Does Your Vintage Classic Car REALLY Need Special Oil? Evidence That It Does Not

It's a recognized fact that flat tappet engines require zinc (zddp) to keep the cam and lifters properly lubed, but there is at least one common engine out there, the 4.0 Jeep, that runs and lasts flawlessly using nothing but commonly available quick-lube oil and no special additives or treatments.
So, is the zinc thing just a myth? Here's what you should know.
#jeep #cherokee #XJ #chrysler
MERCHANDISE:
Get Your UTG T-Shirts Here: uncletonysgarage.com/product/...
Get Your UTG Stickers Here: uncletonysgarage.com/product/...
OUR STORE: uncletonysgarage.com
*SOCIAL MEDIA:
Facebook: / uncletonysgarage1

[@TEN-TIMES-HARDER]

Damn your gonna make me call you out, hell, well your wrong kzbin.info/www/bejne/rqXMY3-Ll5p7p80

[@UncleTonysGarage]

I don't know what to say....but, since you went through the trouble of making that video, I'll pin it here so others can offer their opinions.

[@stevetaylor9265]

Not sure what the pot head is taking about but that reminded me of the old frying pan and egg adds from the 80s. This is your brain on drugs. Any questions

[@brunomahle1618]

punching up for views

[@reaper20015]

@@UncleTonysGarage Mama always said if ya ain't got notthin nice to say.....well you know the rest.

[@reaper20015]

@@stevetaylor9265 Please refrain from blaming him on pot. Thank you.

[@SpecialAgentJamesAki]

Things to consider: spring pressure, weight/drag of valvetrain components, and rpm range. Stock cams usually do fine with regular oil. Regular oil today is around 800 ppm zinc. It is recommended to have the zinc level around 1200 ppm if you’re going past stock, which the rotella is very close to. You won’t hurt anything by running 1200 ppm and the rotella is cheaper than regular oil so might as well. You can overzinc a motor around 2000ppm which will make the oil deteriorate and become acidic quickly and might also ruin catalytic converters if you have them. I have a car with a 230 duration 530 lift cam that got ran on modern Mobil 1 synthetic oil for 20k miles by the previous owner and I have run it on rotella for 30k. Recently had the motor open and the cam was 100% on spec still.

[@averyalexander2303]

I was thinking the same thing, the Jeep engine was in no way built for performance and most weren't run very hard. It doesn't have an aggressive cam or stiff valve springs to put much stress on the oil and it doesn't rev very high. So just because a stock Jeep 4.0 will go 200K miles on low quality oil without problems doesn't mean the same results can necessarily be expected from a high revving performance engine with an aggressive cam and stiff valve springs. The hardness and surface finish on the cam lobes and lifters is likely much better on the 2000's Jeep than something made in the 60's too since metallurgy and machining has improved so much since then. There's just way too many variables to say with any accuracy that someone won't have problems with X oil because it works fine in a totally different engine (not that Tony is saying this, just clarifying).

[@jeremyking5684]

Your absolutely right! Any engine with a high lift flat tappet cam with strong springs you need zinc or your going to wipe it out!

[@SpecialAgentJamesAki]

@@averyalexander2303 I agree! That’s a good way to put it!

[@danhoyland142]

I found some scholarly article done by scientists on one of these oil manufacturers websites four or 5 years ago . I was trying to figure this out and really dug into as much as I could. What the research study said was modern oil is adequate for stock cams under .450 lift. The logic was the down pressure on the lifters onto the cam lobe from the valve train was not great enough to wear the cam lobe. I still felt uncomfortable and ran rotella.

[@joshlambrecht2357]

Good point about the Jeep. Duration on the jeep cam is very short. Allows for less angle on the lobe, so less wear that way also. Old volvo 4bangers and the pushrod straight six were like that too. Very rare to see a factory cam on those thats wiped, even hundreds of thousands of miles later. Of course there is some wear, but its usually even and mild. On the other hand, many a Volvo guy has “rebuilt” his old B20 or B18 4 cylinder with an aftermarket longer duration cam and ive seen more of those wiped in recent years.... all since the mid 90s. Stock short duration cam on my inline six still makes factory lift.

[@car_ventures]

Zinc doesn't protect as zinc is soft. It's the P in ZDDP that does the protecting. The P is Phosphate and under heat it creates a hard glass like film which creates a barrier between the metal. The zinc is the part that carries the phosphate to where it's needed. Without zinc the phosphate wouldn't get everywhere needed, so yes in that sense zinc is important but the part doing the protecting is the phosphate.

[@car_ventures]

High ZDDP oil is usually classed as >800ppm - 1200ppm ZDDP content. Cheap oils will be 1200ppm but they also contain high concentrations of molybdenum and similar. Varies of course by manufacturer but that's typically the ball park.

[@jeffrobodine8579]

After checking out your long subscription list I am surprised Project Farm is not on there.

[@itsthemetho]

Lots of high zinc oil are 1500-1600 ppm. Not saying you need it, but plenty older formulas were that high. Now they replace the ZDDP with friction modifiers like boron or MoS2.

[@user-cs1ne8gx9u]

The AMC 150/2.5 was designed to be built on the same tooling as the old rambler 6, 232/258 and arrived before the 4.0 liter. The 4.0 is basically a 150 with 2 more cylinders and a different bore and stroke. Since the basic design didn't change much since 1964 many parts will or potentially swap between all the 6 and 4 cylinders. Chrysler sure got there moneys worth with the purchase of AMC as they always made a great engine.

