Taking our 4.0L XJ Engine to the machine shop

This week our 1993 Jeep Cherokee 4.0L block heads to the machine shop for some TLC. After it's baked and blasted, Mikey helps us get everything bored and decked so we're ready for paint. Davin also picks up a new skill refreshing the flywheel while we're there.
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[@jhopkins1515]

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]

Well, as with any car, no ?

[@joshuagibson2520]

@@marcryvon indeed, but a lot of Chrysler products, specifically, are known for coolant eating head gaskets when said coolant gets old.

[@bobbytrill420]

The only thing that killed the 4.0 was no maintenance. Poor maintenance wouldn't stop them.

[@stevelacker358]

@@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.

[@seanfrank4158]

@@stevelacker358 Even then they last longer than they should....without oil. I'm sure the 4.0L would run on mud if it had to....

[@jamesford2942]

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.

[@gapratt4955]

Miss the days when you could take your flywheel down to your local NAPA and they would machine it while you picked up a clutch kit.

[@Hagerty]

We're certainly lucky to have a great local shop like Thirlby in our backyard. Makes a HUGE difference for all the projects we do!

[@benspilker6866]

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

[@pboyd4278]

I never tire of watching and listening to Davin work.

[@isaiahwyant3479]

i just rebuilt a head on one of these and installed it in shop class, definitely a nice simple engine to work on

[@MAtogable]

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.

[@Hagerty]

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!

[@scotte2815]

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!

[@skylinefever]

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.

[@MAtogable]

@@Hagerty Exactly! Usability is what keeps cars on the road (and sell more policies), originality keeps them locked in a garage. Never stop Driving!

[@JorgeRodriguez-po7kx]

@@Hagerty Just Asking How many Thousands are remove from the Block and Head ?

[@JayGuitars1]

G’day from Australia 🇦🇺! We love our Jeeps over too!

[@JoshG8408]

I got my hind end off the couch yesterday. Good times.

[@JustJeep_It]

Really diggin this series!!! 4.0 for ever!

[@maskedmotorsdiy3575]

1:10 I have similar cylinder head shipping pods in my living room. Cats love to jump in and out.

[@jw11432]

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.

[@abitdazed]

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

[@hyattbusbey3563]

Whoa, 10!? My 96 4.0 5spd cherokee pulls 21 combined. Only thing that really tanks it is spending a lot of time at 80+mph.

[@stacyromanchuk]

I remember replacing a starter ring in a flywheel in my mechanics class back in the day. My teacher was super old school and was awesome!

[@cargogh]

I'm really enjoying this engine.

[@CanadaBud23]

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. 😉

[@elij.s.7580]

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

[@monkeybarmonkeyman]

Like the machine shop did a very nice chamfer on those bores. Details matter.

[@notsofast5495]

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

[@bobmillerick300]

I got my wife out in the shop working on it.

[@daviswall3319]

Love those Jeeps with the inline 6. My dad had a late 80’s model with over 300k on it. Wish we would’ve held onto it--

[@seanfrank4158]

That was pretty cool. Neat seeing the rebuild process from start to finish.

[@wackowacko8931]

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.

[@retiredafce3373]

It’s a great series so far. Can’t wait to see what you do with it!

[@ajohnson1066]

thanks for that motivation Davin! I do need to get in the shop and get my stuff done

[@patrickwines9551]

Might be worth it to get a 4.2 crank from rockauto and make a 4.5ish stroker motor with those 30 over pistons.

[@cx.silver.bullet]

I would never expect that removing that big tooth ring from flywheel is so easy :D

[@randybarnes8454]

338000 on my 4.0, still running great. I hear the piston slap when idling. Reminds me of a little diesel engine. Oh it's in a 1993 Cherokee.

[@caribbeanerich5629]

I have a 93 with 333800...good choice!

[@twinturbotaj]

I took my Jeep I6 cylinder head to machine shop on a 50cc scooter once, under my feet

[@CanadaBud23]

Lol nice. The blocks aren't really that heavy but probably for you it felt like a second person on though lol.

[@johnnyk617]

I really dig this guy's presentation, seems like a good blue collar regular guy do more with him

[@reallyhappenings5597]

David from Hagerty is right... my work ain't getting done on its own.

[@JohnnyAFG81]

Awesome 2dr 5spd XJ. It’s gonna be a solid build!

[@ronlynch7744]

Yeah, got work done but it was shovelling the driveway. That block should Rock with some paint. 😎👍🇨🇦

[@jasonsari447]

Still have a 4.0 as a daily driver. One of the best motors ever. I’m at 148,000 and still going strong.

[@neophobiagarage1845]

yeah waitin for the cylinder heads, soon they come, back in da garage

[@TheRedgtv2000]

Another technique I have done besides heating the ring gear I have placed the flywheel in the freezer to shrink and made the install easier.

[@PrairieDad]

I want a 4.0L block coffee table someday, but my wife would murder me.

[@marcryvon]

Forget it ! Trust me, I tried and tried again with a clean Honda block. No success.

[@ol_smokey9370]

I'm turning my old Ford 4.6 cams into lamps and my wife doesn't want them in the house either lol

[@justinmckeown9029]

‘Tis better to ask for forgiveness than permission. That’s easy for me to say, though; my wife wants a motorcycle in our dining room.

