S195 Fuel Injection Timing Proceedures

[Henry W]

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

[veggie]

Henry,

Thanks for that.
I noticed they suggest the timing should be 16 to 20 deg. BTDC.

veggie

[Henry W]

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

[flywheel]

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

[Henry W]

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

[veggie]

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

[Henry W]

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

[flywheel]

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

[flywheel]

More pictures.

[veggie]

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

[Henry W]

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

[flywheel]

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

[Henry W]

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

[flywheel]

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

[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