which engine size is best in a Jeep CJ7 - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep CJ Forum > which engine size is best in a Jeep CJ7

JKS Now Available at www.baseline4x4.com, Trackbars, SkidsFS: 2007-2013 Jeep Wrangler "HALO" Angel Eye KitFS: Wranger BRIGHT License Plate LED! Just $3! Great value

Reply
Unread 01-30-2007, 10:00 PM   #1
tmdupre
Registered User
 
Join Date: Jan 2007
Location: MS
Posts: 6
which engine size is best in a Jeep CJ7

I'm looking to buy a Jeep CJ7, which is the best all around engine to go with, a V8, 6, or 4 cyl.? Does the 4 cyl. have enought power. How about torque, are they close or is the V8 way ahead of the 4 cyl. New to Jeeps, figured I'd ask the experts. Thanks for your help.

tmdupre is offline   Reply With Quote
Unread 01-31-2007, 12:20 AM   #2
only in a jeep cj
Registered User
1986 CJ7 
 
Join Date: Jun 2001
Location: Mobile, Alabama
Posts: 4,123
IMO, when looking for a CJ to buy, Id would focus on certain year ranges rather than engines. For example, there are many differences between a 76 CJ-7 with a 6 cyl and a 86 CJ-7 with a 6 cyl. While both have a 258, there are different transmissions, t cases, axle widths, frame differences, interior and option differences, etc. But MAINLY look for a rust / dent free frame and body. An engine is just a component and can be swapped out for another one in an afternoon.....but if the body and frame are rusted and falling apart, you'll battle that for years and may not win (without going broke anyway).
To answer your question, the 6 is the most common and the most liked due to the touqe at low RPMs. There are two 4 cyl engines, a GM and an AMC. Both seem under powerd, but at least the axles are geared 4.10s. The only CJ V8 is a 304 and most will tell you if you'r going with a V8, go 360 or 401. I have both the 285 (6) and the 304 and like the 6 better for overall use. ...but my 304 is 31 years old, worn out and loud.....so I'm not speaking fairly.
__________________
Ed

1975 CJ-6 304 T15 Dana20 30/44 3.73
1983 CJ-8 258 T5 300 30/44 3.31 Looking for full or half hardtop buy or trade
1986 CJ-7 Laredo 4.6 stroker T5 300 30/44 3.31
1986 TJ-7 Trail Jeep project in the works
2003 Inca Gold TJ Rubicon
only in a jeep cj is online now   Reply With Quote
Unread 01-31-2007, 02:01 AM   #3
marmaduke
Registered User
 
Join Date: Jun 2005
Location: Derbyshire U.K.
Posts: 204
Also consider what you're going to use it for, I only use mine at weekends as I have a company car as a daily driver, which is why I've just swapped from a 20mpg 6cyl to a 360 V8 which I haven't worked out yet but I'm guessing does less.

As 'only in a jeep cj' said I was more interested in the body / frame condition than the engine but in an '86 over here they only come with a 6cyl anyway.

Good luck
__________________
'86 cj7, 360 cui, msd ignition, hedman htc's and still upgrading
marmaduke is offline   Reply With Quote
Unread 01-31-2007, 05:27 AM   #4
Oily
Registered User
1985 CJ7 
 
Join Date: Jun 2006
Location: Kerrville, Texas
Posts: 1,564
Quote:
Originally Posted by only in a jeep cj
To answer your question, the 6 is the most common and the most liked due to the touqe at low RPMs.
I have both the 258 (6) and the 304 and I like the 6 better for overall use.
The best engine really depends on what you are gonna use it for.
My CJ 7 has the 258cc 6 cylinder engine and a five speed tranny. I can get my 31.5 X 10s to spin on dry pavement. Not like I would be able to do in a V8, no doubt. Of course, either will easily spin tires in dirt, rock, sand, etc. The thing about 4WD is having traction. Sometimes, more power is not better. Most trail driving is at low speed and the low RPM torque of the six shines.
The wheelbase on CJs are not the greatest for high speed driving considering many have quirky steering. My 6 will comfortably do highway speeds but I do wish sometimes that it had more subtle power such as passing abilities at highway speeds or climbing some of the tall long hills (highway travel). Of course I can drop it down to fourth gear but I still sometimes think V8.
On the other hand, performance gains can be made on the 258 6cyl.
Oily is offline   Reply With Quote
Unread 01-31-2007, 05:43 AM   #5
SuB8HaVeN
Registered User
1986 CJ7 
 
