How would you rebuild this 258? - JeepForum.com
 
LinkBack Thread Tools
post #1 of 10 Old 05-22-2012, 02:25 PM Thread Starter
jduress
Registered User
1985 CJ7 
 
Join Date: Dec 2011
Location: Upper Sandusky
Posts: 16
How would you rebuild this 258?

I am swapping a 258 in my 85 cj 7 to get rid of the 4 cylinder, I was just wanting some input on how you guys would go about rebuilding the 258, its a complete motor out of a 79 cj5. The odometer reads 60,000 and some (correct) miles but it has been sitting since 1997. I am probably going with a carb as I am in college and do not have the money and time for an efi 4.0 head swap. So I wanted to see what you guys have done and what you think on issues like: What carb and intake to use? How far into the motor should I go? Easy and inexpensive upgrades that can be done? Exhaust? Thanks!

jduress is offline  
Sponsored Links
Advertisement
 
post #2 of 10 Old 05-22-2012, 03:28 PM
BioTex
Registered User
2006 TJ Wrangler 
 
Join Date: May 2008
Location: Alpine, Tx.
Posts: 3,173
If it were me, I would save my money, and run stock (OEM) intake and exhaust. The 258 is a low rpm workhorse. You very well could slightly decrease your HP running a cheap header that will rust out after a couple years anyways.

If it were me, I would save for TBI or EFI. A junkyard TBI can be built for a hundred bucks or maybe a little more depending on the adapter.

As for the engine, prime the pump, and run a compression check and go from there. Read the plugs while you are at it...

'85 CJ7, BDS 4" lift, 1" Body lift, 33x12.5, Shrockworks Sliders, 304 V8 with RV cam., T-176, D300, Dana 30, AMC 20.
1986 CJ10-A SD-33 Diesel/727/np208
1971 800B with 345/T-19
06' TJ Rubicon, 4" R.C. springs, BFG/AT 35s M.C. 6" fenders, rockers and surrounds, Currie front & rear adj. tracbars, tattons DC rear shaft, adj. upper - lower CA's. Bilstein 5100's
YJ Buggy Build Current project. Stroker/FI ?
1990 MJ Comanche 4.0L AX15/np231
BioTex is offline  
post #3 of 10 Old 05-22-2012, 04:33 PM
only in a jeep cj
Registered User
1986 CJ7 
 
Join Date: Jun 2001
Location: Mobile
Posts: 5,035
"Low on time and money" .....If the engine runs, swap it in AS IS and keep it all stock. Run it for a while until it needs a rebuild. Now here's what I would do (and DID). It cost the same to rebuild a 4.2 as it does a 4.0 as far as rebuild kits and labor cost. So while it is running fine for now, keep your eyes open for a low buck or free 4.0 that needs a rebuild. The crank and rods in your 79 are the more desirable 12 counterweight version that folks want for the stroker builds. So when the time comes, bring your 4.2 crank and rods with the 4.0 block/head etc to the re builder and do it once. Since it will be a major task to remove the engine and all, doing the harness splice and other fuel injection parts at the same time won't be as bad.

Ed
1975 CJ-6 1983 CJ-8
1986 CJ-7 Laredo 1986 TJ-7 Trail Jeep
2003 Inca Gold TJ Rubicon
only in a jeep cj is offline  
post #4 of 10 Old 05-22-2012, 07:32 PM Thread Starter
jduress
Registered User
1985 CJ7 
 
Join Date: Dec 2011
Location: Upper Sandusky
Posts: 16
I have not tried to start the motor yet, it is still in the cj 5, I have turned it over by hand its not locked up, I was thinking about running a motorcraft carb, have been reading alot of good things about them
jduress is offline  
post #5 of 10 Old 05-23-2012, 03:15 AM
Mickey_Mouse
Registered User
2013 KK Liberty 
 
Join Date: Dec 2011
Posts: 726
new cam+hei distributor, 60,000 miles? Still a good running motor. Chec for exhaust leaks from the exhaust manifold back to the catalytic conveter to the muffler and back. I would run the motor without rebuliding but adding upgrades like the HEI distributor and carb. motorcraft 2100 electric.


http://www.ebay.com/itm/NEW-MotorCra...d26304&vxp=mtr

this guy is who I bought my carb off of. kit comes with a cd/instruction manual with different variations installing.


if you buy a Offenhauser intake: http://www.summitracing.com/parts/OFY-5416: you could install a holly 650 CFM carb. Changes the intake to 4 barrel.

