This might the most amount of love I have ever seen a jeep 4.0 get. Not that they were bad. They were always just expected to work. Just flush the cooling system thoroughly every 50k miles.
@@marcryvon not really… you KNOW a Honda will need regular timing belts to live, for example. A Jeep 4.0 just goes forever unless you don’t even give it oil or something abusive like that.
I had a heck of a time finding a place that would refinish a flywheel for me a year or two back, most machine shops seem to have gotten rid of their flywheel grinders
Nice to see the 6 cylinder engine getting some attention. I'm working on a crossflow head design for Jeep 4 and 6 cylinder engines. I'm starting with a 351 Cleveland head on a Jeep 4 cylinder. Eventually going to cast aluminum heads for both the 4 and 6 cylinder engines.
Here is my tip of the day: if you are tearing up an engine and building it from scratch, you might as well throw some modern after market parts and do incremental improvements to achieve better efficiency. For those saying "is all about originality", well, once the engine has been opened there is nothing original about it.
That's basically what we're doing with this engine. There's no plan to keep it original at all. Looking to do some minor upgrades to give it a bit more power and torque. Should be fun!
keeping cars "Original" is often more expensive. Good for historical reference, BUTT, always remember "originally" the factory that made the car also made many compromises and cut corners (they have to). Do things to make the car YOUR car. Improvements are just that, IMPROVEMENTS!
I like that it isn't expensive to buy pistons and rings made of modern stuff so that they last longer. I often see pistons with performance coated skirts for engines that were invented before it. It's also nice to have piston rings that are made of better stuff. Undercut valves are pretty neat, they can add a little more port flow without porting the cylinder head. That other great thing about rebuilding is that you can hand balance all your pistons and connecting rods. With a little sanding, you can get a better balance than factory. When building a V engine, you will have to have your crank balanced.
There's something therapeutic about taking an old mess of something, be it an engine or anything else, and fixing it up proper. I have an 04 Grand Cherokee I bought from auction on a whim, though it has a 4.7 V8 and I spent the time doing things up right. Love that engine.
Oh that jeppy, she will be so happy lol. Didn't think you'll end up punching it out .030 over. That'll be nice little power bump with the added bit of compression. 😀 Yeah they got some pretty ugly flashing going on. I took a chisel on mine and then a dremal to clean up the roughness a bit. One thing want to say is that the little valleys beside the lifter bores tend to house crud. I don't know about this one I imagine shop is super super thorough but they have drainage holes that are fairly small and can clog over the years. Because of where they are it's hard to clean out on the first pass usually. Another place crud likes to collect up is at the very back of the block at the bottom of the cooling jacket near the bottom of the jug, basically the floor of the jacket. You have to get in there with a long "pokey jabby" and possibly a vacuum to suck the mess back out. It's a cause of overheating/high-temp issues at the back of the engine. Make sure those have gotten cleaned out. Today's oils I don't think cause of much issue with the lifter valley drains but back then with the much cheaper conventional oil I think maybe was the cause of poor oil drainback/pressure issues after a few years of running, with prolonged oil changes if that was the case. Can't wait to see what colour you chose for it! Red might be too flashy maybe a nice charcoal gray. Maybe a little darker red might be nice actually. I plan on painting mine a dark red for my 98 2dr for when I haul the motor out of that one later. I'm sure you got something cool to spray on. 😉
Enjoying the hell out of this. Our Service Advisor just bought a 2001 Cherokee. Blew my mind on your disassembly here that that engine has never had a crossflow head! Checked my guy's 2001 and yeah. Wow. Great engines though. Only part of a Jeep we don't seem to have to fix. His is down to 10mpg though, so I imagine I've to figure that out lol
Sitting here watching this cool video as my son is considering buying. 2001 XJ with a bad motor for $700. Also, have a trailer in the garage half torn apart that I need to get to welding on refinishing. Time to get my butt out to the garage
so lucky you are to have the 6cyl WITH the MANUAL trans! i'm so jealous. i've got a beautiful white 4 door and i've been looking for a stick shift donor for years now
It doesn't look like they put the cross hatching on the cylinder walls. It's important for keeping oil stuck to them. When I bought my '97 five years ago for $500 with 190,000 mi I looked inside with a endoscope and the cylinder walls still had all the cross hatching and the pistons and everything were so clean. That Jeep was well taken care of. It now has 260,000 mi and still going strong. I restored everything over the years, it has no rust anywhere and won't either due to all the rust proofing I've done and continue to do. I only drive it in bad snow or off roading or towing about 30 times a year. I'll never sell it! One day it will be one the only few left and probably worth quite a bit. The '85 Toyota Corolla GTS (AE86) I bought basically mint back in 2004 is another vehicle I have I won't sell. It's worth a small fortune now but I can't part with it. That sits in storage and I take it to the track a few times a year as well as the local shows where it's usually the biggest hit with the younger guys.
