186 in Series 2a timing issue

[BenS2a]

Hi all I have been slowly restoring and driving my 2A 109..(daily)
It now has a series 3 diff, and shortly a fully rebuilt s3 gear box transfer and fairy overdrive.
I recently had a full tune and service on the 186 that was already in when I purchased it, and it was discovered the timing was advanced about 20 degrees (off the charts according to my mechanic. He reset it to normal and after that the car was running nicely but had lost all power. Running hotter and wouldn't climb a hill anymore. I went back and we advanced it about 4 degrees and its much better but still not what it was in the hills.
Mechanic is wondering if the engine may have had a gas cam installed in it?but it had plenty of power before the service. Do we keep advancing the timing to back where it was? Any ideas appreciated.
The old girls done 3-4 trips from Adelaide to the lower glenelg river in Victoria with half a ton of firewood and never missed a beat. Just not sure what to do about this timing situation.

[67hardtop]

Check the harmonic balancer hasn't slipped giving u an incorrect reading. if it has, set the timing statically with a test light on the points after u have found TDC. Should be set at around 10deg before TDC

Cheers Rod:wasntme:

[BenS2a]

Thanks rod I'm pretty sure the harmonic balancer was checked and was fine. It's using more fuel now that the timing has been wound back and is running hotter also. I know that this is the opposite of what to expect.

[Homestar]

As already mentioned - has a static timing check been done? If it has and everything checks out, I'd put it back to where it was running happily. If it's not pinging when hot and under load, then I would just put it where it sounds and acts its best.

[Jordan]

Cam timing gears incorrectly meshed?

Jordan

[Homestar]

Cam timing gears incorrectly meshed?

Jordan

Yeah, I had that though too, but couldn't quite work out if that would cause the symptoms being described - but I think you may be right.

[BenS2a]

Cam timing gears incorrectly meshed?

Jordan

I will look into this thanks Jordan.

[BenS2a]

Sorry about my ignorance but checking if the cam timing gears are correctly meshed with no cam information from the 186 install in 1985 is going to mean pulling the engine apart?

[scarry]

Geez,a long time since i played with one of these,but i think it is off with the harmonic balancer,easy with pullers, and then take off the timing gear cover.Also easy to do.

The cogs have markings on them so you can see if they are lined up correctly.

As others have said,the main issue we used to have with them was the harmonic balancer slipping on the rubber,which upset setting the timing with a light.

[Homestar]

Yes, as described. Off with the balancer and you can remove the timing cover without disturbing the sump if your careful,

[bee utey]

First of all check TDC with a screwdriver held down no.1 plug hole, remark if necessary. Without removing the front cover you can also ballpark check the cam timing by removing the rocker cover and moving the engine across TDC. The rockers on no.6 cyl should evenly rock from exhaust to inlet as no.1 passes TDC at the firing stroke.

[geodon]

186 Holdens are now 40+yo and have probably been dismantled an reassembled several times.
Over the (many) years on lots of makes, I've noticed some distributor drives have been installed from a few teeth out to 180 degrees out thus rendering the factory timing points useless.
It won't hurt to rotate the motor by hand with the plugs out & follow the 4 cycles on No. 1 (suck, compress, fire, blow) to get an idea of when it should fire. Don't forget it goes to TDC on the exhaust cycle when the exhaust valve will be down. The TDC you want is with both valves up. Verify by probing down the plug hole. Mark the pulley- I use liquid paper because it shows up well with a strobe light.
Now twist the dist body so the rotor points at No.1 & that should get it statically timed assuming you have the firing order right.
I then go on the road to a long uphill section. Now advance the ignition (turn the dist body against the rotation of the rotor) and see how it climbs in top gear. If it doesn't ping (a sound like rattling bolts in a tin can) advance it a bit more. Repeat till it starts to ping then back it off.
I've grown to respect my 186. Sophisticated it ain't but it's easy to work with & sure gets the job done

[Bigbjorn]

Got a degree wheel and a dial gauge?

[pk.hoarder]

Gday, if it used to run OK timing gears should be fine. They are keyed and only go on one way. The original fibre timing gears sometimes used to fail but the motor stopped then.
The pics attached are my 186 with timing cover on and two pics with the cover off showing the allow aftermarket timing gears. Hopefully you can see the keyways for each gear in the pics. Getting the timing cover off isnt too bad but putting it back on without dropping the sump is hard and I expect mine to leak as the gasket between the bottom of the timing cover and the top of the sump kept moving as I tried to tighten the bolts up - I think it's designed to have the timing cover go on first then the sump comes up to meet it.

Cheers
Paul

[Homestar]

Gday, if it used to run OK timing gears should be fine. They are keyed and only go on one way. The original fibre timing gears sometimes used to fail but the motor stopped then.
The pics attached are my 186 with timing cover on and two pics with the cover off showing the allow aftermarket timing gears. Hopefully you can see the keyways for each gear in the pics. Getting the timing cover off isnt too bad but putting it back on without dropping the sump is hard and I expect mine to leak as the gasket between the bottom of the timing cover and the top of the sump kept moving as I tried to tighten the bolts up - I think it's designed to have the timing cover go on first then the sump comes up to meet it.

Cheers
Paul

Despite there being key ways, it is possible to have the cam a tooth out from the crank. The OP says the engine was running fine before the mechanic looked at it and reset the timing. It was probably timed by ear and never found to be an issue.

If fitting an alloy timing gear (a very good idea) it pays to open up the oil feed hole on the little squirted aimed between the gears. With standard oil flow - and a half worn out oil pump, the alloy gears can howl a bit.

Yes, the engine was designed to have the timing cover fitted first, then the sump, but you can get away with leaving the sump on - hope yours doesn't leak.:)

[Designosaur]

Over the (many) years on lots of makes, I've noticed some distributor drives have been installed from a few teeth out to 180 degrees out thus rendering the factory timing points useless.


Ha, they won't run if you put the dissy in 180 degrees out (don't ask me how I know this):p

[Jordan]

I believe you, but wonder why it wouldn't run 180 deg out - just firing a different cylinder?

[mick88]

I believe you, but wonder why it wouldn't run 180 deg out - just firing a different cylinder?


Different cylinder and on an exhaust stroke!!!!

[Designosaur]

What mick88 said ^ ;)

[Jordan]

That'd do it. :)

I guess it's the exhaust stroke, because not only is it 180 deg out, but it's only spinning at half crankshaft speed.