Buncha questions about CJ engine swap.

Hey Group, I've got a 84 CJ7 4.2 with a tired engine. I have the opportunity to pick up a roll-over 91 Cherokee 4.0, 4wd. I've been toying with the idea of putting a 4.0 head on the 4.2 but am not crazy about plugging cooling ports on the block. Maybe a whole engine swap is in order. I would love to get the horsepower that a 4.0 would deliver but I don't know how much re-engineering I'm gonna have to do from the Flywheel back. The Cherokee has a AX15 tranny, not sure about theTC. Would my T5 bolt to the 4.0 bell housing? Is the input shaft the correct length? Is the block the same length as my 4.2 or do I have to relocate motor mounts and/or trans mount and skid plate? I know the T5 is not a great tranny... would I be better off using the AX15 and my current 300 TC or is that even possible? What do you guys know that I am missing? Is there a website that covers this kind of swap? I thank you in advance for any and all feedback. Charles E.

91 Cherokee 84 CJ7 81 DJ5L
Reply to
Ervin Charles
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Reply to
L.W.( ßill ) Hughes III

Depending on what you can get away with emissionswise in your state, you probably want to swap the whole engine and use some form of EFI or a carb setup. Advance and Novak are mickeymouse vendors selling a line of shrinkwrapped and often mickey mouse products.

Piss on the overrated small block Chevy. Want a Chevy, buy a whole Chevy, I say.

Reply to
Bret Ludwig

Reply to
L.W.( ßill ) Hughes III

Back in the day when they would do custom work my company had them do several things. They were repeatedly unable to read blueprints, we brought the stuff in-house, and then they went to a production catalog house operation. Yes there are production vehicles with adapters, just like there are production vehicles with a lot of things there shouldn't be.

The small block Chevy is not the right engine for any Jeep product, except the Grand Wagoneer maybe. The four liter late six is a much better engine than it is given credit for.

The stock EFI air system and injectors can be operated from an aftermarket ECU. Several good ones exist, but I'd look at Clifford's if you are not a code-head.

Reply to
Bret Ludwig

Bill,

AA is the place to go to make the 4.0 crank position sensor work too. I figure this Bret fellow bought an adapter from AA or Novak, and expected it to come with instructions and a whole conversion kit. The AA catalog and web site are up front about how more than usual mechanical skill, and ability to fabricate odd parts, are required for this kind of swap.

The problem with the 4.0 is that you would need the wiring, sensors including the speedometer, and the computer. Since the original poster has a roll over Cherokee, he should have everything needed for a successful conversion. It's just a question of which parts to use, and where. My recommendation is to study the AA conversion manual, available at

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figure out what you want to do, and thenrun your plan by one of their sales persons. Or Novak. Earle

Reply to
Earle Horton

Reply to
L.W.( ßill ) Hughes III

Yes, a lot of people put Chevies in anything that rolls. If you wanted a Chevy, shoulda bought a Blazer.

Manufacturer loyalty aside, a hot Chevy in a CJ will get you either killed or really stuck good. Plus, when gas goes to $4-$5 a gallon here like in the rest of the world, which the sooner it does the happier I will be, you will want something more economical. Cheap gas is like cheap heroin, Americans just refuse to see it...until the oil really is all gone and we have a mass workd starvation.

Reply to
Bret Ludwig

Reply to
L.W.( ßill ) Hughes III

I don't want cheaper oil. I want the oil conserved so that we can have some time to deal with the reality of a planet with many billions of humans and no oil. People will not burn less oil unless the oil is more expensive. The Europeans have high oil prices and a basically decent standard of living, we can too.

This is why I want the ANWR off limits-it will result in five years of less expensive oil, then we are back to square one. Leave the oil there for now and if, after we have implemented serious population and consumption controls that are working, it can be demonstrated using the oil will enable people to finish out their natural lives instead of dying of starvation, tap it then.

Paying today's prices for gas for my go to work buggy hurts me like everyone else, but cheap oil is a disaster. Wishing cheap oil on America is like wishing for a cheap supply of crystal meth, heroin or crack cocaine.

