Crane #751111 or #751101

[CW]

It was slow at work the other day so I started going through the cam books and now I am thinking about swapping my comp 250 cam for the Crane #751111 or #751101 is anyone running these cams? The jeep is no longer my daily driver so fuel economy and noise is no longer a problem so the mechanical lifter noise wouldn't bother me. It is a wheeler so I don't want to give up my low end but I would like the extra horses, and the ability to get past 5000 rpms before the valves float, the 7000 on the 751111 sounds more fun. Any oppinions? This on an AP stroker.

 

[Dr. Dyno]

A solid lifter cam will certainly give your engine better breathing at higher rpm and it'll be even better if you raise the CR as well. Unfortunately this'll mandate premium fuel.
Keep in mind that even a ported 4.0 head's performance will drop off rapidly above 5500rpm and the piston speeds of your stroker will be getting pretty high.
If you really want your stroker to survive up to 7000rpm you'll need to invest in a custom billet crank, forged rods, and balance the whole bottom end. The stock timing gear won't survive 6000+rpm, and I doubt even the Cloyes dual roller set would survive much above 6000 either, so a gear drive may be the only option.
A Hesco aluminium ported head will allow the engine to breathe a little better but you'll also need a Flometrics 68mm TB and a 3" exhaust.
Lower the overall gearing of your Jeep and you can take advantage of the higher revs.

 

[CW]

I plugged the 751111 in to desktop dyno 2000 and I am really surpized. It says it will hit 319hp/351lbft with a long flat torque curve, while my comp 250h produces 248hp/346lbft again with a very flat torque curve. That is with the cam advanced 3 degrees, the 300hp number with out a power adder is too tempting to not do this. It will run me around $400 but I am willing to do it. I know I am accurate with the program too because I have files saved for all stock engines and all the stroker combos on Dinos page and the numbers are very close. I don't gain much tourque but from all my playing with the software you don't gain much until you up the displacement beyond 4.7L. The 5.0L stroker that is theoretically possible makes more 25-30 lb/ft more but I have doubts about the block strength with a 4" bore.

As far as rpms I don't intend to ever take it past 6000 and I will just up my limiter to 5500 from 5000. And with 10:1 compression premium is already what goes in the tank. I have 5.13's so the gearing is already taken care of, and I already have a ported head with only 10,000 miles on it so I don't want to go with the he$co head. I have a late model intake that I am going to mount two renix tbs on, or one renix and a smaller tb to keep the combined mm's down around 70mm. Would going gear driven timing mess with my knock sensor?

 

[HandBuiltXJ]

just curious on which cam you went with? I am currently building my stroker with a HO head, 4.2 crank and 40 over pistons and trying to decide on my cam. not looking to go over 5K rpms though, i am trying to build for rocks, and to just enjoy building my first engine. thanks for any and all input.

john