i was screwing around on here today, and i noticed that "iceman ch" sig said he had a double roller timing chain advanced 4. does this mean his timing is advanced 4*? does this do anything? also, is there a way to tweak your ignition timing other than a programmer? what do you guys think?

 

No it,s not igntion timing. I advanced the cam by 4 degrees. There is several differnt reasons to do this and I can't remeber wich site I found it on and frankly I can't remeber exactly what the logic was behind. I know that it sounds lame but, if your in that far it is a good idea to do. Or, atleast I was throughly convinced it was a good idea.

I'll see if I can dig up the info on it for you. I know it had something to do with opening the valves sooner on the stroke so that there was momentum to the gas charge. This increases you low end torque while retarding the cam will increase high end.

Anyways I will look up the info and post it here.

Oh and as far as your other questions. Look up the CPS mod. This is a way to adjust base timing without a programmer but, it can be difficult to reach the CPS. Advancing timing increases power put also increases the chance for detonation.

 

I thought you were suppose to retard it 4 degrees, but I could be mistaken. It happens from time to time.

 

By using special timing sets, you can change the angle of the cam relative to the crankshaft. Spinning the cam forward so that the valve opening events happen sooner is called advancing the cam. Retarding the cam is just the opposite. Most camshaft manufacturers grind in around 4 degrees of advance into their cams so that it is automatic when you install your cam with the zero marks on the timing set. This is very common with street cams but varies with different race cams. Make sure you know what you have.

"Typically, engines respond better with a few degrees advance," Godbold explains. "This is likely due to the importance of the intake closing point on performance. Earlier intake closing leads to increased cylinder pressure and better responsiveness." As a general rule of thumb, advancing the cam will help low-end torque, but if your engine is dying by the flag stand, retarding the cam a few degrees should help extend high-rpm power a bit.

Link http://www.circletrack.com/techartic...retarding.html

I read a couple of other articles real quick too but I'm not going to post them all. There is a ton of information if you google it. The idea is that you increase compression becase you are closing the intake valve coloser to when the pistion is at the very bottom before it starts to come up. The reason why this will effect differnt rpm ranges is beccasue of the momentum of the air entering the cyclinder. if you do it right as the vavle close the air will still rush in until the vavle completly closes essentialy adding just a hair bit of pressure before the cylinder starts to come up. As you get higher in the rpm ranges the air is not entering the intake fast enough for this pressurizing effect to work.

Think of it like this if your driving down the road with the windows down and you roll them up. The momentum of the air entering the vehicle pressurizes the compartment when the windows close completly.

One last thing that I wanted to add. Advancing or retarding the cam dosn't affect power. It just moves the torque cure up or down in the RPM Range.

 

Sweet, so If I loosen the bolt holding my distributor and advance it a few degrees I can slightly improve my torque curve. I'm I getting this right?

 

No. Read the part where he said it is NOT ignition timing. It's cam timing.
Your distributor controls the injector pulse, not ignition timing.

 

so......
"iceman ch", my question to you is, is it worth doing? i do a lot of towing, and i like my torque low in the rpm range. as long as i can get my 6000lb trailer up to 70 mph fairly quickly, i am happy.

 

Okay, just interested in increasing my low end torque like dukhunter said.

 

Lets put it this way. It's worth doing if you are there. I wouldn't tear the motor apart just to do it. If you going to replace the chain then you might as well advance it and throw in a hughes plenum kit. If your truck is slightly modded then you will slightly notice it. If it's hevily modded then you will really notice. Also are chains from the factory came with a nylon coating to keep them quite. Well after about 30K miles this coating wears off. This causes the chain to be effectifly retarded by a little bit. So you are probably sitting with a retarded cam.

Do not move the distributor. You will mess your fuel sync and then you will need to take the truck to a shop. To adjust igintion timing wich is when the spark fires you do the CPS mod. to adjust the cam wich changes when the vavles open and close in relation to where the pistion is at in the cylinder you have to buy a chain set that has differnt keyways in it. Then you install in the keyway that you want.


http://store.summitracing.com/partde...3&autoview=sku

 

Well the CPS mod is not something I'm going to try. I just installed a new timing set from cloyes and it had that option. Well too late now to change it.