Carb'd 4.6 Questions

[Wombat Ranger]

Stock combustion chambers.

4.2 rods .040 over speed pro 4.0 slugs.

[Wombat Ranger]

Fired it today. Broke in the cam to the lifters, then had to head to work. Needs some fine tuning. Hopefully I will take it around the block tomorrow.

[Wombat Ranger]

https://www.youtube.com/watch?v=rhRD3K6r-ew

[sly-jeeper]

Sounds good!

[Flabby]

Howdy Wombat,
Been a bit. I've made a couple changes to my original build plan. Picked up an MC 2150 vice the 2100. $20 at a jeep swap. Now to get a rebuild kit. I have the 7120 4.0 head. Buddy of mine picked up a new Borla manifold he can't use, so I got it for 1/2 price. Are you still using the stock FI intake with the holes plugged? Was looking at the Clifford and also the Offy intakes, but it seems that nothing is a direct fit with a Borla without a little hammering. Thoughts?
Just for fun, I picked up a 93 Cherokee with a 4.0 in it for $500. Been able to use all the brackets for the serp set up and it comes with A/C. Guess my 84 Renegade will be high class now.

[Wombat Ranger]

I used a stock 4.0 intake. I made plugs on a lathe, TIG welded them in, added material around the throttle body opening, machined it flat, made an adapter plate to mount the Motorcraft on it, and then hand ported it out to match. It was a lot of work, but I have $20 in it. It probably wouldn't be worth doing if someone had to pay to have the work done. It works for me. I don't need or care about having the most flow or anything like that, I just need it to work.



















This setup requires some creative throttle cable mounting bracket work by the way.

[Flabby]

Greatly appreciated. The 4.0 FI intake with the filled in holes has been a topic of discussion between me and couple buddies also. Choices of that, the Cliff, and the Offy. I'm leaning towards your solution at the moment. Any one of them requires some engineering for the fit.

I picked up a 93 Cherokee for $500, which has the serp set up and A/C. That will round out the nickle/dime parts. Double roller timing gear, pro-comp cam, and DUI HEI are the big items left to purchase.

[Flabby]

Wombat,
Since we're building the same configuration, which timing gear and cam did you end up going with? Are you getting the mid/high end HP you were looking for?

[myillwillinc]

I'm also building the same stroker, only diff is I already have a Clifford intake.

[Wombat Ranger]

I bought a Mopar double roller timing set. It is a re-boxed Cloyes set for a few bucks more. That was a little disappointing. Cam is a re-ground 4.0 HO bumpstick, just a mild RV grind put on it.

Power characteristics. Background info first. I could have been like all the flat billed hat designer shades wearing COOL GUYS and swapped in a small block if I wanted to go fast. But I love inline 6's for their stump pulling bottom end and durability. This is my Jeep. I take it out into the mountains, I wheel it, I don't stoplight race it. I wanted an engine that I could lug down to 200rpm on the trail and still be smooth and predictable. That is really only something you can get out of an inline. I also was looking for an excuse to build an engine, since I hadn't done one before. Since my '88 YJ came with a 4.2 originally, I could just put a blindfold on, spin around three times, and buy the 1st core 4.0 I tripped over. No need to source the less common crank and rods.


Yes, it is everything I was hoping for. It is a zippy little thing. I wouldn't dare say fast. I can get rubber in 1st with 33's, 3.07's, and a locked rear end if I really want to. Most of the time though, I get up to speed nice and quick, happily going through the gears but never exceeding 2000rpms. A flat predictable torque curve is what I was after, and it is what I got. I have no complaints about the engine at all, except that I am spoiled by the fuel economy of my Dodge diesels. My old twin turbo'd 410rwhp '93 5spd got 19mpg. My daily driven '90 with just minor fueling mods gets 22-24. My stock '04 6spd gets 19. All 4x4's. Why does the jeep that weighs half as much get only 13? (roughly)

[Wombat Ranger]

I bought a Mopar double roller timing set. It is a re-boxed Cloyes set for a few bucks more. That was a little disappointing. Cam is a re-ground 4.0 HO bumpstick, just a mild RV grind put on it.

