Father/Son Project - CJ7 258 to 4.6

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tws4834
Posts: 4
Joined: May 3rd, 2018, 6:11 am
Vehicle Year: 1982
Vehicle Make: Jeep
Vehicle Model: CJ7

Father/Son Project - CJ7 258 to 4.6

Post by tws4834 »

Hi all,

I'm a relative newbie to Jeeps - I've owned Gertrude (my CJ7) for almost three years but still feel like a newbie. I have rebuilt engines and vehicles in the past, but never built a performance engine of any consequence.

So in the process of putting a new head on the 258 (due to a stuck valve) I went ahead and dropped the pan when I found a ton of sludge in the oil galley/lifter area of the block. I need to replace the gasket and RMS anyway and to see how much sludge and debris was in there. While I was pleasantly surprised that there wasn't any sludge in there I was not pleasantly surprised at the condition of the mains. Not *terrible* but my guess would be another 25k miles tops. I didn't check the rods at all. Replaced the oil pan, RMS, and gasket and moved on.

While cleaning out the oil galley/lifter area with a modified attachment for my shop vac, I began to wonder about the lifters so I started pulling them. All were perfectly flat (and the cam lobes looked perfect) but each lifter had a healthy coating of carbon around the bottom 1/3. So I spent $50 on a cheap set from Summit and am installing them with installation lube and adding ZDDP to the new oil. I have new pushrods, new rockers, and rocker pivot kits as well.

Anyway - In the middle of all this I began to think about the future and the fact that I was going to have to spring for a new motor eventually. No two ways about it. Two days ago, my seventeen-year-old video gaming son tells me he's not going to college. He wants to go to tech school instead and learn to be a mechanic and engine builder. This came as a surprise to me because he's never even shown the first bit of interest in the Jeep or any of the work I do on it, but I figured I would play along and began asking him a few basic questions about engines and I presented him with the idea of helping me build a new motor. Turns out he'd been reading up a bit and was clearly enthusiastic about the prospects.

At this point, I hadn't thought of building a stroker. It wasn't until I did a Google search and came across Dino's page, which led me to Robert Bryce which eventually led me here. Now the idea alone has me hooked.

Yesterday I decided to do a Craigslist search just to see what might be around locally. The first thing that popped up was a 4.0 block - it doesn't *look* great, but it is complete and the guy wants it off his lawn and is selling to me for $50. The next thing I found was a 4.2 12 weight crank and 707 rods for $175. I am picking the block up tomorrow and the crank and rods on Saturday. Funny note: Both of those ads were put on Craigslist within two hours *after* my discussion with my son. And both are within 20 miles of me. The guy with the crank is about three miles away... Funny how the world works sometimes.

So I figured I would add yet another project to the list and introduce myself.

The plan is to build a "Poor Man's Stroker" with the shorter 707 rods. I've read up on everything as much as I could and believe that the shorter rod version will work fine for our purposes. My CJ is a daily driver (for the most part, LOL) that hardly sees the freeway. It's also a weekend trail rig but nothing outrageous. I've weighed the pros and cons and I am okay without the added expense of the longer rods/custom pistons. I have a T176 in a box in the garage that needs rebuilding and we will mate it with that instead of the T4 that's in her now. We're also going to buy a used head and port/polish it ourselves and probably go with a stock cam and valve springs. I can build out the wiring harness as well so a computer with plugs and ends off eBay should do nicely. I also found a few 91 - 95 Cherokees in the local Pull-a-Part yards so we are going to spend a Saturday scavenging for anything useful.

Other than that, he and I will discuss the rest of our choices as we move along in the process.

See you around the board!

Tim
tws4834
Posts: 4
Joined: May 3rd, 2018, 6:11 am
Vehicle Year: 1982
Vehicle Make: Jeep
Vehicle Model: CJ7

Re: Father/Son Project - CJ7 258 to 4.6

Post by tws4834 »

So it looks like I already found my machine shop.

It's about two blocks from where I work but I never knew it existed. The guy is super-cool. Spoke to him on the phone and will be dropping the block off there tomorrow right after I pick it up for him to hot tank and magnaflux - $75. He said give him a week or so and come back so he can tell me where I stand.

Said to bring him the crank and rods once I have them he will check them out as well.

And he loves the idea that I'm building it with my son. Just reminded me to double-check his work, LOL
tws4834
Posts: 4
Joined: May 3rd, 2018, 6:11 am
Vehicle Year: 1982
Vehicle Make: Jeep
Vehicle Model: CJ7

Re: Father/Son Project - CJ7 258 to 4.6

Post by tws4834 »

So I've been reading more and thinking more and I have slowly moved into the "spend more now to avoid possible issues later" camp.

With that, I've decided to go with longer rods and custom pistons. I sent Russ an email and asked what he recommends for a daily driver/weekend trail rig.

And since this is a long-range project, not something I have to finish ASAP, my time (and as a result the budget) can be stretched out to accommodate whatever I need to do so I'm good with adding another month or two to the project if I have to due to need for extra cash...
tws4834
Posts: 4
Joined: May 3rd, 2018, 6:11 am
Vehicle Year: 1982
Vehicle Make: Jeep
Vehicle Model: CJ7

Re: Father/Son Project - CJ7 258 to 4.6

Post by tws4834 »

12-wt crank is no longer an option. Bad crack in the journal. So I am on the hunt. Pickins appear very slim however.

Those who have them - even junkyards across the country - seem to know what they have and want an arm and a leg for them. And since when do junkyards have core charges? They're not trading me a reman - it's a pull from a junker. I'm going to have to pay to clean, check, and grind it - and I have to send them a core charge? Bulls**t. Why would I pay $400 for a junkyard pull - sight unseen - plus shipping - when I can get a new SCAT crank for $500? Or I can roll the dice with Autozone and pay $250 *with* core charge and see if I get lucky and get a 723. And if I get the light one, hell - I'll just use it. I don't think I'm going to Moab or anything.

Eh - I will keep looking. It's a long-term project and there's always other stuff I can be doing.
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