Hi Todd,

The Changfa 1115 (12kw) does not have any low level thumps because it has internal counterbalance shafts to negate a thump.
It's actually a very smooth engine. Therefore tires won't make much difference.
What the Changfa's do have is a very loud ignition knock and lots of internal gear clatter because of the straight cut gear teeth driving the counterbalance shafts.
Here's a few of the things that help to tame a Changfa....

- A good (low back pressure) exhaust muffler
- An inlet air muffler (not critical but you will get a pop...pop...pop...without it)
- An enclosure (small box or full shed) lined with acoustical foam. Be careful to keep adequate air flow for cooling.
- RPM....The noise drops substantially below 1800 rpm (if you don't need the full HP output of the engine).

I got the best results when the engine was slowed down and an exhaust muffler added.
Here's a link to discussion and video of my Slow Speed Changfa project on the MicrCogen forum.
http://www.microcogen.info/index.php?topic=477.0

If it's any consolation, I've heard they quite down somewhat after about 1000 hrs. of running  so you can look forward to that.
(I don't have anywhere near that much time on my Changfa yet.)

veggie

*** UPDATE ***

Quantity:2  ONE LEFT
Model: GM90 Listeroid
Power: 8HP, 900 rpm (6HP at 750 rpm)
Combustion: DI
Starting: Hand crank
Price $1395 CAD
Specs available here....
http://www.energymachines.ca/engines1.htm

Quantity:1 SOLD
Model: Lovson full sized 6/1 Listeroid
Combustion: IDI
Power: 6HP @ 650 rpm
Flywheels: None-Spoke type

***GM90 HEAD GASKETS***

Hi everyone,

I have been working with John to produce a gasket for us GM90 users.
I sent a GM90 head gasket to John at "Gaskets to Go" and a gasket is now available for the 6hp and 8hp GM90 models.

John is making the gasket available via an Ebay page here.....

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=150603027096

I have tried the gasket myself and I am happy with the results,
veggie

I have experience running WVO in a Changfa S195 engine. The fuel was unheated and was blended with dino-diesel.
I recently posted this information on the MicroCogen forum. Below an excerpt which may apply to this discussion....


In point form:

1] If you are not planning to preheat the fuel, then blending WILL be necessary to bring the liquid as close to that of diesel as possible.

2] There have been many people who use regular unleaded gasoline (RUG) or dino-diesel with reportedly good results. Bare in mind that the RUG does a good job of thinning the WVO but adds little to (or even takes away from) the combustion process because of it's reluctance to auto ignite under compression. Hence reducing the overall cetane value of the mix.

3] If RUG is used as the diluent, consider using a cetane booster to restore some cetane value.

4] Not all engines react the same way to blended fuels. Some users report excellent service and great engine life while others report reduced engine life in the form of stuck rings and excessive carbon.
This is why the process is considered experimental in each case.

5] As a rule, IDI engines are more forgiving than DI engines when burning WVO or Blends.

I can only offer my own experience with blending which admittedly was not run long enough to give useful info in the way of a teardown/inspection after 250 hrs..

Base stock: Filtered and dehydrated WVO
Acidity:      Low (Titration value of 1.5 to 2)
Blend:        70/30 WVO and Diesel fuel with 1 oz. of turpentine per gallon of mixed fuel
Engine:       Changfa S195
Combustion: Direct injection
Starting:      Excellent
Smoke:        Minimal (light white smoke for 1 minute until slightly warmed up)
Fuel Separation: None

I have had a 1 liter sample of this mix in a glass bottle for over 9 months.
-Still clear
-No separation of the constituents
-No apparent polymerization, gummy film, sticky residue.

Sorry that there is no conclusive internal engine inspection to report, however I thought the blend info and separation resistance of the fuel might be of some interest.
I do intend to keep running this fuel in my direct injected Listeroid.

I used an automotive muffler. The kind that reverses the flow twice inside the muffler.
It's has 2" diameter pipes.
Worked very well.
Outside the garage it was very quiet.

http://www.youtube.com/watch?v=qx5qABD5WD0

veggie

You could install a Tiny Tach diesel Tachometer/Hour Meter.

http://www.tinytach.com/tinytach/diesel.php

veggie

As I see it, the reason why we will always see test results that are all over the map is because there is no standard for the fuel.

WMO is a moving target. It's made up of all kinds of oils, additives, solvents and even anti-freeze.
The varying concentrations of these components means that every user will have a different base fuel to compare to others.
What works for one person may fail miserably for another even though the engines are prepared identically. Why, because the fuels are almost guaranteed to be different (even though they are both WMO).

Here's a chunk of text from a post I did last year when investigating the burning of synthetic oils and why some oils burn better than others.

Just for contrast, here are nominal flash points for various fuels and oils..

Diesel #1 ---100f
Diesel #2 ---125f
Kerosene ---150f
Biodiesel ---260f
Motor oil --- 450 f
Petroleum synthetics--- 485f
PAO Synthetics ---525f
Olafin Ester Synthetics ---725f

As you can see, the high end synthetics have a strong resistance to autoignition

One can clearly see the massive difference in "burnability" (if thats a word ?) and how varying concentrations of these oils could drastically effect the combustion process.

One person may report lots of carbon, another may report excessive ash, while another person may have very clean burning.

IMHO...for this reason, it's a waste of time trying to compare one person's experience with WMO to your own.
Chances are, no two fuels will ever be alike.

Let's everyone share your findings with WVO and it's filtration and preparation, but let's also accept that your personal findings may vary greatly from what others post.

veggie