| have to fork over an extra $1750 for new cams . I have JUN 256 9.5mm lift cams and springs, titanium retainers. The Tomei cams are of similar lift and duration for their solid grinds. I wonder if there would be any adverses affects of using the solid lifters on my JUN cams? It is dependent on the lobe profile. I was doing research and the solid cam grinds in general have rise up ramps in the profile to gently take up the valve lash so they don't slam open or shut too aggressively. This can be referred to rate of rise per degree of cam rotation. The rate of rise on the solid lifter cams are lower initially to take up the lash. On hyrdaulic cams, the lifter is in constant contact with the base circle so the initial rise could be higher. I talked to Z1 and their cam regrinds were not done with having solid lifters or hydraulic in mind. They have put solid lifter in two cars with no problems running so far. I will be reving to 7500rpm max. I don't want risk lifter pump up. Lifter pump up happens when the valves begin to float from high rpm. The spring cannot keep up contact of the cam lobe on the lifter at higher rpms. What happens is the hydraulic lifter will automaticaly take up this slack from the cam not touching the lifter and pump up/ self- adjust. This pump up will cause the valves not to seat fully on the base circle of the cam i.e valves held open. Hence, you loose compression and power and can risk the valve hitting the piston at higher revs. That is why solid lifter don't have this issue at high revs should float occur because they don't self adjust when valve float happens. Also solid lifters are lighter and less prone to float.
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