[@QuietDriver97]

Had a 2000 TJ with the 2.5 and had the head taken off at 152k miles just for a refresh. The shop said the cylinders looked near new.

[@googleusergp]

The reason Chrysler bought AMC was for the Jeep brand and for some production facilities. The rest was table scraps and went away fairly quickly.

[@user-cs1ne8gx9u]

@@googleusergpChrysler also got a lot out of AMC's last engineering work. Think of how many YJ's and XJ's were produced after the purchase all being of AMC design. Even in the TJ Chrysler kept the AMC engines and the 2.5 also went into Dakota's until 02. Then there's the PowerTech family of engines also of AMC design that was used till 13. Not to mention the LH platform they made millions of that AMC developed with Renault. Chrysler got a lot more out of buying AMC than just the name Jeep.

[@92powerdiesel61]

@@user-cs1ne8gx9u The powertech engine's basic design is still in use to this day with the 2.4L multi air that they throw into a lot of stuff. Mind you the modern stuff is over complicated and much less reliable however it is cool to see the basics of engineering reused over and over.

[@Jaysunn00]

@@user-cs1ne8gx9u AMC also designed the jeep ZJ they never produced it before the sale but Chrysler did and it sold like hot cakes

[@alleyoop1234]

I'll place a bet the cheapest modern oil would out perform the most expensive oil from when that engine was first introduced back in the 60's

[@jeffreyyeater1780]

Correct

[@MiguelGarcia-vj7oo]

If im not mistaken Project Farm cut opened an old Pennzoil from over 100 years ago and had the same quality or better then modern oil.

[@oldsjetfire8975]

Keep in mind that spring pressure will be higher on a performance engine and can play a part in this.

[@111000100101001]

Yes a “performance” grind cam in a big block Chevy is tough on lifters and mating cam lobes. It could use all the EP to keep it alive.

[@tinkersspeedshop8401]

😂🤣😂 if you dont understand that, probly should stick to changing oil, leave the wrenching for a mechanic.

[@donaldfrederick1557]

4.9 Ford inline six sold from 1965 till 1996 to the public. Serious work horse was put in many application's. Farm equip., generator's, delivery companies vans; etc. I use Rotella in my 96 F150. Great engine.

[@grand73am]

I've been driving my 75 Pontiac Lemans, with Pontiac 350, for over 20 years. Original, untouched engine. It had 62K miles on it when I bought it in 2002. Now it has nearly 190K miles. I haven't used special high zinc oil in it or additives. Just Valvoline 10W40. It runs just as good as it did when I got it. No cam problems. Of course, it's not a high performance engine, but it's still pretty peppy for a heavy car.

[@davidcamp3045]

I would love to see a picture of that car...

[@unicornsteaks6769]

It almost seems like it's a new cam/lifter issue.

[@jimsix9929]

that valvoline 10w 40 has plenty of zinc for a stock engine, you are doing the right thing, dont ever change

[@apachebill]

I’d switch. To the Valvoline VR1 10-40 High Zinc flavor. Same exact oil. More zinc. Keep her protected. One Lemans man to another. 😉

[@rickobrien4014]

The right answer is that it depends!! If you have a flat tappet cam with aggressive ramps and high valve spring pressure than zddp is a strong recommendation. But for a super mild motor like the 4.0 Jeep, not needed!!

[@jseal21]

Absolutely agree. I'm not a master mechanic and have only a handful of engine builds under my belt, that being said all but one engine were street only and they got zinc in a can for initial then off the shelf oil after, but the 50/50 got a half can in every oil change. ( I refuse to go roller, just love the sound of solid flats )

[@scottrobertson6949]

He also confirmed that 4.0 uses a.904 diameter lifter which is the largest used by a manufacturer. If you have more surface area and a gentle profile the lifter will have less tendency to overcome the oil film strength. These engines won't have heavy valve springs.

[@googleusergp]

Slight correction: The 4.0L six-cylinder engine was first used in a Jeep XJ platform in 1987. From 1984 to 1986, they used the GM sourced 2.8L V6.

[@thekikendallsautoandrandom1271]

One of the things as well that helped the AMC designed inline series of motors was the top end oil drainage. literally drains directly back from the rockers onto the cam.. The camshaft and lifters are FLOODED with oil from both the oil passages, and from the oil draining back off the top of the head. Coupled with fairly low (for modern vehicles) valve spring pressure, the lifters being vertical and not having to fight gravity to rotate under load makes them one heck of a good design. The piston skirt issue is common, usually on cylinder 6, due to the length of the engine and that cylinder always runs a bit hotter (due to the length of the cooling jacket from the radiator). Youve got another good XJ Tony. Cant wait to see you swap the flexplate on the AW-4 trans sometime soon. Just a word of advice- the factory shift linkage on the 4wd is sometimes janky, couple companies make a better designed replacement linkage thats alot smoother.

[@bluetoes591]

VW was doing flat tappet cams until the mid-2000s in the base model stripper 2.0 cars they sold in Canada, the City Golf and the Jetta City. That engine was also developed in the late 60s/early 70s and used for close to 40 years.

[@oldblueaccord2629]

Would that be over head cam as in no lifters?