The rough casting flash left on the block can be removed by using a punch and a hammer, it usually isn't necessary to use a carbide bit to remove it. The place that you should use a carbide bit on are around the outside edges of the block where there are sharp lips of casting flash that can cut up your hands. Removing these can make it easier to handle, and make the paint job look more professional.
Saw the Tahoe in the vid and it made me wonder what vehicles do the Hagerty crew choose to daily! Would be great if y'all would make a video about this! Something like what you drive, why, and what mods ypu have done!
That 4.0L flywheel has a taper built into it for smooth engagement. If your machinist grinds it out your new clutch will shudder. Trust me! I have a 98 wrangler 4.0L with a 5 speed
Could see the polisher/tumbler running in the background on the bench. What make/model is that? I need a little tumbler to clean parts and can’t seem to find one I like.
Science! aka the starter ring. Probably could have frozen/chilled the flywheel too to demonstrate such things. I've used it myself a few times too, to freeze/heat something to fit over or easy press fit in 👍
Yup! heat is easier though, unless you're using uncommon methods like liquid nitrogen you can only cool double digits while its easy to heat into the triples.
i dont have a shop i have a parking lot. so getting out there to do work well not so motivated. i have a 99 xj and it needs work but have to wait on weather conditions.
David what is the painting process and products they are using to paint the engines for you guys? I sent my block off to be machined and when it comes back I am planning on giving it a nice paint job. I am an automotive painter and am thinking of epoxy primer, base coat that matches the body and a semigloss clear coat. Can you do a detailed paint process video on this block? Thanks.
So what liters would this bring the 4.0 too after it being bored .30 over ? And if you put the 4.2 crank in while it’s bored .30 over what would the liters be then?
Boring and honing with a torque plate is of course better, but perhaps for this lightly loaded, closed deck, cast iron block they aren't critical to getting adequately circular bores?
A trick i love using for stuck bolts nuts everything stuck to hell i use oksy acetylin heat it cherry red and douse it in water My friend is about 40yo and allways heat things up normally then trying to get it unstuck an he thaught it wasnt going to work tried his method, dident work Tried my method came right off:) so try that one or another time:)
Question: 4 thou off the top of the block shouldn’t affect compression too much, but 30 thou over six cylinders combined with the block skim and new pistons/rings should give it reasonable giddy up, or not really?
Actually not a whole lot HP wise. Torque numbers may come up a bit though. These engines are designed for torque, and that comes from stroke mainly. Were I to go this far on the rebuild, I'd go ahead and do a 4.7 stroker crank and rods. Either way its bulletproof, because these do nothing powerwise after about 3800 rpm (redline is 5200), so it'll never grenade from being overreved.
RULE OF THUMB / approximation of the rate of expansion due to temperature for steel /iron For every 100 degrees Fahrenheit, steel will expand 0.001 inch for every inch of material. This is not EXACT butt, it is pretty darn close. If you have a circle of steel that is 12 inches in diameter and heat it 100 degrees F it will expand about 0.012 inches.
