Machine shop, was setting the valve lash for me after about the 10th time of taking them in and out. He tightend them too quickly and didn't keep the pressure equal so clean snap... That was a jwt s1 intake cam. However i replaced them with bc stg2 that i cryo treated gave them a bronze color, should be a photo somewhere in my album of them.
I've heard about the s1 cams, they usually do that anyway. that's y a lot of ppl go for the c1 cams they are stronger from what I c. ur car is not the first car to snap those s1 cams, I've seen 3 like this so far.
Report