Join Date: Dec 2006
Location: Tampa, FL
Posts: 2,287
20mpg with the 258 I6? I don't know if something's wrong with mine, but I ususally do about 10-13mpg.

Anyways, when I was looking I wanted a CJ7 with the 4.2L 258 I6. IMO, it's easiest to find aftermarket for this motor because it was the most popular. Not to mention, it's a great motor and seems to last forever. I had the 258 I6 in my 87 YJ and sold that with over 220k miles and she was still running strong. It had never been rebuilt or anything, and didn't leak or burn a drop of oil. My CJ7's 258 I6 is at 134k miles and still runs great although that wonderful plastic valve cover AMC used is leaking oil down onto the exhaust manifold. It's one thing after another on these things...
__________________
1986 Jeep CJ7 4.2L I6 T176 (restoration in progress)
1961 Willys 4x4 Wagon L-226 I6 T90 (restoration also in progress)
SuB8HaVeN is offline   Reply With Quote
Unread 01-31-2007, 06:23 AM   #6
Redmanchew
Web Wheeler
 
Redmanchew's Avatar
1982 CJ7 
 
Join Date: Oct 2006
Location: Central Virginia
Posts: 1,537
I get 20 with my 151. AS for jeep stuff, marmaduke and only in a jeep are dead on! foundation, foundation, foundation. I only have the 4cyl in mine and this being my first jeep it probaly saved me on more then one occasion learning the little nuiances on how to drive a jeep safely. Granted it dosent pull up a hill very well but the lack of horsepower also gives you a few extra seconds during the "oh shoot" moments. the 4 has great torque in 1st and 2nd for traill riding and 3rd is good for getting up 40 ish MPH but after that in 4th you better be on flat land or going downhill with the wind if you want 60.
__________________
1982 CJ-7 2003 4.3 chevy vortec, 4L60E, Clocked Dana 300 35 x 12.5 x 15 KM2 on Cragar 399's. Vanco Brake Booster. Power steering conversion. Warn front and rear bumpers with swing away. Moser 1 piece rears. Rear OX.

Support your local MS foundation. You don't know how much this disease sucks until it affects someone you love.

http://main.nationalmssociety.org/si...al&fr_id=18331

Quote:
Originally Posted by twoleos617 View Post
To reiterate for the 1,067th time, when towing...
remove rear axle, xfer in N, trans in 5th, remove neg batt cable, key to Run and go??
Redmanchew is offline   Reply With Quote
Unread 01-31-2007, 07:06 AM   #7
Gixxed
Registered User
 
Join Date: Jul 2006
Location: Lake Stevens, WA
Posts: 131
I had the 258 for years ad I agree it is a great motor. But when I put the 33's on it Then I realized I want and need more Power so now I am putting in a 401. So it will come down to what you want as far as power
Gixxed is offline   Reply With Quote
Unread 01-31-2007, 07:29 AM   #8
tmdupre
Registered User
 
Join Date: Jan 2007
Location: MS
Posts: 6
First. Thanks for all the replies, a lot of good info to think about.

