New found power via timing belt

[ChIoVnIdCa]

Why would ignition timing even be a factor in timing belt replacement.

[wildBill83]

I have DOHC experience, never messed with SOHC differing from stock timing.

On a DOHC you can buy timing kits that replace the cam pulleys with a ton of adjustment. It will run like shit at the extremes but you can fine tune it and get the maximum out of it. They adjust a tooth forward and a tooth back generally.

http://www.goodiegarage.com/cam-gear...2a1-h22a4.html

[GeoffM]

Why would ignition timing even be a factor in timing belt replacement.

If the belt was a tooth off then I would have no ignition timing results.

[wildBill83]

If the belt was a tooth off then I would have no ignition timing results.

I feel this statement is incorrect, you should be able to still time ignition but it will either run rich or hesitate... again I have not messed with the valve train timing on a SOHC, just DOHC and that is where I am speaking from.

[GeoffM]

I feel this statement is incorrect, you should be able to still time ignition but it will either run rich or hesitate... again I have not messed with the valve train timing on a SOHC, just DOHC and that is where I am speaking from.

It might be. I was just guessing.

[reklipz]

How do you do that? Go have a friend hit the gas?

Some advanced timing lights can measure RPM by means of the inductive pickup on the plug wire. Otherwise, you need something that can tell you the RPM, like the tachometer on your dash.

If you are a tooth off your timing is advanced/retarded... I consider "off" timing as a non-running situation (valve interference).

If the belt was a tooth off then I would have no ignition timing results.

I feel this statement is incorrect, you should be able to still time ignition but it will either run rich or hesitate... again I have not messed with the valve train timing on a SOHC, just DOHC and that is where I am speaking from.

wildBill started to hit on the subject with his last comment. Ignition timing is completely independent from valve train timing, although the two are obviously related via the crank, and need to be in sync. Read on.

If the timing belt is off a tooth, in either direction, this affects airflow into and out of the cylinder, and because our cars use a distributor which is run off of the valve train, the distributor timing will be "off" by that tooth as well. You can account for the distributor being off when you set your ignition timing (base ignition timing), but you can never account for the valve train being off from the crank, and that is the real issue. As mentioned, some crank gears allow you to account for being a tooth off with the mechanism that also allows for you to adjust valve timing. I have no experience here, but presumably these cam gears allow you to tune the valve timing for when you change up the air/fuel mixture, or change the burn rate by running a different / higher octane fuel; it also has the added side-effect of allowing you to fix an off-by-one timing belt issue.

Basically, you need to fix the off by one timing belt issue, and that cannot be done by changing the ignition timing. You can make it run better by adjusting ignition timing, but the difference in valve train/crank timing from stock will still be there. The ECU cannot compensate for this, as this is a mechanical constraint emplaced by the timing belt.

Next note: --

Why would ignition timing even be a factor in timing belt replacement.

So long as you never removed your distributor, and it had proper timing before you started your work, there is really no need to adjust your base timing. It can't hurt to make sure it is correct, and to ensure that the timing advance mechanism of the ECU is functioning, however.

[Domesticated]

Timing belt change = many horsepowers!

Your threads never cease to amaze. Geoff you're cam timing was probably off and you just failed to check it correctly before hand.

If you are a tooth off your timing is advanced/retarded... I consider "off" timing as a non-running situation (valve interference).

My JDM H22 was off a tooth and it ran. Drove it like a week or two before that because I couldn't figure out the problem. Car had been sitting for over a year before hand so figured there was something wrong somewhere else. But it ran fine, it was faster than my Subaru. When I checked cam timing it was off by one so I fixed it and now it runs like a champ.

[PR CB7]

the timing might have been on point but that old belt might have stretched a lot making the car feel sluggish over time, something you wont feel since it will stretch in increments, by the time you changed it, the left side was probably wobbling like a mofo, that wobble equals lost timing, hence a slightlly retarded cam

[wildBill83]

Here is the tuning cam gear for SOHC motors.
http://www.horsepowerfreaks.com/perf...gine/Cam_Gears