some Jeepers have installed TBI on their Jeeps.
Mickey_Mouse is offline  
post #6 of 10 Old 05-23-2012, 09:01 AM Thread Starter
jduress
Registered User
1985 CJ7 
 
Join Date: Dec 2011
Location: Upper Sandusky
Posts: 16
I like the looks of his kits, I sent him a message asking questions about my particular setup, Which brand of distributor and cam would you recommend?
jduress is offline  
post #7 of 10 Old 08-08-2012, 06:31 PM
prew32
Registered User
1984 CJ7 
 
Join Date: Jul 2012
Location: lincoln
Posts: 1
Quote:
Originally Posted by Mickey_Mouse View Post
new cam+hei distributor, 60,000 miles? Still a good running motor. Chec for exhaust leaks from the exhaust manifold back to the catalytic conveter to the muffler and back. I would run the motor without rebuliding but adding upgrades like the HEI distributor and carb. motorcraft 2100 electric.


http://www.ebay.com/itm/NEW-MotorCra...d26304&vxp=mtr

this guy is who I bought my carb off of. kit comes with a cd/instruction manual with different variations installing.


if you buy a Offenhauser intake: http://www.summitracing.com/parts/OFY-5416: you could install a holly 650 CFM carb. Changes the intake to 4 barrel.

some Jeepers have installed TBI on their Jeeps.

Is anyone else running one of these carbs?? Debating on whether or not do a howell fuel injection or just switch to a better carb, I just did the team rush upgrade and my 258 still isnt running quite right
prew32 is offline  
post #8 of 10 Old 08-09-2012, 07:14 AM
aggiejon
Registered User
1979 CJ7 
 
Join Date: Jan 2009
Location: Temple
Posts: 637
I swapped in a motorcraft 2100 carb and HEI. Ran well. My motor was pretty wore out. Found a deal on a parts jeep with a fresh drivetrain.

Watched Craigslist and swapped the motor and did a junkyard mpfi. Thanks to Craigslist, eBay, some patience and searching, and the scrapyard, did the whole thing for nearly even money.

Was a daunting task, especially pareing down a harness, but was worth it now that it starts on the third spin and idles like a top. So smooth it's like silk.

My opinion, swap it in and run it. Make upgrades as you have funds. Get it running and driving. It is more enjoyable that way. Everyone wants to go for a ride, not look at it in the garage.
aggiejon is offline  
post #9 of 10 Old 08-09-2012, 08:56 AM
twinstickd20
Registered User
1979 CJ7 
 
Join Date: Jun 2010
Location: nashville
Posts: 1,898
Quote:
Originally Posted by aggiejon
Everyone wants to go for a ride, not look at it in the garage.
I know that feeling, it's been down for a month. Now waiting to hear back from the machine shop.
Attached Thumbnails
image-1174167302.jpg   image-421863329.jpg  
twinstickd20 is offline  
post #10 of 10 Old 08-09-2012, 10:12 AM
baldfatdad
Registered User
1984 CJ8 
 
Join Date: Nov 2009
Location: florida
Posts: 625
I'd do a compression test on the motor. You won't get real good numbers with it cold and turning it by hand, but you will see if anything is real bad, if you come up with a cylinder with no compression. If it passes that: I'd change the valve cover gasket. A lot easier when its out of the vehicle. Maybe the valve cover, if the old one is warped or cracked. Rebuild the carb. I've run a BBD for 20 years, no problems. Just follow the instructions in the kit in order and exactly. New plugs, wires, cap and rotor. Run it.
Then read, learn, decide what you want to do with the jeep and build the engine to do that. I rock crawl, my engine hardly ever sees 2k. My buddy runs mud, his idles higher than that (that's a joke), and runs to 5k. They both are built for what they do.
baldfatdad is offline  
Reply

Tags
258 , advice help , cj7 rebuild question , engine swap , motor

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.



Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Jeep Forums Replies Last Post
Cj7 rebuild SuperSloth2005 Jeep CJ Forum 4 02-08-2011 07:07 AM
Carter BBD rebuild: Does it matter which rebuild kit I use? Ken4444 Jeep CJ Forum 2 06-14-2010 11:01 AM
T15 rebuild kit JGS08 Jeep CJ Forum 2 01-14-2009 02:50 PM
What do I really need to rebuild my SBC 350? CJman77 Jeep CJ Forum 2 06-05-2008 06:02 AM
CJ tub rebuild paraman72 Jeep CJ Forum 5 06-07-2005 10:06 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome