XVNVX

I swear I have searched before, but couldn't find answers to these anywhere. Probably because they're such noob ones.

So I have a d15b2+z6 that I paid someone to do. I'm going to rebuild it, now that I have more knowledge, so I'm going to need some info on timing issues.

So first - When you adjust the cam gear to 4.75, do you retard it or advance it? Is it only because of timing belt half tooth issues, or does it have anything to do with valve clearance too?
----- Do you adjust the outer part of the cam gear (bc of the belt), or the inner part? If you only adjust the outer part, how will you get more valve clearance? If the valvetrain is not going to move?!
Also, if you move the outer part, do you need to draw new TDC marks on the gear?
Or do you move the inner part only, adjusting the camshaft/valvetrain, and TDC markings stay intact?

Second question: Distributor timing/ignition timing. I've read that it needs to be 16-18 degrees before TDC. Since my head was milled, the most accurate way to find out how many degrees to set the dizzy to, would be using a strob light, right (don't know the correct term in English)? But how do I set ignition timing? Is it adjustable in the dizzy, like in the old ones, or is it only possible via ECU mapping?

Thanks!

welfarepc

Use a Y7/Y8 cam gear, install it, time it like a Y7 or Y8, use the TDC marks on the cam gear.

Crank @ TDC, cam gear @ TDC, belt on. You are over complicating things.

If you have an adjustable cam gear, go half a tooth one way, can you set your ignition timing with the timing light? No? You went the wrong way with the cam gear. You shouldnt have any piston to valve issues with a half tooth timing error.

Theres two ways you can set it up, a 50 50 chance with no possible consequences if you get it wrong. Just go out and turn some wrenches.


Ignition timing should be determined by what ECU you are running. If you are running a P28 or Z6 ecu, and the timing maps are still stock, use Z6 ignition timing values, which IIRC are 16deg BTDC. You set this by loosening the distributor and turning it, just like usual. The purpose of this operation is to match or sync the actual physical spark event to what the ECU is expecting.


What do you mean, to get more valve clearance? Dont you dare draw new TDC marks! Lol. If you are adjusting an adjustable cam gear you loosen the set screws and rotate the actual cam, while the outer ring that is toothed maintains the same relationship with the belt and crank gear.