Opinions on Predator Hemi Build
The 26 lb springs are supposed to work just fine with the hemi. The 308 cam I am not familiar with but if it has 308 lift you better check valve to piston clearance before milling the head. SI is supposed to be looking at making .200 longer valves for the hemi but I don't know if that is a one off run for their friends or for sale to general public. If they were available you could use your 37 lb springs but if it were me I would use the 26lb springs with SS valves and good retainers thin .010 head gasket and some mild port cleanup in the bowl and very carefully radius the SSR and would not mill the head. That way you could get away with stock rockers and pushrods. If you were to get the longer valves then you had better know how to get the geometry correct and with stock rockers that you can't move the piviot point the only thing you can do is change pushrod length which may or may not be enough to get the geometry correct.
i can purchase 26lb springs thats no big deal. the cam works out to .310 lift with the stock rockers. i am doing the mild port work as we speak. i was told by a member on bobs 4 cycle that this combo works very well and makes great power through the whole power band. what is the ideal clearance between piston and valves?. before i mill head i can place some modeling clay on the piston and check the spacing pre-milling
ok, spoke with JD (SI Valves), he can do them, but at this point they would be custom order... still not a bad price, but he will confirm the price with me in the morning.. so dont wanna say an estimate... they did intend to make them in larger quantities but for now can make them to order... if they decide to keep producing them, the price would be a little better, but done know when...
to order you can call SI Valves and ask for JD... if anyone else is interested, they can let me know, so i can give him an estimate of how many would be needed...
to order you can call SI Valves and ask for JD... if anyone else is interested, they can let me know, so i can give him an estimate of how many would be needed...
ok for clarification... at this point he (SI Valves) can and will do the valves but they are custom... in the future when they are made in bulk they would only be available through a dealer (like Isky or ARC), then you would prob get them from them, at that time, at a lower cost, because they buy them in bulk...
ok, wanted to post JDs answer here in case anyone else needs the valves... price for the valves at this point works out to $25.97/ea., as they are custom and considered custom when not made in bulk for a dealer... if interested you can contact SI Valves and speak to JD... number is 800-564-8258, they have been selling but they are made per order and not made in advance
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