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Unread 02-21-2012, 04:48 AM   #16
CadCaman
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Quote:
Originally Posted by titomars View Post
That sounds like a good plan. Just so you know any intake set up will leave the power steering brace too low to mount correctly on the intake. But it's an easy work around.
My intake is a Clifford Research the Holley is an #8007-4 which is a 390CFM.
i am old school and carbs used to be my specialty. So I a a bit stuck in the past.
Besides if i ever do decide to go with FI, I have a 94 Cherokee 5 spd. as my beater. I already have everything i need to do a conversion.
Tito, I am going up to Muskegon this afternoon to get (2) 7120 heads ($40 a piece I thought I should just grab both in case someone else needs one), two valve covers, a computer, a wire harness, and an intake (pics attached). Will I need the computer to run the fuel injection when I put that on (I don't have a computer now)?

Thanks,

Jeff

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Unread 02-21-2012, 08:45 AM   #17
titomars
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Yes you will need the computer for the MPI injection so grab it. Technically your 83 did have a computer in it. If its still there its not any good for anything but the original Carter BBD and the smog controls.
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Unread 03-02-2012, 01:27 PM   #18
CadCaman
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Originally Posted by titomars View Post
Yes. You are planning a fairly very easy swap. The booster is not an issue since there is no carb to get in the way. if you are planning on the 4.0 MPI injection system, you will need the distributor and intake off the donor too. Remember to pull the entire ECM harness from the donor. It is easier to thin it out after you get it home. I would suggest going to the pick n pull yard and looking at the Cherokee line any 91 to 95. It will have what you want. if your Jeep is a stick look for a Cherokee with a stick for the ECM. Not Essential for you but us Californians have to have the right ECM to pass smog (check engine light). Why not just use the factory exhaust manifold off the donor? They work just fine. Just try and find the updated one with the bellows joints between the end cylinders. the ones without tend to crack. If you are planning a TBI system, there are other guys out there that are more knowledgeable on that than me.
Last word of advise while collecting parts for this, when is doubt grab it. It's better to have more than you need than extra trips to the wreckers. Also don't be surprised if you end up collecting parts off a few of them. It might help to take a few photos before you rip and tear off the donor for reference later.

i went with a carb on mine here is a photo for you.
Tito, I just noticed something I didn't think of. My clifford intake does not have screws for the bracket that holds the throttle mechanism (tranny kickdown assembly). I noticed in the pic that yours doesn't either. What did you do for that?

Thanks,

Jeff
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Unread 03-02-2012, 01:41 PM   #19
CadCaman
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Originally Posted by titomars View Post
Yes. You are planning a fairly very easy swap. The booster is not an issue since there is no carb to get in the way. if you are planning on the 4.0 MPI injection system, you will need the distributor and intake off the donor too. Remember to pull the entire ECM harness from the donor. It is easier to thin it out after you get it home. I would suggest going to the pick n pull yard and looking at the Cherokee line any 91 to 95. It will have what you want. if your Jeep is a stick look for a Cherokee with a stick for the ECM. Not Essential for you but us Californians have to have the right ECM to pass smog (check engine light). Why not just use the factory exhaust manifold off the donor? They work just fine. Just try and find the updated one with the bellows joints between the end cylinders. the ones without tend to crack. If you are planning a TBI system, there are other guys out there that are more knowledgeable on that than me.
Last word of advise while collecting parts for this, when is doubt grab it. It's better to have more than you need than extra trips to the wreckers. Also don't be surprised if you end up collecting parts off a few of them. It might help to take a few photos before you rip and tear off the donor for reference later.

i went with a carb on mine here is a photo for you.
Tito, one other thing. The APN exhaust manifold that i purchased interferes with the Clifford Intake (the tube farthest from the front collides with the intake manifold). So I am a no-go on that exhaust manifold. I notice in your pic you have one with some nice bellows on the outermost pipes. What kind is that?

