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Unread 02-06-2012, 08:27 PM   #16
JeepJon15
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thanks guys, thats the same advise i got from a couple mechanic friends of the fam. I did not know i could put a 4.0 in just like that though. I did some searching for 4.2s to get some kinda idea and was having trouble.

Thanks for all the input, and i can post a pic of what i found in the oil pan if that is still something you want to see. Its on my brother's phone though so it will have to be tomorrow.

I have a guy who said he'd take my old engine out and drop the replacement in for 300-400 bucks. Sounds good to me, but its my first engine swap.

If i put the 4.0 in, does anything else need added or fabricated at all? If this is a common thing to do ill search the thread and you can ignore this question.

Thanks for everyone's input
Jon.

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Unread 02-06-2012, 08:58 PM   #17
laybackman
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Originally Posted by JeepJon15 View Post
thanks guys, thats the same advise i got from a couple mechanic friends of the fam. I did not know i could put a 4.0 in just like that though. I did some searching for 4.2s to get some kinda idea and was having trouble.

Thanks for all the input, and i can post a pic of what i found in the oil pan if that is still something you want to see. Its on my brother's phone though so it will have to be tomorrow.

I have a guy who said he'd take my old engine out and drop the replacement in for 300-400 bucks. Sounds good to me, but its my first engine swap.

If i put the 4.0 in, does anything else need added or fabricated at all? If this is a common thing to do ill search the thread and you can ignore this question.

Thanks for everyone's input
Jon.
If anyone tells you an engine swap from a '88 YJ to a post '91 YJ 4.0 engine swap is a no brainer the hairs on your neck should stand on end UNLESS you are a fully competent YJ mechanic, who is familiar with this type of upgrade.

You do not simply pull the old engine drop in the new one and you are good to go.

I have seen plenty ads for vehicles where the current owner was into a vehicle, started a rebuild and then 'lost interest' In English that means he got over his head and over budget with no end in sight.

Proceed slowly and make sure you get all your ducks lined up before you end up with a half yanked apart YJ...
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Unread 02-07-2012, 02:55 AM   #18
JeepJon15
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Yes sir, a money pit is the last thing i want. Thats why i value the opinions on here so much.

I'll do a much research on the subject as i can before i purchase anything. The person actually performing the engine swap is a mechanic who is familiar with the process. I just wanted to make sure i had everything he'd need when i drop it off.

laybackman: thanks for your concern, any tips you can provide to prep the engine compartment or gather materials would be awesome!.

Thanks again.
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Unread 02-07-2012, 07:39 AM   #19
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Once the YJ engine repair gets underway if you have no clear plan or specified absolute budget for expenses a project like this will get away from you real fast. You can’t do the work because you do not have the experience. It is good to acknowledge your limitations…and cheaper in the long run.
You’re talking a $1000.00 for expenditures? That is not going to cover the overall costs unless you had another good engine ‘laying around’ and all the talent and tools to do the swap. Why buy another old high mileage 4.2 that some guy yanked out of his pre 1991 Jeep? It is almost as dead as your engine is.
You can buy a 4.0 engine from a later model Jeep. Say you want one that has no more than 100,000 miles on it. Great! But, they do not sell for $250.00unless they are near death also.
IF you could find a later model wreck that would be the best bet since you get EVERYTHING needed to do the swap. They don’t sell them for a grand either IF you can find one at all.
So, buy another engine….. Which way to go? Find another 4.2 or go with a newer 4.0?
You will probably not be able to rebuild your current engine. I could be wrong but when a piston ‘goes freestyle’ in a cylinder that has a lot of wear already most gouges made will be deeper than the limits of the bore that can be done on it before you are cutting into the water jacket. I think that piston has already made the ‘journey’ through the cylinder wall and into the water jacket.
You could go with a 4.2 short block and have your head re-done. You could go with a 4.2 long block also. But not for $1000.00.

Another option is to find a later year 4.0 with all associated wiring that includes the PDC and the brain. Now what needs to be addressed is mating that harness to your dash harness for the ignition circuit/starter circuit and stuff like that. You will also need to modify the fuel delivery since you are going from a carb to fuel injection….. but not for $1000.00.