If people have to commute more than five to ten miles to work, they need mass transit or economical cars, and freight needs to go by rail instead of the Interstate Highways that result in a colossal subsidy of the trucking industry. If Class 8 trucks were to pay their share of road maintenance in the US based on diesel fuel, it would have to be at least $7 a gallon.

I don't call that liberal. I call it the laws of thermodynamics. If you don't like them, complain to the Great Legislator.

Reply to
Bret Ludwig

Hey Guys, I didn't mean to start anything vicious, I just wanted to tap into your combined wisdom. Bill, I want to stay with a Jeep 6cyl. I've done several engine swaps and (IMHO) the payoff for the labor involved is usually minimal. Maybe just shoddy engineering on my part but I think I'll stay with the AMC/Chrysler 6. That being said... What about the AX15 tranny along with the 4.0.... will the Dana 300 fit or do I have to lose that too? And then must I change driveshafts? I realize the yokes will probaby be different. (Christ, Now I gotta run a hydraulic clutch!) Earle, The Cherokee has a cable drive Speedo head and no adapter box along the cable (that I can see). What part does the speedo play in the fuel injection? This early a model..I don't think it even has a VSS. I thought the fuel timing was a product of Vacuum, Crank Position, RPM and O2 readings Charles

Reply to
Ervin Charles

Bill, If you want to be THE King of the Hill... Gravelrama is one month from tomorrow in Cincinnati

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Reply to
Billy Ray

Reply to
L.W.( ßill ) Hughes III

In the short term I just want gasoline prices to be stable. The price changing 20-30 cents from one day to the next is for the birds.

If the OPEC folks want $60 a barrel that's fine. The US and Canada produce most of the worlds corn, wheat and beef. Let's tie the price of their food to the price of our oil.

You screw with us we'll cut off your food.....Payback's a bitch

Reply to
Billy Ray

Russia has far more oil than they can use. Their known reservesw are second only to Saudi Arabia. They can't sell it because they have no way to transport it and no western company is going to build the infrastructure needed and risk nationalization AGAIN.

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I'd be willing to bet that engineers could build a pipeline across the Bering Straits if the Russkies could get the oil to their side. The US would buy all the oil they could pump.
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Reply to
Billy Ray

Reply to
L.W.( ßill ) Hughes III

Reply to
Will Honea

Correction, the '91 does not use the '87 to '90 Renix electronic fuel injection system.

Reply to
L.W.( ßill ) Hughes III

First, don't worry about things getting "vicious". We are just sharpening our claws. We do it a lot here. I see that the thread has already degenerated into another ho-hum debate about oil.

I could have been wrong about the speedometer. If you traced the cable back to the gauge with no electrical connection, then you are fine on that score. Since you have the donor vehicle right there, you can answer questions like this probably better than we can here. Another thing to think about is the fuel pump. How are you going to generate the 30 or so psi required by EFI injectors? You'd better plan on replacing every piece of rubber fuel hose too, with hose suitable for fuel injection. You will probably have to replace the fuel tank too, possibly with a YJ tank, to make the EFI pump work. I have owned vehicles with an external EFI pump (Volkswagen) and I don't recommend going that route. EFI pumps don't have very good suction.

Now there are basically two ways you can go with this donor power plant. You can bolt the AX15 to the Dana 300, assuming it will fit, or you can bolt the 4.0 to the CJ's bell housing, again assuming it will fit. This page

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lists an AX15 to Dana 300adapter, number 50-8603. Call or email AA, and find out if it will do whatyou want. This page
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lists aharmonic balancer kit, to relocate the crank position sensor to the front ofthe engine. That is how your would use the 4.0 with your T5. Earle

Reply to
Earle Horton

You do not need to replace the fuel tank to go to an in-tank pump, although I don't like in-tank pumps on principle. The in-tank pump mounts on a plate and it is not a bad fab job to mount a pump on the plate for the tank, assuming the hole is big enough.

I would replace all the rubber no matter which else I did.

Reply to
Bret Ludwig

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