Replacing Distributor Gasket -- Timing mark doesn't match up?

[acfortier]

OK, so I'm following the FSM procedure for taking the dist. out so I can replace the leaking gasket. I scribed a mark on the housing below the left side of the number one spark plug, like it says. I turned the engine so that the rotor was approaching the scribe mark, but I couldn't find the timing mark. I kept turning it clockwise until I did find it:

 

 

I'm assuming that's it, with the mark and painted white around it.

 

So, if I move that back to the 0 marking:

 

 

This is where my rotor is:

 

 

You can see the white mark on the housing... they're not even close. It's not clear if they're supposed to be? The next step is to align the trailing edge of the rotor blade with the scribe mark. Is it supposed to be moved that much?

 

Pic from FSM for reference:

 

 

[Ωhm]

1 hour ago, acfortier said:

 

 

This timing mark has two (2) different meanings for CYL#1.

 

1: compression↑TDC↓power

or

2. exhaust↑TDC↓intake

 

When you're dealing with IGN timing use #1.

[acfortier]

44 minutes ago, Ωhm said:

 

This timing mark has two (2) different meanings for CYL#1.

 

1: compression↑TDC↓power

or

2. exhaust↑TDC↓intake

 

When you're dealing with IGN timing use #1.

 

Hmm, OK. I understand the concept that the cylinder is a TDC twice since it's a 4 stroke, but I'm not sure how that helps me with this issue.

 

If I rotate the balancer one revolution, I'm just an exact 180* from where the rotor was pointing in my picture, so still not near the #1 on the dist. cap.

 

I took out the spark plug for #1 and put a screwdriver in. When the cylinder is at the top, the rotor is pointing in the correct position where I marked the dist. housing, but the timing mark on the balancer isn't close to 0. In fact, I can't even see it. Thing is true for another revolution around.

 

So I'm guessing that the harmonic balancer "slipped"? I see in the PO's thread that he mentions that the harmonic balancer is on it's way out, so maybe that's what he was referring to?

 

Anyways, I continued on, pulled the dist. out after making a few more marks, put on the new o-ring (was definitely leaking, the original gasket was still on the block, and a new one was on the housing, so essentially double-gasket-ed) and reinstalled based on my marks. Fired it up, and doesn't seem to be running and better or worse than it was, so I think I'm good?

[Ωhm]

Yeah, tip of the rotor in the picture compared to the tip of the rotor in the FSM was 180° off. I thought that was your problem. Maybe I'm looking at the picture wrong. Good to hear its back on the road.

[acfortier]

16 minutes ago, Ωhm said:

Yeah, tip of the rotor in the picture compared to the tip of the rotor in the FSM was 180° off. I thought that was your problem. Maybe I'm looking at the picture wrong. Good to hear its back on the road.

Right--even rotating it another revolution, the tip of the rotor was still way off... weird.

[Htchevyii]

I have had the outer ring slip before. Yours does look pretty bad in the pic. You could get #1 on compression and use a dowl or something through the spark plug hole to estimate TDC to get you going temporarily, but I'd replace the balancer before it comes apart and index it using Cruiser's tip at that time.

 

https://cruiser54.com/?p=68

 

[acfortier]

42 minutes ago, Htchevyii said:

I have had the outer ring slip before. Yours does look pretty bad in the pic. You could get #1 on compression and use a dowl or something through the spark plug hole to estimate TDC to get you going temporarily, but I'd replace the balancer before it comes apart and index it using Cruiser's tip at that time.

 

https://cruiser54.com/?p=68

 

Yeah, it doesn't look great. I'll add that to the list of things to replace. Yup--that's exactly what I did, seems to be running just fine. I did check out Cruiser's tip for distributor indexing, but it was a bit more confusing to me than the FSM. I'm not sure about this step: "Place the distributor housing upside down in a soft jaw vise. Scribe a line 1/2 inch from the end of the distributor locating tab. Cut the distributor locating tab at the scribed line with a saw." Is that more so you can move it around more than before?

 

I did use the tip to find TDC from Cruiser, and that worked great.

[Htchevyii]

Yes, exactly. The factory notch for the bolt isn't necessary in the correct spot, so cutting it off let you adjust it to perfection.

[acfortier]

Hummm, I replaced the gasket with a 024 o-ring, and I'm still getting a leak. Is the distributor installed correctly based on that clamp? Or does it need to go down more?

 

 

 

 

[AZJeff]

As long as the flange on the distributor housing is in firm contact with the machined surface on the engine block, the o-ring should seal no problem.  The forked clamp really plays no part in determining leak resistance other than making sure the distributor stays seated on the engine surface.

 

If you are still getting leaks from your distributor, I have to wonder if your crankcase is getting pressurized due to the crankcase ventilation system being plugged up.   Have you ever checked to make sure that the crankcase vent tube between the valve cover and the manifold is not restricted?

 

One sure sign of crankcase vent problems is that oil vapors leak out around the grommets in the valve cover, and/or the air filter box is full of oily residue.

[acfortier]

I'll have to check, there might be a gap but it's hard to tell.

 

Not sure about the crankcase ventilation, but if it's not sealing correctly, it's going to leak... and if it is sealing correctly, then it shouldn't leak, regardless of pressure being built up, right? It's a pretty common area for these to leak from, so not sure.

[Ωhm]

Wonder if the hold-down clamp has flattened out or could that bolt have stretched and is bottoming out, if possible. 

[AZJeff]

Here are two things to consider:

1.  The distributor gasket's purpose isn't to seal against pressure, it's to prevent weaping of oil from out of the hole.   If you are seeing oil leakage immediately upon startup, and the leak is steady, the o-ring/gasket isn't designed to handle such leakage, and crankcase pressure might be the culprit.

 

2.  The distributor clamp's job is to prevent distributor rotation once the timing is set correctly.  The amount of pressure needed to keep the distributor stationary isn't very high, if all parts are in good condition.  If you grab the distributor, and try to turn it by hand with substantial force, and it does not move, the clamp is doing it's job.

 

 

[acfortier]

I definitely haven't noticed it leaking steadily while running. If anything, it's just leaking/seeping enough to cause a spot on the ground, but not enough to see it in action, if that makes sense?

 

Is the vent tube from the valve cover the one in front of the oil cap, or the one towards the back? The one at the front was definitely oily, so I wonder if that's the issue? I did take that elbow off, but it wasn't like it was restricted, or anything.

 

I decided to remove the oil pressure sending unit + fitting and re-apply thread sealant to those and tightened back down. It's possible it's oil from those that was leaking out, and moving it's way towards the distributor.

 

Makes sense about the clamp--I did notice that loosening the clamp was easy (as if the bolt itself wasn't tight) so I tightened it back up. We'll see if it continues to leak.