engine swap

hey guys, I need some reassurance... my 85 cj6 jeep has an engine with a manual transmission....i found the same engine that i would like to swap in but it has an automatic transmission...is the only difference the flywheel? will I have issues with the wiring harness or cpu?

 

'85 CJ-6? Are you positive? Iirc there wasn't a CJ-6 built that late.....
What engine and transmission do you have? That would be helpful to know for technical questions.


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Cj8???

 

help me out here.

 

Yes, CJ-8/Scrambler. Big difference.
You still don't say what engine you have. Is it original? Has something else been swapped in other than factory?


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this jeep has recently been purchased so my knowledge on the specifics are lacking.....what I do know is it is a 4 cylinder that will not pass smog....its been in the shop for a few weeks now and i dont think my mechanic will be able to tweek the engine to pass calif smog.....so iam thinking engine swap....I found a 4 cyl engine in a 1985 cj7 that is currently connected to an automatic transmission...was thinking of either swaping motors or using it as a donor vehicle to get me through my smog test....so before buying this motor i wanted to get some input from my fellow jeep owners/community....any thoughts?

 

Is your mechanic suggesting this swap? The idea is to replace the worn-out engine with the same type engine in better shape?

You should have the AMC 150 cid 4-cylinder in this Jeep. It is a fine engine, but it will never be a hot rod in that chassis.

What's your budget? A CJ-8 is a valuable vehicle, even with the 4-cyl. If it were mine, I would first determine that the problem with the engine is that it's actually worn out. This Jeep would have had a catalytic convertor from the factory, and it may need to be replaced. There are also many emissions devices on engines in this era, and the California emissions standards are strict. I expect the engine has to be really, really tired to be so bad that it can't be made to pass smog... though it would clearly fail if the needed devices (like a catalytic convertor) are missing or not functioning.

Again, California is really strict about emissions, both in terms of tailpipe tests and in terms of the visual inspection. All the factory devices must be there and working. If you are missing some stuff, it may be worthwhile to find a donor vehicle and grab the parts you need in order to bring the car to conformity. But I'm not sure that a new engine is what you need.

 

I agree with Timgr.
I'd find out from your mechanic why it is not passing emissions and what the root cause is before arbitrarily wanting to replace the engine. If the engine is worn causing the issue, then that may be a viable solution. Just make sure the replacement is in good working order or you may have wasted your money.


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Well I appreciate all your input guys...the mechanic says he cannot get the carb adjusted under load ? What ever that means? I was under the opinion that my engine was missing smog equipment and I thought it would be easier to just purchase another engine for its parts.

 

Well, unless the engine is in a running car that passes smog, I kinda doubt you can lift the parts you need and expect them to be in any better condition than what you have.

If you are missing stuff, that's a different story. But I would just buy what's missing - no need to buy a complete engine.

There are lots of shops that work on carburetors in the San Diego area - https://www.google.com/search?q=carburetors san diego - maybe you could take some pictures of your Jeep, and go and talk to a few of them. If nothing else, it will be educational. The right thing to do is to put the car back to factory condition, and replace any defective emissions devices.

If it were mine, I'd buy the 1986 Jeep TSM and compare the descriptions of the systems for that year to what you have. I would make sure all the devices are present, and the plumbing is connected correctly. Until all that is squared away, you are working in the dark.

 

Not to say anything negative about the mechanic but I don't understand why he can't get the carb adjusted under load. If he can't, I would assume he has enough knowledge to figure out why and then tell you what it needs.

If it is a money deal, then do as Tim suggests. Haul it home and spend some time getting to know your jeep. Get an official service manual, not a Haynes but one from the factory that a service department in a dealership would use. Find a local jeep club and someone that can/will help. Normally jeep folk are very helpful. Figure out what is missing/wrong/no working and replace it.

As others said, if the motor is bad enough to fail emissions, I'd rebuild it if funds are avaliable and be done with it long term. The CJ8 is very desirable and I believe it is money well spent. IF you want to swap or find you can do it for less, you might want to look at a bigger motor. You can find an inline 6 and swap it in with not too much trouble compared to other motor swaps. But I don't know California laws so make sure what ever you do is legal.

From the one pict, it looks like you have a great jeep in really good shape. Take care of it and do things correctly. Don't rush into throwing money at it to fix the problems that might be a simple fix.

 

+1

That's what I was thinking too.

IIRC California law will allow an engine swap from the same year or newer vehicle, in the same classification (ie you can't put a truck motor in a car). You have to bring along all the emissions devices from the donor vehicle, and the result must pass the tailpipe test for the donor. So a complete 258 from a newer CJ would be acceptable. A passenger car donor may also be allowed (not certain - logically it should be since their emissions standards are stricter than utility vehicles). So a newer EFI small block Chevy would seem like a good choice.

Note that it's probably equipped with a T4 transmission, or maybe a T5. These are light-duty transmissions, and I would swap the transmission if I went to a larger engine. The T176 from a 258 CJ donor would be a good choice.