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TJ Engine Swap x2
 
 PostPosted: Tue Jul 15, 2008 11:24 pm 

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Last week after we got back from Silver Lake I heard that my brother-in-law blew up the 4.0 in his TJ while driving to work. The shop he had taken it to wanted about $4K to R&R with a fresh motor.

I talked with my wife about how it'd be a great time to help her brother out by giving him my low mileage (50K) 4.0L from my jeep, and then I'll upgrade to a V8. Amazingly, she bought it!

So, now I've got to upgrade. While at Silver Lake, Mike was talking that instead of swapping in a 4.7 V8 he already has, he is going Hemi for whatever he does next. He's already found one, so now his 4.7 is needing a home.

Now the plan is that my brother buys the 4.7, bellhousing, flywheel, radiator, and I swap my 4.0 in his TJ.

To keep costs down, my plan is to keep the NV-3550 and keep the same drivetrain location so I don't have to rework driveshafts. The benefit of this is that the weight will be pushed packed further in the chassis since the V8 is shorter than the L6, hopefully this will help in climbing. One thing that could screw this up is if the wider v8 interferes with the firewall, then I'll have to move it forward, but that's not the end of the world.

I really didn't find much in the way of other folks doing this. But here's a couple of links:

http://www.burnsvilleoffroad.com/articles/00_12.aspx

http://www.worldofwoo.com/Jeep/4_7_v8.htm


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 PostPosted: Wed Jul 16, 2008 7:47 am 
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FWIW, when i originally mocked up the 350 to go in my green tj, I aligned the rear face of the block right where the rear face of the 2.5 was, and both of my valve covers were going to clear. I was going to need to make room for the distributer, but you won't have that problem.

I ended up mounting the engine as far forward as I could and it climbed a ton better than it did with the 2.5....... I can only assume that the extra weight of the V8 being placed as far forward as possiable helped to keep the front springs from unloading. But, if you can get to your axle with your winch I would agree that you can just winch it down and not have to worry about that.

Good luck. :thumb:

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 PostPosted: Wed Jul 16, 2008 9:08 am 
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Are you going to try to use the same radiator? I assume the L6 had a mechanical fan which I personally support. I've had much better luck with mechanical. With that in mind, how much difference in length do you have? Can you make up the difference with a good shroud? It may make sense to keep it tucked back to the firewall.

I wouldn't think that the difference of a couple inches front to back would make much difference hill climbing. You're still front of center and your pull down will benefit you more. Is the V8 actually heavier than the 6? By how much?

By the way, I think V8's are way over rated. :lol:

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 PostPosted: Wed Jul 16, 2008 11:15 am 

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I think I'll be swapping radiators because the inlets are on the opposite sides. I'll probably end up with an electric fan like Jess and Mike are running.

Quick specs I looked up, so I dunno exactly how accurate they are.

4.7 V8
Weight: 438
HP: 230@4600
Torque: 290@3600

4.0 L6
Weight: 515
HP: 190@4600
Torque: 235@3200

The pics below are from the link above, neither are my engine.


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Last edited by JohnnyJ on Wed Jul 16, 2008 11:36 am, edited 2 times in total.

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 PostPosted: Wed Jul 16, 2008 11:25 am 

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doesnt geo have a hemi with trans and such?


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 PostPosted: Wed Jul 16, 2008 2:17 pm 
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Lose 75 pounds
Gain 40 hp
Gain 55 ft lbs of torque
Gain V8 bling.

Sounds good to me.

I know I'm beating a dead horse but if it comes with a mechanical fan I would consider it. Maybe it's because I have always run higher hp but I've had numerous problems with aftermarket electric fans. A mechanical fan never fails.

BTW I think geo sold the Hemi

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 PostPosted: Wed Jul 16, 2008 3:04 pm 

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I hear you Jim. It's a factory electrical fan for that engine, so if I have a good rad, it should be fine.

Jess's bone stock 350 was kept comfy cool taking a beating at the dunes using the same fan.


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 PostPosted: Wed Jul 16, 2008 3:06 pm 
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WhiteRhino wrote:
Lose 75 pounds
Gain 40 hp
Gain 55 ft lbs of torque
Gain V8 bling.

Sounds good to me.


I would actually say none of those attributes are worth the headaches or expense of a swap.

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 PostPosted: Wed Jul 16, 2008 3:54 pm 

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strangler wrote:
WhiteRhino wrote:
Lose 75 pounds
Gain 40 hp
Gain 55 ft lbs of torque
Gain V8 bling.

Sounds good to me.


I would actually say none of those attributes are worth the headaches or expense of a swap.


I have mixed feelings on the 4.7L... but then again I always seem to go overboard.

if you can wake the 4.7 up a little bit and get closer to 300hp then I think I'd be more in favor of it.

let us know how it goes!

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 PostPosted: Wed Jul 16, 2008 8:41 pm 

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I have driven the 4.7 in both a 5 speed Dakota and a fullsize Ram and Durango. The 5 speed Dak was quick and had plenty of juice. In the ram and the durango, it was way over taxed. The TJ with a stick and 488s should be pretty nice.

I am actually a bit surprised that it makes more torque than the L6, it will probably still feel substantially different. No tractor like torque at 400 rpms, but with some seat time, you will overcome the difference in off idle grunt. Maybe we can adapt the flywheel from a dauntless, weren't those in the 80 lb range or something stupid like that?


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 PostPosted: Wed Jul 16, 2008 10:34 pm 

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I think I'd rather have a nice light flywheel that spins up like mad, rather than a slow rise.

We just got home from the fun round trip of picking up the cherry picker and TJ from Dryden and Lake Orion. There is no fast way to get to either of those places from Hartland. Add in driving through two storms that forced us down to < 10mph and it was a fun ride.

