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Unread 04-05-2008, 12:50 AM   #16
CompGuru
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How did it handle at 65-70? Did you run it long at those speeds? What kind of passing power did it have? 60 in 4th sounds low. But of course I have a 258 and know nothing about diesels. Has anyone mated a 4bt to a T-5? Would this tranny hold up against the torque in the 4bt? I have 131k on the odometer and am giving this swap some serious thought. Getting better gas mileage than 13.5mpg sounds freaking great!

Dustin

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Unread 04-05-2008, 06:38 AM   #17
BigTorqueCJ
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My Jeep has just about always handled great at high speeds. Before this swap I could hold the AMC 360 out at 90mph for as long as I liked. With the 4BT it is comfortable to run at 65-70 for any extended period of time. The engine has tons of passing power at highway speeds, you just might have to wait a second for the turbo to spool up. I personally wouldn't hold the Jeep and engine at 79mph, just because I don't drive that fast.
If the T-5 transmission is the Aluminum cased 5-speed behind the 258 6cyl that I'm thinking of: then I would say it would definitely not hold up to the diesel.
Oh, and when you put your 4BT in your Jeep, you will have to start saying, "fuel mileage". (And it'll be somewhere in the high 20's!)
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Unread 04-05-2008, 07:38 AM   #18
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Would this be a good swap for a CJ-5? My assumption is the engine bay is the same as far as space goes, but what about the tranny and t-case are they going to be too long? Currently I have the T-4 and D-300 and the AMC 151. I know the D-300 will hold up but I'm afraid the T-4 will turn to powder.
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Unread 04-05-2008, 07:12 PM   #19
BigTorqueCJ
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Quote:
Originally Posted by jeepsta View Post
Would this be a good swap for a CJ-5?
That is a loaded question.
I would answer by saying that this swap will work for a CJ-5. I was actually able to lengthen my rear driveshaft by 5 inches, but I have the engine forward about an inch more than my old AMC. I think that some other swaps have a T-18 or maybe T-19 tranny, but you really should have overdrive with a diesel. For me, it just makes sense to go all Dodge and have the HD-NV4500; however, I do understand that makes for a long drivetrain in a CJ-5.

If you want to decide if a diesel is a good swap for you, then you may want to do some more research by jumping over to the 4BTswaps.com website.

I have done a ton of modifications to my CJ-7 over the past 10 years and I would have to say that putting the 4BT in it is the most dramatic change ever, but I like it!
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Unread 04-05-2008, 09:23 PM   #20
supraman1990
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It can be done in the CJ5. Just use an AX15, plus youc an move the setup foreward some too since you will be fabbing mounts anyway.
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Unread 04-20-2008, 02:26 PM   #21
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I like that you shared the common dodge and cummins compatibility. Knowing I can use 6BT engine parts interchangably and dodge tranny and starter offerings is a huge deal and will make it much easier.

Care to share the cost of this adventure to the nearest hundred dollars or so?
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Unread 04-20-2008, 03:07 PM   #22
BigTorqueCJ
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Yeah, I'm a huge fan that all the 6cyl Dodge parts work with the 4BT. It is cool to think that all those parts were made to handle an engine with more than twice the power of a 4BT in stock form.

I have heard that the average cost of conversion can be as high as $8000+. It all depends on how far in depth you go with the conversion and what existing parts you have beforehand.

I feel that I was lucky to walk away with my conversion for $3700. But as you well know, there is always more you want to do with the Jeep. If I were to have bought everything new, I'm sure I could have had twice in it what I did. Like I said earlier in this thread, I didn't rush this conversion and was able to find a lot of used parts on eBay and from friends.

Just an FYI: If you want to justify this conversion on fuel mileage alone, I figured it will take approximately 45,000 miles for me to break even for the upgrade. For me, that will take like 8-10 years!

Keep in mind, with the 4BT I've heard it'll go to 700,000 miles before any major engine work is required!
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Last edited by BigTorqueCJ; 04-20-2008 at 03:33 PM..
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Unread 04-20-2008, 03:15 PM   #23
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Thanks for the swap cost numbers. I think $3700 is a great deal and actually quite a bit less than I anticipated. I'm a patient shopper myself and think I'm going to scrap my 4.0 head swap and pursue this as a project instead. The required tranny will add quite a bit for me, but double the mileage will put my jeep back on daily driver duty and we could get rid of one car.

Justifying the cost will become even less miles as the price of fuel climbs. Also, diesels last 2-3 times longer than gassers before rebuilding is needed. That would probably be a never again issue for me. With a diesel and a 20 gallon tank, my range should go up to over 500 miles per tank. This will be very nice when exploring around for SE Oregon desert and mountain lands.

Last edited by jeepmor; 04-20-2008 at 03:25 PM..
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Unread 04-21-2008, 09:44 AM   #24
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In your first post, I see that you have the NV4500 connected to the Dana 300. I was just looking at Advance Adapters and the adapter kit that they have only goes from the Gm variant NV4500 to the 300. What did you use to connect the two together?

Brian
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Unread 04-21-2008, 03:18 PM   #25
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Quote:
Originally Posted by TUPPERCJ7 View Post
NV4500 connected to the Dana 300
Brian
That is a very good question, because I can't remember where I sourced those parts. I originally swapped out my T-150 and Dana 20 for the NV4500 and Dana 300. That was about 8 years ago. At that time, I bought a kit that had: (1) a new retaining ring and (2) sealed input shaft bearing for the t-case to mount to the trans. I'd have to look around to see where you get that stuff now, but I thought I got it from Advance Adaptors. I know JB Conversions has a lot of that stuff too. I am very certain that I did not have to replace the input shaft on my Dana 300.
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Unread 05-06-2008, 09:33 AM   #26
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Here is some pictures of the 4BT swap I did back in 2002. It turned out pretty good, runs nice, drives OK. Setup is the one listed in my sig. Wish I had more time and $$ to get everything else that I want to get done on it.

http://rides.webshots.com/album/122922291GyWgdR
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Unread 06-24-2008, 02:08 PM   #27
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I know you said that the 4BT was about 700lbs but can you tell me what the weight difference is between it and the other motors 258? GM 350? AMC 360/304?
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Unread 06-24-2008, 09:08 PM   #28
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I am very much intrigued. I believe I have a blown head gasket in my 78 cj5. I love doing my own work. I am definitely going to check out the links you sent and see what I need and start bargain hunting. Thanks a ton for the info.
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Unread 06-25-2008, 07:02 PM   #29
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Quote:
Originally Posted by The_CJ_Way View Post
weight difference between it and the other motors 258? GM 350? AMC 360/304?
First off, this swap didn't weigh down my front end a bit, and I have soft springs.

4BT is 60lbs > AMC 360, other engines I don't know.
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Unread 06-26-2008, 11:13 AM   #30
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Thanks for the info Bigtorque that was enough info to help me think, also have you put any power adds on your 4BT or now anyone who has used 6BT upgrades on a 4BT?
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