Thanks again,

Jeff
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Unread 03-02-2012, 02:08 PM   #20
wendell
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I did the 4.0 head swap on my 87 258. I ended up putting my ported and polished 258 head back on. There was no 40 hp increase, just a little better topend. The 258 head keeps my peak torque in the lower rpm range better than the 4.0 head. The 4.0 head may work better with FI, or is better on the highway at higher speeds, but the 258 head responds better off road at a crawl and lower speeds. I have a holley TA 470 4 barrel, offy intake, comp cam, rollor rockers, (now) ported head, hipo pistons, header, HEI, and MSD. The 258 head worked better with this setup. The 4.0 head pulled a little better in the higher rpm range, but lost a little lowend where I tend to operate when wheeling. With the ported 258 head, it's still very fast on the street and has awesome lowend torque when off road. I paid over 400.00$ from clear water for the 4.0 head -vs- 250.00$ to port the 258 head. Just wanted to share my experience before you did the swap. You gain a little at the top, but lose some at the bottom, at least with a carb as you don't have a computer to make any kind of corrections. Not saying don't do it, but there is no 40 hp as have been sugested and you lose some lowend.
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Unread 03-02-2012, 08:43 PM   #21
titomars
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Quote:
Originally Posted by CadCaman View Post
Tito, one other thing. The APN exhaust manifold that i purchased interferes with the Clifford Intake (the tube farthest from the front collides with the intake manifold). So I am a no-go on that exhaust manifold. I notice in your pic you have one with some nice bellows on the outermost pipes. What kind is that?

Thanks again,

Jeff
Hi Jeff. mine is factory Mopar taken off a 94 Cherokee in the wrecking yard. From what i learned mine is the factory replacement for the cracking non-bellows manifold.
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Unread 03-03-2012, 09:14 AM   #22
titomars
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Originally Posted by CadCaman View Post
Tito, I just noticed something I didn't think of. My clifford intake does not have screws for the bracket that holds the throttle mechanism (tranny kickdown assembly). I noticed in the pic that yours doesn't either. What did you do for that?

Thanks,

Jeff
Jeff: Your right, the the bolt bosses do not exist for the stock carb linkage. It would not work for a Holley mounted in a conventional position anyway. I used a cable bracket i modified off a 1988 Olds delta 88 with a Q-Jet. The bracket fits the jeep cable perfectly you have to cut it in half at the span between the 2 bolt holes and weld in a spacer to match the Holley bolt pattern. The stock I6 accel cable reaches and fits perfectly. I have a 5spd so automatic kick down linkage was not an issue. If i had an automatic I personally would not use the kickdown anyway. I like to shift manually, yes even an automatic
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Unread 03-03-2012, 10:33 AM   #23
CadCaman
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Quote:
Originally Posted by titomars View Post
Jeff: Your right, the the bolt bosses do not exist for the stock carb linkage. It would not work for a Holley mounted in a conventional position anyway. I used a cable bracket i modified off a 1988 Olds delta 88 with a Q-Jet. The bracket fits the jeep cable perfectly you have to cut it in half at the span between the 2 bolt holes and weld in a spacer to match the Holley bolt pattern. The stock I6 accel cable reaches and fits perfectly. I have a 5spd so automatic kick down linkage was not an issue. If i had an automatic I personally would not use the kickdown anyway. I like to shift manually, yes even an automatic
I actually found something from Lokar that replaces the old kickdown assembly. But please share a little of that "shifting an automatic". I would love to be able to do that.

Like you warned me I did have to do a little fitting of the exhaust and intake to get a gap for thermal expansion. My Holley arrives on Monday. The old head is off and I am leaving to get all my gaskets and a goo torque wrench.

If you don't mind I woul love to know how "shift an automatic.

Thanks for everything Tito,

Jeff
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Unread 03-03-2012, 02:18 PM   #24
CadCaman
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Originally Posted by CadCaman View Post
I actually found something from Lokar that replaces the old kickdown assembly. But please share a little of that "shifting an automatic". I would love to be able to do that.

Like you warned me I did have to do a little fitting of the exhaust and intake to get a gap for thermal expansion. My Holley arrives on Monday. The old head is off and I am leaving to get all my gaskets and a goo torque wrench.

If you don't mind I woul love to know how "shift an automatic.

Thanks for everything Tito,

Jeff
I get it. Shift the automatic. Maybe I should think about it before asking.

