Farymann 18W Fischer Panda

[GBW]

I bought a used one with a declared fault.  There was water contamination of the oil.  Suspecting the cylinder head gasket (in ignorance), I dismantled the head.  There is no gasket but there is a copper ring that looked fine.  The two red O rings that connect the water circuit were shot and have been replaced.  All fine but!

The valve push rods are operated by a cam on a shaft in line with the crankshaft i.e. "fore and aft".  The valve rockers are on a shaft at right angles to the crankshaft.  To connect, the push rods follow a 90° twisted route .  They are enclosed in a protective shroud.  This shroud detaches when the head is lifted.  The push rods then become free and the original arrangement is lost.  The conundrum commences.

 

The rotation of the crankshaft is counter-clockwise when viewed from the power output end (in my case, the generator coils).  There is a decompressor.  In my very limited experience, decompressors operate on the exhaust valve(s).  If I arrange the pushrods to achieve this, the firing sequence is wrong - inlet, exhaust, compression, fire. 

If the decompressor operates on the inlet valve, the sequence becomes correct.

 

Am I suffering a mental block?

 

The Fischer Panda UK agents have been very helpful but it is the weekend and I don't expect an answer for a few days.

 

Any views please?

[Tony Brooks]

I can see no reason not to decompress using the inlet valve, but some exhaust valves are made from a different (harder) material so it may not be a good idea to stop an engine that decompresses on the inlet. Anyway, it is bad practice so to do in case the piston hits the valve..

[BEngo]

Repair manual is at

 

 https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.manualslib.com/products/Farymann-Diesel-18w-Series-3602251.html&ved=2ahUKEwjtiNmq7YX7AhUQQEEAHYySD0AQFnoECCIQAQ&usg=AOvVaw0z4wOEX2GMfozlddyvgs8R

 

Also at scribd.

 

N

[GBW]

17 hours ago, BEngo said:

Repair manual is at

 

 https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.manualslib.com/products/Farymann-Diesel-18w-Series-3602251.html&ved=2ahUKEwjtiNmq7YX7AhUQQEEAHYySD0AQFnoECCIQAQ&usg=AOvVaw0z4wOEX2GMfozlddyvgs8R

 

Also at scribd.

 

N

I have three manuals but, frustratingly, none shows the arrangement I seek.  There is a steer - "Intake push rod to be placed Into tapped top hole closest to cylinder".  I can't find a tapped hole and "top" is difficult to understand as they are both at the same height.  Both rods are identical in length.  "Closest to cylinder" implies the inlet valve is operated by the decompressor.

 

18 hours ago, Tony Brooks said:

I can see no reason not to decompress using the inlet valve, but some exhaust valves are made from a different (harder) material so it may not be a good idea to stop an engine that decompresses on the inlet. Anyway, it is bad practice so to do in case the piston hits the valve..

The valve lift from the decompressor is minimal at 0.8 mm.  There is around 1.4mm clearance.    Close!  

Is it fundamentally a good ides to (possibly) fill the inlet manifold with unburnt fuel?  Better surely to dumP it through the exhaust manifold?

However, this concern must apply to all valve based decompressors?

[Tony Brooks]

1 hour ago, GBW said:

I have three manuals but, frustratingly, none shows the arrangement I seek.  There is a steer - "Intake push rod to be placed Into tapped top hole closest to cylinder".  I can't find a tapped hole and "top" is difficult to understand as they are both at the same height.  Both rods are identical in length.  "Closest to cylinder" implies the inlet valve is operated by the decompressor.

 

The valve lift from the decompressor is minimal at 0.8 mm.  There is around 1.4mm clearance.    Close!  

Is it fundamentally a good ides to (possibly) fill the inlet manifold with unburnt fuel?  Better surely to dumP it through the exhaust manifold?

However, this concern must apply to all valve based decompressors?

 

Assuming the thing starts as soon as you close the decompressor then at a maximum of about 1 pin head worth of fuel per cylinder per every two revolutions I don't think fuel mist in the inlet manifold would make a lot of difference unless it was drawn into the cylinder and it ignited before the next injection.

[GBW]

I have this morning received from Fischer Panda UK another more detailed workshop manual with a view of the push rods showing they are indeed as I described - decompressor operates on the inlet valve.

I van now complete the rebuild.

Thanks to all for the help.

[STEPHEN BARNES]

The farymann 18w has no way for water to mix with the oil , except for the oil cooler sometimes fitted at the bottom of engine which replaces the original inspection cover standard factory fit .

The cylinder head and water jacket cylinder are the two items that are water cooled as standard .

farymann did not supply oil coolers they were created and fitted by the generator builders 

The pushrods are in a twist formation they cross each other on install see workshop manual .

The engine does not normally need the use of the decompressor where a starter motor is fitted .

regarding rotation anti clockwise at flywheel is standard farymann did make engine that rotated in clockwise direction this is normally indicated by a letter B on the engine plate but the.se were for special applications 

[GBW]

Thanks for your response confirming all I have discovered laboriously elsewhere!

 

There are two water connections between the cylinder block and the head.  The joint is made with two high temperature O rings.  Both these on. my engine had disintegrated.  That joint could provide a route between water and oil although somewhat tenuous.

[STEPHEN BARNES]

hi the o rings simply seal between the cyl head and cylinder , if the water leak is excessive and pooling around the base of the liner its possible that it could find a route but it is unlikely your problem i would test the oil cooler if one is fitted .