I made a PDF file on S195 Fuel Injection Timing Proceedures.
We will leave this open for a while so others can add to this topic. Once we feel the topic is covered it will be locked and put in a location so it will easy to find.
Open the attachment below.
Henry
Henry,
Thanks for that.
I noticed they suggest the timing should be 16 to 20 deg. BTDC.
veggie
We must keep in mind that this came from a Manual that was written for an IDI S195 engine.
Timing might be different for an DI engine.
Henry
Quote from: hwew on December 28, 2009, 03:26:16 PM
We must keep in mind that this came from a Manual that was written for an IDI S195 engine.
Timing might be different for an DI engine.
Henry
The injection timing procedure is the same for both DI and IDI engines. What will be different is the number of degrees before TDC fuel delivery begins. This will vary depending on engine model and can be found in your owners manual.
Examples - S195M IDI engine fuel delivery begins 17 degrees BTDC, ZS1115GM DI engine fuel delivery begins 22 degrees before TDC.
flywheel
Hello Veggie,
Your correct the procedures are the same for timing the engine. The degree's BTDC is what we need to find out. The ZS1115 engine is larger than the ZS195.
Most things or possibly all of these things are different on the ZS1115 compaired to the ZS195 are:
Block Deck Height, Rod Length, Stroke, Bore, Camshaft, Compression, Nozzle Pop-off Pressure and Fuel Rate.
All these parts can effect the way the engine is timed. So we need to find out what the factory spec's are for the DI S195 engine. And then make minor adjustments if needed.
Bob is pretty good on figuring stuff out like this. He should be able to expound on this.
Henry
On the subject of injector timing...
What's the best way to determine "Top Dead Center" if you don't want to remove the cylinder head and your flywheel has no markings?
If the injector is removed, can the piston be seen using a light? (on a DI engine).
veggie
Well you can remove the injector on the DI engine and use a Dial Indicator with an extension.
But the safest and best way is to remove the head and mount a Dial Indicator so the slider touches a part of the piston that is not angled like the bottom center of the dish. Or flat part on the side of the piston. I would prefer getting close to the center of the piston as possible.
Henry
Here are a few pictures that may be helpful from two different owners manuals.
It may be hard to accurately locate TDC by removing the injector IF the piston is dished or has a big tit sticking up in the middle of the piston. Such is the case with many direct injection engines.
If the piston has a flat top a dial indicator will work just fine in the injector opening in the head. Check and see if the timing mark on the hopper alligns with the TDC mark on your flywheel. Sometimes the factory marks are off a couple of degrees and you will only know this if you accurately locate TDC yourself.
Most singles have a timing mark scribed on the side of the hopper or radiator. If you remove the radiator or hopper your timing mark is gone.
ANYTIME YOU HAVE THE HEAD REMOVED ACCURATELY LOCATE TDC and make new timing mark on the flywheel and a reference point and/or new pointer.
flywheel
More pictures.
Thanks flywheel,
According to your manual a 0.2mm (or .007") shim will change the timing by 1 degree.
I only added a .004" shim so I guess I only retarded the timing buy about 1/2 degree.
Darn, I have to take the thing apart again and add more shims. >:(
veggie
Hello Flywheel,
Nice pictures! Thanks.
Regarding: ANYTIME YOU HAVE THE HEAD REMOVED ACCURATELY LOCATE TDC and make new timing mark on the flywheel and a reference point and/or new pointer.
I see no reason to make new timing marks. The Piston, Rod, Crank and Flywheel will not be touched. If they are touched than it might be a good idea to check the marks.
The timing should not change when removing and reinstalling the Head. The only thing that can change very little is the compression by a different head gasket thickness. The valve timing will be corrected when re-adjusting the valve clearance .
Henry
Quote from: hwew on December 28, 2009, 06:30:11 PM
Hello Flywheel,
Nice pictures! Thanks.
Regarding: ANYTIME YOU HAVE THE HEAD REMOVED ACCURATELY LOCATE TDC and make new timing mark on the flywheel and a reference point and/or new pointer.
I see no reason to make new timing marks. The Piston, Rod, Crank and Flywheel will not be touched. If they are touched than it might be a good idea to check the marks.
The timing should not change when removing and reinstalling the Head. The only thing that can change very little is the compression by a different head gasket thickness. The valve timing will be corrected when re-adjusting the valve clearance .
