NEW GUY AND A CJ

[nitro]

alright ya all i've been building jeeps for a while now and found this site because cjoffroad is MIA . i lurked for awhile and now getting ready to tear my 99 4.0 motor apart and loot whatever i need for my stroker from my 85 cj7 .
i've done four 4.0 swaps in CJs but now its time for a 85 cj7 with a 99 4.0 stroked running a 94 OBD1 injection and ecm from an xj with a stick ecm (no speed sensor)

so any input would be helpful....


thanks in advance .......

[Cheromaniac]

What's your budget, what are your goals with the stroker, and what grade of fuel do you want to be running? These are going to be the main considerations when deciding upon the specs of your new engine.

[nitro]

well , the mortgage company wont let me spend too much and i have a wife with a wallmart addiction . its probably gonna be real cheap . stock bore with a re-ring with all bearings , and cut the crank to run the serpentine belt setup
its a frame up restoration so the motor is only part of my expense

[Cheromaniac]

Well, it looks like you'll be taking the poor man's stroker route.

[obryan]

Slightly off topic. But i am new to the whole stroker build idea. I am getting mine back from the the machine shop. I am super concerned about the compatability between the 4L flywheel and the 4.2L crank and how it relates to how the crank sensor on the bellhousing matching up. I have an 01 TJ (head cracked....new head) and i put in 4.2L crank and rods. 20-30 thou overbore. sealed power pistons. mild lift crane cam. performance timing set. new head is ported and polished with a 3 way valve grind. compression will be around 9.5-10..... If anyone can point me towards somewhere in the forum that has covered the flywheel thing and the maybe the camshaft sensor toothpick procedure i would be eternally gratefull


thanks

[4.whoa]

You said flywheel so I take it its a stick. The flywheel bolts on only 1 way - no chance to screw up , but you might need to get a different pilot bearing. Compare the I.D. Of the cranks.
Just do a search-toothpick method

[Cheromaniac]

I am super concerned about the compatability between the 4L flywheel and the 4.2L crank and how it relates to how the crank sensor on the bellhousing matching up. I have an 01 TJ

Not a problem, Just bolt your '01 flywheel onto the 4.2 crank (it's impossible to get the orientation wrong) and use pilot bearing 53009180AB.

[obryan]

You guys were right on the flywheel. impossible to screw up. so I have another question...here are the motor specs

01 4L block
4.2L crank and rods
30 thou over bore (stock style pistons = 13cc dish)
comp cams 68-232-4
19 thou deck height
.042 head gasket
quench is 0.0615

says my static compression is 10.1:1 and dynamic is 8.7:1 so should i be running premium....i was realy hoping to run 87...i used the compression calculator on the website to get these numbers..

any thoughts????

[YJason]

Thats similar to my engine except I've got the 68-231-4 cam and I have to run 93 octane or it will ping.

[obryan]

Thats similar to my engine except I've got the 68-231-4 cam and I have to run 93 octane or it will ping.

Since mine is efi i had to go with that cam....what year is your motor/jeep and what the setup? I was realy hoping not to have to run premium....what are you getting for gas mileage out of it?

[4.whoa]

[quote="obryan"]Since mine is efi i had to go with that cam..quote]
Just because they say a cam will/wont work w/EFI doesn't make it absolutly true. they are just being "safe". The main reason they do that is that the vaccum isnt as strong on bigger cams so it can screw with some sensors.

[YJason]

Thats similar to my engine except I've got the 68-231-4 cam and I have to run 93 octane or it will ping.

Since mine is efi i had to go with that cam....what year is your motor/jeep and what the setup? I was realy hoping not to have to run premium....what are you getting for gas mileage out of it?

96 XJ block, head, wiring harness, AW4 trans, and ECM in a 93 YJ w/ D44's and 4.10's. Last time I checked when it had 33's on it, I was getting 17ish mpg mixed driving. I haven't had a chance to check it with the 35's.

Here's a link to where I was going to sell it with all the info, but I have decided to keep it.

http://www.jeepstrokers.com/forum/viewt ... 257#p23257

[obryan]

17mpg... That's not too bad. I have 373's and am running 33" tires with an ax15 behind the stock motor. With the old 4L I was lucky to get 17....my fuel injectors were plugged full of crap and I have antifreeze seeping out of the head.... Not one of the motors finest hrs I'm sure but I hope that I'm at least at the same fuel economy or a tiny but better. Thanks for the help, appreciate it

[YJason]

17mpg... That's not too bad. I have 373's and am running 33" tires with an ax15 behind the stock motor. With the old 4L I was lucky to get 17....my fuel injectors were plugged full of crap and I have antifreeze seeping out of the head.... Not one of the motors finest hrs I'm sure but I hope that I'm at least at the same fuel economy or a tiny but better. Thanks for the help, appreciate it

I went from12 w/2.5 5 spd to 13 w/stock 4.0 AW4 to 17 w/stroker AW4, but I'm feeding it premo ga$ now. I'd probably get better mpg's if my right foot wasn't made of lead. I'm happy

[SilverXJ]

With 8.7:1 you will most definitely have to run premium.

On the EFI vs. cam selection I believe that the Jeep PCM is pretty forgivable on cam choices. The CC 68-231-4 is a popular choice and I have never heard of it interfering with any sensor or PCM. I have ran it on two different strokers and never had an issue. As long as you stay reasonable you should be ok. I.e. Don't get a cam with a lot of duration for "that muscle car sound". Besides a cam like that wouldn't be good for the stroker and would be considered over camming the engine.