i was wondering if anyone can tell me what i should set my valve clearances at on my 00 si. the previous owner told me that he had a stage 1 head job done on it but i have no way to prove that the cams in the car are aftermarket( i kno when v-tec kicks in it is noticably loud and the sound changes, i was told this is sometimes due to aftermarket cams). but my question is: will i be safe adjusting the valves to oem factory specs(intake:.15-.19mm / exhaust: .17-.21mm), even if there is diff cams in it???? i do not have original cams to compare to nor have access to somone that would be able to tell me off hand. thanx in advance.

 

please, any idea? the valve gaps are way off and the ticking is getting annoying! will i be fine setting it to oem specs even if i might have diff cams in it???

 

The sound change when VTEC kicks in, is normal.

As far as the valve adjustment goes, if they are aftermarket camshafts, they most likely will not use the same specs as factory. Talk to the kid you bought the car from and find out the details.

 

any more input?? anything would help. need to adjust them asap. thanks

 

talk to the kid then call the place who made the cams and ask them

 

My aftermarket cams have all had different clearance specs than my OEM cams on my '99 Si.

 

ya i would but the car came from 15 hrs. away from where i am located and i no longer have his #. i have a feeling the cams r oem b/c the valve clearences are .003in off of factory specs which isnt too much considering how loud the ticking is. i feel i am fine adjusting them to the greatest tolernce that the factory gives.

 

i put cams in my 94 teg and set the valves to fwat stock clearence would be and mine has never ran or sounded better. They should have did a valve adjustment when they installed the cams originaly anyway so y r u doing one?

 

If they are aftermarket cams they may have different lash specs. Lash specs are dependent on the design of the opening and closing ramps of the lobe profile. You can try adjusting them to stock specs (write down what they are at now before you start in case it starts making noise so you can go back!) and see how it turns out. You also don't want them too tight because when the engine is warm it will hold the valves open which is particularly bad.

Here is a picture which shows a cam profile. In this case the blue arrow points to the closing ramp but you can see that the ramp is very long and gradual. The height of this ramp is what determines the lash and is different between designs. Poor designs usually have poor ramp designs. It is very common in the aftermarket for fly-by-night cam companies to design cams with crappy ramps. Ramps that are short and sudden will make a lot of noise and while that may not be the case with your engine it sure is a possibility if it has aftermarket cams and they aren't even marked so you can tell whose they are.

You can lose as much power with bad ramp designs as you would if you chose cams with the wrong lift and duration.

 

ok ill keep this in mind. thanks for all the information and help scott