Henry
I should have said when the head is removed you should verify that the stock timing marks are correct with the pointer ( some factory timing marks are not very accurate). What do you do if the hopper is removed for thermosiphon or remote radiator cooling, your timing is gone. A TDC mark can be placed anywhere on the flywheel when the engine is at TDC and you have a pointer or other reference point.
flywheel
You are right about verifying the marks when removing the head. Also about the Marks on the Hopper and Radiator. Not very good locations in my opinion. I would make a pointer to mount on the block on the flat machined surface where the Engine model and serial number is engraved. Just make sure to move the numbers at a different location or write them down and put them where you can find them when needed.
Henry
Here is why you should verify your timing marks are correct. This is one of my engines that TDC was located with the head off and a dial indicator used.
The stock timing marks are over two degrees off. If I used the stock marks then all my settings will be off by a little over two degrees. Will the engine run -yes it will run but it will operate better if set correctly.
In the pictures this engine is at TDC, look how far off the pointer the timing marks are.
flywheel
How to measure and mark your flywheel in degrees for spill timing.
TDC must be accurately located and timing marks verified or your spill timing will be off.
Look in your owners manual to see how many degrees BTDC fuel delivery begins and write this number of degrees down.
Measure around the outside diameter of the flywheel on the flat surface next to the ring gear with a flat fiberglass or metal tape measure in millimeters.
Write this number down and divide it by 360 - (number of degrees in a circle)
Then measure how many millimeters are in one degree.
Example - one degree equals 5mm. Say you need 18 degrees before TDC for fuel delivery to begin so you would multiply 5mm (one degree) times 18 degrees which is 90mm.
Make a mark on the flywheel 90mm BEFORE your TDC mark. Remember that fuel delivery starts before TDC so your mark is placed BEFORE the TDC mark.
You can then add or remove shims from under the injection pump to make fuel delivery begin at the proper number of degrees before TDC. It may seem hard to do but it really isn't.
flywheel
Quote from: flywheel on December 28, 2009, 06:02:49 PM
Here are a few pictures that may be helpful from two different owners manuals.
It may be hard to accurately locate TDC by removing the injector IF the piston is dished or has a big tit sticking up in the middle of the piston. Such is the case with many direct injection engines.
If the piston has a flat top a dial indicator will work just fine in the injector opening in the head. Check and see if the timing mark on the hopper alligns with the TDC mark on your flywheel. Sometimes the factory marks are off a couple of degrees and you will only know this if you accurately locate TDC yourself.
Most singles have a timing mark scribed on the side of the hopper or radiator. If you remove the radiator or hopper your timing mark is gone.
ANYTIME YOU HAVE THE HEAD REMOVED ACCURATELY LOCATE TDC and make new timing mark on the flywheel and a reference point and/or new pointer.
flywheel
Hello Flywheel,
What manual did you get the pictures out of. They look much better than the ones I copyed yesterday.
Henry
The pictures are from my Changchai and Rufa brand engine manuals,
both more detailed than the Changfa manuals.
flywheel
Flywheel,
Thanks for posting the flywheel marking procedure. Very helpful.
My problem now is how do you find TDC? (without taking the head of) :(
veggie
My S195ZN direct injection engine came with a "IDI" manual. :(
Does anyone know the injection timing for a "DI" 195 Changfa ?
Once I get that number, I can retard it by 2 or 3 degrees for slow speed operation.
veggie
They sure are the best I have seen.
What I would like to see is a couple good manuals posted here and in white pages.
It would be a good Project to work on.
Henry
Quote from: veggie on December 29, 2009, 12:16:20 PM
My S195ZN direct injection engine came with a "IDI" manual. :(
Does anyone know the injection timing for a "DI" 195 Changfa ?
Once I get that number, I can retard it by 2 or 3 degrees for slow speed operation.
veggie
I need to find a ZS195 Manual also.
I guess for now you can always retard the timing until the engine is hard to start. (I think white smoke is a sign of a retarded engine but I am not a 100% sure) and then try bumping it up two deg and try it.
Bob, can you help here.
Henry
iirc the di engines are timed to the same spec as the idi engines,
for the project at hand i would go back to about 15 btdc and start there and see how it works out
according to engineering text
a typical diesel is timed to inject at 18 degree's btdc then there is the delay angle, and combustion
starts at 5 degree's btdc
if you back off to 15 degree's, and accounting for the same delay angle (that won't change anyway
with timeing as it is independent of timeing), then combustion should start at 2 degree's btdc
that should be just about right because the sharp pressure rise should just about coincide with the piston
being just after tdc instead of a few degree's before, where it will beat the living hell out of the big end brg,
the wrist pin/bushing and possibly crack or break the crankshaft.