I’ll offer you my unvarnished opinion is of your current situation. Assuming that the engine is gone and I dare say that is a safe assumption a $1000.00 budget won’t get you running again since you are hiring the talent to do the work.

Part out the YJ add your $1000.00 budget to what you make and buy a newer YJ or dare I say a TJ and just worry about the monthly payments.
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Unread 02-07-2012, 10:05 AM   #20
JeepJon15
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Thanks a lot... not exactly what i was hoping to hear, but i appreciate the honesty.

If i switch to a 4.0, i will keep my carb. Not that FI wouldnt be nice, i just like the simple set up of a carb. I read some threads on putting a 4.0 head in the 4.2?

I have a friend of a friend willing to pull my old engine and put the new setup in for about 400 bucks. And actually, if i'm not mistaken, i believe i saw a newer modle wrangler on my local CL that was wrecked but the motor looked fine...

Having the part out the YJ hurts, but its been in the back of my mind the whole time.

So would putting a 4.0 head in my 4.2 and keeping it carbed be an affordable alternative? Or if i find a good 4.0 engine and throw a carb on (like was suggested earlier)?

I the mean time, i will be shopping for hopefully another YJ. I'm just apprehensive to write mine off just yet, i know what i've done to mine, and what needs done. Starting over with another one is... scary, though will be exciting at the same time.

Thanks for your help, i hear you.

Jon
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Unread 02-07-2012, 10:22 AM   #21
laybackman
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Thanks a lot... not exactly what i was hoping to hear, but i appreciate the honesty.

If i switch to a 4.0, i will keep my carb. I wouldnt mind going FI, but i also dont mind my carb right now. I read some threads on putting a 4.0 head in the 4.2?

I have a friend of a friend willing to pull my old engine and put the new setup in for about 400 bucks. And actually, if i'm not mistaken, i believe i saw a newer modle wrangler on my local CL that was wrecked but the motor looked fine...

Having the part out the YJ hurts, but its been in the back of my mind the whole time.

So would putting a 4.0 head in my 4.2 and keeping it carbed be an affordable alternative? Or if i find a good 4.0 engine and throw a carb on (like was suggested earlier)?

I the mean time, i will be shopping for hopefully another YJ. I'm just apprehensive to write mine off just yet, i know what i've done to mine, and what needs done. Starting over with another one is... scary, though will be exciting at the same time.

Thanks for your help, i hear you.

Jon
If your YJ is in good condition then to you, that YJ has much value.
Have your mechanic check out the wrecked YJ. Let him make the decision on whether it is a good candidate or not. If you can buy the engine and engine harnesses to include the brain if it is injected. The only other issue is fuel pump pressure. That can be remedied with a stock FI fuel pup or an aftermarket unit IIRC.

If you can grab the whole YJ for $800.00 or less grab it, do the engine swap then part out everything left over to recoup some of your costs.

Everything you do will be based upon how much this mechanic is willing to help you with it all.
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Unread 02-07-2012, 10:34 AM   #22
JeepJon15
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How about the fact that im staying carbed? Will this save me money on the install at all?
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Unread 02-07-2012, 11:40 AM   #23
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How about the fact that im staying carbed? Will this save me money on the install at all?
If you want to I guess you could carb a 4.0 engine using the intake exhust manifold from your engine. Then all of your issues are mechanical and not electrical.
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Unread 02-07-2012, 12:01 PM   #24
JeepJon15
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That is definitely the rout i'd go if i put a 4.0 in. I understand this would save having to redo the fuel pump and ?lines? I'd like to keep it simple, and obviously if thats cheaper its a win/win.

From browsing C/L the only engines i've found have 180-200k+ miles on them. Of course everyone says they still run perfect, and to come hear it. I'd just hate to put in a high mile motor like that and something go wrong with it after a couple hundred miles. So i'll keep searching.

I plan on putting a new carb on eventually, but i just recently rebuilt my carter so ill keep it for now unless it will cause any problems with the 4.0.