[@tombridges5946]

Loved it! I just rebuilt my 4.0

[@paulcochran1721]

Dang, Davin, drag a comb through that hair! 🙂 Just givin' ya crap! Looks good, keep up the good work!

[@wayanfrombali4513]

Nice work🔥🔥

[@georgesantiago6005]

A balance parts is a good option.

[@paulprescott7913]

Ahhh i love these vids.

[@DustinSeiger]

Amazing work as always.

[@joes3461]

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 👍

[@russellv6234]

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.

[@justinsmith653]

Thanks for the life advice

[@gjagger9331]

great video👍 can't wait to see the next one

[@sidneysanders5726]

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

[@brandangillogly9913]

Oh, we got a Kyle cameo!

[@vettekid3326]

You need to have a project like an old Dodge Power Wagon so your shop has a 4 wheel drive shop truck to use in the winter.

[@Hagerty]

It's like you listened to the conversation we had in our office last week... 🤔😉

[@Friedbrain11]

A flat afce for the clutch disk to sit against...lucky you. The stepped flywheels can be a real pain.

[@free2chasehappy]

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!

[@buddah13]

i wish i had a shop . . .and some work . .

[@muzzy109]

Крутьь!! Дэвин как всегда на высоте

[@johnnyutah565]

Fantastic vid keep um coming

[@johnwilliams1091]

Done swolled up

[@jefferykirk2322]

Sweet

[@billtruett8593]

ARP rod bolts “dang” supercharge it 😉

[@hayzersolar]

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.

[@rickfulton2353]

weird how loud this video is. thx for content

[@robertmarcum3917]

When you get back to the vintage dirt car project?

[@Hagerty]

Soon!

[@mattstidham8041]

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.

[@Jesse-B]

The raw cast looks pretty cool, perhaps a coat of semi-gloss clear?

[@thundermite1241]

I want to see this 4.0 stroked to the max and then supercharged

[@broman1536]

Pays to have a skill

[@melvinthemechanic]

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:)

[@joseguadalupecadenamunoz6340]

Le da un parecido al Ford 200 6 cilindros en línea 🧐

[@erickdealmeida4456]

I had the same xj jeep but i make a swap engine for a ford 3.6 litre engine six in line from argentina

[@jormoria]

CHINGON!

[@alexyo3927]

Nice dude

[@THROTTLEPOWER]

Great vid, really enjoyed!! 👍👍👍

[@NOrlando952]

Just saying it might be pretty funny to put this in an XJ6 jag.

[@joshuagibson2520]

1:23. Yeah. I bet slamming that block around on a wrench and the bench doesn't kick up any burs at all, huh?

[@caseyjones1999]

Yeah i saw that rouge crescent wrench get squished buy the crankshaft bearing surface

[@sakilaalatas9083]

Slam dari Indonesia

[@jacobcow111]

Awesome

[@tyronejk]

What's the purpose of running the engine block through the open-flame oven? Is that for cleaning?

[@AndrewDRoyappa]

Honing without a torque plate! 😩😩 Sad day

[@scotte2815]

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.

[@dadstoygarage1878]

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.

[@jakobbratcher9395]

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?

[@donroy53]

F.Y.I.: the ring gear usually is worn in two places, because an engine normally stops in one of two places, 90% of the time

[@eproehl]

Did you re-balance the flywheel after grinding and the new ring gear?

[@brianc2341]

What happened to the race car you were working on???

[@lucasr6587]

Better make this thing a stroker

[@mitchellwashington6874]

Why did you have to put it into an oven?

[@teds3242]

Team Hagerty, What happened to the dirt track racer?

[@amandawatson5931]

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?

[@scottdoubleyou563]

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.

[@moparedtn]

All I want to know is: Is *Davin* enjoying this build? I don't sense any great excitement from him on this one. Might just be me.... - Ed on the Ridge

[@FilmJunkieOutdoors]

how much would it be for me to do this to my 4.0 6cylinder tj ??

[@Verywell15]

What’s the purpose for the heat at 2:45?

[@erichimes3062]

Where is the Machine shop?

[@johnwilliams1091]

Boom, or Blam?

[@ofirs5830]

5:00 what does that green machine do?

[@rdyer8764]

How do you make sure that when you recondition a rod that you don't change the journal to pin distance?

[@CanadianParamedic]

Why do you BBQ the block?

[@marcryvon]

To burn any caked in grease, dirt etc. Best method.

[@gregarmstrong552]

Isn't the oil pump an issue on these? Is there an upgrade for it?

[@billbeyer657]

For that matter you could've just clocked the ring gear an eighth of a turn and been fine too. Ring gears only wear in 4 spots on 4 stroke engines.

[@Ozsmallbore]

Actually the number of wear spot corresponds to the number of cylinders

[@billbeyer657]

@@Ozsmallbore you're right, 2 on 4 cyl, and 4 on 8 cyl so I'd guess a 6 cyl would have 3

[@ianatkinson8464]

😎👍

[@ofirs5830]

9:42 is that a primer layer before the paint is done?

[@bomberaustychunksbruv4119]

How much will 30 thou over give you?

[@ezequielsilva2709]

Muito bom 👏👏

[@dennygood6261]

Why no torque plate when you rebore?

[@prevost8686]

It’s a low revving closed deck cast iron block. Honing with a torque plate is unnecessary for good oil control .