[@hotsaucehead]

I just did my first rebuild, and because of modern issues I used the old cam and lifters. 200,000 miles and no visible wear on the cam and lifters.

[@rogerdavenport9618]

As I said in an earlier video you had about cam failure the Rotella oil was recommended for my 454 big block with a roller cam, my nephew is the maintenance supervisor at the county bus shop and you know the abuse that a bus gets, and that's all the manufacturers recommend for those buses Rotella T. Thanks for another great video.

[@hotcuda]

Uncle Tony is a National Treasure!!! Always the best content!

[@robertdinicola9225]

Im in the marine biz. I love "the dealership said my engine is toast, its making a noise". Big boats have flexplates with springs in the hub. They break. Im always a hero!

[@DannyCsaszar]

Huge fan, keep up the great videos!! My Jeep 4.0 xj I bought with 200k miles and till the engine was replace at 360k mile never seen a zinc additive and ran perfectly fine. Only reason for replacing it is the oil leaks and wanted a 4.6 stroker. I rebuilt my 4.0 after I got a junk one from a reputable builder and use zinc additive every oil change. Maybe I am worried of new parts now days being not so good quality like you so I want to be safe.

[@mpetersen6]

Engineering test 4.0s with roller cans were built sometime after 1994. Due to the tight fit between the curtain wall and the block proper the lifter retainers were mounted underneath the lifter bores. I actually saw blocks being machined in the Tool Room of KEP to take the roller lifters. IIRC around 50 were built. The cams were probably ground by an outside supplier or at one of the Chrysler development shops in Troll Land*

[@stevelacker358]

I got bit by the XJ bug about 15 years ago... they really are just about perfect little machines. The thing that probably surprised me the most is that it turns a tighter circle than *any* other vehicle I've driven short of a forklift. A solid-axle 4x4 does that. No kidding... just incredibly nimble little vehicles. Still love 'em.

[@billybobholcomb8768]

Great video. I just got the shirts that I ordered. I can feel my hair growing back already. Can't thank you enough.

[@CanadaBud23]

I knew you'd love them. 🙂 I run regular 10w30 whatever is on sale specials. Usually it's the Castrol Edge Ti stuff that on sale for 22 bucks. I use them on my stock XJ motor and my very modded motor. It's always fine.

[@willtws9920]

Tony my first vehicle was as a 93 Jeep Cherokee 4.0L 2x4. It was great! Good power and surprisingly smooth ride. If I saw one for sale in good shape for a decent price I would absolutely buy one again.

[@viktorhardindyrvold4234]

The way I've heard it is that the zinc hangs on to the cam lobe, so that _if_ the oil film breaks under the extreme stress from the lifter, you still have a backup form of lubrication. However, with a high quality modern synthetic, in theory you should be able to maintain that film of oil on the cam at all times - even with aggressive cam lobes & springs.

[@jimsix9929]

yes zinc puts a coating on the high pressure areas like cam lobes, it does not drain off and is needed for engines with high spring pressures or flat tappet cams, the best oil around will not keep a hotrod engine alive without the zinc

[@victortaveira8271]

@@jimsix9929 Zinc increase a lot friction, despite lubricating. Today there are more modern oil additives, which do the same job better and without much friction. Esters base oil and high molybdenum content help more. This characteristic is what a modern synthetic motor oil is designed for

[@rickss69]

@@jimsix9929 That is not even remotely how ZDDP works lol. Neither you or anyone else has ever removed a camshaft and witnessed a "sweater" of ZDDP...it does not "coat" anything. ZDDP is only activated by extreme heat and pressure in the localized spot. What makes or breaks a engine oil is the additive package...not ZDDP or greater percentages of it.

[@BradMillsOK]

So glad I can follow your XJ adventures. Have one and love it like a family member.

[@gurneyforpresident2836]

Great video Tony. You're analogy is spot on and helpful.

[@adamrodenberg1557]

I'm starting to think viscosity plays a big role in it too. Some modern engines recommend/require 0W20 and 0W40 which is so thin it looks like water when you drain it out. Those same modern engines are also known for eating up cams and lifters. Lots of folks are now running slightly higher viscosity (like 5W30 instead of 0W20) oil than what's recommended just to avoid the dreaded "lifter tick of doom". Makes you wonder if "they" are purposely sacrificing longevity and durability for bigger claims of power output and fuel efficiency.

[@adamrodenberg1557]

The original high-mileage, worn-out AMC/Rambler 232 in my 65 Marlin still runs smooth and quiet with Rotella and a bottle of STP oil treatment.

[@kainhall]

I've got it on good word from a Ford tech that 5w-30 is just better VS 5w-20 . It even helps the cam phasers stay more "stable" on a 5.4

[@blackhawk7r221]

Yes, it’s all for claims of tiny fuel mileage improvements. Unless you are in the great white north, 10w-30 is fine.

[@jeffrobodine8579]

@@kainhall Our fleet with formerly E250, 350 vans now Transit 250 and 350 vans have all been run successfully on 5W30 oils instead of 5W20 oils for hundreds of thousands of miles. We had a 2003 E 250 with a 4.2 L V-6 go over 500,000 miles of hard abuse on the original motor ( and two transmissions) until it rusted beyond drivability using conventional 5W30.

