yallaair

Hi!
I'm planning to put the tuned pipe designed for MVVS 35cc (3268) on a 50cc gasser. Will this pipe be a too small for this engine, or is a 50cc engine within the range for this tuned pipe? The bend designed for the MVVS 35cc will fit directly onto my 50cc gasser.

DarZeelon

Yallaair,


This #3268 tuned pipe is not only designed for the 35 cc engine, or its 40 cc sibling from MVVS; but it is also designed for an RPM range most 50 cc engines will only use the lower part of...

With an engine spewing out more exhaust gas per cycle and wanting to spin circa 7,000 RPM... It will be within the effective RPM range of this pipe, but with too large doses of exhaust...

It is surely more restrictive, but I cannot be sure how well it will work.

yallaair

Thanks for prompt reply!

I think I have to test this combo. Looks interesting to have a long, sleek pipe instead of the chubby ones. Not sure if this long narrow shape of the 3268-pipe is as effective, but it's surely more "good-looking"!

pe reivers

The pipe still works for the 40cc. With the 50cc it will move up in tuned rpm, probably to the 7000 - 10000 rpm range. The range in the 35cc engine is 6000 - 9000, so you may want to put some extra header length in series with the standard MVVS header.

YBP

Hi. I´m putting this pipe on a 45cc engine which runs approx.7200-7300rpm with the standard muffler on a xoar 20x8 prop.
I´m mounting a 21x8 xoar with the pipe. I guess I need to lenghten the headerpipe since the 21" prop will take the rpm´s down a bit? How much will be a good starting point?


Lars.

pe reivers

Just add some extra length, and then shorten one inch at a time until you are satisfied. No one can predict exactly what happens when you try out a new pipe/engine combination.

YBP

Thanks, pe. I´ll give it a shot when the pipe arrives.

Lars

YBP

The pipe is now mounted and it is a success!

First, the rpm on 20x8 was wrong. I measured and it was around 7000rpm. (sealevel, about 60-70deg. F)
I then tested the Xoar 21x8 and got 6500rpm
The chinese FTL45 had to be replaced because of a faulty seal on the shaft. I put a slightly used CRRC 45 on the plane, which is the same engine more or less.

I used the FTL carb and muffler and got 6500 on the CRRC too. After a couple of flights the rpm increased to 6600.
Enter the tuned pipe!
With one inch in addition to the std. header I´m now getting 7050rpm on the Xoar 21x8 prop. And more important the throttle response is way more crisp than before and very, very silent!

I´m sure I can get even more RPMs by shortening the header furter, but I don´t need the extra revs, and sooner or later the curve will become peaky and harder to manage.


Lars.

pe reivers

so much for peaky tuned pipes.