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Need help with motor build/ correct comp cam!!

Posted: January 11th, 2017, 8:03 pm
by kaspbrochill
Hey guy's i'm in the process of rebuilding/ minor stroker motor on my 96' 4.0 Grand Cherokee ZJ and really need to input/ advice on my build. I was originally going to build a 4.7 stroker but i've decided against because I am custom swapping in an AX-15 5spd trans. when I drop the motor in rebuilt and I know for sure that the trans. WILL NOT be able to handle the HP of a 4.7...i'd be lucky to keep it intact til 3rd gear before blowing through it so I decided to do:
-complete engine rebuild w/ hi flow oil pump
-bore it over .30
-Comp cam https://www.summitracing.com/parts/cca- ... /make/jeep
-Comp valvetrain
-Comp timing chain/gears
-Port/match my head (pulled a 93' XJ head), intake manifold and Gibson header's
-Performance Distributor's Firepower ignition (screamin' demon coil pack allows you to gap spark plugs to .065)
-Roller Rocker's..can't decide whether to get Harland Sharp 1.6 adjustable rockers or Yella Terra's ( I can get the Yella Terra's cheap)
-SCT tune
-Custom full 2.5" exhaust back (Magna. Hi flow cat, Flowmaster 44 muffler)

I already have the Comp Cam kit( https://www.summitracing.com/parts/cca- ... /make/jeep ) however, i'm not sure if the cam is too lopey for a non- comp. head or modified head...anyone have any advice or two cents?
Also if anyone has any suggestion's or critique on the build, I am all ears for suggestions!

Thanks guys!

Re: Need help with motor build/ correct comp cam!!

Posted: January 11th, 2017, 8:41 pm
by IH 392
What makes you think the AX15 won't hold up to a stroker motor?

Re: Need help with motor build/ correct comp cam!!

Posted: January 11th, 2017, 9:14 pm
by kaspbrochill
IH 392 wrote:What makes you think the AX15 won't hold up to a stroker motor?
I don't like to cut corner or half ass thing's so i'd be going all out with upgraded fuel pump,line's 60lb injector's, 68mm throttle body, roller rockers, SCT tune, etc. and it being under my lifted, locked, regeared, trussed ZJ with a B&M short throw shifter, Centerforce Stage II clutch and 35's...that trans. wouldn't wouldn't stand a chance and I feel like I would just be kicking myself in the ass wasting all the money on the trans., clutch and have then have the Jeep down again, have to find an NV3550 and new clutch then be ready for the trials. I'm trying to properly budget this and get it done ASAP so I can pull my 5.9 motor and begin my 408 build.

Are a lot of people running AX-15's behind a 4.7?

Appreciate your input, i'll take any advice I can get, thanks!

Re: Need help with motor build/ correct comp cam!!

Posted: January 11th, 2017, 10:27 pm
by Russ Pottenger
The 68-232-4 isn't that aggressive of a cam that I'd be concerned about. The only issue you'll have with running that camshaft is your on the borderline of being able to use your stock valve springs.

Both the Yella Terra and Harland Sharp roller rockers are good choices. If you decide to go to a valve spring upgrade I'd recommend running a 1.65 ratio with that camshaft. I stock them in the Harland Sharps.

Russ Pottenger
Bishop-Buehl Racing Engines
(626) 673-2203
Email/PayPal: [email protected]

Re: Need help with motor build/ correct comp cam!!

Posted: January 11th, 2017, 11:08 pm
by kaspbrochill
Russ Pottenger wrote:The 68-232-4 isn't that aggressive of a cam that I'd be concerned about. The only issue you'll have with running that camshaft is your on the borderline of being able to use your stock valve springs.

Both the Yella Terra and Harland Sharp roller rockers are good choices. If you decide to go to a valve spring upgrade I'd recommend running a 1.65 ratio with that camshaft. I stock them in the Harland Sharps.

Russ Pottenger
Bishop-Buehl Racing Engines
(626) 673-2203
Email/PayPal: [email protected]
Well I mean I already have the Comp Cam Springs they'll supplied with that kit so I guess I might as well use them keeping my budget in mind bc I've already bought a NP231 rebuild kit, Alloy USA HD chain..still gotta pick up an SYE kit, along with another 650-700 bucks in custom driveshafts; still need to pick up truss/axle kit for a HP D30, WJ knuckles (already have WJ twin piston caliper's) and still have to build custom 1 ton OTK steering. However, I am interested in HS roller rockers..I'll PM you for pricing, thanks! What do you think about intake and exhaust valves..is it worth porting and running oversized valves??

