Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

Has anyone used these or know anything about them?  I would welcome any device that reduces the loudness of a small engine exhaust as long as it is not detrimental to the performance of the engine.

http://www.jackssmallengines.com/strapmain.cfm

Guys,   I have seen many people try to quiet motors down.   Honda mufflers are better,  but the they are pricey,  also you would need one that would handle the same flow of exaust volume...  Also the flange is diffrent and would have to be cut off and replaced,   not to mention it has to fit in a spot on the thrower (without breaking off or hanging in midair to break off from vibration)

      The biggest group of people that came into my old shop that  wanted quieter mufflers were people that had bought Coleman generators ( or other brand ) and found out they were too loud for a campsite.,.. regardless of the engine the motors were not built to be quiet,  some exaust noise can be reduced, but there is a TON of "valve train noise" in the motor.  The valve train is quieted on higher dollar motors by not having straight cut gears on the cam, or in the Honda, belt driven overhead cam..... (The valves swimming in oil of  a overhead cam motor will also dampen the noise)  

Also,   remember that a car has a bigger engine and the exaust is still quieter,  Most of the reason is that the exaust airflow mellows out to a steady breeze by the time it reaches the end of the 13 foot  pipe,  Taking away the indvidual pop - pop of every cyclinder  

Also the air cleaner or lack of one also affect the noise ot the motor....and the plastic absorbs alot of noise in the shrouding.

     Briggs used to make a muffler kit for generators (up to 8 hp) if it would fit anything now I don't know.   The kits were about $130 --- 15 years ago...    I only sold a few,  I tried to talk people out of them,   On the L-head engines they were only quieting the exaust so much,   The motors still had the internal mechanical noise  like a  bicycle  with a loose chain pedeling at 120 miles per hour ....

Sorry to bust any bubbles, I have seen people put on car mufflers and have mixed results... but nothing that would bolt on and make people happy for the cost..

Good Luck,

Friiy 

Just a thought...  with automotive engines, you can tune the exhaust to maximize engine performance and efficiency within certain rpm ranges.  For example, short pipes would give you lots of noise with high HP, but long pipes would give you a lot less noise and more torque (and HP at lower rpms).  I wonder if anyone has figured out what length pipe would give a B&S (or Tecumseh, or Subaru, Honda, etc.) engine maximum torque at 3300rpm?  Before you say that the mfr. engineers have probably already done this, I would wager that they have not, since they are trying to produce these engines to meet a price point, not for maximum performance at a given rpm.  These same engines are used in lawn mowers, generators, pressure washers, etc. all at different rpms - doubt they would put much R&D into tweaking extra performance for a specified rpm.

With that being said, maybe go-cart racers would have some knowledge on exhaust tuning.  They are always trying to tweak every last bit of performance from their engines - maybe one can derive a formula from using empirical information about different lengths of exhaust pipe on these little engines. 

What I'm getting at is, if you have room on your snowblower, what if you could add an extra 12 inches of exhaust pipe and get a couple more ft-lbs torque at 3300rpm, which will in turn allow the machine to blow snow farther and more consistently with less plugging?  Thoughts?

The exaust tuning book I read years back was mostly about 2 cycle bikes,   and had some good info... Not much on 4 stroke.......

     The big thing on 2 scycle motors is the pressure wave reflecting back off the expansion chamber (i think it was called that)...  and hitting the exaust port of the motor at a specific RPM to help seal the lower end and piston rings from scavengening.....

Friiy...

It works the same with four-stroke engines.  By tuning the length of the exhaust pipe, you can get the pulses to scavenge, or suck, the exhaust gases from the cylinder(s), but only at a specified rpm.  If we could fine-tune the exhaust to 3300rpm, you might get enough extra oomph out of your snowblower to help it throw further consistently, keep it from plugging in wet heavy snows, etc.  Anyway, just a though...