Jeff
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Unread 03-03-2012, 05:12 PM   #25
titomars
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Originally Posted by CadCaman View Post
I get it. Shift the automatic. Maybe I should think about it before asking.

Jeff
Yeah it's no big secret. When you want to pass and stab the gas pedal just down shift to get your desired rpm yourself. Just like you would in a manual. Almost every automatic I have owned; I installed a manual valve body. Shifting an automatic is normal to me. If you look at GM throttle brackets in the wreckers i am sure you can find many with dual cable hook ups. anything with a Q-Jet and a TH350 or MV4 from the 70's or 80's.
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Unread 03-03-2012, 06:02 PM   #26
foggybottombob
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I did the 4.0 head swap on my AMC 258 using the Tim Weaver article which does not seem to exist any more. Like someone else said, I could not tell any difference from it at all. Unless you do MPFI with the head swap you will not notice any horsepower increase. You will get a lot more bang for the buck from HEI or team rush ignition upgrades.
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Unread 03-03-2012, 06:13 PM   #27
GPER
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I have been seeing where some people are using the 258 push rods and some are using the 4.0 push rods. so who is using what and how does it run????
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Unread 03-03-2012, 08:44 PM   #28
titomars
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I have been seeing where some people are using the 258 push rods and some are using the 4.0 push rods. so who is using what and how does it run????
From what I can see from various people is there is no one way to go with push rods. On mine after measuring, the old 258 push rods were the right length. But I have 4 sets of different length rods from 258's and 4.0's.
Mine is not just a 258 with a 4.0 head slapped on. I built my motor for the combination and it runs like a raped ape.
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Unread 03-03-2012, 09:07 PM   #29
gone2hatteras
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Originally Posted by foggybottombob View Post
I did the 4.0 head swap on my AMC 258 using the Tim Weaver article which does not seem to exist any more. Like someone else said, I could not tell any difference from it at all. Unless you do MPFI with the head swap you will not notice any horsepower increase. You will get a lot more bang for the buck from HEI or team rush ignition upgrades.
I used an 88 258 block (1/2” headbolts) to replace my 83 258. At the start I used the 258 pushrods with the 7120 head (per the internet source). To put it bluntly do not use the 258 pushrods, they are too long. Use the 4.0 pushrods to retain proper geometry if you are building a later model 258 block (1981 to 1990). The 258 pushrods for these engines are 9.700” in length and the 4.0s are 9.639 per Melling’s spec sheet. The 258 pushrods will not allow the valves to close properly and will cause damage to the valves.
My engine now runs very well with the Weber 38/38 and at idle has 18 inches of vacuum at sea level. It pulls strong from idle to over 4000 rpms. I drive 60 mile per-day 5 days a week and average 16 to 18 mpg with mid-grade 89 octane gas. The 4.0 will raise the compression and mine does not like regular gas of any kind. Yes, I drive my CJ daily and mpg is accurate. The variation in mpg is due to if it’s nice and the top is down I have a tendency to be very heavy footed on my way home. I did get a noticeable improvement in performance over the old 258 but that also could be due to the Comp Cam, larger carb and lack of blow-by.
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Unread 03-03-2012, 11:47 PM   #30
titomars
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Originally Posted by gone2hatteras View Post
I used an 88 258 block (1/2” headbolts) to replace my 83 258. At the start I used the 258 pushrods with the 7120 head (per the internet source). To put it bluntly do not use the 258 pushrods, they are too long. Use the 4.0 pushrods to retain proper geometry if you are building a later model 258 block (1981 to 1990). The 258 pushrods for these engines are 9.700” in length and the 4.0s are 9.639 per Melling’s spec sheet. The 258 pushrods will not allow the valves to close properly and will cause damage to the valves.
You really need to measure for the correct push rod length. If you change cams and go with something with a higher lift. That changes everything since cam manufacturers accomplish lift by changing the base circle which changes the the length of the push rod needed. Camshaft lobes can be no higher than the journals. Milling or surfacing the head or block changes the length required. Also head gasket thickness factors into this. Not all head gaskets are the same compressed thickness. If your head had a valve job it is possible the valves sit deeper meaning the stems sit higher. That should not happen if you have a good machinist but it can. The bottom line is measure for correct length.
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