there is also another concern i would have, that being the critical speed of the engine
critical speed is roughly defined as the specific rpm where the engine operates and exhibits
a dramatic increase in vibration.
you don't want the engine to run anywhere close to the critical speed, and definitely run under load
at that speed or bad things "will" happen. broken crankshafts are common bad things.
anyone that has been a passenger on a ferry boat, and i assume any other large diesel powered boats
that use very large low speed diesels will remember what critical speed is, it is the rpm range at which
the engine as it is throttle up moving away from the dock that the whole boat vibrates violently and very harshly
the captain of the boat must increase rpm up past this rpm as quickly as possible and once past the critical speed
he can slow the acceleration to whatever rate he likes.
another application where many folks have witnessed it or can witness critical speed operation is down at the rail yard
when the engine is brought up from idle it goes through a critical speed that can clearly be felt through your feet
in some cases hundreds of feet away. its a really rough harsh vibration, but as with the boat captain the engineer
accelerates the rpm through the critical speed as quickly as possible, and should never pull a load at that speed.
in large ships the crankshafts are built to where one cylinder is spaced offset a few degree's to alter the critical speed of
the design, but with singles and twins this is not an option.
just something to be aware of when when working on re-engineering the changfa for 900rpm operation, i don't know what
the critical speed of your engine is, and even if i did, anything you attach to the engine will have effect on the specific rpm
where the critical speed will be. things like your choice of frame, driven components, etc all have some effect on critical speed
so basically even if we knew that a changfa di 195 had a critical speed of for instance 850rpm, the frame choice and drive components
might lower the critical speed by 50 or more rpm, or raise it by 50 or more.
i am sure there are tons of formula's to determine exactly what the critical speed might be, but it is probably quicker, easier and more
accurate to determine it by testing the final result.
if after all it ends up that 900rpm is going to be putting the engine under load at or near its critical speed, you will have no choice
but to either speed up or slow down a touch in my opinion.
bob g
Yo Bob!
Every so often I learn something new from you. I mean really new. Something I've never heard about before. Not that I know it all. Far from it; it's just that you've worked around this technology for a long time while I've just been a tinkerer.
You mentioned the critical speed, which was something I have observed from time to time with engines and drivetrains, and thought I pretty well understood, but didn't know there was a name for the phenom. So I googled it and came across this little gem, contemporaneous with Dr. Diesel himself:
http://books.google.com/books?id=2fRMAAAAMAAJ&pg=PA112&lpg=PA112&dq=diesel+engine+critical+speed&source=bl&ots=h01ieiA6N9&sig=pV73x5I3P0zVq-SZRwvc2KLR8f0&hl=en&ei=t3E6S5qvL4_asgPL5oTABA&sa=X&oi=book_result&ct=result&resnum=7&ved=0CCUQ6AEwBg#v=onepage&q=diesel%20engine%20critical%20speed&f=false (http://books.google.com/books?id=2fRMAAAAMAAJ&pg=PA112&lpg=PA112&dq=diesel+engine+critical+speed&source=bl&ots=h01ieiA6N9&sig=pV73x5I3P0zVq-SZRwvc2KLR8f0&hl=en&ei=t3E6S5qvL4_asgPL5oTABA&sa=X&oi=book_result&ct=result&resnum=7&ved=0CCUQ6AEwBg#v=onepage&q=diesel%20engine%20critical%20speed&f=false)
Copied it to my desktop, saved it as a .pdf and now I'm going to add it to Dr. Diesel's book that I also got from Google Books.
Thanks, Mon!
Quinn
[Edit: Oh My Heck! Here's another one! This one is from Busch-Sulzer that Diesel was going head to head with back when the technology was on the cutting edge.
http://books.google.com/books?id=FEV-AAAAIAAJ&printsec=frontcover&dq=diesel+engine&cd=9#v=onepage&q=&f=false (http://books.google.com/books?id=FEV-AAAAIAAJ&printsec=frontcover&dq=diesel+engine&cd=9#v=onepage&q=&f=false)
(Sorry for the interruption)
q.
Quinn:
thanks for the kind words, it only seems fair to share a bit of my experience especially in light of the fact that i learn
so much from you and others on this forum.
figure if i try to put back as much as i can, as i take away from this forum in things i learn. maybe it will make for a better forum?
i want to thank you for the last book link, that one is cool
i gotta go find a hard copy!
did you read about the "economizers" pretty cool indeed, where the figure a total efficiency at something over 80% iirc
looks like there are some nice plates in that book as well.
sure would have been nice to have been able to tour some of those installations when they were in thier hayday!
bob g
Bob and quinnf,
Thanks for sharing all the good stuff.
