It's almost ready to run

[saygold]

My car ran reasonably well for quite a while.  Then I decided to rebuild the cylinder head due to a little blue smoke showing up when I shifted gears.  The valve guides were replaced, the cylinder head milled very slightly, and the valves and valve seats were ground (new intake valves were installed).  I finally finished installing the head and am trying to get the engine to fire, without any luck.

Here’s what I’ve done so far:

1. I removed the distributor cap and wires when I began tearing down the engine, but did not change the settings (at first) so I thought that the timing should have been the same.
2. I set the intake and exhaust valve settings at 0.003 and 0.007 inches respectively.
3. I cleaned the spark plugs and re-set the gaps at 0.020 inches (plugs were almost new-maybe 500km on them).
4. I refilled the radiator after tightening all of the hose clamps.
5. I changed the oil and filter (it was rather old, and I will change it again shortly after I get the engine running).
6. I recharged the battery.
7. The engine turns easily and rapidly using the starter drive, with no funny noises (no indication of valves hitting the cylinder head at that speed).  The engine did not start running.
8. I used a strobe to insure there was power getting to the spark plugs.
9. I changed the fuel filter.  I then removed the fuel lines from each cylinder, put each into a small container, and turned the engine over several times.  Each cylinder is receiving approximately the same amount of fuel.  (Then I reinstalled and tightened the injection lines).  The engine did not start.
10. Thinking that the fuel had deteriorated since I last used the car, I drained (most of) the gas and put in 4 gallons of premium.  Again, the engine did not start.
11. I have turned the distributor in both directions trying to get the engine to start.  Alas, it has not started yet.

One cylinder would fire at the first moment I turned the engine over, but it sounded more like a backfire rather than a normal ignition.

I pulled the distributor cap and looked at the rotor position with regards to where the engine timing mark (0 ° TDC) was.  It did not look to be where I thought it should be, so I pulled the spark plugs and turned the engine over by hand until the lobes on cylinder 1 were in the 10 o’clock/2 o’clock position and the notch in the thrust washer behind the camshaft sprocket lined up with the mark on the bearing support post.  It confirmed my previous thought.

Does anybody have some photos showing the distributor rotor in place when cylinder 1 is at 0 ° TDC?  That might give me a good place to start.

Any other ideas would be appreciated.



Ken
'66 230SL (4-speed, euro)

[A Dalton]

When the #1 piston is at TDC of the compression stroke , the rotor should line up with the index mark on the distributor case top circumference face/lip. This index mark is also where the plug wire for #1 plug on the cap should be.
 Remember , the crank turns 2 revs for every single rev of the cam/dist.  That is why compression stroke is specified  [ rather than than exhaust stroke]

[saygold]

Thanks for the clarification.  Back to the drawing board, or in this case, removing the cam sprocket so that I can turn the engine over one more time.  

Ken

[jeffc280sl]

Hi Ken,

I suggest you also look at the distributor cap and the firing order of the plugs.  It's poosible that when you reinstalled the cap and wires the firing order was upset.  As you know the firing order is shown on the top of the cylinder head cover.  #1 plug is nearest the radiator and #6 nearest the firewall.  #1 plug should be connected to the distributor cap connector directly above the notch in the distributor body.  From that connection on the distributor cap in a clockwise direction proceed to next install the #5 plug wire in the next distributor connector.  The third distributor connector should be connected to the wire from the #3 plug.  The #6 plug wire should then be connected to the next open distributor connector. The next clockwise open connector on the cap should be connected to plug #2 and the last open connector should bve connected the the wire from plug #4.  

I must admit to having some confusion of my own involving the firing order.  I have seen documents that take the firing order from the perspective of the distributor cap and not having my thinking cap on at the time I have miswired the plugs.  The sound you describe is not unlike that you would hear if the firing order were incorrect.

Just a thought.

Jeff C.
1970 280SL 4-speed

[ja17]

Hello Guys,
Be careful to key the distributor in correctly. The two prong cog on the distributor bottom is very slightly off set, and can be forced into the bottom gear 180 degrees off! This will damage the distributor eventually.

The firing order is cast on the valve cover. With #1 positioned directly over the slash mark on the distributor rim. The order proceeds clockwise 1,5,3,6,2,4. The initial postitioning of the distributor at the factory varies can be viewed easily in several BBB  factory photos.

The "timing advance" distributors on the early 230SL's ( early 230SL BBB Fig 00-16/1)have the vacuume cell oriented in a different place than the later W113 engines with a "vacuume retard" distributor (see later 280SL BBB fig 00-9/2) for the later.  

Now if you have replaced your original distributor with a aluminum replacement the orientation of the vacuume cell may be different from the original.

In any case the firing order will remain the same. Just make sure the distributor is orineted correctly at the two pronged cog and the plug wires are in order.
On compression stroke numbe one cylinder the rotor in the distributor must be pointing to #1 spark plg wire.








Joe Alexander
Blacklick, Ohio

[saygold]

My car runs now!

It sure runs a lot better if the engine is timed on the #1 cylinder compression stroke instead of the exhaust stroke (thanks for your clear information, Mr. Dalton).  

Thanks for all of the members' advice as well.

Ken Deter
'66 230SL (white, euro and running)