Slow Speed Changfa Project

[Henry W]

My recommendation would be to put red Locktite between the two flywheels where they press together over the entire area.

My sugestion would be not to use 271 Red Loctite. If you ever need to take the flywheel apart both parts need to be heated. Loctite has a retaining compound called 680 (Green Color Loctite) that is made for that purpose. We use it every day and no failures with it at all. I would also recomend NOT using a primer like Loctite 7649. It will not give you enough time to work with the assembly of the flywheel. The Locktite will start setting in 2 minutes if you use 7649 primer. On cleaning the surfaces of both pieces I would highly recommend using Acetone to get all grease and oils off.

Most people do not know about Loctite 680. it is a great retaining compound that will allow you to remove parts with a high powered press if needed. But it will hold parts from spinning and what you have there is so much surface area that hell will freeze over before the parts will ever spin.

I have plenty of 50ml bottles of Loctite 860 here and if you want some send me a pm with your address and I will send you a bottle. It is expensive stuff but I will never use it all.

Henry

[WGB]

That is one fine job Veggie!
You a John Deere fan?

[veggie]

That is one fine job Veggie!
You a John Deere fan?

Thanks WGB,
John Deer? ..... Nope! I just like the color  

veggie

[veggie]

Regarding the bolts.....

Thanks everyone for your comments and ideas.
During the machining process, I increased the number of bolts from 6 to 8 at the last minute.
The thread engagement into the stock flywheel is over 1 ".
The clamping force created by 8 X 1/2" bolts torqued to 60 lbs is tremendous.
Also, the spigot fit between the two flywheels has just a few thou. clearance.
Just enough to allow the two pieces to be tapped together before bolting.
Then...if that's not enough...the bolt holes in the second ring are machined to be a slight "drag" fit to the shoulder of the 1/2" bolts.

Now what about the throttle linkage? I would like to get this puppy to idle at 500 rpm (unloaded) but she cuts out at 750 to 800 rpm.

cheers,
veggie

[veggie]

Have you conducted load tests to find the limits at 900rpm?

Cheers, Wizard

Hi Wizard,

I have not yet conducted any load tests because the drop in engine speed no longer drives the gen head at 3600.
First I wanted to see if I could get the engine running nicely at the low rpm.
My plan now is to change the sheaves and apply some load to the system.
I will report the results after the changes.

cheers,
veggie

[Crofter]

Your injector may not have a smooth delivery curve from full to zero displacement. In other words it might regulate smoothly from 100% down to say 10 percent then further movement suddenly takes it to zero displacement. If 5 or 6% delivery rate is what it would take to give the desired rpms then you are out of luck without doing micro surgery to the injector pump internals.

The mico pump on the listeroids will allow you to reach very low rpms but even so I notice on mine that there is a point where it cuts fue off abruptly somwhat short of the fully closed position.

[rcavictim]

Your injector may not have a smooth delivery curve from full to zero displacement. In other words it might regulate smoothly from 100% down to say 10 percent then further movement suddenly takes it to zero displacement. If 5 or 6% delivery rate is what it would take to give the desired rpms then you are out of luck without doing micro surgery to the injector pump internals.

The mico pump on the listeroids will allow you to reach very low rpms but even so I notice on mine that there is a point where it cuts fue off abruptly somwhat short of the fully closed position.

That is useful information.  I have seen this first hand trying unsuccessfully to get extra slow idle from my Petter PJ-1.

[veggie]

Yep, that's probably what is happening with the Changfa. I may have to settle for 900 rpm as the magic number.
The Lister(roid)s can get much lower of course. I've seen some idling as low as 240 rpm.
Lots are driving alternators at 300 to 375 rpm.

Like this...

http://www.youtube.com/watch?v=2sgXeDEZyXE

http://www.youtube.com/watch?v=qVT-dNWt3I8

but this one is the winner at 240 rpm ! (Sounds like it's going to break something  )

http://www.youtube.com/watch?v=O4WTSJEVMvM

veggie

[Henry W]

The Lister running at 240 rpm does not sound good at all. I wish him well with it. It sounds like it's hammering itself to death.

