Got my stroker crank! Woo-hoo!

I can hear and smell my tires peeling out already

I just FINALLY found and purchased a stroker crank last night. The guy seems legit, I just spoke with him, and he's a fellow Jeeper, which definitely lends him some credibility. I do feel bad for the guy I beat out in the bidding on EBay, I got him by $.99 in the last 2 or 3 seconds of the bidding. If you know him, please tell him I'm as equally thrilled as he is disappointed

The crank is supposedly out of a '79 258, which means it *should* be the 66lb, 12-counterweight casting, reported by Dr. Dyno to be supposedly the strongest of the 258 casts. I don't care regardless, I got it for what I consider to be a good price, regardless of the cast. I'll be picking it up from the guy (screw the shipping, I'll save money and get it sooner picking it up myself) this weekend. Hopefully, I'll be able to pick up headers, a cam, a high-flow Hesco water pump, a good 3-row, a Mean Green alternator, 68mm Flometrics TB, and an A/C compressor (it's still a daily driver after all). I would like to have the motor built and installed by spring or at the latest, early summer.

I do have a few questions. Will my stock 01 ECU be a good chip only for 87 octane, or can I use a 91 octane compression ratio with it? Obviously premium costs more also, but is it worth going with high compression for the extra power, or is it too small an increase? I plan on having the heads worked (ported intake & exhaust ports, 3-way valve job, springs, rocker arms), and also plan on either getting somebody to custom bend me some 2.5", or getting some exhaust piping and some mandrel bends, and bending one up myself. I of course would use a high-flow cat also.

Thanks guys. I can't freaking wait for this, this moment has been 5 or 6 years in the making. I am salivating to surprise some ricers, and hopefully anybody else who thinks my Jeep is slow

This one?

http://cgi.ebay.com/ebaymotors/AMC-...027784541QQcategoryZ33617QQrdZ1QQcmdZViewItem

Yep, that's the one

Good buy/bad buy?

Looks good from here. The low mileage is a plus, as well as it being spare parts. That usually means they wouldn't have a problem using it themselves. So it should be a good lookin' shaft when you get it. I can't say anything on the price though. Never researched them, so I don't know what a deal is.

oh man you got hosed.....i bought 2, yes two 258's one for $100 w/ 39k and one for $50 w/ 100k

i just sold a 12 CW crank for $35 to my buddy cuz i was tired of looking at it

Oh well......at least I finally found the stupid crank I wanted, and feel like I'm actually going somewhere with this project. I can feel the torque already........

I talked to the guy, he thought it may need .010" ground. He said on the phone that somebody at his local machine shop said all it really needed was some polishing.

What about my other questions though, especially compression/ECU? Those are the items I'm most concerned with, so I can start planning everything else.

The rough sketch of what I was gonna do is Dyno's 4.7L medium-buck stroker build, using the 258 crank and rods.

EDIT: 242 rods

tealcherokee said:

oh man you got hosed.....i bought 2, yes two 258's one for $100 w/ 39k and one for $50 w/ 100k

i just sold a 12 CW crank for $35 to my buddy cuz i was tired of looking at it

Click to expand...

you get another one you let me know, lol.

son of a bitch, that was the one I was bidding on too.

Sorry man! I really do feel sorry for you. Know this: that crank will be put to good use. I hope to have it built to around 270-280HP when I install it, and after I get some more funds together and turbo it, I'm hoping for around 400 crank HP.

Congrats, hope you love your stroker as much as I have mine. I've been running a stroker for about three years now. Been real lucky not to get any tickets. It sure surprised some Mustangs and ricers.

that doesn't help me out much!
oh well, I got a neighbor that is parting two cj-5s out to make one trail rig. He's keeping the 304 out of one, and giving up the 258 from the other. I don't know if it's 12CW or not, but beggars can't be choosers.

This is true. I just HAPPENED to check out EBay 2 days ago, and just HAPPENED to have some money available, so I figured what the hell, I'd bid on it. I wanted to get it for a lot less, but I'm still happy with the deal.

I can't freaking wait to build this thing. Anybody also know of any short blocks in the area? I am loathe to check a junkyard, even though the block will be getting bored and sonic checked and should be "good as new".

Oh, 1 other question (still no answers to my original questions): I was reading up on the first stroker built, Dr. Robert Bryce I think his name was, and he mentioned something about getting the "rotating assembly" balanced. I want this motor to last, and understand it could potentially lengthen the motor's life to get this done, but how important a step is this? I was thinking of asking the local machine shop to make sure the crank is balanced, and the rods are all weight-matched (or is that even necessary?). The pistons will, of course, be custom, so they should theoretically be matched pretty close to each other.

its gunna be sick, just like mine, if i ever put it together lol
4.8 or 5.0 anyone

I bought a reground crank for $135, with new main bearings, from my local Napa. You screwed yourself.

The compression ratio, and consequently, the type of fuel you need to run depends on the pin height of the piston you choose, and the length of the connecting rod you choose.

