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4bt cummins jeep tj
- Thread starter dzljon
- Start date
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dzljon
Advertiser
My motor is 38.5" tall with the turbo up top and put the bottom of the oil pan about 1" lower than the stock motor with stock suspension so I think it will be fine. The cummins length is 27" with out a mech fan compared to 39" the 4.0 gasser is with the machanical fan
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dzljon
Advertiser
I have typically used a product from magnet paints to coat chassis and it is also designed to paint over rust and is a good product but I picked up a quart of por15 for rocko and **** it did a good job going on the surfaces, since the jeep was shipped to me from Boston it did have some corrosion I treated it with naval jelly to convert the rust to a fairly good paint able surface and applied the por15 and I am happy with the results
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dzljon
Advertiser
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dzljon
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wmonroe
Elite Member
Getting down to the small items now. What are you planning to do with the old engine?
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dzljon
Advertiser
I am planning on selling the gasser, I should have it out this afternoon
handirifle
Veteran Member
Be mindful, as I am sure you are, of the gearing you plan on using. I had an '01 TJ for 5 years, loved it, but I know as torqey as that motor was it will be nothing like the 4BT will be, even stock, much less a built one.
Back to the gearing. Personally, since you will be doing freeway as well as off roads, and I am sure MPG goals are part of that (mine got 15 MPG highway) I would not go lower than 3.73 ratio. Any lower and it will be a rock crawler only. I am sure 4.10's will be drivable, but if you get up to 65 the RPM's will eat your gas. As I said, I am probably preaching to the choir here, but just thought I'd throw it out there.
Plus the taller gears (3.42 or 3.73 vs. 4.10) will be stronger, since there is less teeth per gear, thus more metal on the teeth.
Also I noticed on the intercooling plumbing, the top tube, on right hand side (in the pic) looked like it had a pretty decent size kink in the bottom of it. Big restriction. Or was that a mock up?
Back to the gearing. Personally, since you will be doing freeway as well as off roads, and I am sure MPG goals are part of that (mine got 15 MPG highway) I would not go lower than 3.73 ratio. Any lower and it will be a rock crawler only. I am sure 4.10's will be drivable, but if you get up to 65 the RPM's will eat your gas. As I said, I am probably preaching to the choir here, but just thought I'd throw it out there.
Plus the taller gears (3.42 or 3.73 vs. 4.10) will be stronger, since there is less teeth per gear, thus more metal on the teeth.
Also I noticed on the intercooling plumbing, the top tube, on right hand side (in the pic) looked like it had a pretty decent size kink in the bottom of it. Big restriction. Or was that a mock up?
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dzljon
Advertiser
Good advice!, I currently have 3.07 gears, I will try them and make a decision on gears after I get some miles on it
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