to
be a very good replacement for the Hatori 822 and 823.

Troy

From: nsrca-discussion-bounces at lists.nsrca.org
[mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of Bill
Glaze
Sent: Wednesday, November 04, 2009 9:05 AM
To: General pattern discussion
Subject: Re: [NSRCA-discussion] Looking For Props & Header

Troy:

Will the new header stay attached to the 1.40 L? Bill Glaze

	----- Original Message ----- 

	From: Troy Newman <mailto:troy at troynewman.net>  

	To: General pattern discussion
<mailto:nsrca-discussion at lists.nsrca.org>  

	Sent: Wednesday, November 04, 2009 12:35 AM

	Subject: Re: [NSRCA-discussion] Looking For Props & Header

	I don't believe there is such a prop made as the 18.1-11 Narrow.
It doesn't exist. I may be wrong but I have been involved with running
and testing the APC props in the 18.1 series and WPN series.  There is a
prop that is designated as just 18-11 and this has a narrower blade than
the 18.1-11.  The 18.1 series of props have a very wide blade. The 18-11
is more like a 17-13 or 17-12 in terms of blade shape but its 18in dia
and 11 pitch.

	I know there is a 16.5-12 I just pulled one out in my
box-o-props and it has a profile like a narrow prop very similar to the
17-10N...however it doesn't have the designation as 16.5-12 narrow. It's
just called the 16.5-12. If you handed it to me with the name scratched
off and said it was a 16.5-12 I would have said it was a Narrow.  Same
goes for the 18-11 regular it's a narrow essentially as well.

	I don't know for sure why the "W" designation or the "N" for
narrow is left off of some props and added to others. I think it has a
lot to do with the equations and program that is used to create the prop
profile. 

	To sum up the props APC has the prop if it is or has been
produced.  I don't think Fred throws any of the molds away. So if a prop
was produced at one time it might be possible with some convincing to
get some of them produced again. I have been to the factory where the
props are produced. It amazing how they are produced, and the quantity
and quality of props produced for a given size.

	You may not be asking for it by the proper
name/designation....the 16.5-12 (is actually like a narrow) and the
18-11 is like a narrow version of the 18.1-11

	As for Headers.....the new header is in testing and is
performing well. The jury is still out, we are working hard to insure
the bugs are worked out. Right things are going well and real progress
has been made in the last couple months. It will be sooner rather than
later from the looks of things on the new headers.

	I hope this helps answer the questions

	Troy Newman

	From: nsrca-discussion-bounces at lists.nsrca.org
[mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of
rjo626 at aol.com
	Sent: Tuesday, November 03, 2009 8:20 PM
	To: nsrca-discussion at lists.nsrca.org
	Subject: [NSRCA-discussion] Looking For Props & Header

	     Hello all! I'm looking for APC 18.1x11 narrow, and 16.5x12
narrow. Also,

	anyone have a good NMP pattern header they're willing to part
with / sell? I've 

	tried Central Hobbies and APC with no luck. Thanks a bunch!

	     Later!

	            RJO

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