Cam Timing - Yes, Its Performance Related!

Hi Lads,
The other night I was messing with the position of my timing gear. The backplate was melted off and without a timing light, I moved the gear 2 teeth forward to feel the reaction. The car idled like crap.
So I then decided to move it back or "retard" it bu one tooth. My "ass-o-meter" told me that this position kicked butt!
Last night, I borrowed my friends timing light to see for sure where I was. The kick butt position is actually 20 degrees BTDC while the original position was correct to the factory spec of 10 degrees BTDC. I decided to put it back to 10 degrees and now I think it sucks again.
Am I dreaming or is it really possible to advance the timing that much without causing some problems? It just seems weird to me that I could stray that far away from factory spec yet have a car that seems to run much better in that position?
BTW - It's pretty close to a 10 degree difference for a 1 tooth move on the gear for anyone that was unaware...

Thanx
Looking forward to your advice.

FWIW, the timing gear refers to the gears the timing belt rides on. I'm assuming you were not messing with those. If you were, it is really best to keep the cam within approximately 5 degrees of spec on a stock motor. Changing your cam timing will affect ignition timing also.
Advancing your ignition timing will improve low end power and throttle response. The downside is at large loads (accellerating in 3rd gear at 25 mph or up a hill) you will experience detonation or pinging. Usually you can get away with a degree or two of advance without excessive detonation. When you drive listen for pinging (sounds kinda like marbles in a tin can) when you acellerate. If you do not hear it when you are 10 degrees advanced, there may be other issues you need to deal with (fuel mixture, cam timing, crank pulley slipping, etc.) Good luck.

Hi Dan,

You are correct. I have shifted the timing "gear" 1 tooth forward. I am not talking about advancing the distributor. Can't do it on my car (B230FT). When the gear was set to the factory alignment mark(s) (10 degree BTDC timing mark), the car felt sluggish. Moving the cam gear forward one more tooth advanced the timing and the valvetrain (20 degrees BTDC). I confirmed this all using my timing light.
With the gear advanced 1 tooth, the car feels more repsonsive and quicker in all ranges.
I have not heard any pinging thus far and was pulling 9psi yesterday at 90mph on the freeway. I think I am good to go but still wonder why being 20 degrees is yielding this sort of difference?
I am testing gas mileage back at the original position today and if I do not see a significant savings in fuel, it is going back to the 20 degree position....

Cheers

The cam timing should be set to TDC at the crank and the marks on the cam and head should line up. The marks you are referring to are for ignition timing not cam timing. Do you have a manual? As the timing belt ages it will retard the cam timing due to stretching. Maybe by advancing it one tooth you are only moving it a few degrees advanced (stretched belt made it several degrees retarded). If your belt is over 40k old you might consider replacing it. If you get everything to "spec" it may run even better. If you do not have a manual someone should be able to tell you the procedure for setting the timing belt. Glad you're enjoying the power.

Hmmm,
Maybe I am confusing you or me .............LOL

I set the cam gear to the crank by rotating the crank to TDC and then aligning the cam gear marks. This is the factory procedure and I did it correctly.
What MAY have this confused is that by aligning these 2 marks, the ignition gets set at 10 degrees BTDC which is also factory correct. I confirmed this using my timing light. I may have you confused into thinking I set the crank to 10 degrees BTDC to align the cam gear (not the case).
With the cam gear set one tooth advanced in reference to the crank, my valvetrain and my timing gets advanced since the rotor lives on the other end of the cam.
When I rechecked my ignition timing after moving the gear ahead 1 tooth, it was showing 20 degrees BTDC. So, I have advanced ignition forward by 10 degrees from factory spec but because I have shifted a tooth on the gear, I have also advanced the valvetrain with reference to the crank.

Confused now??
LOL

The timing belt looks fine but I haven't changed it myself. I guess I should just to be safe.