Sounds like you may need to do a bit more research on engine building before you dive into this........

Indeed, I would deserve a smack upside the head if I thought any differently. However, I think you misunderstood my question. I want to know if my stock ECU (in particular, the fuel mapping and spark advance/retard) is a good enough unit to use ON a high compression motor, not in order to gain high compression.

I do need to do more reading up on this before I start the build, but until I decide upon a compression ratio, I won't know what spec pistons to purchase. I only know I'm going .060" over on bore.

I wish I'd have checked NAPA then, I assumed (and looks like I mad an ass out of myself in the process) they'd charge something more in line with prices I see for new cranks at other places (c. $250). Oh well, too late. It's only money after all, right?

There are many HO based strokers out there running 9.5 to 1 compression, the upper limit on an iron head with 87 octane. You may hear some knocking under certain conditions, though, as the HO computer does not have the provisions for a knock sensor like the Renix models.

Overall, if you keep your compression below 9.5, you will be happy.

krakhedd said:

Indeed, I would deserve a smack upside the head if I thought any differently. However, I think you misunderstood my question. I want to know if my stock ECU (in particular, the fuel mapping and spark advance/retard) is a good enough unit to use ON a high compression motor, not in order to gain high compression.

I do need to do more reading up on this before I start the build, but until I decide upon a compression ratio, I won't know what spec pistons to purchase. I only know I'm going .060" over on bore.

I wish I'd have checked NAPA then, I assumed (and looks like I mad an ass out of myself in the process) they'd charge something more in line with prices I see for new cranks at other places (c. $250). Oh well, too late. It's only money after all, right?

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CRASH said:

I bought a reground crank for $135, with new main bearings, from my local Napa. You screwed yourself.

Click to expand...

You got a deal, they are $195+$55 in the NAPA on line store. So far the best internet price I've found is $199.99 with bearings and rods from JC Whitney

I picked up my '78 258 for free....complete. :wave: You really just need to shop around and be patient.

I don't have an answer to your specific question, but I wanted to let you know that I started a stroker writeup for the 4.6L rockcrawler:
http://www.projectxj.com/mods/stroker.htm

It has good links in there for you to read so that you have a better understanding of what you're getting into.

And just to give you a hard time.....it took you 5-6 years to drop $150 on a crank. Man, this is going to be one slow build up for you. :laugh3:

From what I can gather from the rather confusing writeup of the final article on the stroker in JP magazine once you swap to the 24lb injectors it should do fine.

It seems the important thing to remember with regard to what gas you'll be running is to make sure the quench height is tight like the factory ie I think around .040" so you have adequate turbulence in the combustion chamber to cool hot spots. I don't wanna buy the even more expensive 89 or higher octane either. I am seriously considering the aluminum head, which will pull even more heat out of the combustion chamber, should be able to bump the compression .5 or so and still get by with 87 octane, on the v-8's they commonly bump it up a full point.

Trust me, my friend was grilling me enough about it last night, especially when I told him that the remaining parts I need would cost $2000 retail

Until I pointed out that, with s'more patience (hopefully 2-3 months not 5-6 years), I could probably get away with $1k or less on EBay.

I still am wondering if my ECU would work well for a high compression (in the range of 10.5 or 11 to 1) application. If it weren't a freaking 01, I'd drop a Renix in so I could have the stupid knock sensor.....WHY would you take a knock sensor OUT in later models? Oh yeah, to save money, duh....stupid Chrysler....

EDIT: Sorry Randy didn't see your post. I had JUST hit lunch break, and was urgently awaiting the break so I could visit "the office".

Now that I'm back and feeling better....I am going to stick with the cast iron heads, I'd like the aluminum heads but am trying to keep this build relatively inexpensive. Also, aluminum being so easy to warp, I don't want to hit a puddle and need new heads. Seems I heard something about even the aluminum Hesco heads being a tad (or more) shy on reliability when compared to the stock iron units. I've got hood vents also, which evacuate a lot of heat (read: a very significant portion, and if this were a ricer, I'd have gained at least equivalent to a 50 shot of nitrous ), so that should allow the heads to remain relatively cool (compared to other iron heads). I'm going to do a full upgrade to the cooling system as well. I dunno how much I believe Poweraid's claim the TB spacer they make swirls the air well enough to make a more homogenous mixture of air and gas in the combustion chambers, but I also use a little acetone, which not only boosts octane slightly, but breaks down the surface tension of the gas as well, helping it to spray better, as well as helping keep everything cool by simple fact it evaporates so easily. That, and the fact whatever injectors I get will have a much better spray pattern than these stock units

I'm not necessarily going to build a high compression motor, but chances are a lot better that I will if my ECU will work well in a high-compression setup....any takers on answering that question?

Speaking of fuel additives, maybe I'll build a 500HP stroker once I get my turbo, where the motor would just dump gobs of alcohol into the motor when I lean into boost do I hear 30psi, anyone?