Bob I experianced the vibration on the ferry boats near Seattle years ago. I thought it was a prop that was out of ballance. But as the ferry speeded up the vibration dissipaired. I think I understand a little more why the manufactures post the operating speed range of an engine. It makes sense.
Quinnf that is some good reading material. I need to spend some time and read it.
Thanks guys,
Henry
Yep, when we go on the ferries in BC, the same phenomenon can experienced.
I will watch out for vibration that is uncharacteristic of the S195 engine.
Fortunately, for many pieces of equipment in use today, the critical frequency is well outside the operating range of the unit.
This is a design criteria in many products.
Bob, thanks for the comments on injection timing for slower running.
veggie
bob,
Is there any danger of retarding too far? What are the symptoms?
On a gasoline engine, the danger is burning an exhaust valve because of fuel still combusting when the exhaust valve opens.
Can diesels burn a valve if the timing is too late ?
veggie
i suppose anything it possible, but on these engine's highly unlikely that there will be any damage
i would suspect at some point slower than 15deg btdc the engine might be harder to start, smoke more
or other issues such as dramatic loss of power, long before you risk burning a valve.
i have to keep reminding myself you plan on burning an alternate fuel as well, so you likely will have to tweak
the timing to suit the fuel and whatever rpm you settle on, balanced against, ease of starting and smoke and
expected power output.
your entering uncharted waters with this project in my area's, so as suggested i would start out conservatively and work slowly
making one change at a time, test and retest, tear down to inspect for signs of stress, followed by another slight change,
wash/rinse/repeat till you get to where you have a happy balance.
make sense?
i hope so, not sure some days if i make sense to myself
:)
bob g
I really wish this had come up when I had the head off the "Walla Walla Xing Dong"! I can't help it every time I think or say Xing Dong
that dadburn old song about the witchdoctor runs through my head........ oo ee oo ah ah walla walla ding dong. HElp......! ::)
Ok, I have a grip now! All I have for a timing mark is a double hash on the flywheel and a STICKER! yes, a gummy stick on sticker, with an arrow, on the hopper!
I really need a better system.
Ron
Quote from: vdubnut62 on December 29, 2009, 09:37:09 PM
I really wish this had come up when I had the head off the "Walla Walla Xing Dong"! I can't help it every time I think or say Xing Dong
that dadburn old song about the witchdoctor runs through my head........ oo ee oo ah ah walla walla ding dong. HElp......! ::)
Ok, I have a grip now! All I have for a timing mark is a double hash on the flywheel and a STICKER! yes, a gummy stick on sticker, with an arrow, on the hopper!
I really need a better system.
Ron
Ron,
You really should remove that sticker and put it in a safe place so you can get it out whenever you need it! Otherwise it could come off and get lost. Then where would you be? ;)
Bob,
That was really good to learn about 'critical speed'. I experience it on my VW plant at very low RPM. Now I know what that is. It manifests itself as a very horrible vibrational shaking of the entire machine like the engine is gonna come apart.
Quote from: rcavictim on December 29, 2009, 10:23:04 PM
Bob,
That was really good to learn about 'critical speed'. I experience it on my VW plant at very low RPM. Now I know what that is. It manifests itself as a very horrible vibrational shaking of the entire machine like the engine is gonna come apart.
Wrong ! That's just how VW's run. It;s normal. ;D
Kidding.... ( I have a VW diesel)
veggie
RCA:
thats exactly how it manifests itself,
i remember studying about it in the engineering text years ago, but never gave it a lot of thought, until i experienced it on my first
ferry boat ride out here in seattle 20 odd years ago, the whole ship shakes and vibrates like it is going to come apart for a second or so
but feels like minutes to someone that is accustomed to what a diesel should sound like.
it wasn't till today writing about it here, i realized i have heard that going way back in locomotives when they startup from idle
they too sound like all hell is coming lose.
trucks do it as well, usually at very low rpms, if you miss a gear and overshift into to high a gear, the engine lugs down and you get
that familiar heavy vibration that tries to shake your teeth out of their sockets.
when i feel that i am reminded of the text books warning about, "if you must operate an engine within its first critical speed, get through it
to a higher rpm as quickly as possible and do not operate under load at this critical speed if it can be helped"
the ferry boat has to as it accelerates the prop as it moves away from the dock, but
a good captain will accelerate quickly through the critical speed as evidenced by the first puffs of black smoke and once
clear of the vibration he will slow the acceleration somewhat to limit more heavy smoking as he continues to increase rpm.
