I'm currently flying a CG EXT 330 w/OS 46fx and a Tower Hobbies muffler....performance is much better than stock but I would still like a little better throttle response so I am going to build a MCM.. I did a search and all questions were answered accept length of header....with the .46fx do you need to order the extra long header or is the standard long enough after you cut the inlet piece????


Thanks in advance,

Jason

I believe extra long and standard refer to the bend in the header. The extra long comes out farther from the exaust port than the standard length header . Either one of these headers has to be cut or tuned to your engine and Mouse can muffler.

I guess that still doesn't answer my question....my question is after cutting the piece off of the header and using it for the inlet is there still enough length left to get max rpm....in the thread on the MCM there was a warning that when making a mousse can for a .46 you may want to make the inlet out of something besides a piece of the header......is there plenty of length on the header left after cutting the piece for the inlet??

Thanx

Jason

If I understand the question..but if you need some extra header pipe material, go to the scrap yard and get some old tent poles. I got a couple of these years ago and have made several headers/spacers etc. from them.

I hate to tell you Jason, but the header needs to be tuned to the geographical area that you live in, the header style your running, and ecspecially the prop that you are going to run. Ideally, you would re-tune the header for different props. Needless to say, we don't, though normally don't change props radically. My point is, the measurement of my header would not necessarily be the same for yours because of the different areas that we live in and the props we are running, though I am real perticular.
If, after you cut your header you need more back pressure, you can always pinch the stinger some, or change the stinger to a smaller dia., or go with a larger moose can for more expansion.

Regarding the std. vs. long & extra long headers, Joe's right, these are different length pipes from the engine head. The extra long will have less back pressure over the long, and the long has less than the std. Check out Mac Product's website. They show the dimensions there.
Sorry - you're just going to have to tune it yourself!
Kevin

I appreciate all of the replys but my question is not how to tune a header.....I know how to tune a header....yes I worded the original question wrong.....my question is whether or not there is enough length left on the header to find the sweet spot after you make the exhaust inlet on a .46fx or if I need to use something else besides a piece of the header to make the inlet....I am not asking for the exact length of anyone's header I just don't want to screw up a header by cutting the inlet off.....thanks for your replys everyone....chuckauger thanks for the idea as I have some old tent poles....I think I will cut the inlet from one just to be on the safe side...

I think I know what you are asking, I had a GP Giles with a .68 mds (dog engine) but I had to go to the Macs Xlong header to get the rpms I wanted. The Cut was kinda on the radius of the header but there was enough left to fasten the mcm to.
It worked great gained 1200 rpms over the stock muffler. I have been fooling around with these muffler quite a bit and have found for the smaller engines like the 46fx that a ronsen butane lighter(smaller can) refill can and a 3/16 stinger with about 3/4-1 inch sticking out will add at least 1000 rpms over the stock OS muffler.
I have had a few engines such as my Webra's gain 2000 rpms Try running a 11-4 APC prop.
If you don't like the OS Try a Webra .50 speed more power swing a bigger prop 11.5-4 apc.
Scott

Heliplane,
On a 46 size engine, just cut off about 1.5" from a new header, then JB Weld that piece into the mousse can. Use a can that measures 1.75" diameter by 6.5" long. For the stinger, use a piece of 5/16" OD tubing. The length of the stinger doesn't really matter. The purpose of the stinger tube is simply to allow you to fine tune the mid range throttle response later on by altering the outlet area with a pair of pliers. (the photo shows the stinger outlet on my TT 42GP w/MCP in my Fazer.)

My nephew is flying a CG Extreme 330 with a TT Pro 46 w/MCP and an APC 12.25x3.75 prop. He liked it before adding the MCP, but now he loves that plane!

I agree w/ Dave McDonald. I did that on for my TT46. I went from 13,000 Rpm on 11x4 to 14,800 on the same prop, same tank of fuel. time was less than 10mins apart. Just enough to do a muffler change. And the sound they make is just awesome. I used a moosecan that was 6.5" by 1.75" for my TT46. But my exhaust outlet whole was 1/4" outside diamter.