[@connor3288]

It's all about politics and money. Compare OEM and Mobil 1 website oil specs for the same car/engine in Canada, Usa, Mexico, and UK. Would rather use thicker oil and have engine last longer, it's ok if i get .05mpg less. Obviously you wouldnt use the same oil in Alaska in winter and Mexico in summer.

[@timporter1978]

Glad you added initial engine brake in that zinc is needed. Once broke in correctly the requirement is not as necessary. But remember zinc will kill catalytic convertors with extended use. Most oils recommended for vintage cars that don't have a cat are perfect for continuous zinc use. Lucas Oil Hot Rod and Classic Car oil is a great example, expensive but great for older cars without cats.

[@gearheadgregwi]

I've always used Rotella or Delvac in my Ford 300 and Mercruiser engines. Extra insurance on older engines never hurts. Good topic. No longer an issue for me these days. I'm a now Honda J35 convert because they're reliable sewing machines.

[@scottsmith1386]

Absolutely I got something out of that. Just like I do in every one of your videos. You are truly the Gearhead Monk. Absolute wealth of knowledge and thought. Don't ever stop.

[@charlesatwell6658]

1992 Honda Accord with 479k miles using Havoline 10w40. I am switching to Rotella next oil change because it's getting hard to find Havoline and it comes in a silly bag in a box which is supposed to be good for the environment! Love your videos Tony, very helpful!

[@MrTheHillfolk]

Yo I'm down with a box of wine occasionally, but just say no to bagged oil 😁

[@johnpublic6582]

479k. So you aren't running the break in oil anymore.

[@keithshepherd4693]

@@MrTheHillfolk or wine that comes with a screw top or in a can.

[@bwatt1383]

Wow hows the oil consumption on that thing

[@gearheadgregwi]

Honda J35 fan-boy here. We currently have four in the family fleet. 20 years of weekend wrench turning. I've worked on everything. Subaru probably the weirdest. Honda engineers are like Sony engineers. They like to flex and 95% time they hit the mark.

[@bobbyz1964]

That assessment agrees with what a lot of oil company experts say, you need zink on the initial break in. I will use zink on the 318 I'm building, new cam and lifters. On the stock 74 318 I've been driving since 2011 I'll keep dumping in whatever oil is on sale. If it ain't hurt it already I'm thinking it'll be fine.

[@someguy2741]

I have several buick 455s and have found that 10W30 syntech synthetic works well. It sticks well and the oil pressure does not change with temperature like conventional oils. I figure its a good combination because buick oiling is not great but it has huge bearings. So I dont need a ton of film strength I need it to get where it needs to be.

[@kaboom4679]

I would love to see what you and DV can do with a 4.0 and a stroker version . There has been a lot done with this motor already , but , I am sure DV could really bring this mill to it's full potential .

[@cammer68oliver2]

I seen a video recently somewhere on KZbin of like a 1000 hp 4.0! Somebody turbo charged it and everything! Brought it up-to-date. Was an awesome engine!

[@GJM866]

The following includes advise from my trusted old school mechanic. I own a 2002 Jeep Wrangler 4.0l 6cyl. Did my research and took mechanic's advise and just went with regular conventional oil, no zinc, no additive. I also have a 1986 Plymouth Gran Fury 5.2l 318. With that I did put in the zinc additive because back then the oil had it in. But in the end, I don't think I needed to. Just the way I handled it.

[@PSA78]

All engine oil contain ZDDP, and adding more after is called "chemical Russian roulette" for good reason. Get the right oil to begin with. (The 🤡in the video don't even have basic knowledge)

[@randywestrum6416]

Rosella and Delvac are both refined to a higher degree than other motor oils, due to the trucking industry’s request to having a longer lasting oil for extended oil change intervals. Another trusted oil, Phillip 66 x/c 20w60 aviation oil. Engineered for radial aircraft engines from run in to teardown.

[@jeffrobodine8579]

I dated a girl named Rosella back in school.

[@randywestrum6416]

@@jeffrobodine8579 That was a really fat finger, hope I didn’t offend. PS was Rosella well fed?

[@CharredSteak]

phillips x/c is no joke, really expensive but worth the money. always used delvac in my older stuff, diesel or not

[@AnzaValley]

Years ago I drove VW bugs and buses. I used AeroShell 80w which is actually a 40 weight oil.

[@cherokeefit4248]

I love my xj. It’s tucked away from another winter. Best Jeep ever made in my mind.

[@johnpublic6582]

I guess that's why I didn't wipe out my 318 cam before I learned about zddp. 3x10w40 and 1.5x20w50 with a filter every 3000 until I get to the rebuild.

[@davestarkey7519]

I knew this subject would fire up all the experts. Good topic Tonester.

[@jameskrys5286]

We had a 97 Grand. Leaked oil and the 4.0 used to eat water pumps. An oil change guy told me oil for foreign cars still have zinc in them.

[@archieguitarz4700]

Thanks for the vid Tony. I've been using Walmart brand diesel oil in my stock 340 & 383HP cars for about eight years now with no issues. Usually I add half a bottle of ZDDP just to plus up the zinc level. I've heard too much is just as bad as not enough, hopefully I'm in the ballpark. I can see where the correct amount of zinc could be critical if your running a high lift cam & high pressure springs.

