I have an ITR Exh. cam but on the vtec lobes it has "flat" spots. The INT cam are all rounded. I assumed it was normal for "duration" purposes. But all my other vtec cams are round. Is this normal? I was told it was normal but I am super sketchy about the ITR exh cam. I tried my best to get a close picture of the lobe. Any input would be greatly appreciated. Thanks

 

not normal. the cams that came out of likely has damaged rockers as well.

 

bump!

my itr ex cam looks similar to this. the rockers have wear but its even and they are not worn out. ive been using zinc additive in my oil too. what causes this and how bad is it really? do you just loose some lift and duration?

 

The only way to know for sure how bad it is, or isnt, is to measure the lobe(s) with a caliper or micrometer.

Measure the tallest point, then measure the base circle. Subtract base circle from your first measurement, and then multiply that by 1.55 (b series rocker ratio).

That will at least tell you if you have lost any LIFT. That wont tell you a thing about duration.

 

Identify the cam using the rings on the end of the cam, and as mentioned previously, measure the lift of the cam lobes and compare to a known good example of the same type. I have seen many "ITR" cams installed that were not ITR cams.

The wear on the lobe looks normal from its shape. It is not gouged or pitted, and looks to have ran normally before you pulled it. Which leads me to ask....

Why are you even asking this question? Did you pull this out of your car, or are you putting it in? Do the rockers pass a fingernail test? (Does your finger drag across the surface?). Where did it come from, and what are the circumstances behind it?

 

I purchased them from a guy. I did identify them as itr cams. I was sketchy at first when I inspected them but the deal was good. the cams are replacing the b16 cams in my b20vtec. I haven't measured the lobes yet but I ended up using the itr intake cam and using a gsr exhaust cam. but thanks for the help.

the "stock" build made
185whp
143ft/tq

 

i remember hearing at one point in time that 1.55 was the low cam rr and that the vtec rr was 1.49. any truth to that?

 

If you want to get super technical, the rockers are actually a variable ratio, most people just average then out at 1.55. I do not believe that the vtec rockers are any different ratio than the others, but, I have never personally measured to confirm. I have however measured plenty of stock cams, multiplied by 1.55, and gotten the proper end result. Ymmv.