Power characteristics. Background info first. I could have been like all the flat billed hat designer shades wearing COOL GUYS and swapped in a small block if I wanted to go fast. But I love inline 6's for their stump pulling bottom end and durability. This is my Jeep. I take it out into the mountains, I wheel it, I don't stoplight race it. I wanted an engine that I could lug down to 200rpm on the trail and still be smooth and predictable. That is really only something you can get out of an inline. I also was looking for an excuse to build an engine, since I hadn't done one before. Since my '88 YJ came with a 4.2 originally, I could just put a blindfold on, spin around three times, and buy the 1st core 4.0 I tripped over. No need to source the less common crank and rods.


Yes, it is everything I was hoping for. It is a zippy little thing. I wouldn't dare say fast. I can get rubber in 1st with 33's, 3.07's, and a locked rear end if I really want to. Most of the time though, I get up to speed nice and quick, happily going through the gears but never exceeding 2000rpms. A flat predictable torque curve is what I was after, and it is what I got. I have no complaints about the engine at all, except that I am spoiled by the fuel economy of my Dodge diesels. My old twin turbo'd 410rwhp '93 5spd got 19mpg. My daily driven '90 with just minor fueling mods gets 22-24. My stock '04 6spd gets 19. All 4x4's. Why does the jeep that weighs half as much get only 13? (roughly)

[Flabby]

I'm also building the same stroker, only diff is I already have a Clifford intake.

Muillwillinc,
Having any issues matching the clifford to your intake? Probably going with the FI intake and plug the holes like wombat, but I have a line on a used clifford. I'm fully tracking that my borla's aren't going to match up with any intake at this point in the game. It's the big hammer and grinder adjustments I'm dreading.

[Flabby]

I bought a Mopar double roller timing set. It is a re-boxed Cloyes set for a few bucks more. That was a little disappointing. Cam is a re-ground 4.0 HO bumpstick, just a mild RV grind put on it.

Power characteristics. Background info first. I could have been like all the flat billed hat designer shades wearing COOL GUYS and swapped in a small block if I wanted to go fast. But I love inline 6's for their stump pulling bottom end and durability. This is my Jeep. I take it out into the mountains, I wheel it, I don't stoplight race it. I wanted an engine that I could lug down to 200rpm on the trail and still be smooth and predictable. That is really only something you can get out of an inline. I also was looking for an excuse to build an engine, since I hadn't done one before. Since my '88 YJ came with a 4.2 originally, I could just put a blindfold on, spin around three times, and buy the 1st core 4.0 I tripped over. No need to source the less common crank and rods.


Yes, it is everything I was hoping for. It is a zippy little thing. I wouldn't dare say fast. I can get rubber in 1st with 33's, 3.07's, and a locked rear end if I really want to. Most of the time though, I get up to speed nice and quick, happily going through the gears but never exceeding 2000rpms. A flat predictable torque curve is what I was after, and it is what I got. I have no complaints about the engine at all, except that I am spoiled by the fuel economy of my Dodge diesels. My old twin turbo'd 410rwhp '93 5spd got 19mpg. My daily driven '90 with just minor fueling mods gets 22-24. My stock '04 6spd gets 19. All 4x4's. Why does the jeep that weighs half as much get only 13? (roughly)

Wombat,
I'm a lover of the straight 6 myself, that's why I switched out the 258 for the 4.7. My first build also. Picked up the HEI DUI which was matched to a 258, which makes sense to me since I'm using the 258 crank and will get the mild cam to compliment. Have the 2150 and the borla. Need the intake manifold that will be the least amount of butt pain. Either way, I've enjoyed your thread, which helped me avoid some pitfalls. I'll most likely beg for some more of your trial and error wisdom in the very near future.

[myillwillinc]

Flabby, I'm still collecting parts, my intake is still on my 90 258 engine

[Wombat Ranger]

The stock 4.0 EFI intake route like I took is A LOT of work. I would guess that the Clifford intake would be much less work. You could also use a stock 258 intake, as long as the mating surface is flat (mine was warped or something) it would work fine. I could have just machined mine flat, I did that with my 4.0 intake anyway. Overall I am happy with how I chose to do it though, it all fits together very well, and looks factory. Everyone I show it to is impressed how cleanly set up everything under the hood is. People expect it to be all frankenstein'd together. The only messy wiring left is some factory stuff I haven't cleaned up yet. I am training a guy at work who has a 510rwhp '94 Cobra Mustang. Took him for a spin in the Jeep today and hit some nearby dirt on lunch. He told me probably 6 times that he was really impressed with how strong it was, and that he'd never seen a Jeep that would move like this one. That made me feel good.