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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.
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
Got a degree wheel and a dial gauge?
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.Quote:
Originally Posted by pk.hoarder
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.:)
Ha, they won't run if you put the dissy in 180 degrees out (don't ask me how I know this):pQuote:
Originally Posted by geodon
I believe you, but wonder why it wouldn't run 180 deg out - just firing a different cylinder?
Quote:
Originally Posted by Jordan
Different cylinder and on an exhaust stroke!!!!
What mick88 said ^ ;)
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.