[@petesmitt]

Adding zinc to oil doesn't work; kzbin.info/www/bejne/pZm1ZqWZqr6DqJI&ab_channel=Myvintageiron7512

[@OldcarsNmusic]

Nice to know that about the Jeep 4.0 because I have two, one in a '96 Grand Cherokee and one in an '88 Comanche. Sounds like six quarts of Traveller 15w40 will do them both just fine.

[@mitchelkane2641]

Love this channel. Always talking about stuff I think about!

[@bobbova8708]

Interesting video.A thought crossed my mind,even though it doesn't concern vintage cars.I used to help a mechanic in Stamford, Ct.who was in his own shop since 1967 or so.Customers would bring in newer cars with service engine lights. The complaints were that the cars were not running right along with the service light.These cars all had the variable valve timing engines. One of the first questions to the customer was when they last changed the oil and every time it was a day or 2 . The solution was simply to change the oil,as the "quick oil change place"(you can go thru from a to z) purchased their oil in 55 gallon drums and in every case the oil was a very low viscosity and in each case simply putting the correct oil into the cars solved the problems. Again,this has nothing to do with vintage cars but I wanted to throw it out there.

[@crautoguy8384]

You are completely right Tony. I started as a mechanic in the late nineties never heard of such a Thing. Castro gtx all I ever used. Would build brand new engines swap Cam shafts flat Tap it cams never even thought about it in fact never even did proper breaking procedures like we do nowadays and never had any problems Only cam I've ever had to go flat with one I built for myself 383 small block Chevy. that had 570 Ish lift and huge stiff valve Springs I learned that Lesson About the stiff Springs only about 6 or 7 years ago heard of using zinc additive.or diesel oil On flat Tapit Cam shaft I think that once they're broken in Will work perfect for a very long time they should be fine. I think it's more important when doing a breakin or the fact that we have c*** Chinese lifters on the market even the top Cam companies are selling them. They took the zinc out of motorolas a long time ago for catalytic converters Like 30 years ago. So?

[@captainsergeant]

I bought my 1991 XJ for 1200.00 for the same reason. The seller thought the engine was bad. Having done my research in advance, I knew what I was hearing. When I pulled the flex plate it was completely cracked/broken all the way around - 360 degrees. You can shift the loose part in the middle around about a quarter of an inch each way! I hung it up on my shop wall as I have never seen anything like that before.

[@briantruck2284]

Seen that happen

[@Digitalsharecropper]

Tony, you nailed it. Never thought about this one

[@adamculbertson7850]

Great video! Thanks UTG.

[@Jimmysidecarr]

Tony, even modern chemistry restricted engine oils(API/ILSAC) DO HAVE ZDDP, it's just in there at a reduced amount compared to oils we used to have or current diesel oils. Your point however is exactly correct, most non-performance type(grocery getter or truck) flat tappet cam engines will survive just fine, using common readily available API licensed oils that do have reduced zinc(ZDDP). To clarify, the zinc is reduced, not removed. It's actually the phosphorous that is limited to 800ppm, but that's part of the ZDDP compound.

[@DarkLinkAD]

Phosphorous is limited to 1200ppm max for the latest CK4 forumlation. Rotella T4 has 1130ppm VOA and T6 has 1260ppm.

[@bryonhills6172]

My xj has 290,000 and I've been running quaker state 10-30 most of its life. I changed the valve cover gasket and oil pan gasket at 250,000 with 0 sludge build up. I couldn't believe how clean it was.

[@flinch622]

You have to research all oil offerings these days - the parts store [with rare exceptions] does not know. Mobil1 for example has a dozen different zinc levels, largely varying around viscosity ratings. Zinc isn't gone, but levels in some offerings are half of what was used in the 80's. It would be interesting to dig into the details of that jeep engine oiling system. Grooved bores? EDM holes in lifters? Something else? I've never worked on the 4.0.

[@charlesroyal3428]

I have a 91 Cherokee with the 4.0 she runs great for a high milage vehicle, I have been using Rotella 15w40 or the Kirkland brand from Costco for a long time now.

[@christophernava6685]

I have a 1993 XJ with the AX-15 and I use Rotella T4 on engine and no complaints. 301k miles and still going.

[@scotth9881]

It's great you're getting into XJ's. There's just something about them.

[@MrSmith-ok7tl]

Good video, but you may want to distinguish between everyday engines with low spring rate (lower force/pressure on lifter face/cam lobe) and higher spring rate high performance engines. High performance engines with high spring rate flat tappets should always use ZDDP oils. I have an old go-fast powerboat with twin 454 big blocks and flat tappet cams and use oils with around 1,100 to 1,200 ppm or so of zinc.

[@3.2Carrera]

Interesting point and welcome to XJ's. I figured you would gravitate to them being a fan of the inline 6. I have the last year XJ that had low miles and a cracked head. I got a new head from Clearwater, bolted it on, and it's great. Super easy. I gave it to my son and he's in the Marines. We drove it from S Florida to California in January and took the long way on I40 to hit snow and other areas of interest. Had a blast. Anyway that engine is a low performance engine so probably the springs pressures won't be an issue. But I just dove into the Porsche world and rebuilt an air cooled flat 6 a couple of weeks ago and with the obscene money that thing cost, I can't take any chances with racing valve springs and rewelded cams. But from an engine design standpoint that engine has an amazingly engineered oiling system. Anyway I broke the engine in with Lucas for 60 miles and then switched to the new(er) Castrol GTX classic 20w-50 for it's zinc content.

