cam selection

[shawnxj]

ok i have everything for my stroker except my pistons and cam. the blocks going to the machine shop next week to find out what size pistons to order. so far my parts list is:

258 4 wt long nose crank
4.0 rods
99 block
0630 head
99+ intake, throttle body, injector rail
kb 944's
going in an 88 cherokee most likely with some type of fuel management

my problem right now is i have absolutely no idea how to pick a cam. i start reading all the stuff here and my head tries to implode. i was thinking about doing the 505 performance roller cam but yet again i have no idea what to pick. i want something with a good smooth idle and good low end but also has to be streetable since this will be my daily driver while i rebuild the motor in my truck. i thought about just doing the comp cams everybody talks about but after silvers problems with them i've decided against it.

the main purpose of my jeep will be running the beach and yanking out stuck idjits on the texas coast but like i said it will be street driven and i'd like it to have good throttle response and decent power at cruising speeds. i'm not gonna port and polish the head because i don't wanna move the torque curve too high and there's a possiblity of a turbo in it's future though that's not set in stone yet.

also what do ya'll think of an external oil pump? i've seen 4 or 5 oil pumps go bad in the last year or so and the brand new 1 i put in my jeep when i rebuilt the renix motor went out in under 15 hours and caused the crank to eat a rod bearing.

[jbxx]

I'm doing almost the exact same build into an 88 Cherokee too!
I chose the Comp 68-232-4 , but that is just from knowledge gleaned from the Net.
I am going to start out with the Renix controller and I think #24 Ford injectors.
Let's stay in touch here, my build spreadsheet is in the file sect of the Yahoo group.
J.B.

[shawnxj]

how's that running for you? i thought about using the renix computer and i'm still debating on using it but eventually i think i want the tuneability of a stand alone setup

[jbxx]

Just starting.
Still assembling parts.
I was thinking about a Megasquirt but I'm only going to mod as little as possible at first
I think that it will make it easier to troubleshoot.
J.B.

[nukfyrsq]

I built my stroker from a ’92 block with a DIY port and polish 7120 head and dropped it into a ’99 wrangler sport. Read a lot about early cam death and ZDDP. I’m using a 68-232-4 Comp Cam with mopar performance P5249464 valve springs, daily driver with 2000+ miles on this set up with no apparent problems. A couple of thoughts/opinions and things I did regarding early cam death. I rented SilverXJ’s lifter bore grooving tool and grooved my lifter bores along with a high volume oil pump; makes 50-60psi. It seems a lot of guys will use this cam with stock springs or the performance springs and feel that the slightly higher spring pressures are within acceptable limits. I chose to have my spring bosses machine deeper into the head to bring the seat pressure to within the spec for this cam. In theory this should reduce overall pressure on the cam lobes and hence wear. For the initial break in and up to 5000 miles I’m running 15w40 Rotella and CompCam oil additive. Then I’ll decide if I’m going to synthetic. Based on a recent chasis dyno run I pull GREAT flat torque ~220ft/lbs from 1000-3800rpm which is the cam spec range.

[shawnxj]

nukfyrsq are you using 258 rods or 242 rods? what compression did you end up with and quench?

where are ya'll buying your cams? summit has 1 mopar performance cam and like 2 crane then like 30 comp cams and jegs only lists 2 cams total. i want to look into more of the mopar cams but can't find anyplace that sells any other then the 1 summit has. after hearing about all the 68-232-4 comp cam failures i'm really trying to stay away from comp cams completely and i think i've talked myself out of the 505 roller cams but only because of the $1200 price tag. if there was a justifiable cost then i'd get it but so far it's an unproven cam from what i've been reading. does anybody else have a roller setup?

[nukfyrsq]

This is my first go with a non-stock cam. I read a lot of articles regarding various manufactures’ cams within this forum along with Google searches by brand and specific part number. I would suggest look through the threads/post here and you'll see there are three or four guys that are real sharp with a wealth of experience! I picked up my comp cam through an eBay store as a kit, be careful with the kits, mine was listed as suitable for 4.0 and 4.2 applications. The cam works in both, however the springs, retainers and locks were all specific to the 4.2/258.

I don't have my book with all of the specific values with me at work so I'll do the best I can from memory.
Block bored .040, Shaved .030, Head shaved .010 to improve quench height – believe it worked out to ~.053 with a Mopar .043 MLS head gasket, I intentionally didn’t go zero deck height to allow for learning and future tweaking, lifter bores grooved
DIY P&P, Combustion chambers 56cc, 3 angle valve job (reused stock valves), recessed spring bosses ~.030 to reduce seat pressure with custom brass inserts to prevent spring walk at high rpm
258 long nose crank and rods, 677p pistons enlarged dish from 14 to 22cc to reduce Static CR to ~9.5, dynamic CR per the CR calculator on this site ~8.8, rods and pistons weight matched to within <1.5grams, crank balanced – not a purist, yet, so harmonic balancer, flywheel and clutch assembly were NOT balanced as part of the rotating assembly
Cloyes Dbl roller timing chain set (indexed at 0 can be set 4 degrees advanced/retarded) , Hi volume oil pump, High volume water pump, DIY polish of thermostat housing, 160 degree T stat, aluminum single row oversize radiator w/Ford Taurus 2 speed electric fan, Bored Throttle body to 62mm w matching 1” spacer, K&N FIPK, SS header, Borla cat back SS exhaust, Accel coil, Off the shelf Advance Auto ‘performance’ plug wires and cap, NGK spark plugs, I believe I went two steps cooler, burn and color looked good at 500 miles, compression test 165psi average +/- 5psi/cyl, LUK clutch assembly, 175 amp alternator.
Broke it in on 91 octane, running mid grade 87 octane with no ping. This is a DD and my goal was 225ft/lbs of torque (peak on the dyno was 230) and mid grade gas looks like I got both. Fuel mileage is ~12 avg with 50/50 highway/residential. It should get better; I can't help but bark the 33x12.50 mud tires from time to time and jumping out in traffic with no fears of acceleration!!

Planning on adding an oil accumulator/pre-oiler and a PCV catch can (to keep from blowing oil vapor back into the intake), Increasing the exhaust pipe size to 2 ½” from the header back. Possibly 21# or 24# injectors with an AEM FIC piggy back computer to tweak fuel management. Plus some drive line up grades.