993/964 Timing sanity check please!
03-19-2012, 06:53 PM
#1
Pro
Thread Starter
993/964 Timing sanity check please!
Hi Guys
I have cross posted this on Pelican in the hope of getting a response by tomorrow when I can fix things!
Today I timed my 993 engine which is fitted with the early 993 cams with the woodruff key and sprockets from the 964. This is part of a rebuild so was done from scratch.
I followed the instructions from the board and set the lash to 0.10mm (using a 964 rocker arm) and valve lift to 1mm with the opposing cylinder at TDC.
I am worried about being 360 degrees out somehow, so can I confirm that when No1 LHS cylinder is showing 1mm lift and the z mark at TDC then the camshaft dot should be down, and No4 should be showing camshaft dot up.?
Because that is the way it is on my car at the moment. Here is a pic of my dial gauge set up.
Many thanks... Berni
I have cross posted this on Pelican in the hope of getting a response by tomorrow when I can fix things!
Today I timed my 993 engine which is fitted with the early 993 cams with the woodruff key and sprockets from the 964. This is part of a rebuild so was done from scratch.
I followed the instructions from the board and set the lash to 0.10mm (using a 964 rocker arm) and valve lift to 1mm with the opposing cylinder at TDC.
I am worried about being 360 degrees out somehow, so can I confirm that when No1 LHS cylinder is showing 1mm lift and the z mark at TDC then the camshaft dot should be down, and No4 should be showing camshaft dot up.?
Because that is the way it is on my car at the moment. Here is a pic of my dial gauge set up.
Many thanks... Berni
03-19-2012, 07:54 PM
#3
Pro
Thread Starter
Hi Bill,
In that case I have it wrong, and both the cam punch marks should always be either up or down at the same time, and never as I have them at the moment. So I must be 180 degrees out on one bank.
Many thanks
Berni
In that case I have it wrong, and both the cam punch marks should always be either up or down at the same time, and never as I have them at the moment. So I must be 180 degrees out on one bank.
Many thanks
Berni
03-19-2012, 08:19 PM
#5
Pro
Thread Starter
Hi Pete
Thank you for taking the time to point this out.
Yes, I actually used the oval handle of a large screwdriver under the ramp. With a bit of modulated twisting and levering I could tension the chain to the point where the tension just stopped affecting the reading. Also the photo I posted was taken before I had set the lash so the locking nut is undone and the gauge is not in its final position.
Many thanks
berni
Thank you for taking the time to point this out.
Yes, I actually used the oval handle of a large screwdriver under the ramp. With a bit of modulated twisting and levering I could tension the chain to the point where the tension just stopped affecting the reading. Also the photo I posted was taken before I had set the lash so the locking nut is undone and the gauge is not in its final position.
Many thanks
berni
03-20-2012, 05:49 AM
#6
Rennlist Member
wouldn't it be easier to mount chains for timing as procedure in factory ?
Crank at TDC
look from the back of the engine, on the back of the cams.
The cams have grooves for cam tools.
both grooves should be vertical.
Left cam groove, vertical to the left of the cam center
right cam groove, vertical, and to the right of the cam center.
you cannot go wrong,
and you cannot be off 360 degrees, does not exist.
following your progress berni
cheers
Crank at TDC
look from the back of the engine, on the back of the cams.
The cams have grooves for cam tools.
both grooves should be vertical.
Left cam groove, vertical to the left of the cam center
right cam groove, vertical, and to the right of the cam center.
you cannot go wrong,
and you cannot be off 360 degrees, does not exist.
following your progress berni
cheers
03-20-2012, 06:02 PM
#7
Pro
Thread Starter
Hi
Thanks for the reply. I was tired when I wrote that and meant 180. That's my story anyways
. I have not read that about the grooves anywhere before, very interesting. It certainly would have made understanding where things should be easier. I will check in the morning. I do have both punch marks pointing upwards now. I do not have the factory tools so timed it what I understand to be the traditional manner.
I really hope that this rebuild ends well!
All the best
Berni
Thanks for the reply. I was tired when I wrote that and meant 180. That's my story anyways
. I have not read that about the grooves anywhere before, very interesting. It certainly would have made understanding where things should be easier. I will check in the morning. I do have both punch marks pointing upwards now. I do not have the factory tools so timed it what I understand to be the traditional manner.I really hope that this rebuild ends well!
All the best
Berni