Re: Need help with motor build/ correct comp cam!!

Posted: January 12th, 2017, 2:41 pm
by SkylinesSuck
An AX-15 will hold a N/A stroker just fine. That is no reason not to build the motor you want.

Re: Need help with motor build/ correct comp cam!!

Posted: January 12th, 2017, 2:51 pm
by SkylinesSuck
And contrary to popular internet lore, the NV3550 hasn't been proven to be stronger than the AX-15. As matter of fact, the AX-15 in our jeeps shares lots of the same guts as the Toyota Supra trany can be built to handle considerable power. I think a company called rock land gear or something along those lines was building a "Terminator AX-15" but I can't find anything on then with a quick google search.

Re: Need help with motor build/ correct comp cam!!

Posted: January 12th, 2017, 3:27 pm
by Russ Pottenger
SkylinesSuck wrote:And contrary to popular internet lore, the NV3550 hasn't been proven to be stronger than the AX-15. As matter of fact, the AX-15 in our jeeps shares lots of the same guts as the Toyota Supra trany can be built to handle considerable power. I think a company called rock land gear or something along those lines was building a "Terminator AX-15" but I can't find anything on then with a quick google search.
X2,

The AX-15 is a pretty decent transmission and not to be confused with the Peugeot transmissions of the Renix era Jeeps. Unfortunately I have one in one of my 88 XJ's

Re: Need help with motor build/ correct comp cam!!

Posted: January 12th, 2017, 3:39 pm
by Russ Pottenger
kaspbrochill wrote:
Russ Pottenger wrote:The 68-232-4 isn't that aggressive of a cam that I'd be concerned about. The only issue you'll have with running that camshaft is your on the borderline of being able to use your stock valve springs.

Both the Yella Terra and Harland Sharp roller rockers are good choices. If you decide to go to a valve spring upgrade I'd recommend running a 1.65 ratio with that camshaft. I stock them in the Harland Sharps.

Russ Pottenger
Bishop-Buehl Racing Engines
(626) 673-2203
Email/PayPal: [email protected]
Well I mean I already have the Comp Cam Springs they'll supplied with that kit so I guess I might as well use them keeping my budget in mind bc I've already bought a NP231 rebuild kit, Alloy USA HD chain..still gotta pick up an SYE kit, along with another 650-700 bucks in custom driveshafts; still need to pick up truss/axle kit for a HP D30, WJ knuckles (already have WJ twin piston caliper's) and still have to build custom 1 ton OTK steering. However, I am interested in HS roller rockers..I'll PM you for pricing, thanks! What do you think about intake and exhaust valves..is it worth porting and running oversized valves??
If Comp.Cams sold you a valve spring i'm assuming it was the
926 spring and maybe they included the 744 retainers.

If so that set up is for 3/8 stem 258 head and will not work with the later 4.0 head.

Re: Need help with motor build/ correct comp cam!!

Posted: January 15th, 2017, 11:36 am
by 6TIME
If you're using the stock aluminum valve cover, Those springs will likely rub since they are much bigger in diameter. Also the 926 spring specs are overkill for your engine application and cam choice... Even though Comp recommends them. They made alotta noise in my motor. I pulled them and swapped LS beehives in and that quieted it down a bunch when i was running the 232-4 cam.

Re: Need help with motor build/ correct comp cam!!

Posted: February 9th, 2017, 6:05 pm
by kaspbrochill
Russ Pottenger wrote:
kaspbrochill wrote:
Russ Pottenger wrote:The 68-232-4 isn't that aggressive of a cam that I'd be concerned about. The only issue you'll have with running that camshaft is your on the borderline of being able to use your stock valve springs.

Both the Yella Terra and Harland Sharp roller rockers are good choices. If you decide to go to a valve spring upgrade I'd recommend running a 1.65 ratio with that camshaft. I stock them in the Harland Sharps.

Russ Pottenger
Bishop-Buehl Racing Engines
(626) 673-2203
Email/PayPal: [email protected]
Well I mean I already have the Comp Cam Springs they'll supplied with that kit so I guess I might as well use them keeping my budget in mind bc I've already bought a NP231 rebuild kit, Alloy USA HD chain..still gotta pick up an SYE kit, along with another 650-700 bucks in custom driveshafts; still need to pick up truss/axle kit for a HP D30, WJ knuckles (already have WJ twin piston caliper's) and still have to build custom 1 ton OTK steering. However, I am interested in HS roller rockers..I'll PM you for pricing, thanks! What do you think about intake and exhaust valves..is it worth porting and running oversized valves??
If Comp.Cams sold you a valve spring i'm assuming it was the
926 spring and maybe they included the 744 retainers.