Henry

[rcavictim]

The Lister running at 240 rpm does not sound good at all. I wish him well with it. It sounds like it's hammering itself to death.

Henry

I agree.  Probably running below critical speed.  Sounds and looks like a punch press in operation.  Punching it's own lights out in this case no doubt.

[veggie]

**** UPDATE ****

Ref: Low speed load test

So, I conducted a load test on the slow speed S195 with some interesting results.
I changed the gen head sheave to get the correct speeds for testing.
A 4.12" driven sheave gives me 3600 rpm generator speed when the engine is at 900 rpm.

Below are the results from the test:

Engine speed: 900 rpm
Load bank: Restive heat elements with a max. load of 3 kw

Condition:            load(kw)    Sound         Exhaust color
==============================================
30% loaded (Warm up)  0.9 kw    little change     clear

50% loaded            1.5 kw    stronger knock       clear

80% loaded            2.4 kw    Same as above      clear

100% loaded           3.0 kw    grunting but ok     slight black   

I was quite surprised to see this kind of output from the engine at 900 rpm.
Although running for long periods at 3kw would be too much, I would not hesitate to run the unit at 2.5kw indefinately.
This would be ideal for battery bank charging of 50 amps @ 48 volts ( or 200 amps @ 12volts).

Cudo's to Mobile_Bob for his accurate estimate of what the engine could produce at this speed.!

Below are video links showing the engine running at each of the test points.
In the last video, I switch from 2.5kw to 3kw and the black smoke is noticeable.

Loaded at 1.5 kw
http://www.youtube.com/watch?v=XhT29UL1YWw

loaded at 2.4 kw
http://www.youtube.com/watch?v=H76Cw0TuxXM

loaded at 3 kw
http://www.youtube.com/watch?v=2Qsq_Kb2MKY


Thanks for everyone's input on this project. I consider it a success. 
veggie

[Henry W]

Hello Veggie,

It seems like it runs good at 2.5kw. It seems stable.

I can't get a good view on 3 kw. I did hear it load up though. I sounded like the engine slowed down a bit.

Try testing it at 2.5kw. Take temp readings, get an oil pressure gauge on it, get it nice and hot by running it a couple hours and see how the oil pressure looks.

Oil pressure is the only thing I am concerned about. If you have 20 lbs or more you should be ok. An oil pressure gauge would be a good thing to have on your project anyways. It will show if you are having excellerated bearing wear down the road.

Nice work,

Henry

[mobile_bob]

that looks like a pretty useful conversion, nice result too.

i am with Henry, probably out to put a pressure guage on it so you can monitor that
and might also check the big end of the rod brg for wear or unusual signs of stress periodically
to see if anything shows up there.

how hot was the coolant when you were pulling 3kwatt load?

wish i could talk you into doing some fuel consumption tests???



if even by volume i would be interested in the results

bob g

[veggie]

I need some coaching on where and how to install a pressure gauge on this engine.
Can one be mounted in place of the little red indicator/sight glass on the valve cover?
Or do I have to cut into the external oil line running from the crank to the head.

Bob, I only pulled 3 kw for about 5 minutes because I think it's a bit too much for the engine. (still breaking it in).
I don't want to break a piston ring if the engine is hammering too much.
I did not stop the engine between tests so it ran for about 30 minutes straight. The engine water was only at 150 f after all the testing.
Not sure if you guys noticed, but I don't yet have a fan on the radiator 

I removed the belt driven fan in favor of a high speed electric motorcycle rad fan I picked up on eBay.
It will be wired through a snap disc temp switch so that it comes on when the engine gets warm (180 f).
Until I get that installed, I will stick to short run times.

veggie

[Henry W]

Utterpower made a Banjo Bolt at one time to hook up an oil pressure gauge.

Remove the fitting bolt that holds the oil line near the valve cover and screw it on.

I'll see if I can remember to take a picture of the one I purchased this weekend.

George still might have some.

Henry