Dan--no, he's referring to cam gear timing. For sure.
Bernie--I know exactly what you're referring to. Same with me.
With my custom set-up, I couldn't get the backplate to fit. So I don't even have it on. Which means I have no reference for cam gear timing. I figured it was absolutley TDC in relation to the valvecover mounting deck. But at that setting, it was 1/2 tooth off the belt with the crank at TDC, so I installed it to the closest 1/2 tooth it was near, which put it at about 11:30 in relation to the VC deck. It ran pretty well. In trying to diagnose a problem that later turned out to be fuel-related, I tried moving it forward and backward one tooth at a time. One back was terrible, both idling and driving. Two teeth forward was just as bad. However, I found that one tooth forward seemed to be even better. My idle lope was reduced, it idled better, and while driving it seemed to be more responsive, have more power, etc.
After setting it to approximately 12:30 in relation to the VC deck (one tooth advanced), I called the dealer and several Volvo-only shops in the area to find out exactly where the mark on the (missing) back cover was supposed to be. As it turns out, I was right from the beginning: 11:30 in relation to the VC deck. But it just seemed to do so much better at 12:30.
BTW-I have a Unitek Phase-1 cam (I've been told it's very similar to the V15).

And for those wondering why my backplate wouldn't fit on my B23F: It turns out the B23 uses a different VC than the B230. The front of the VC has a raised lip which covers the back of the cam gear instead of the backplate, and the mark is stamped on that lip. The B230 VC doesn't have that lip, and so the backplate extends up to take over where the lip would be on the B23. I'm using the B230 VC on a B23 block ('91 531 Unitek head between the two).

That's great news Shane...... whew!

I guess my question to you would be ----- "did you leave it there?"
MY gut instinct tells me not to screw with the factory alignment but the hotrodder in me tells me "to hell with the factory, follow the ass-o-meter......!!!!!"

?

It's Stayin' There!

Well,
I advanced it a tooth at lunch again.
I am leaving it.....
The car idles smoother in Park and in Drive
Jumps off the line
Hauls a** throughout the "legal" range (0 - 100mph?)
And I also find that the engine runs much quieter
There is NO detonation

Screw the gas mileage, I mean how much different could it be and who cares when I am having this much fun!

Thanx for all the help fellers.......

changing your cam timing will alter your ignition timing. and thats what you've measured on the timing light.

the timing light is measuring ignition timing. and it's change because the rotor arm is on a shaft that is plugged into the camshaft itself. therefore advancing the cam has therefore altered the way the rotor is orentated in relation to the dizzy cap (Ex. it's a little bit advanced).

is you system LH2.2 or LH2.4 if it's 2.4 then your timing is adjustable or so i believe B230FT or not.

what i'm waiting to see if what effect dales cam gear will have on my car (B230ET, motronic fuel/ignition system) as it's got a fixed postion dizzy like LH2.4 cars

ravennexus said:

changing your cam timing will alter your ignition timing. and thats what you've measured on the timing light.

the timing light is measuring ignition timing. and it's change because the rotor arm is on a shaft that is plugged into the camshaft itself. therefore advancing the cam has therefore altered the way the rotor is orentated in relation to the dizzy cap (Ex. it's a little bit advanced).

is you system LH2.2 or LH2.4 if it's 2.4 then your timing is adjustable or so i believe B230FT or not.

what i'm waiting to see if what effect dales cam gear will have on my car (B230ET, motronic fuel/ignition system) as it's got a fixed postion dizzy like LH2.4 cars

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If your ignition system has a knock sensor, the computer will automatically adjust timing to compensate. I think youll be OK. Just make sure it doesnt go bad, I did on my 92 240.

yeah i'm sure LH2.4 has knock sensor. but my motronic hasn't

Yes, we know about the ignition timing changing when changing the cam timing. Simply re-set the ignition timing after moving the cam timing. This, of course, only possible if the cam timing is either set at TDC, or advanced one tooth. More than one tooth, or retarded one tooth, and you run out of room for adjustment on the distributor.
Mine is LH2.2, head-mounted distributor. Adjusting the ignition timing is easy. Block-mount distributors are also adjustable. I don't know about LH2.4, though.