If so that set up is for 3/8 stem 258 head and will not work with the later 4.0 head.
Sorry for the late response, I haven't checked the forum in a bit..

I mean it was a complete cam/ valvetrain set up w/ springs, seats, retainers, lifters, timing chain etc. for a 4.0 so I figured they we're all kitted together for a reason..or at least i'm hoping haha I have read that I should machine down the lower part of my head to properly run the cam and larger valves.. need to do more research into porting my intake/exhaust ports so run larger valves..more specifically which valves lol i'm so to speak trail and error building 2 different heads just for school sign off creds. and if performance sucks or I screw them up then pick up a Promaxx or Titan Engine's head because I also have free dyno access so it'll be cool to see what a modded OE head can output and monitor the longevity.

Re: Need help with motor build/ correct comp cam!!

Posted: February 9th, 2017, 8:42 pm
by Russ Pottenger
The only parts that will work in the kit Comp sent you for your 4.0 is the Camshaft, Lifters, Timing Set

Re: Need help with motor build/ correct comp cam!!

Posted: February 9th, 2017, 9:20 pm
by kaspbrochill
6TIME wrote:If you're using the stock aluminum valve cover, Those springs will likely rub since they are much bigger in diameter. Also the 926 spring specs are overkill for your engine application and cam choice... Even though Comp recommends them. They made alotta noise in my motor. I pulled them and swapped LS beehives in and that quieted it down a bunch when i was running the 232-4 cam.
No, I plan on running one of Crown's valve cover's to address the clearance issue (unless anyone has ANY other manu. that make aftermarket 4.0 valve covers!!)

Springs and cam overkill for my motor app.? It's not a stock 4.0...it's a custom 4.7 stroker? I figured that cam would be lopey enough to give me decent power but didn't see it being overkill.. What cam set up would you recommend to better accommodate a 4.7 stroker?

Again, i'm new to stroker motor's so I absolutely could be wrong, so i'm not going to get butt hurt over knowledge or criticism..I joined the forum as a noobie looking to learn. I am all ear's to any and all two cents, advice, or suggestions because by no means is this my specialty nor have any first hand experience stroking an inline-6, figuring out the right compression and stroke and everything else it entails...

Thanks!

Re: Need help with motor build/ correct comp cam!!

Posted: February 10th, 2017, 2:43 am
by dwg86
The valve springs and retainers you got with the kit will not fit the 4.0 valves. The kit is designed for a 258 not a 4.0. The valves in the 258 head have a larger diameter valve stem. Send the kit back and buy just a cam and lifters and timing chain.
The ax15 will be able to handle the 4.7 stroker. You will get more HP and torque, but this is not a ground pounding high hp and torque engine. it's still a relatively small cubic inch engine. A 4.7 is around 286 cubic inches. If you could get 1hp per cid, you would have 286hp. You will not get that with a small torque cam and bad flowing head. Going from a 4.0 to 4.7 is 42 cid. If you could gain 1HP for each 42cid that you gained from stroking, added to the stock 190hp you would get 232hp. Now that's good for a inline 6 cylinder tractor engine, but barely transmission breaking hp. Down low torque and rpm is great for Jeep.
Don't get me wrong, I have built a 4.6 stroker and it was an improvement over the 4.0, and I'll build another when my current 4.0 needs rebuilding, but don't expect to break any land speed records. My 2 cents.

Re: Need help with motor build/ correct comp cam!!

Posted: February 10th, 2017, 3:16 am
by dwg86
Oh yeah, do not try to run 60lb injectors. Even a 4.7 stroker won't run on 60 lb injectors. If you are doing a 4.0 rebuild, keep the stock injectors. If you are building a 4.7, you will need 24 lb injectors. I ran 26lb injectors on my 4.6 and they were too big. The engine would "lope" when it was cold (too much fuel in open loop), but then would smooth out when in closed loop. BTW a .206 duration @ .050 cam will not "lope". My cam was .214 @ .050 with .501 and 112 lobe separation. It ran as smooth and quiet as a sewing machine after it warmed up and went into closed loop.