thinking back on this i believe the locomotive engineers do the same thing, you get the initial puff of black as they push it through
critical speed as quickly as possible and then slow the acceleration rate to limit the amount of smoke.
that is those operators that are concerned with putting out clouds of smoke anyway
bob g
With the ferries (are we still allowed to call them that?) there are a couple of other issues in play. I wish Shipchief would show up; he knows all about this stuff and can talk about it more intelligently than can I. When power is first applied to a propeller, until smooth water flow is established past the hull in front of the propeller, the propeller tips cavitate, momentarily spinning in voids of vacuum as the water is physically ripped apart, then the voids collapse and water slams back into the propeller with enormous force, which is felt as vibration. The force of these impacts is so great it can actually erode pits into the leading edges of propellers, which only makes the problem worse. I suspect the auto ferries are in service for so long, their props probably get pretty beaten up before they're reworked or replaced.
There is also a bearing called a cutlass bearing that supports the prop shaft just ahead of the propeller. All of the radial loads the heavy propeller generates from imbalance, or while the ship is maneuvering, and from every submerged deadhead a propeller blade bonks into is transmitted to the hull through this bearing, causing it to wear. After a while the shaft is said to "shiver" in the bearing, and that is what I think you're feeling on the ferries when running at constant speed. So I bet in the case of ferries, it's actually the propeller shafting, or drivetrain, that is generating the noticeable vibration, rather than the engine.
That said, the engine close-coupled transmission will likelly have its own critical speed, the power train components their own critical speed, so when starting up from the dock there are probably only a few "sweet spots" between critical speeds that the ferry skipper can choose.
Quinn
Quinn:
you may very well be right, but i seem to remember the heavy vibration before the outdrive is engaged while they are spooling up the
engine.
however i do recall the vibration from the screw cavitating as well.
guess it is time to go take another ride on a ferry,, boat that is,, thought i better clear that up before someone made a crack,, er joke
awe forget it!
:)
now i know i have heard similar when a locomotive comes up off idle, it goes through an incredible rough rpm where it shakes the tracks, ties and surrounding ground heavily.
according to the engineering texts, anything that rotates has a critical speed, obviously some rotating assemblies are worse than others.
bob g
Bob,
I know I'm right. ;D That's why I said the engine/transmission likely have a critical speed, then you engage all the shafting with that heavy propeller hanging off the end and you've got at least one other critical speed. Couple them together, and there's a whole lot o' shakin' going on!
And come to think of it, don't the ferries up your way have props on both ends so that one pulls, while the other pushes? If so, then there is an awful lot of rotating mass available to vibrate.
Sure wish Shipchief would decloak.
q.
Hello Guys,
quinnf,
After thinking about what you wrote it makes sence. Just recently I purchased a small Evinrude 4 Deluxe outboard and I made an emergency turn to miss a log at full speed on my jon boat and the boat slowed down and I heard the engine load up and then the prop cavitated. It was awfull!! I thought I broke a shear pin or shreaded a gear in the gearcase. I lowered the rpm's and the cavitation dissapared. The vibration from cavitating was unreal.
The prop I use is a pusher prop for heavy loads like displacement hulls that sailboats use. Even though it is only a 4hp outboard it can push more than the 6 hp yamaha outboard I had. I was surprised the little 4 hp had enough power to cavitate the pusher prop. I tried the standard pitch prop on my boat and the engine had problems moving the boat to the speeds it can go with the pusher prop.
I guess if you have enough hp, torque and the gearing is right you can cavitate any prop.
Henry
Uh.. Ahem.. Easy on the VW stuff please! ;)
Reference the moniker of the present poster. ;D
Just kidding, the things WILL just about shake your teeth out, and mine had silicone filled engine mounts!
Some of the old Rabbits had a big lead weight inside the front bumper that was mounted on springs to try and soak up some vibes.
Ron
Quote from: vdubnut62 on January 02, 2010, 12:49:06 AM
Uh.. Ahem.. Easy on the VW stuff please! ;)
Reference the moniker of the present poster. ;D
Just kidding, the things WILL just about shake your teeth out, and mine had silicone filled engine mounts!
Some of the old Rabbits had a big lead weight inside the front bumper that was mounted on springs to try and soak up some vibes.
Ron
Ron,
My genset is using a small 1.5 litre NA diesel from a 1980 Rabbit.
Well rcavictim, have you got a 10lb lead weight mounted to the frame on leaf springs so it can flop around? :D
Also, do you have the hermetically sealed, lead lined, time lock equipped vault ready for my @#$%# little sticker?
I would really hate for the thing to get damaged! ::)