No timing marks on my 8T engine

Hi OB,
the flywheel positioning on the crankshaft flange on these engines is marked with a chisel mark on both parts at The Factory--the trick is that the flywheel bolt pattern has equal spacing's for all bolts/studs and so can be set in position anywhere the studs/holes allow.

Later series engines have one bolt staggered to the others so as to prevent mistiming the flywheel to the crankshaft flange.

If you have someone check for the flywheel timing marks on the F/wheel as it is turned you will likely find the marks are around half piston travel in the bores--may vary as to the number of studs/bolts in the pattern--hence the degrees it will be out of time.

Found this several times over the years at The Dealers.

One that comes to mind was a D399 engine, I was sent to re-fit the Injection Pump etc.
It was being overhauled and was awaiting liners etc.--crank fitted, flywheel fitted etc. no liners or pistons fitted so could not instantly establish a piston at TDC for timing--looked down the liner opening and saw the crank pin was not aligned with centre of No 1 bore at the timed by TDC flywheel mark and timing pins--oops.
Needed the just fitted Generator to be removed and re-position the flywheel.

It was common to work on an older engine and find this problem from past workers not realizing to look for the often hard to see Chisel Marks or were used to staggered bolt spacings--especially if things were not cleaned up well.

First job was always to check flywheels for correct fitment before starting these sort of tasks.
Cheers,
Eddie B.

I can't find it either. I know I have read it somewhere in one of my books.

The procedure is to remove the injectors and put a rod or wire down through the PC chamber to rest on top of the piston. Then for each pair (1&6, 2&5, 3&4) turn the crankshaft in either direction just until the rod appears to stop moving up. Make a temporary mark on flywheel. Then rotate engine past TDC and approach TDC turning engine in the opposite direction until your indicator appears to stop rising. Make another mark. Permanent mark should be 1/2 way between the two temporary marks you have made. Of course careful attention to detail is important here!

Sounds like you must have set a dial indicator on it. That would eliminate the guess work. I can see that once you found minimum/maximum indicated value it would be most accurate to mark either side of that and then center.

The D7700 engine has timing marks. If the engine will run, use sandpaper on a stick through the hole to clean the flywheel shiny. They can be very light marks.
Wait, are you saying that when the flywheel was removed that it was cleaned to hospital spec and no marks at all? Very strange.

Oldbeek, I sent you a email about a cat tdc tool I have.

Thanks Steven. I have multiple dial indicators. I was just trying to do it without pulling an injector. My fly wheel is very clean but it may be stamped very light.. Need someone to turn engine by hand while I look for marks closely. Will have my cataracts removed by March 8. That may help also. LOL. Getting old is the pits.

Hi Team,
now thinking back I use to use a brass oxy welding rod with a rounded end, the other end had a 2'' or so loop so the rod could not fall into the cylinder.
I would bring the unit to around TDC--no piston movement, and with the rod angled to sit against the sides of the precomb. bores in a repeatable angle posture, and level with a suitable sighting edge, would then mark the rod with a file mark.
Then I would make another mark around 3/8" higher than the TDC mark.
Then I would take then engine back some 60 Deg and then bring the engine back towards TDC and when I reached the 3/8" mark I would mark the flywheel or front pulley with the first temporary set point--repeat from the after TDC side and split the two marks for true TDC--repeat until repeatable results were obtained--this is pretty much what CCJ described above but likely more confused.
Hope you can sort thru this confusion.
Stinking PTSD pills make it hard to recall and write meaningfully these days, sorry.
Some days I think I should sit back and not contribute.
Eddie B.