Proper adjustment technique for adjustable cam gears??

[DetroitStroker]

hi guys
I have oem camshafts with findanza adjustable gears. My powerband with a 60-1 falls off at 6500 with the peak extremely close to 6k rpm. I am interested in tuning my cam gears a little to minipulate my powerband a little higher.



I have done lots of research on theory and principal behind advance and retard of both intake and exhaust however I haven't found a write up detailing the proper method.

My car runs properly so I am not looking to "degree"
the camshafts for install. Just minipulate +/- 3-4* advance or retard.






Do I want to make sure cylinder 1 TDC and dowel pins up?

I've read that you want to then do 1 camshaft at a time. Loosen the 4 adjustment bolts in the keys ways then spin the camshaft slowly both ways until you hit the piston. Make note that this is your threshold and do come within a few *; do the same in the other direction and then the other camshaft.



Since I'm on stock camshafts and only plan to move within a specification that I know will not cause PTV clearance I may just skip this step if that's okay?


Do I literally just adjust the camshaft from the 12 point bolt in the gear? With all 4 retaining bolts loose - just turn the cam the 2* in the desired direction and tighten down?



Does cylinder 1 being TDC or on compression/exhaust stroke matter?


Any other things to note?



Thanks guys!

 

[GST with PSI]

I doubt you'll be able to do much to shift power north of 6500 RPM on stock cams regardless of how you adjust the cam gears.

The only real way to see how adjustments to individual cam timing affect the power band for a given setup would be to guess and check on a dyno.

 

[lasthope05]

Also note that every time you make adjustments to the intake cam, you need to reset the base timing of the motor back to 5° btdc if your are using a 1g cas.

To adjust the gears, you loosen the outer bolts and move the camshaft itself(remove valve cover.) The gear is in a fixed position.

 

[JusMX141]

I doubt you'll be able to do much to shift power north of 6500 RPM on stock cams regardless of how you adjust the cam gears.

+1.

Tune in as much overlap as you'd like...eventually you're going to run out of duration on stock cams.

http://www.dsmtuners.com/threads/cam-gear-tuning-for-dummies-understanding-what-is-happening.375887/

 

[bastarddsm]

I'd be tempted to retard the intake to promote late cycle filling. Opening it early helps if you have low exhaust pressure to promote scavaging, I'd suspect the opposite, you'll have high pressure, and it will just fill the cylinder with exhaust gas.

Try it each way and see what works. If you have a maf, you should be able to see maf hz increase (assuming constant boost) if you went the right way.

 

[DetroitStroker]

Thanks guys! Got the information I wanted and insight I needed to hear

^^ turboglenn's thread was actually one of the reasons I was considering taking advantage of the cam gears I have!

 

[miliman13]

Another thing, depending on your internals you may never actually touch anything when turning the cam.

I checked the max adjustment both ways on each cam during my build/ cam degreeing and i never got close to the min distance to compensate for expansion.

That said, i don't believe that to be a good method.

 

[DetroitStroker]

I'd be tempted to retard the intake to promote late cycle filling. Opening it early helps if you have low exhaust pressure to promote scavaging, I'd suspect the opposite, you'll have high pressure, and it will just fill the cylinder with exhaust gas.

Try it each way and see what works. If you have a maf, you should be able to see maf hz increase (assuming constant boost) if you went the right way.

My plan was to retard the intake 2* and possibly advance the exhaust 2* as well. and since I do run a gm maf I can log hz and notice if they increase in my powerband or just earlier in general?


im holding off going e85 until after winter due to its sitting properties and this car is a track/weekend warrior and would be on the same tank all winter. By that time I should figure out which 272 grind would be best for me...and maybe tax time will bring me to make the jump to an SMIM and FP black for next season...