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93 4.0 swap using 258 parts build

4K views 15 replies 7 participants last post by  boduke5051 
#1 · (Edited)
93 4.0 swap using 258 parts build help needed

Well my old 1981 258 engine is toasted due to running out of oil and I can pick up a 93 4.0 engine out of a grand for a good price.

I have read the official 4.0 swap thread but it doesn't really cover what I want to do.

I am getting the full 93 4.0 engine but due to time and money constraints I plan on using my '1986' intake and Carter-Weber BBD carb on it. I will save the FI intake for a later project. I read the grand isn't the best harness to use anyway.

I know I need the exhaust manifold and a chunk of down pipe to hook that up and will need to trim the intake a bit some place right?

Is there a good RTV to use or what intake gasket should I be after? Mine is about 10 years old.

The engine has no starter or alternator. I figure I can use my 258 flywheel and starter ok.

I figure my waterpump and fan can swap over.

I also figure my engine mounts will swap over.

I will need a new pilot bushing or can I pull my old one and swap it. Any part numbers on that?

What else do I need?

Can I use my AC Delco alternator and my PS pump? (engine should also have a PS pump on it, but a serpentine pulley)

What about the crankshaft pulley? Will my V belt one from an 81 engine swap over ok or are there gotchas?

Then there is the distributor. I read that someone used the 4.0 distributor but can't really see that working or? Will the 258 one swap or??

I will also need an electric gas pump, 'shudder', what type is best? I will want a self priming one with low psi I believe. Suggestions? I have the 20 gallon poly tank on it so will go inline for now.

I do know how to wire it in using the oil pressure sender and fender solenoid's side posts for power so it will see power in start and with oil pressure.

Anything else?
 
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#2 ·
Mike almost all your stuff will swap over the only areas that will give a a little heart burn are the top bracket for the PS pump. The top aluminum may not work since it goes under a 7/16 head bolt and the 4.0 are 1/2 inch. While the diameter isnt that big of a deal finding one extra long head bolt will be. Your starter and flywheel will be fine.

The next area that be a pain is the intake and exhaust manifolds I used Permatex gold fuel ingection RTV since there isnt a lot of matting area on the intake. I am not sure if anyone has successfully used a cast iron intake in this combination. I did use a Gale Banks header and had to clearance the crap out of it to make it fit. I still have it if you want PM and Ill give it to you you just pay shipping.
 
#3 ·
So the swap is in progress and is going quite well.

I got a 5-9 psi electric pump with prefilter that I installed just in front of the rear spring hanger at the low point on the frame and plan on using a switched power for it via the oil pressure switch and the soleniod S post for dual powers, both start and run.

I want to give a big thanks to 85YellowCJ7 for his photos of doing the intake manifold. I ground mine exact to his and it fit like a glove first try. http://picasaweb.google.com/85YellowCJ7/40HeadSwap#

I found a couple gotchas so far, but not many.

The waterpump 'needs' a gasket, RTV won't work it has to have the space the gasket gives or the impeller hits the cylinder wall inside.

The 4.0 pilot bearing will 'not' work on my T5, it is way too sloppy so I punched out the bushing from the 258 using grease and a cut down old shock tower pin as a hydraulic piston. I pulled out the oil wick from behind the bushing, then filled the hole with grease. I then found that a shock tower pin with one wrap of black tape on it fit the bushing hole exact so I cut off the threads that were in the way and put it in the bushing hole, then gave it a good smack and out popped the bushing. It took 3 grease fills and 3 smacks to pop it all the way out. Slick.

I then found out that the bushing was too big to fit int he 4.0 crank so got the well greased shock pin back out and put the bushing on that, then I spun it on a grinding wheel. This peeled down the outside diameter until the calipers said it was the same size as the bearing and away I went, it tapped in great.

Didn't have a clutch tool so I just eyeballed it using a socket wrench extension and well, got it, it slipped together quite well.

Noticed that even after nearly ten years, my clutch disk has almost no wear on it, same for the flywheel and pressure plate.

The harmonic balancer went on and lines up tithe waterpump pulleys, haven't set the alternator or PS pump yet.

The 258 distributor was a real bear to get out! Took pipe wrenches and vise grips and tons of penetrating oil. The 4.0 one just slipped on out.

One of the never used holes in the 4.0 block that the CJ engine mount needs was totally wallowed out from rust. It was so far gone that a 1/2" tap ended up being used to rethread it, then we used a die grinder to wallow out the hole in the mount to 1/2" also.

And I don't care who you are, I am pretty darn good and the gent helping me is a 25 year experienced pro mechanic and we 'still' needed a chain pull, a 5' 2x4, a 4' heavy pipe, a floor jack and several pry bars to make the sucker line up right so don't ever be afraid of a little 'persuasion'..... The mount holes lined up nice, we didn't even get to any good cussing...

Tonight I hopefully will finish up putting it together to fire it up. I am using a nice newly met neighbour's garage with a sweet I beam and chain pull for this and have to wait until he gets off work to go back at it.