[@alale923]

Love my 99 and 98 jeep xjs. Pretty sure my 99 classic has the same issue of a broken flexplate. Ill be looking out for the video on diagnosing those sound differences.

[@jerrodrhoades404]

'99 XJ original owner here. Been watching your channel for a while now and was wondering if you were going to bring up the Jeep 4.0 concerning lifters. Jeep 4.0 are known for having lifter tick or collapsed lifters after 150k miles. Planning ahead, you buy lifters and change them out when your head gasket burns between cylinder 3 &4.

[@double01red54]

That only has enough spring pressure to control the valves to 5000 rpm. If you can get it to rev past 4500. That’s why it doesn’t have a rep for eating cam lobes.

[@jim55282]

As of this date, I dont know if there is a TSB for cam and lifters on the 4.0 but when I was a dealer tech I saw 3 that ate the cam and lifters. No, this didn't happen at extremely low miles but indo recall one being a warranty job.

[@stevelemmen7048]

Tony, I'd like to see an engine teardown on an older engine that was not damaged from lack of zddp.

[@zenrill8723]

Loved every xj I ever had. Always used standard oil. Most of them leaked so much I just changed the filter and topped off the oil. Dad had one with 350k miles on it before it quit.

[@daleschuler1720]

For longevity I'll stick with the T4, just as soon play it safe.

[@grad0n]

I’ve owned many XJs since 1994. The 88, 92, 94, and 96 were 2dr 2wd 5-sp 4.0 SE stripper models. I built a 4.6l stroker for the 96 and had that street rod for a dozen years and 125kmiles. I now have a 99, also chili pepper red like your 98, 2dr 4wd that I swapped a 242 t-case for awd mode, 5-sp 4.0(4.7or8 stroker to come), and an eaton tru-trac out back. XJs are the best all a-rounder hands down.

[@mitchmasterfix5292]

Love you Tony for keeping the ground shaking with the power of classic Mopar mills, but you owe your audience a follow-up. Today's oils don't have "no zinc", they have less zinc or to be more accurate less of the zinc/phosphate compound known as ZDDP. Because phosphorus "poisons" catalytic converters the industry has been reducing the amount of ZDDP. This became a noticeable problem around 2004 when the SM oil standard was introduced with a limit of 800ppm. Newer oils are supposed to have improved anti-wear formulas to make up for the lower ZDDP levels but for older flat cam engines especially those with higher spring pressures, a high ZDDP oil (which may conform to the latest API specs) is a good idea. BTW I recall Chrysler issued a bulletin on some 4.0L to replace the valve springs. The factory springs were so weak the valves would sometimes fail to close when carbon got on the stems. Car makers run the softest springs they can for fuel economy reasons. Grab your favorite beverage, curl up with a warm laptop and do some googling - plenty of good info out there (some bad info too... check the source) PS. Be careful with modern diesel oils. Diesels now have converters and other exhaust devices that require oils with less phosphorus (low "SAPS") so you may not get the level of ZDDP you got in the older oils.

[@raiderjohnthemadbomber8666]

I used Royal Purple for the cam break-in, I replaced it with the same and yes a 20 minutes run with a low micron filter is expensive but I really wanted a good break-in. After the replacement oil came out I too have been using Rotella. BTW, roller lifters for a Gen I is prohibitly expensive!

[@tinkersspeedshop8401]

Never use royal purple for break in, the parts wont wear together, and you will get some funny bidness, just not right off, and thats if you even get the rings to seat.

[@raiderjohnthemadbomber8666]

@@tinkersspeedshop8401 thanks for that. I'd heard that about synthetics. In your estimation, what's a good oil to use for a 20 minutes?

[@ultimafuego]

Been using diesel oil and all my vehicles. Two or four wheels for the last 15 years. If they're older than the year 2000. Never let me down.

[@bigredauto6774]

I ran just straight conventional oil in my cadillac 500 for almost 20 years before I learned about Zinc in the oil. As a car guy, it somehow never made it into my brain for years. I still run conventional oil in my 300 inline 6 that has over 200k miles because at this point it appears it matters very little. I recently rebuilt my caddy with a roller cam, but the factory tappets were still in great shape. I only rebuilt it because it was out of the car for restoration. I only went roller because I was my builder didn't know what was going on with flat tappet cams at the time.

[@GregsAirplanesandAutomobiles]

Fiat 1.4 engines which say MOPAR right on the valve cover use flat tappets on the exhaust side. It does have rollers on the intake side.

[@merr6267]

I just pulled apart 3 of these units for various projects. None had flat cams, though the one with 200k on it had some obvious wear, but it went right back in the wife's YJ with a 258 crank. Haha.

[@rednecklite]

Never thought about this, I had a 95 ZJ with the 4.0 and remember surfing the old Jeep Forums seeing guys say to only use diesel oil for the zinc, and yeah you're right there are 200,300, even 400K 4.0s out there that have only used "regular" oil without zinc. Still, a bottle of Rislone zinc additive is like $2 on sale, so worth it for my old 460 Fords. And cheaper than buying Rotella.

[@petesmitt]

Diesel oil doesn't have zinc anymore and adding zinc to oil doesn't work.

[@brthdan]

@@petesmitt It contains more zinc than traditional oils but not as much as it did before being reduced in 2006.

