USMCGunner

iTrader: (1)

Ok, so here I am at the point of making some decisions. I've been doing a lot of reading and a lot of searching. Unfortunately, most performance build ups I've read about are for speed and quickness. So I want to tap the knowledge base and do some learning. Obviously it would still be a beautiful thing to smoke a pony at a stoplight in a Jeep. I mean, that would just be humiliating for the other guy. But that's not my goal. I want to build up a stout motor that will provide a lot of low end torque as well as give me some decent mileage per gallon (that's why I selected the 4 speed OD trans). So I don't want to gear the **** of it to achieve that torque.

The engine is currently at the machine shop getting the crank turned and new bearings ordered. From there, I'm sort of in limbo. I don't want to break the bank, but while this little guy is torn down, now is the time to put some decent replacements in.

Can I get some build up recommendations from you all? I'm definitely looking at the roller rockers vs. stock. Specifically Crane Cams' setup. But, 1.7 or 1.8? Cam specs? Piston design? Compression? Piston rod length? With so many variables to choose from and not being a mechanic (this is my first engine build-a sort of life goal of mine) I'm a bit lost. Any insight would be appreciated. Once again, keep in mind this is for a trail/rock crawler Jeep.

SMOKY

iTrader: (4)

Dont worry about the roller rockers stockers are fine for what youll be doin. All you need is a basic rebuild, just with arp or katech rod bolts. Id run a 224 cam or even the asa for a nice torque curve and longevity of the valve springs. Get a good oil pump and push rods. Ls2 timing chain will be strong enough and get a good balancer. Youll need a small converter 2800 rpm should be high enough and still give you good lock up for mpg's

ShevrolayZ28

iTrader: (4)

What kind of Jeep? Sounds like fun!

...The stock rockers work fine, they are nice and lite. Keep them!

Rock crawling is low speed, off idle stuff. Right? So I think you want to stay away form the high duration cams (Stay less than 220). But picking a cam should be a careful choice. I don't think I know enough to really help you out. I'd call a sponsor and pick their brain. Make sure to give thorough details on what you want from the cam and how the vehicle will be used.

Who knows, maybe the stock cam would work well for you. Or maybe something like TR's "Old man truck cam".

http://www.thunderracing.com/catalog...&vid=9&pcid=51

YJ LS1

I put a slightly modified LM7 5.3L Gen III truck engine in my 87 YJ I used the 700R4 trans (would go 4L60 or 80 E if I have to replace it tho) Atlas II 5:1 transfer case 4.10 diffs. It's a great combo. I can blow off other semi fast vehicles like GT Mustangs and held my own pretty well with my sons 4.6L Cobra. The truck engine has a lot of low end torque for rock crawling which is what I do the most of. Playing in the washes and bouncing off the rev limiter is fun too. My install is in the php slide shows on my website if you are interested. Don't forget if you have stiock Jeep axles you're gonna probably blow 'em up. I ripped the rear axle off the springs twice and that was being careful. Had to weld the housing both times. I have since built much stronger rear axle ( True Hi-9 with a Detroit in a spidertrax style housing with 3/8 inch thick axle tubes) and have Superior shafts in the Dana 30 front. I have a 62:1 crawl ratio without considering the torque converter advatages. I think if you went stock parts you can't go wrong...you want reliability off road...stock stuff offers that.
http://www.parksrinehart.com

USMCGunner

iTrader: (1)

My plan is pretty similar to yours. I have a rebuilt 700r4 from an 86 Suburban. Although after some research, I discovered the trans is an 88 or newer. (aux. valve body) Not sure which torque converter is in there yet. Behind that I'm going to throw in an Atlas as well (when funds are available). The build up comes first.

I'm swapping out the stock axles for a HP44/60 combo out of a 79 F250. Already got'em, but they're far from ready. I probably going to go somewhere between 35 and 37 in tires. And I'm not sure on gearing for this setup yet. I've been looking for a 4l60/80e, but nothing affordable yet. I might put my 700 up for sale and splurge for a 4L60e if I can find one just for PCM purposes.

As far as the power side of things, it is going to be just for medium trail use and remain streetable to get to the trails. But I wouldn't mind lighting up a Stang here and there just for fun.

YJ LS1, I found your site a while back and thought about contacting you for some advice/guidance. I'm not a mechanic, and this is my first engine/jeep build adventure. Just something I always wanted to do. Ironic I find you in here too.

Here's the link to the build thread. Clciky There's a lot of joking around in it too, but the guts are there.