The one thing I have going for me right now is that I have put about 30 minutes of planning into this project. I can't see what will go wrong.


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 PostPosted: Thu Jul 17, 2008 8:37 pm 
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JohnnyJ wrote:
The one thing I have going for me right now is that I have put about 30 minutes of planning into this project. I can't see what will go wrong.


Perfect, the only way to do it. Why over complicate things by thinking about them!! :thumb:

I say: "I'm putting in a patio". Wife says: "do you know how?". I say: "Not really, buy don't bother me with details"....

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 PostPosted: Thu Jul 17, 2008 8:43 pm 

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Yeah, there is no way to get to Matt's that doesn't suck.

Did you get those motors swapped yet? I'm in for Sat, how early do you want to start? 8:00?


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 PostPosted: Thu Jul 17, 2008 9:06 pm 
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I think i'm about the only one that likes that family of engines, 3.7/4.7 chrysler, they really aren't that bad of engines. I hove no idea on durability, etc. but i like their power bands.

I also tend to have homosexual tendencies so take my opinion for what it is worth. :thumb:

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 PostPosted: Thu Jul 17, 2008 10:04 pm 

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JeepM715 wrote:
Yeah, there is no way to get to Matt's that doesn't suck.

Did you get those motors swapped yet? I'm in for Sat, how early do you want to start? 8:00?


I plan on rolling out of bed and getting in the garage. Get here whenever you can/want.


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 PostPosted: Sun Jul 20, 2008 9:02 pm 

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The first part of the plan is done. My brother-in-law drove his TJ home today with my old engine in it. Big thanks to Jess for coming over all day Saturday and helping move engines.

In order to make pulling my old engine easier, I pulled the driver's fender and grille (pass fender has been off for a while). It's really strange seeing the TJ sitting there with no front end.

Problem is, it makes the mind do strange things like want to rework a few of the problem areas up front. :devil:

Some pics as it sits now, it's like it's begging to have the coilover hoops pushed up, steering moved down to the tie rod, and track bar flattened out.


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 PostPosted: Mon Jul 21, 2008 6:20 am 

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JohnnyJ wrote:

Some pics as it sits now, it's like it's begging to have the coilover hoops pushed up, steering moved down to the tie rod, and track bar flattened out.


why not? it's not like it's going anywhere in the near future! :poke:

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 PostPosted: Mon Jul 21, 2008 3:23 pm 

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do it now. that way when your sick of working on engine swap you can work on that. and still get it done before flat nasty

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 PostPosted: Mon Jul 21, 2008 3:48 pm 

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Quote:
95geo why not? it's not like it's going anywhere in the near future! Stick Poke


What are you talking about, the exhaust was still hot from Silver Lake when we pulled the motor out...

I agree with Chevotass though, we need to cut the front end off at the firewall and start over. Can we get through the firewall to tie in to the front hoop, or doesn't it go down to the floor, I'm drawing a blank on your front cage?

Your rear is already tubed out from behind the drivers seat correct?

Sounds like Jeep night is moving to Hartland soon...


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 PostPosted: Mon Jul 21, 2008 4:07 pm 

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it's tied into the frame up front.


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 PostPosted: Mon Jul 21, 2008 4:38 pm 
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there must be something wrong if you can trailer it for three hours and its still hot, are you sure you dont have a injector bleeding down that has a small fire going in the cat or muffler

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 PostPosted: Mon Jul 21, 2008 7:10 pm 

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Not any more he doesn't, maybe Brandon does...

I just talked to Haines, he said he has the bell housing for you too, all you need is the 4.7 flywheel. That shouldn't be too bad to find.


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 PostPosted: Mon Jul 21, 2008 10:50 pm 

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Awesome. I gotta call him.


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 PostPosted: Fri Jul 25, 2008 12:14 am 

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I got out to the garage late, but I managed to drop the jeep down to what I would like full compression to be. I also pulled the body lift out of the grille and put back in the stock mounts, so it's sitting one inch lower than the rest of the body.

As it sits in the pic it's about 15" to the belly (under trans skid). My goal would be to run about 5-6" of uptravel to give a belly ride height of about 20-21". Not much different than before, but optimizing for up travel.

I need to drop the engine in as it sits and mock up a radiator to make sure everything clears.

I think for other suspension changes, I may leave the upper link on the driver's side, but just move the frame mount up about 3". This should lower front anti-dive quite a bit. Right now the link lengths are setup to be about 34" lowers and a 26" upper (75% length of lower). I don't think I'll bother with making the upper longer.

I also looked at what I'd need to do to flatten out the track bar. I have about 1 1/4" clearance between the frame and track bar now. When it sits at full stuff like this the track bar is pretty much parallel with the ground. I think what I will do is notch my frame and use some 3"x.200 wall tube to make a bump out for the track bar to move up into. I could try and squeeze the frame side down a bit, but that is also pretty tight on the tie rod now that it's running on top of the knuckle rather than below.

I've thought about flipping the frame side track bar mount to the outside of the frame, but I don't know if it's worth the extra couple inches of length.

The ram is moving down to hook on the tie rod. I'm copying the setup we did on Jess' buggy. Then I have to plate the cracked knuckle.

I've rethought selling my coilovers. I'm just going to cut and move my hoops onto the top of the frame and push the shocks a bit further inboard. In looking at what I can fit, I think that they aren't a packaging constraint with my setup.

Finally, I think I'm moving my orbital back a bit, and probably up. Right now it's kinda where the stock steering box was. With dropping the grille, there not a lot of room where it was. But with the shorter engine I think I can move the box onto the engine side of the radiator and just shorten up the stock steering shaft a bit more.


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 PostPosted: Fri Jul 25, 2008 6:28 am 

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that looks pretty good for full stuff :thumb:

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