Anyway, if anyone is around central ohio with a good 4.0 they'd like to get rid of, im looking. Also looking at Yjs in the area (incase i end up having to part mine out).

So from my research ill need : 4.0 motor and all accessories, CPS (or can i use mine?), flywheel/flex plate.

Does keeping my carb setup get rid of the need for the 4.0 computer? Do i need the 02 sensor and charcoal cannister or will mine still work? And lastly, can i keep my fuel pump/lines?
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Unread 02-07-2012, 12:42 PM   #25
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Originally Posted by JeepJon15 View Post
That is definitely the rout i'd go if i put a 4.0 in. I understand this would save having to redo the fuel pump and ?lines? I'd like to keep it simple, and obviously if thats cheaper its a win/win.

From browsing C/L the only engines i've found have 180-200k+ miles on them. Of course everyone says they still run perfect, and to come hear it. I'd just hate to put in a high mile motor like that and something go wrong with it after a couple hundred miles. So i'll keep searching.

I plan on putting a new carb on eventually, but i just recently rebuilt my carter so ill keep it for now unless it will cause any problems with the 4.0.

Anyway, if anyone is around central ohio with a good 4.0 they'd like to get rid of, im looking. Also looking at Yjs in the area (incase i end up having to part mine out).

So from my research ill need : 4.0 motor and all accessories, CPS (or can i use mine?), flywheel/flex plate.

Does keeping my carb setup get rid of the need for the 4.0 computer? Do i need the 02 sensor and charcoal cannister or will mine still work? And lastly, can i keep my fuel pump/lines?
If you stay with a carb'ed engine the fuel system stay as is. I would think your electronics stay the same also. You are using the short block from the 4.0 to replace the short block of the 4.2.

Did you look for a rebuilt 4.2 short block? I believe that they are available.
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Getting older, I have developed some special skills. I have the ability to cough, sneeze, fart and pee at the same time.

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Unread 02-07-2012, 12:51 PM   #26
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You buy a 4.0. You use all of your 'stuff' for the intake/exhaust/carb that bolts directly to the engine. You will keep the original emissions system stuff also. Use your flexplate or if you have a stick your flywheel, O2 sensor etc.
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Unread 02-07-2012, 02:34 PM   #27
JeepJon15
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okay, the picture is getting clearer... and i did a quick search for rebuilt 4.2s, it was 1800 for the engine or 800 for the core.

Ill talk with the guy who is puttin it in for me and make sure he is okay with putting the 4.0 in. The price he gave me (3-400) was for a direct bolt in swap. Seems like it should be, but i read something about having to do something to the manifold.

I appreciate all your info. Sorry if i'm repeating my questions, just trying to wrap my head around it.
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Unread 02-07-2012, 03:18 PM   #28
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EBAY:
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Getting older, I have developed some special skills. I have the ability to cough, sneeze, fart and pee at the same time.

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Unread 02-07-2012, 04:20 PM   #29
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Your mechanics direct swap approach probably doesn't include you having him swap intake and exhaust manifolds along with your other bracketry changes for your alternator.I believe there is some minor modifying to get the 4.2 intake and exhaust to hang on the 4.0 engine. It might be vice versa.I could answer many of these questions for you in about a month I'm building a 88yj and swapping the 4.2 for a 4.0 while keeping a carb setup and eliminating all pollution and unnecessary vacuum items under the hood.If you are not doing much of the wrenching for this, project plan for a extra 500 needed.Buy a donor yj and pull everything needed from it.I would stay carbed and don't fool with a fuel injection swap right now.
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Unread 02-07-2012, 04:23 PM   #30
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I'm in the middle of doing a 4.2 block and 4.0 heads with the carb. Not my wants but finances dictate. I'll get around to the FI down the road I'm sure. But for now finding an affordable donor vehicle and the time and patience (or expense if I paid someone) to figure out and run the wiring is not in my mechanical/ financial relm right now. The carb option is going to be the most affordable all the way around. Either easier for the mechanic or easier for you.

Good luck man don't give up on the jeep dream. Step back and take a deep breath.
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