302 performance cam question
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Freshman User
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302 performance cam question
I recently bought a crane energizer cam off of ebay. The cam has .512 lift and I am wondering what all I would have to do to install it in my 93 block. I plan to rebuild it, install roller rockers, stronger valve springs, exhaust headers, balance the pistons, and dual oil coolers. also note that this is going to be instaled in a 91 ford f150 whith the mazda 5 speed (4 speed with overdrive) manual transmission. I am would like to know if I need larger (21 lb) injectors or something like that in order to make it work? any input would be helpful.
91 f150
91 f150
Last edited by cedarratt; Jul 15, 2004 at 12:07 AM.
Senior User
Joined: Apr 2004
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From: NH
make shure because if the pistons get intimate with the valves things get realy ugly quick. as for the injectors i can't realy say i'm baseing my answer off my motor but that's a 347 which i have changed injector sizes 3 times at the request of the motor builder and pro-m.
Senior User
Joined: Jan 2004
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From: Illinois
I don't think "just barely" is going to be enough clearance. I have heard that max lift is somewhere around .520, not positive on that figure. I second robduval, triple check that valve clearance, also keep in mind that if the engine ever overheats there might be enough piston expansion for it to slam into the valve. If that happens you might end up with a 5.0 paperweight. If your going to rebuild it anyway get a set a pistons with valve reliefs. The reliefs will not hurt performance in a noticible way.
Sanders
Sanders
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.512 may be okay depending on the duration at .050. Duration at .050 may be more important to consider than lift, provided the lift is still fairly close to .500. If the duration at .050 exceeds about 225, then it gets dicey. You need much more clearance with the exaust valve (due to heat) than with the intake valve. A lot of cams have more lift and duration on the exaust side, so this can cause problems, even though the intake valve is much larger.
FWIW, Stock short block 5.0 HO's(except the 86) can typicaly use the B303 roller cam with a 1.7 rocker, no problem. Here you end up with .512 lift (.480 with 1.6 rocker's) and 224* at .050. on both the intake and the exaust. .500 valve lift, with a duration of no more than 220* at .050 is considered very safe on all stock engines with the double eyebrow valve relief pistons.
Having said that, always check to make sure on each engine, and don't just follow rules of thumb.
FWIW, Stock short block 5.0 HO's(except the 86) can typicaly use the B303 roller cam with a 1.7 rocker, no problem. Here you end up with .512 lift (.480 with 1.6 rocker's) and 224* at .050. on both the intake and the exaust. .500 valve lift, with a duration of no more than 220* at .050 is considered very safe on all stock engines with the double eyebrow valve relief pistons.
Having said that, always check to make sure on each engine, and don't just follow rules of thumb.
