Ign' timing question

[arcturus]

Here we are. Number 1 and 4 pistons at TDC. From the cam position (I know that they are being viewed from below) which piston is on the firing stroke? Oil pump/dizy drive dropped out and I need to be sure of correct position when I replace it.

[kishor]

Originally Posted by arcturus

Here we are. Number 1 and 4 pistons at TDC from the cam position (I know that they are being viewed from below) which piston is on the firing stroke?

hi
number 1

[Ron Kwas]

Arcturus;

I would agree with OP...and for the reason that lobes on Cam for No 1. are definitely off to the side, which means that (both) valves are closed. That looks less to be the case for No 4...but that is what you want to double check to be certain!

Good Hunting

[Clan]

Originally Posted by arcturus

Here we are. Number 1 and 4 pistons at TDC. From the cam position (I know that they are being viewed from below) which piston is on the firing stroke? Oil pump/dizy drive dropped out and I need to be sure of correct position when I replace it.

It is fairly easy to lift out the distributor drive gear and move it around from the top when you get the engine back together ...

[arcturus]

Thanks. It's what I thought. Just wanted second opinion. Another question. How easily should the pistons move up and down when I turn the crank. Should there be a noticeable drag or should the "glide" up and down at this stage with little effort? Or putting it another way, should the assembled piston and rod push easily into the bore with only hand pressure?

[v8250]

You will feel 'natural' drag of the engine components rotating...but should feel no tight/pinch points :. the engine should rotate freely with spark plugs out.

[mocambique-amazone]

Originally Posted by arcturus

Thanks. It's what I thought. Just wanted second opinion. Another question. How easily should the pistons move up and down when I turn the crank. Should there be a noticeable drag or should the "glide" up and down at this stage with little effort? Or putting it another way, should the assembled piston and rod push easily into the bore with only hand pressure?

Hello George,
the piston assembled with rings into a fresh honed cylinder won't go "easily" in by pushing with hand.
to start the engine truning by hand is rough, when turniing it should turn smooth like v8250 wrote, without valvedrive! (including without followers/lifters)

Did you check the bearings of the cam?
Did you find any shiny material in the sump?

good luck, Kay

[arcturus]

Thanks. I'm sure everything is OK. Just that there is no one here to give advice or opinion.

[Clan]

Originally Posted by arcturus

Thanks. It's what I thought. Just wanted second opinion. Another question. How easily should the pistons move up and down when I turn the crank. Should there be a noticeable drag or should the "glide" up and down at this stage with little effort? Or putting it another way, should the assembled piston and rod push easily into the bore with only hand pressure?

If the engine cylinders have been bored with new pistons it could be almost stiff , and make a scraping noise , On the other hand with 150000 miles ( just run in ! ) it will be fairly easy to spin over by hand , spark plugs out of course .

anywhere in between it might be slightly stiff but still turn freely

[arcturus]

Re' the above discussion, what would be the recommended mileage after fitting new rings, before the first oil and filter change. Would it be after about 500km or sooner or later?