[@petesmitt]

@@brthdan not enough zinc for the purposes of flat tappet cam break-in like it used to; that's the point.

[@robertdinicola9225]

I ran delo r0 in 98 vortec from day one. Did intake gaskets at 120,000 and was blown away at how clean it was inside. Did intake gaskets again at 220,000 and still just as clean. They stopped making delo so went to rottella

[@superduty4556]

My Ford 300 inline 6 does well with flat tappets.

[@allhailinternalcombustion]

You could fill a Ford Six with coffee and marshmallows and it would still run forever.

[@superduty4556]

@@allhailinternalcombustion facts.

[@MrTheHillfolk]

As a gen tech, it's one of my favorite industrial engines ever. Damn things are sewing machine smooth. What a joy when they are city water cooled ,no damn fan noise and it just whirrs away.

[@jeffkeryk3550]

For a flat tappet cam with higher valve spring pressure, I like the new Castrol GTX. HDEO oils were the fix years ago, but there are better oils out there now.

[@stevodakine1]

Rotella is the most universal oil in my opinion. I use it in the classic car and in my dirt bikes many people use it in their dirt bikes. It’s really a one stop shop oil. You just can’t go wrong.

[@davebonds250]

189k on my '93 XJ. FLATTENED #3 exhaust lobe 3wks after buying it. These engines have a notoriously difficult time with lifter tick and piston slap due to the short skirts. Its not just Zinc. Its also Phosphorus that helps cushion and heat insulate/ wash barrier. Also, oils have changed massively over the years. The same brand and weight had massive changes in its additive pack throughout the years.

[@race8427]

My brothers 98 Cherokee 4.0 gave up the ghost at 344,000 mi with occasional oil changes (monkey boy oil). Now has north of 370,000 on a rebuild, and back to the occasional oil change regimen.

[@bobinforapples911]

I used to use Valvoline synthetic high mileage on mine since it has the most zinc out of the commonly available oils based on data sheets, kept it nice and quiet at over 200k

[@jeep2nv92]

The XJ with the 4.0L and AW4 trans were indestructible. The 4.0L also had wrist pin issues. They would rattle until they got warm. I bought one from a dealership I worked at because they thought the engine was junk. I slapped new pistons in it and drove the crap out of it. I sold it to a friend and her daughter is still driving it, and beating the crap out of it. The best vehicle I ever owned was my 1992 Wrangler YJ. I bought it in 96 at the GM dealership I worked at right out of high school. I sold it in 2018. It had 64k miles on it when I bought it, and 480k when I sold it.

[@goodday2u936]

Aah the famous 4.0l that engine is known for being bulletproof! i own a Jeep Wrangler 2006 Sahara edition and love it, thanks for the info Uncle Tony! 😁

[@jimjungle1397]

The AMC 6 cylinder 4.0L and its sister 4 cylinder engine don''t like high RPM's, or they will break. Keep the RPM's down and they will last.

[@goodday2u936]

@@jimjungle1397 Yes you are right the AMC 4.0l is never made for high revs as it works with an underlying camshaft and push rods( overhead valve engine) if you were to run the engine at high revs the valves would start to float and cause damage, so thanks for the info

[@harvestblades]

The lowly XJ or Cheap Jeep can be rather addictive. We've had 4 in the household & still have 2- 2000s. My biggest aggravation with them is the electronic locks & windows. My dream XJ would be a 4 door (even a 2 door) 4.0, 4x4, manual with manual locks, windows.

[@noneyabiz0987]

Fun fact, Shell Rotella DIESEL oil, while it works, is NOT formulated for the higher RPM use of high performance gas engines. Additionally, the newest specs for DIESEL oil have even less zinc due to the emmisions equipment & regulations. So be careful of what you buy.

[@DarkLinkAD]

Wrong, my entire fleet uses drums of 15w40 Rotella T4, doesnt matter what it calls for. We see millions of miles, 0 issues.

[@noneyabiz0987]

@@DarkLinkAD pretty sure i said it WILL work. Lol

[@DarkLinkAD]

@@noneyabiz0987 Yeah I read that wrong, my fault. I will ad though, that VOAs show that CK4 (The latest Rotella formulation) holds just as much Zinc as the older (CJ4 API). In both the Rotella T4 and T6.

[@rescuedandrestoredgarage]

Great information brother

[@michaellehmann2803]

That definitely wasn’t the last engine with a flat tappet cam. The Honda 3.5 and 3.7 V6 uses solid flat tappet cams and 0w20 synthetic oil, and they go at least 100k miles without even needing adjustment. Granted it is an overhead cam design, and I’m sure the metallurgy has changed over the last 50 years, so not necessarily comparable to classic car engines, but it shows that flat tappets can last just fine on low zinc oils.

[@dquad]

Vast majority of modern engines are still solid flat tappet when overhead cam. The thing is that valvetrain mass is so much lower and the tappets are twice the diameter of traditional pushrod engines that the loads on the cam lobes are minuscule. Even the valve springs are a whole lot less stiff now, you don't even need a tool to remove them from the head.

[@petesmitt]

@@dquad Yep; I've got an 80's Mazda OHC solid flat tappet cam engine and have only used basic engine oil; after 300,000 km's, I rebuilt the head and when I checked the cam, lobes like new.