The main way I would use the jeep is to go back and forth while hunting and fishing. Using it on dirt roads, having to go through mud at times. Something to get me there and back. Thats why I wasn't sure if the I4 would be strong enough for that, or do I need to go with at least the I6 or V8. Since I'm not driving it a lot on the highway, the four may be okay. Just want someone's opinion has or had one. Again Thanks

Tom
tmdupre is offline   Reply With Quote
Unread 01-31-2007, 02:50 PM   #9
bigjoe
Registered User
1977 CJ7 
 
Join Date: May 2006
Location: New Paltz,NY
Posts: 2,049
I've got two CJ7's at this time. One with the 258, (I-6) and one with a 151
(4 popper). Both have been used from daily rides to now weekend and snow plow work. I find that both could do the task that you want a jeep for. The only draw back I found for the 151 was lack of power for climbing hills. It's running 31x10.5x15's. When loaded with camping/hunting gear, it's a dog on hills. However, I use this jeep for snow plowing and it does a hell of a job. It also gets better gas mileage then the 258 with a quadra-trac xcase (full time 4wheel drive). If was getting a jeep be it a CJ YJ or TJ I would go with the bigger engine. You can't beat power. Just my 2 cents. Goodluck.
bigjoe is offline   Reply With Quote
Unread 01-31-2007, 03:45 PM   #10
Bard
Registered User
1985 CJ7 
 
Join Date: Oct 2005
Location: The Granite State
Posts: 2,662
454 FI , it fits, but has plenty of torque.

I would stick with a 6 cyl and have it geared for your set up tires, lift, etc.
__________________
85' CJ7 Laredo, 383 GM, Turbo 350, NP 203. SOA, 2" frame lift, 34" TSL swampers, Dana 30 open, AMC 20 w/ detroit locker, 4:10's, 1 Piece Mosers, 35" boggers to abuse when needed.
Bard is offline   Reply With Quote
Unread 01-31-2007, 03:56 PM   #11
Mr.Crowley
Registered User
1980 CJ7 
 
Join Date: Sep 2006
Location: nj
Posts: 2,774
I would look for one with the Inline 6 and proper gearing for the tires..Thats key...I have the 6 pack in my 7 and dread the 3.54's with 31's..Going to eventualy swap them out to 4.56's...and bigger meats.

**********edit*******I should have read the last post...
__________________
1980 cj7 258 weber,5'' of lift,33'' boggers,lincoln locked,lockright and a snorkle...Khaki Jeep Club member No. 1
1984 cj8 350 on 35's..the wifes
[QUOTE=Me]
"offroad it, and wave then you might understand"[/QUOTE]
BLS Home Chapter... Where it all Started
:hahaha: yj

My low Buck Rock Crawler project Project..Stop by and check it out..[URL="http://www.jeepforum.com/forum/showthread.php?t=497896"][B][COLOR="DarkOrange"]The lizzard Queen[/COLOR][/B][/URL]
Mr.Crowley is offline   Reply With Quote
Unread 01-31-2007, 04:17 PM   #12
gtrpup2
Registered User
 
Join Date: Jul 2006
Location: UT
Posts: 673
I dig my 304.... that is, I think if it werent so beat to hell and tired.. it'd be perfect. I'm upgrading to a rebuilt 360 in about 6 months. I was going to rebuild the 304 but the guys on here talked me into the 360. Go figure.
gtrpup2 is offline   Reply With Quote
Unread 02-02-2007, 06:51 AM   #13
tmdupre
Registered User
 
Join Date: Jan 2007
Location: MS
Posts: 6
any more! thanks for all the replys so far.
tmdupre is offline   Reply With Quote
Unread 02-02-2007, 08:15 AM   #14
Havasu Living
Member
 
Havasu Living's Avatar
1980 CJ7 
 
Join Date: Jan 2006
Location: Lake Havasu AZ
Posts: 307
It wasn't the engine I was concerned about but the rest of the cj. When checking it out I noticed the front rotors had grooves and was able get a reduced price. It turned out I had to dump $400 to replace rotors, bearings, hubs, spindles. Just make sure you check the entire rig out. It has the 6 and I love it. 99% of the time it is off road. Might go with a v8 later. Good luck
Havasu Living is offline   Reply With Quote
Unread 02-02-2007, 09:16 AM   #15
whit450
Registered User
1977 CJ5 
 
Join Date: Oct 2006
Location: Bertram, TX
Posts: 136
Ramjet 350, they look perfect under the hood and probably perform well to. Sure wish my pockets were deep enough to afford one.
whit450 is offline   Reply With Quote
Reply
Thread Tools


Suggested Threads





Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.