Mach375 said:

Yes, we know about the ignition timing changing when changing the cam timing. Simply re-set the ignition timing after moving the cam timing. This, of course, only possible if the cam timing is either set at TDC, or advanced one tooth. More than one tooth, or retarded one tooth, and you run out of room for adjustment on the distributor.
Mine is LH2.2, head-mounted distributor. Adjusting the ignition timing is easy. Block-mount distributors are also adjustable. I don't know about LH2.4, though.

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LH2.4 isn't adjustable on head mounts at least.. it's a 1 position input for the cap and rotor, any adjustments that do get made to the rotor are because of you fiddling with the cam gear on the other side...

Cam timing

Because I am wrestling with mucho ping after installing a manual boost controller, I want to see it a "one tooth" cam gear adjustment might help.

So I understand what you did....

Did you adjust the gear one tooth "Clockwise" or 'tother way?

Just a note, (and forgive me if it was already said) each tooth on that cam gear is something like 10 degrees i think. If your car is LH2.4 changing the CAM timing will not change the ignition timing, since Ignition timing is decided by the position of the crankshaft and crank sensor. Timing on a 2.4 car is not adjustable! Having a 2.4 car and fighting a smoke and ping problem, im learning more and more about it. Changing the cam timing, or moving the distributor only changes where the spark comes off the rotor. There is a plastic insert in the slot on a 2.4 distributor, which does not allow rotation (unless this has broken and fallen out) An LH 2.2 car, with the hall effect sensor in the distributor, the ingition timing will change when you change the cam timing. Also, make sure that the harmonic balancer has not slipped, this has thrown many many people off in diagnosis of timing issues. One other thing, the knock sensor in the ignition system can only retard the timing so far and so fast. Some good points though!
Mark

volvorod85 said:

Just a note, (and forgive me if it was already said) each tooth on that cam gear is something like 10 degrees i think. If your car is LH2.4 changing the CAM timing will not change the ignition timing, since Ignition timing is decided by the position of the crankshaft and crank sensor. Timing on a 2.4 car is not adjustable! Having a 2.4 car and fighting a smoke and ping problem, im learning more and more about it. Changing the cam timing, or moving the distributor only changes where the spark comes off the rotor. There is a plastic insert in the slot on a 2.4 distributor, which does not allow rotation (unless this has broken and fallen out) An LH 2.2 car, with the hall effect sensor in the distributor, the ingition timing will change when you change the cam timing. Also, make sure that the harmonic balancer has not slipped, this has thrown many many people off in diagnosis of timing issues. One other thing, the knock sensor in the ignition system can only retard the timing so far and so fast. Some good points though!
Mark

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My '89 is a LH 2.2 with Hall Effect Sensor. What I just need to know is which direction to move the cam gear, clockwise or counter-clockwise, one tooth.

(I inspected the harmonic balancer closely before installing it)

Correct me if im wrong guys....Crankshaft turns clockwise...therefore so does the camshaft. Turning the camshaft back or counter-clockwise one tooth is going to retard the cam timing (letting the valves open too late), which should theoretically leave you with no low end power, but a ton of top end power. Turning the cam clockwise one tooth will advance the cam timing, which will give you the low end these motors lack, but then you wont have high end. Allowing the valves to open too soon hence the advance term. I messed with this on my car to try to solve an idle problem, but put it to factory spec in the end, though I may just for kicks now, to see if it helps my black smoke/ping problem. (for those of you that dont know, its been a long time problem with no definate answer yet).
Mark

I am confused though as to how the car will pull so well with a 10 degree advance on the cam timing, it just seems awfully agressive to me. I can see going, oh 6 degrees though. Oh well.

Rotation of engine (and cam): CW. Therefore, to advance the cam, rotate the gear CW in relation to the belt. Loosen the belt and slip it off the cam gear. Slightly move the cam gear CW. Slip the belt back on and tighten it. You have now advanced the cam gear.

Shazam! That be da sh*t!!
Mark

(just wanted to make sure i wasnt losing my mind, seein as i keep finding peices of it everywhere )

Just did this. I now have cans of marbles for anything more than 50% throttle.

I did notice induction noise is now louder, which is cool. Factory airbox with pre-heat hose routed to bumper.

I'm putting it back to 0-tooth advance but I'm sad I'll lose the intake noise.