Slow Speed Changfa Project

[Henry W]

I'll get back to you in a second.

[Henry W]

Let me try taking a picture of the Golden Flying Fish Injection Timing procedures. It is much better than the Changfa Copy I have.

Give me about Ten Minutes.

Henry

[mobile_bob]

they are terrible about timeing marks in my opinion and i had a hopper!

i waited till i removed the head, and located tdc from the piston
then made a wire pointer and tweaked it to match the flywheel marks
which btw, those marks on the flywheel are all in chinese, and god only knows what they mean.

i ended up measuring the diameter of the flywheel, dividing by pi, then by 360 to get an idea of how many
degree's to the inch of circumference, and then measured and marked for 20 degree's and worked back from there.

checked my work with the oem setting and found it to be setup for 18 degree's btdc, so i guess i am close enough
for the girls i run with, then did the shim thing to try to see how reduced timing affected starting, smoke, power and noise

didn't see much difference so i put it back to oem spec's at the time, although i may go back and revisit this issue
again now that i have the ability to very accurately measure bsfc in gr/kw/hr

bob g

[dubbleUJay]

which btw, those marks on the flywheel are all in chinese, and god only knows what they mean.

bob g

Chinese mark for Thor, god of lightning!

[Henry W]

I tried taking Pictures and they all came out blury.

I'll bring it to work and make photo copies and I'll try to get it posted.

Henry

[veggie]

I tried taking Pictures and they all came out blury.

I'll bring it to work and make photo copies and I'll try to get it posted.

Henry

Sounds good !

[veggie]

*** UPDATE ***

The two changes discussed in this thread were flywheel weight and injector timing.

FLYWHEEL:
The heavier flywheel has been machined and installed.
The weight of the steel ring is 60 lbs and when added to the stock 65 lb. flywheel it makes a total weight of 125 lbs.
A spigot was machined into the stock flywheel to locate the new ring.
8 X 1/2" bolts were used to secure the ring.

TIMING:
The timing was retarded by 2 degrees from the factory stock setting

RESULTS:
- The engine ran surprisingly smooth at the target 900 rpm.
- Mechanical noise was reduced significantly.
- The noise reading was 84 db at 3 meters.
- There seemed to be a reduction in diesel knock compared to the previous test run

Here is a video of the engine at 900 rpm...

and here's some pictures of the flywheel modification...

veggie

[veggie]

Next step:
I took the speed down a bit lower to see what she could do.
This is where I encountered the next obstacle in the project.
It seems the fuel rack/governor assembly shuts off the fuel when trying to run lower than 800 rpm.
The engine is very stable at 840 rpm.

I am not familiar with the internal workings of the governor and the rack on these engines.
Perhaps Bog, Henry, Flywheel, and others would have some ideas about how to get the throttle system to be more precise and responsive at the lower speeds. (Throttle spring tension )

Ideas anyone?

- Engine runs very smooth at this speed
- Noise level dropped to 79 db at 3 meters
- Exceptionally low vibration

Veggie

[Wizard]

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

Cheers, Wizard

[mobile_bob]

kudo's

now i wanna hear how much load it will carry and still run reliably and reasonably well mannered.

very nice!

be nice if it will do 3kwatts or better at ~900rpm, and i think it just might do that.

bob g

[Henry W]

Hello Veggie,

Nice flywheel!!! The only thing I would think of changing on it is the mounting bolts. I would change out those grade 5 bolts to grade 8.

About the fuel rack cutting out. My S195 does the same thing. What I would do is try to work on 900 rpm's and get a load on it and see what it does.

Oh, I would recommend putting on a oil pressure gauge and get the oil nice and hot and see where the oil pressure is running at 900.

Keep us posted how it is working.

Henry

[veggie]

Good idea Henry, I will get the bolts changed to grade 8.

Bob, I would be ecstatic if I could get 3kw at 900 rpm.!
I was planning on getting 1.6 kw out of her to drive a Delco 12si at 80 amps.

(80 amps X 12 volts / .60% alternator effy. = 1600 watts of power)

If I am lucky enough to get 2.5 or 3kw at 900 rpm, I may have other plans for this beast.

One way to do a quick power test is to change the sheave on the current generator head so that it revs at 3600 when the engine is at 900 rpm. Then I could apply my resistive loads incrementally until she grunts.
Those poly-V sheaves have to be ordered in. May take a week or so.
Perhaps that will be my next update.

(I don't have the tools to properly measure fuel consumption so that's not on the agenda at this point in time)

veggie

[rcavictim]

I would not switch to Gr.8 bolts.  They have hardly any stretch and will be brittle, plus they may cause the threaded section of the original flywheel to become sloppy through constantly being banged on sideways.  My recommendation would be to put red Locktite between the two flywheels where they press together over the entire area, then torque down the eight, Gr.5 bolts with lockwashers as you have now. The clamped surfaces should of course be free of any paint or grease, oil etc. Once that Loctite cures you won't have any sideways hammering of the bolts..  If you think you might someday wish to separate the two flywheels then go with blue Locktite.

Did you drill and tap 8 holes in the Changfa flywheel or did you drill 1/2" holes clean through and use nuts on the backside?  I suspect you drilled and tapped because you have split locks under the bolt heads.

[mobile_bob]

those 8 bolts will be there till hell freezes over!

a class 8 truck with a 15" spicer 2plate clutch only uses eight 3/8" bolts with lock washers
and no loctite, and i have never seen a single one work loose in 35 plus years,

they run for hundreds of thousands of miles, all sorts of shock loading, high temperatures and
extreme vibration brought on each time the clutch is engaged.

those bolts aren't going anywhere, provided they are torqued down properly, iirc about 55 ft/lbs is about
right for a grade 5 half inch bolt.

bob g

[mobile_bob]

it looks like you have the juncture painted well, keeping an eye out for cracking of the paint
would indicate if there is any movement between the two bolted together parts.

i don't expect any movement, but it would be easy to check over time.

bob g