stroker question

[fluidmotion]

im doing a stroker motor in my cherokee. its prolly gonna be around a 4.6L. the quesiton i have is for the camshaft. i had picked out this cam but i called up crane and i even called comp cams today and they said that i couldnt run that cam because i would have to get my computer totally reprogramed. it was my understanding that i wouldnt have to do any computer mods though.

if you guys know of a good cam im all ears. what im looking for in a cam is good mid range power(2000-5000 rpms). i have an auto, 4.56 gears, i will have the 2000 intake manifold, 62mm throttle body and i will be at 9.5:1 compression ratio. i do a lot of trail riding not much crawling. i still drive my jeep on the highway as well. any suggestions or comments

 

[Gil BullyKatz]

If you're building a Renix stroker...

It shouldn't be an issue

 

[fluidmotion]

nope, i should of added that. its in my 92 HO

 

[rsalemi]

The Comp cams 68-235-4 extreme 4X4 works fine with the renix Computer. I see no reason the 91 - 95 OBD1 computer would cause any problems - the 96+ OBD!! systems are much more sophisticated and might cause problems. The Comp Cams are dual pattern shorter duration cams using newer designs are more efficient than the old long duration Comp, Crane, Clifford cams. My 4.7 89 stroker pulls 16" of vacumn at idle - very close to the stock 4.0 cam.

 

[fluidmotion]

so then you think the cam listed above should work just fine with my 92 computer?

 

[old_man]

My opinion is that it should be fine, but I would like to hear DrDyno put his valued opinion in here.

 

[fluidmotion]

id love to hear what Dr Dyno has to say about this. i havent seen him around in a while, wonder if he went on vacation or something

 

[Dr. Dyno]

I was away on a four-day weekend, 1000-mile road trip in neighboring Oman. Beautiful country and wonderful people.
The Crane 753941 will work fine with the stock computer but the question is why would you want a longer duration cam? Unless you're going to spend a lot of time revving the engine above 4000rpm, you're much better off with the smaller Crane 753905 cam that I'm using. Up to 4000rpm, the smaller cam makes more torque and my engine also pulls 16" Hg vacuum at idle like Robert's.
The 753941 will feel a bit weak below 2000rpm. My 753905 is tractable from 600rpm, comes on strong at 1500rpm, and stays strong up to the rev-limiter. For an operating range of 600-5250rpm, it really is the optimum cam to choose for a 4.6 stroker. The bigger Crane is better suited to a 4.8 stroker with a CR in the 10's.

 

[fluidmotion]

then that cam sounds like it should do the trick. im not going to be running high rpms or anything. i just didnt want a cam that didnt give me good power throughout the whole rpm range. so based on what you said the 753901 looks to be the best choice. and since after this project gets done im looking into a front axle swap and going up to 37's or 38's the good low end will help to get me rolling

 

[fourwhldrv]

The Comp cams 68-235-4 extreme 4X4 works fine with the renix Computer. I see no reason the 91 - 95 OBD1 computer would cause any problems - the 96+ OBD!! systems are much more sophisticated and might cause problems. The Comp Cams are dual pattern shorter duration cams using newer designs are more efficient than the old long duration Comp, Crane, Clifford cams. My 4.7 89 stroker pulls 16" of vacumn at idle - very close to the stock 4.0 cam.

So why is it that Comp doesn't recommend these cams for fuel-injected engines--the X4254H grind you have and the X4262H grind that Golen uses in their 4.6 litre?

Comp lists the X4250H-13 for FI engines. It has somewhat less lift and duration than the cam you are using.

Does your idle have excessive lope or anything?

Thanks,
DJ

 

[rsalemi]

Idle with the cam can be as low as 500 RPM with no lope. I have the idle set at 800 RPM and the cam will pull down in high gear to 1100 RPM (at light throttle) without any problems. If I were to build another stroker I'd probably go up one more cam level - don't know if thatwould hurt the MPG - I can see 22 MPG (3.73 - 235X15 snow tires - 300 mile highway trip) at 2350 RPM - 70 - 75 MPH.