I am just putting it in as I got it, all covered with oil from a leaky valve cover (what else can you expect eh) and am getting some photos that I will put up later. I will have to clean the engine later, no real matter except is is messy to deal with.
 
#4 ·
Success!! :D

I just eyeballed the distributor in because we had no timing light and it fired up at the first crack of the key, no starter noise at all.

It then idled down very nice after warming up, to 700 rpm with no exhaust connected yet, very nice, it just purrs and sure seems to like that old Carter-Weber BBD carb. :)

It will be a couple days before I can hook up the exhaust, set the timing correct, (though it sure runs right as it) and give her a good run, but it sure sounds nice now.
 
#6 ·
Pics or it didnt happen! :D Come on Mike you know the rules!!
 
#7 ·
Mike keep us informed when you get it on the road. I really want to know what you think of the power of it over the 258. I have a rebuilt 258 and junkyard TBI I am getting ready to swap in my 86 and now I have been having second thoughts and thinking about swapping to a 4.0 MPI or a 4.3 TBI Chevy instead. I like the I6 but a TBI 4.3 would be a clean and simply swap. Looking forward to you next post. Thanks for sharing.
 
#8 ·
Thanks for the post.
I'm working on putting a 93 4.0 from a grand in my 8.
I'm looking at pulling the crank and rods from the 258 that I'll be pulling out and putting them in the 4.0 and keeping my TBI that i have on the 258.

My biggest concerns were what would bolt up to the 4.0 from my 258.
 
#9 · (Edited)
So I have been really swamped with work and a new property we are setting up for 'off the grid' living on and haven't had a chance to do a follow up.

The 4.0 using the Carter-Weber BBD carb and 81 distributor just rocks. It has tons of power and the gas mileage seems to be up in the 20's also. It runs about 1 turn richer on the mix screws and 1/4 turn richer on the vacuum piston so far and just purrs at idle and holds the hills better on the highway in 4th than our 2000 Cherokee 4.0 does, the Cherokee has to downshift to hold 110 kph, the CJ will accelerate up from 110 kph on the same hills. Haven't had a chance to do a proper mileage check yet, just $20.00 runs using regular gas.

The power is higher than both 258's I have had before, considerably higher, even at low RPM bog points and this engine has 280K KM on it. I am using it as a logging skidder and the Utility Vehicle it is around our woodlot and it chugs along nice. I was expecting to need more rpm to hold power low.

And then there was the distributor.... Well that thing had been in there since 1981 and seeing as the timing never goes off on these electronic distributors, it had never been moved. I soaked it for days in penetrating oil, tried vise grips, a chisel ('don't' do that, the lip breaks..) and finally a pipe wrench with a BIG hammer which started it moving. I then worked it a little turn at a time with penetrating oil over 3 days and finally with one of us pulling up like crazy and the other turning back and forth, it worked it's way up and out.

I will bet I could win a prize for the fugliest engine swap photos ever posted here, but time, a parking lot and a borrowed garage and functionality beat out cleaning and painting the old leaky thing I pulled out of a Grand. I did tighten the finger loose valve cover bolts which seemed to fix the leak... ;) Man these are soo slow to load, I am on a wireless 3G USB stick modem way out here in the bush. Makes me lust after a 56K phone modem..... Hope this post doesn't ttime out on me....

More photos in the next post.
 

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#10 ·
More photos:
 

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#11 ·
So local Jeeper I met online came buy needing his carb(2150) tuned and he brought a timing light. Turns out my ear was right on, no adjustments needed.

The system runs great, but I will have to buy a PS pump belt that is an inch shorter because of the moved bracket, mine squeals way too easy and can't be tightened any more. Grr. brand new belt too. Oh well.

I am still just using it for logging and winching logs into place for my new place's frame so haven't had a chance to test the highway mileage for sure. It just purrs along great at low speeds, much more torque than I was expecting.
 
#13 ·
She was run dry on oil so the crank was likely in bad shape, the oil pressure was way down...

This engine runs sweet though, got to do a couple highway runs today and it holds a nice 110 kph easy even against gale force winds and hills. Have lots of gas pedal left even.
 
#14 ·
Ok, so I have run a tank of gas through her with mixed highway, city and bush lot/logging skidder use. I didn't have money today to fill her up, but was still just below 1/8 tank showing. well above E and I have put 605 km on it. It is the 20 gallon tank so figure I used 18 or so.

So that is about 375 miles on 18 US gallons or 20.8 mpg mixed. Sweet.... :) :)

The old 258 engine got that on just highway mpg.
 
#15 ·
Another followup. The mileage on the highway is a nice 25 mpg on regular gas. I keep it in 4th at 2300 rpm or so to get this with my T-5, 3.31:1 gears and 33's.

My son also did this swap into a 89 YJ Renegade he gave me for Xmas and it also gets 25 mpg using 5th gear at about the same rpm with 4.10:1 gears and 33's.
 
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