tom steele
New Member
what does it take for these motors to spin at 8 to 9 thousand rpms and still be reliable? i am guessing valve springs for sure maybe cams and rods of course but what else would you need?
If I remember correctly the "Screaming Eagles "Race team in GTP (I think..) run by the actor guy had problems with the cranks on these engines over 7000 rpm with the std. crank at 600 hp levels....They went to flat plane cranks and the engines were more reliable I believe..They were breaking the crank for some reason, harmonics were wreaking havoc on them..
Any one that can confirm this ? I still have the magazine , Turbo and High tech mag with the article..
If you want to do it on the cheap, just make sure you use the early model rods with ARP bolts in them.Then you can spin it to 8500rpm.
You won't make power unless you do other things but you will still be able to rev it to 8.5K.
Tom why would you want to do this kinda build when you have a supercharger.
I rev my 4.7 to 10,000 regularly and have no dramas with crank or anything really. Just pulled the crank out and the bearings hardly look used - I use 100 psi oil pressure though and have my oil holes radiused. I think it may be the light ally rods that help, and of course our short runs in drag racing.
I am converting to titanium RB26 retainers and dual valve springs and will see how that goes I may even rev it higher lol.
PC