??? stroker idea ???

[jeep_87_cherokee]

i have a thought of my own stroker biuld up that is just a few twist on the idea of a streetable/ dialy driver jeep with a stroker that could run off of regular gas.
-the biuld up would be for a '87 jeep cherokee 4.0L 242cid engine with 178k miles
it would go like this:

CRANKSHAFT: Jeep 4.2L 3.895" stroke crank ( i really want the '72-'80, casting # 3214723, 12 counterweight crankshaft )

CONNECTING RODS: Jeep 4.2L 5.875" rods

PISTONS: .030" over pistons with 11cc-22cc dish

HEAD GASKET: Mopar Performance #P4529242/Victor Reinz Dana #5713----0.043"

CAMSHAFT: Crane #753905 204/216 degree cam

INJECTORS: Ford Motorsport 24.0lb/hr @ 39psi (Part no. FMS-M9593-A302)

further, i would have the block decked .010" , shim the rocker arm bridges or get shorter push rods, get an adjustable MAP sensor, use an bored out throttle body and spacer from XJ-armor,use a stock 195 degree thermostat, i would use the original head and possibly have it ported at a local shop, and possibly use the stock rockers unless i could find some heavier duty stamped rockers at a decent price, replace the oil pump with a aftermarket/heavy duty pump, use a double roller timing chain and gear set, and replace the freeze plugs.

what i would like to ask is where i can purchase the pistons that are dished and the rings ???, where can i find and buy the crankshaft at- what do i do if the cank is ground???, where can i find some possibly new connecting rings that i want to use??? would it be worth the price to have the head ported at a local shop??? what kind of replacement oil pump can i use on the build??? and would it be alright to use the original valves, springs. and keepers in the stroker???

so what do u think of my idea for the stroker? i guess the compression ratio would be around 9.4:1 with the low volume dish in the pistons and that would be ok to run 87 octane with i think ?, and i would estimate the size to be about 4.6 liters, with horsepower almost at a modest 260 ponies...., but keep in mind that i tried to keep a balance between overkill and driveablity. and yet not be $broke$ . i want it very streetable as well as VERY offroad capable cherokee, so what do u think ??? will it work ??? thanks Luke

 

[xjoe]

I am very interested in this thread. There is a lot of info on building strokers with the newer(non-renix heads) and I'd like to see what people who have built a renix stroker have used.

I have a running renix 4.0 on a engine stand getting ready to tear down, and I just picked up a 258 crank and rods(thanks to John at auburn car care). So I need to source the rest of the parts still.

I will keep an eye on this thread as your build sounds about what I would like to do. Joe



I

 

[Dr. Dyno]

A Renix stroker built to those specs will be putting out more like 230-235hp with 310-315lbft of torque. That's still a decent slug of torque even if it isn't spread as high up the rev range as in a HO stroker with a ported HO head.

 

[xjoe]

Dr. Dyno, I have been reading everthing I can find on 4.0 strokers. I have a couple of questions for you. First, I read a post where you indicated that I could still build my renix based on one of your stroker recipies. Based on what I am working with what Which would you recommend?

my 87 xj is not a d.d. I am running locked d44's f/r w/5.13's, 36" Iroks and an AW4. I am mostly interested in low-to mid-range, my xj is mostly driven offroad but does still see a fair amont of highway(to the closer local trails) and around town driving.

I plan on using all renix parts, block, head and intake. I have picked up a crank and rods from a 258.

I have a cold air intake and bored renix throttle body. I also plan on having the renix head ported and refurbished.

I know I will also need Bigger(24#?) Injectors and a adjustable map sensor.

So what do you think? I am not trying to be lazy, but I feel there is no need to spend a bunch of energy on something that many have already researched and built many times before. I apreciate your input, Thanks.

 

[jeep_87_cherokee]

ok did the tread just get hijacked ???, besides Dr. Dyno i see where u mean that it would produce about 230-235 HP like the 4.6L low-buck "rockcrawler" stroker combination on the website www.jeep4.0performance.4mg.com/stroker.html ( great write ups )
but i would would only deck the the block .010" rather than .035" so my point would be that i would thus have a high compression ratio and probably just a little more HP if i ported and used a HO head and 2.5" exhaust......and would be using 13cc dished pistons compared to 30cc dished pistons have any effect on horsepower ?

so REALLY would my idea WORK !!!! ?

 

[jeep_87_cherokee]

ok this is what i am trying to point out, is that "option 2" is just a fine variable of the "rockcrawler" build and that just with those slight changes that you can go from 235 HP to 262 HP with just the use of a 22cc dished piston rather than a 30cc piston, beefier cam and a slighty larger exhaust !!!!!

and these are copied and pasted straight some the website!

4.6L Low-buck, low CR "rockcrawler"

Jeep 4.2L 3.895" stroke crank
Jeep 4.2L 5.875" rods
Silvolite UEM-2229 +0.030" bore pistons
Increase piston dish volume to 30cc
8.8:1 CR
Crane #750501 192/204 degree camshaft
Ported HO 1.91"/1.50" cylinder head
Mill block deck 0.035"
Mopar/Victor 0.043" head gasket
0.058" quench height
2.25" exhaust
Ford 24lb/hr injectors with stock 39psi FPR for '87-'95 engines, stock injectors with stock 49psi FPR for '96 and later engines
235hp @ 4500rpm, 327lbft @ 2000rpm

Option 2: Same as "rockcrawler" except:
Piston dish volume 22cc
9.5:1 CR
Crane #753905 204/216 degree camshaft
2.5" exhaust
Ford 24lb/hr injectors with adjustable FPR or MAP adjuster for '87-'95 engines, Ford 24lb/hr injectors with stock 49psi FPR for '96 and later engines
262hp @ 4800rpm, 325lbft @ 3500rpm


where can i purchase the parts i first listed at ???

 

[xjoe]

ok did the tread just get hijacked ???, besides Dr. Dyno i see where u mean that it would produce about 230-235 HP like the 4.6L low-buck "rockcrawler" stroker combination on the website www.jeep4.0performance.4mg.com/stroker.html ( great write ups )
but i would would only deck the the block .010" rather than .035" so my point would be that i would thus have a high compression ratio and probably just a little more HP if i ported and used a HO head and 2.5" exhaust......and would be using 13cc dished pistons compared to 30cc dished pistons have any effect on horsepower ?

so REALLY would my idea WORK !!!! ?

Sorry about the hijack!

 

[Dr. Dyno]

ok did the tread just get hijacked ???, besides Dr. Dyno i see where u mean that it would produce about 230-235 HP like the 4.6L low-buck "rockcrawler" stroker combination on the website www.jeep4.0performance.4mg.com/stroker.html ( great write ups )
but i would would only deck the the block .010" rather than .035" so my point would be that i would thus have a high compression ratio and probably just a little more HP if i ported and used a HO head and 2.5" exhaust......and would be using 13cc dished pistons compared to 30cc dished pistons have any effect on horsepower ?

so REALLY would my idea WORK !!!! ?

Decking the block 0.010" instead of 0.035" will leave the CR 0.5:1 LOWER, not higher. That's not what you're looking for if you want to maximize torque output (note I didn't say HP).
I think you're confused about the 235hp stroker recipe. You'll get roughly that output either with the "rockcrawler" recipe with ported HO head, or with the Option 2 recipe (higher CR, bigger cam) with unported Renix head. The difference is that the latter will make less torque at low/medium revs.