Riverdancer

My Feedback: (5)

Good Day Sir,

Top of the new year to you and yours..

I was looking at the stainless headers for these two engines..Nice :0)

I am curious if they would work well with the MVVS Canisters.. or would the header be too long. Have you done any testing with this combination.. I like the idea of having the engine inverted.. (With the MVVS headers the engine has to be canted to put the canister down the center of the fuselage, which will mess up the cowling ( In my mind anyway)

Thanks in advance for your help.

Riverdancer

DarZeelon

Riverdancer,


The original headers have a special way they connect to the #3204 canister muffler, with the Teflon™ sleeve and the springs holding the flanges together.

I don't think a Krumscheid sleeve will connect the same.

See photo of the #3202B header.

Riverdancer

My Feedback: (5)

Good Day Mr Zeelon,

Thanks for the quick reply.. :0) I am capable of welding an addaptor for the header to match the Mvvs can attachment. I was curious if the addtitional header length would affect the performance of the MVVS can?

Thanks again for your help.

Riverdancer

DarZeelon

Not really, Riverdancer.

The canister is a tuned muffler, relying on the Helmholz resonator principle.
It is similar, but not identical to the tuned pipe principle, with its emitted and reflected sound waves.

...Although the effective RPM range may be slightly changed.

Riverdancer

My Feedback: (5)

Thank you Sir.:0) Sorry, if I miss-spelled your name.. I have trouble spelling my own from time to time..

Thanks for the information. Would it be possible for me to order the headers from your website? I would like to set up the 45 this spring in a H9 Extra 260.

Again, thank you for your time.

Riverdancer

DarZeelon

It is OK, Riverdancer.


David Moen has these items in Canada.

It would be easier for you to get them from him. He is also a responding member of this forum (MVVS Support).


If he cannot supply them currently, I can order them in for you.

Riverdancer

My Feedback: (5)

That will be great.. I have talked with Dave before, I will get in touch with him to see what I need to complete my set up.

All the best.. great service..

Riverdancer

pe reivers

I have done some testing with both.
The weld seam of the flange can be filed off. It,s no big deal. Throw a drop of oil in the seam, so the flange sleeve will not fret when removing it after done filing.
The MVVS steel header is quite heavy. There is no need to let go of the weight advantage of SS headers just because of the excellent mvvs construction. I too like the simple teflon coupler better. It gives me more room to adapt header length and check resulting performance.

David_Moen

I used a KS can on on of my airplanes. I used the MVVS header but I removed the flange and tried to join the header and cannister with a high-temp silicone hose and some clamps. It never held together well at all, I was replacing the hose on a regular basis. I ended up building a flange for the KS can so that I could use the MVVS coupler, it held together all last season without any problem whatsoever. I used the KS can because it's outlet is further forward than the MVVS cannister. Using the MVVS canister I had to shorten the header about 1.25" which made my 45 very sensitive to carb adjustments and very rich in the mid-range. Next time I will build the airplane so I can use the MVVS can!

glofuel

speaking of headers, what is the optimum length for the 3204 and 58pro using a 24x8 2 blade prop ?

pe reivers

Silicone will not hold up all that well.
I use teflon couplers now. They tend to slip forward or off the header. To prevent that I place a hose clamp in front of the coupler, and wire the coupler clamp to the hose clamp. This works very well.
The muffler part never slipped off in my applications.
Using this system, the muffler is free to expand, and can be supported any way you like.

pe reivers

The 3202P header has the optimum length, and is about 18 cm long. Longer headers are not critical though, and often used.

glofuel

Pe,

Is there any way of getting a header length close to 18cm in length when the engine is inverted (180deg) with cannister directly behind the head but still central to the fuselarge, without canting over the engine at an angle ?

I was hoping to silver solder my own header using the MTW/KS individual parts but with 3 x 90deg bends and a short straight comes to about 25cm long, How much affect will this have if I do ?

Thanks Ian

pe reivers

If you construct a swan neck of parts the header does get longer. MTW mufflers need this added length to get in tune. The non-tuned MVVS 3204 muffler is very strong with added length headers as well, and does not seem to care much.
FWIW, Best ~6000 rpm power figures reported were with a 25cm header combined with the 3204 canister!
I would not worry too much. This canister is very forgiving.

glofuel

Pe, Thanks for the quick response, I will proceed with what I intended.

Thanks Ian

glofuel

DarZeelon say's canister is a tuned muffler, Pe say's it is a non-tuned muffler ?

Sorry but am I missing something, I thought we were all talking about the same 3204 and header lengths [sm=confused.gif]

Ian

DarZeelon

Ian,


I would call the #3204 a 'semi-tuned' Helmholz resonator...

It makes much more power, without added noise, than a Bison Pitts, for instance.

pe reivers

Of course Dar is right, and so am I.
Every chamber open to the air with a wall thickness (pipe length) is a resonator with an own specific frequency. Such a resonator also has a Q-factor which defines the width of the response relative to the frequency.
High Q, like 40 or so, gives 8000/40 = 200 rpm power band, very narrow, but very well tuned within the range.
Low Q, like 1, gives 8000/1 = 8000 rpm power band. This is non-tuned, because there is no rpm preference.
Values smaller than one will cost you dearly.
From this, it can be clear that even the pitts muffler is tuned, and probably even has a high Q-value. The pity is, that the power band lies obove practical operation rpm. [&o] . that means, the pitts also will slurp a lot of power, giving nothing in return.

DarZeelon

Nicely put, PĂ©.

This is a good general description of the tuned muffler's power-band!

glofuel

Glad I asked [sm=bananahead.gif]

I going to have to think about this and try to understand

Thanks any way[sm=47_47.gif]

Miketc

DarZeelon, Pe, David

Attached are two pics from my latest project, H9 Extra 260, can you see my probelm?
This is a standard MVVS 45.0 INT canister, with the standard header, there is no way to line up the header with the canister!

I have tried inverted, but there is no way the header will get even close to what I need.
Is there any reason I should not go for a side winder installation? Great fit in the cowl, great airflow, what about lateral balance of the plane?

Any suggestions will be appreciated?

Mike

janch

Hi,
I wold like to recomend you my web .

http://poletovani.webzdarma.cz/edge540.htm

Miketc

Thanks Janch, I will take a look at your site.

pe reivers

I think you need a 25mm ball header with 58cc flange, which can be adjusted to the plane dimension you need without moving the motor out of position. After the adjustment, the balls can be brazed, so the joins will not move again.
See http://www.mvvs.nl/MTW/Headers.htm
This is MTW's patented solution. If you file the weld off the canister header stack part, and take off the MVVS coupler adapter, the 25mm header pipe will fit with a 25mm teflon coupler. Put a drop of oil in the join between mvvs adapter and muffler stack first. That will allow the adapter to slide off from the muffler stack without fretting.
I then put a piece of round 20 steel in my vice, fit the muffler end over it, and with a very coarse file on edge press some indentations in the canister stack. Allow the canister to rotate while doing this. That gives the teflon coupler sleeve something to hold on to.

Miketc

Thanks Pe Reivers, I will do some homework on the your site. Is it a must to braze the joint, or can I leave it as is? Do you ship to Kuwait?

Miketc