Ignition: Timing 170 OHC 6 cyl engine

[RSykes]

My shop manual shows the oil pump tongue used to engage the slot in the distributor shaft at horizontally parallel (I know it's offset toward the top). When my #1 piston is at TDC, the oil pump tongue is at approximately 2 o'clock-8 o'clock. Is the vibration damper out of position?

[StudeRich]

If you are truly on the Compression stroke of #1 instead of Intake Open when the pointer is at TDC, the Rotor would be at #1, but since with the Dist. out you can't see that, it IS important to know.

If it IS on Number 1 firing position, then the most likely situation is that the Oil Pump drive gear was not "Timed" on installation to the Camshaft which must be done if you want the Dist. position and wire positions to be as built. But you can reposition them to correct the error.

[RSykes]

I took it through 4 movements of 360* and never got the alignment of the oil pump tongue I am reading about in the repair manual. Thanks for your response. There is a local expert who may help me get the adjustment you are saying I can achieve. Before I consult him, I will go through the rotations again to see if I am doing things properly. I thought that when the pointer showed TDC on the damper that I should be on compression/fire stroke. Maybe I need to take it through two rotations and check it again?

[Dwight FitzSimons]

You state: "I thought that when the pointer showed TDC on the damper that I should be on compression/fire stroke."

Recall that the crankshaft rotates twice (thru 720 deg.) for each firing of a given cylinder. So, when the pointer is at TDC on the damper the #1 piston could be on its exhaust stroke or it could be on its firing stroke.
-Dwight FittzSimons

[RSykes]

Follow-up on 6-cyl distributor installation.

Thanks Dwight,

I did think of that last night, so took it through several rotations checking TDC on the damper and the position of the oil pump slot referenced above. No matchups, although I do think the TDC markwas 180* from where it should be. That makes me think the TDC marking area, which is, according to the repair manual, supposed to be "roughly aligned" with the key way in the crank is off. I took the grill panel and radiator off. Now, I need to know how to lock down the crank so I can take the vibration damper bolt off and check the TDC and keyway alignment.

[StudeRich]

Since the Vibration Damper Hub has a keyway, it can only go on ONE way.

The Vibration Damper has offset bolt holes so it can only go on ONE way.

I think this process is a huge waste of time. Also the Oil Pump Drive Gear to cam is still the most obvious problem as I said in post #2.

The permanent, correct fix is way too much work as most of the engine must be disassembled, Camshaft removed etc.
That is why I said just rotate the Dist. and wire rotation to correct it.

[Skybolt]

Are you using the distributor that matches the 170 OHV engine? The earlier ones don't line up and will play havoc with your mental faculties trying to get the timing right. The vacuum advance will also be different. If you have the right distributor and are on the no.1 at TDC the Rich is probably right about the gear during assembly.

Len

[RSykes]

All you've said makes me think the assembly was improper. So sad. I had one of the premier SDC mechanics re-build this engine.

Thanks guys. Thank goodness for Studebaker Forum.

[StudeRich]

Well it IS a Six, I think only Mr. Bill Cathcart actually knows them well. Sorry to hear that.

I had to learn that lesson the hard way myself, on my '54 Champion Engine I rebuilt back in 1963.
When I sold that engine to replace with a 299 V8, I first took it apart and fixed it.

[RSykes]

1-How do you determine whether the piston is on exhaust or firing position?
2-How do you set the distributor rotation if the #3 piston is at firing position because the oil pump drive gear was not set on the cam properly? I have Petronix, so not sure when it's showing firing position as would be possible with a rotor.

[Dan Timberlake]

To determine compression stroke -
1 - Feeling for compression at the plug hole as the engine is turned in the correct direction.
2 - With the valve cover off observe the valve opening action while turning the engine in the correct direction. At firing TDC the intake valve will have been closed for nearly 1/2 rotation. With a non-hydraulic lifter engine there will be clearance at the intake and valve tips, and both pushrods should spin easily .

[StudeRich]

1-How do you determine whether the piston is on exhaust or firing position?
2-How do you set the distributor rotation if the #3 piston is at firing position because the oil pump drive gear was not set on the cam properly? I have Petronix, so not sure when it's showing firing position as would be possible with a rotor.

1. Feel the compression at the Spark plug Hole.

2. Do not worry about WHERE the wires are now, they obviously are wrong.
Start over by putting #1 in the Cap where the Rotor Points to. Yes Pertronix Systems do Have a Rotor, you can not run without it.
Mark the outside of the Dist. case where the Rotor points to before installing the Cap, rotate the Dist. to line them up and snug the lock bolt down. The precision Timing comes later with the Timing light, when finished this process should make it run.

Then proceed to go COUNTERCLOCKWISE around the Dist. using the Firing Order, to plug in the rest of the wires, really simple High School Auto Shop I stuff.

Oh I am sorry, I think some reality disconnected school systems discontinued those years ago!