question for you engine experts..?

[Jamo]

Like these (they ALL need to be lined up at the same time)

I strongly disagree with the 1st part, that dimple mark can be way off and cannot be relied on simply because the lower cam cover can move and is not fixed.

Maybe it's different on the AAN, but for ABY, ADU and 3B you cannot use that mark as reference.

Andyp had a tool to check TDC of the piston to the crank mark, that was perfectly matched to the cam cover mark but that lower cover was off on both my ABY and my Stroker.

I didn't know any of this until I queried the forum and S2central was the one to highlight this issue

[euro_urs4]

As long as the crank pulley/flywheel marks are at TDC, and the cam pulley mark is at TDC with both sets of valves closed for cyl 1 i dont think you can get it wrong.

For sanity sake i always double check, as you turn the engine over cyl 1 moves down the bore (power stroke), then ~BDC the exhaust valves will open as the piston comes back up. The crank will now be at TDC marks again but the cams will be 180 degrees out. Continue to rotate the crank another 360 degrees (through the intake/compression stroke) and you should be back at TDC for both the cams and crank marks. Its good practice to turn an engine over by hand a few times, then double check timing marks and belt tension. If you have a 3B or 7A move onto installing the distributor and turn the engine over a few times, then double check, and check it all again for good measure :-)

this is what i have done sorry for the confusion, but i have both marks aligned and i cranked the motor over by hand a few times and still stays at TDC, what i was asking is that when they are at TDC, and you crank it over for the crank to do one full rotation it still is at TDC, and the cam pulley is 180 of from its mark, then another full rotation on the crank pulley, makes the cam pulley be at the TDC mark and the crank pulley then is at the TDC mark, so just wondering if at each instance when the crank pulley does one full rotation does the intake and exhaust valves do on full sequence upon one full rotation of the crank pulley, or on 2 full rotations do they run one full sequence of up and down, does it make any sense now?

[mcandmar]

Ooh right. Camshafts rotate at half the crank speed, so two full rotations of the crank shaft for one full rotation of the camshafts. Its a four stoke engine you see, pistons goes up/down twice for each combustion cycle.

[UrS4boy]

..., so just wondering if at each instance when the crank pulley does one full rotation does the intake and exhaust valves do on full sequence upon one full rotation of the crank pulley, or on 2 full rotations do they run one full sequence of up and down, does it make any sense now?

For the valves on one cylinder to go through one complete cycle, e.g. intake valves open, intake valves closed, exhaust valves open, exhaust valves closed, you need two complete crank revolutions.

[euro_urs4]

For the valves on one cylinder to go through one complete cycle, e.g. intake valves open, intake valves closed, exhaust valves open, exhaust valves closed, you need two complete crank revolutions.

So just like you just said i's it possible for the timing to be of cause the exhaust valves and intake valves might be open at the wrong time or vice versa exhaust open and intake closed?

[UrS4boy]

So just like you just said i's it possible for the timing to be of cause the exhaust valves and intake valves might be open at the wrong time or vice versa exhaust open and intake closed?

Just time your crankshaft and cam together, properly, and be done with it. Then you will find out whether you have any damaged valves (e.g. intake valves) because things were out of proper timing (low or no compression/runs like cr*p).

I think you have enough information to do it properly.

[euro_urs4]

Just time your crankshaft and cam together, properly, and be done with it. Then you will find out whether you have any damaged valves (e.g. intake valves) because things were out of proper timing (low or no compression/runs like cr*p).

I think you have enough information to do it properly.

i checked it twice and the motor is timed correctly, and compression is 150+ or so, i also checked the crank sensor which is good, the flywheel pin is intact, and motor is timed correctly, so now im still stumped why it wont start, a buddy refered that the crank pulley that is connected to the timing belt, has a tooth on it and that could possibly be sheared or slighlty sheared away causing it to be of by a little and not starting, i might check that out, any other opinions what to look for guys?

[mcandmar]

If you have confirmed the timing is ok then i think its time for a new thread. There are a million and one things that could cause a no start. Give us a little backround info on what was done, engine conversion, rebuild? First thing i always check with no starts is immobilizers and or after market alarm systems. Then determine is if you have no spark or no fuel and go from there. Also do you have vagcom to verify the ECU is alive and check sensor readings?

[UrS4boy]

... a buddy refered that the crank pulley that is connected to the timing belt, has a tooth on it and that could possibly be sheared or slighlty sheared away causing it to be of by a little and not starting, i might check that out, any other opinions what to look for guys?

Here is what a slightly cracked crank pulley "key" looks like. They can be worse and can be in bits, leading to serious out-of-time, even if the marks appear to be lined up.

[euro_urs4]

If you have confirmed the timing is ok then i think its time for a new thread. There are a million and one things that could cause a no start. Give us a little backround info on what was done, engine conversion, rebuild? First thing i always check with no starts is immobilizers and or after market alarm systems. Then determine is if you have no spark or no fuel and go from there. Also do you have vagcom to verify the ECU is alive and check sensor readings?

hmm which immobilizers do you mean, and what should i look for with after market alarm systems, how could that have affect with starting the motor?

and here is a link to the new thread thanks

http://www.s2forum.com/forum/showthread.php?p=593200#post593200

[UrS4boy]

hmm which immobilizers do you mean, and what should i look for with after market alarm systems, how could that have affect with starting the motor?

and here is a link to the new thread thanks
http://www.s2forum.com/forum/showthr...200#post593200

*IF* you were running on a North American AAN ECU, there is no immobilizer. As for what VEMS might have, why don't you contact Marc S. at EFI_Express?