[@dquad]

@@faststang85 They are still technically flat tappet

[@thisisyourcaptainspeaking2259]

I go in the woods, too. If you feel the need to add something to your oil for cam protection, I suggest "Camguard".

[@dongeorge4037]

I am SO ready for an engine sound program. I once tried to get an "engine sound" 8 track from an old guy down in Texas who was putting them out but he had died by the time my order got there. So yes, do an engine sound program. Maybe even do a CD?

[@mcawrse]

You make a good point, lots of them out there, no special love and they aren't known for cam trouble. I have seen a 4.0 that wiped a lobe, it had a strange intermittent lifter type noise and a misfire. Customer had us repair it and it's probably still on the road somewhere. It was a fluke, they are a tough engine. Most straight 6 engines seem to hold up well. It's hard for me to think of any manufacturer that had a bad straight 6 design (I am sure that the internet can find one though.) I run 15w-40 diesel engine oil in most everything on the farm except for my modern 2005.5 Jetta, but I hear that the zinc and phosphorous has been cut back a lot even in diesel oils. Most semi-trucks on the road today have roller valve trains. The additives that help our cams live unfortunately poisons the catalysts in the modern vehicles (gas or diesel), so I see why they want to cut it back, but I still don't like it!

[@RichXCSP]

The zinc is bad for cats. But only in very large doses. The reduction in zinc was directly related to the manufacturers being forced to warranty the cats for 100k miles. They called for the reduction in zinc So now you can burn 2 quarts every 1000 miles and not damage the cat. The zinc reduction came decades after the catalytic converter.

[@robertkolb228]

Brother i love your videos! Nobody else schools us the way you do. I have a question for you, what if you are running a high lift flat tappet cam with lots of valve spring pressure? I would think it would be important to have zinc rich oil in that scenario.

[@Trebor-gw8lt]

Those 4.0s run very little spring pressure, which helps in keeping the lifters and lobes alive. With that said, play it safe with flat tappet cams. Castrol’s new GTX “classic blend” and Valvoline VR1 are available literally everywhere, in addition to a wide assortment of diesel oils. Those 4.0s have phenomenal UOAs with Rotella 5w40synthetic.

[@jasonr6763]

Bought one of these last year for my Teenager. The seller was convinced it had a blown engine. I did the mechanic thing and told them there was nothing wrong but a blown hose and transmission solenoid. They wouldn’t believe me, well for $300… I took it…. The kid has his first vehicle and it runs great. I think I might get one actually, its a lot of fun.

[@kzbuster]

See a lot of youtubers pouring Rotella into all kinds of old engines in the assumption that it is an overhaul in a can. I used it to break in my 73 Dodge 340 but never after that. I just change my oil every 3k and add a little STP (792 ppm zinc) and my engine runs fine. I'm not a big oil additive guy but a little STP won't hurt. I'm sure a lot of people will say STP is junk but I feel good about the stuff with the added zinc.

[@heathenamerican8149]

Yeah, between my two 70's dodge pickups I put Rotella in the 74' and it runs a little smoother I think, then my 78' where I run only conventional oil in it, not as smooth but runs just as strong. Both have 360s and roughly the same milage.

[@keniferusxj7047]

My xj is a 87’4.0 and I’ve been using 15-40 shell t4 rotella for years and the 4.0 runs amazing ,does not burn any oil at 232k .. using 10w-30 the top end makes some noise..so 15-40 rotella works amazing

[@Welcometofacsistube]

Been using shell rottela in my classic mopars for 20 years. Not one problem

[@dalton456]

You know I'm excited that you got into xj's. There's just something about them that's awesome, mine is frustrating The hell out of me right now, built a 4.7 l stroker for it and can't get the damn thing to run. Yet I work on modern GM vehicles everyday and successfully conduct more intensive mechanical diagnosis and repairs. But the old tractor motor is stumping the hell out of me

[@connor3288]

What are you having issues with?

[@dalton456]

When you crank it over it'll spin a bit then backfire through the intake, almost like it's 180 out, I have verified that the timing chain is installed correctly and the marks lineup, I have also verified that the cam pickup is being installed with number one at TDC on the compression stroke. Even if you install the cam sync 180 out it still does the exact same thing. It's got 170 psi compression, 55 PSI of fuel pressure, I have good spark and it is pulsing all three coils, and it is flashing a noid light on all six injectors. So I'm at a loss

[@joshlambrecht2357]

Im neither a gm nor a mopar guy but i wonder about hydraulic lifters that are not pumped up? If you have hydraulic lifters i would make sure your oil system is fully primed. Weve had a few brands of oil filters where the check valve wouldn’t open so we had to take the filter off, prime to the filter, then install a cheapie filter with no check valve, then the thing primed up. Hyd lifters can do weird things when not pressurized. Doesnt make sense....hope that will help.

[@connor3288]

@@dalton456 Did you have the engine working fine when it was a 4.0, before the stroker conversion?Same cylinder head, valves, valvesprings, and cam after making into 4.7? Sometimes you need to take a step back and check the basics. Fuel, good spark at right time, good compression with right cam timing. Will it idle at all? Where you said compression test was good, i would suggest your next approach should be to verify proper ignition timing at idle. Perhaps the crank pickup was changed or reinstalled incorrectly. If spark timing at idle is correct i would next do a leakdown test to check for proper valve sealing. If that is ok i would inspect valvespring condition carefully, broken valvesprings can potentially test ok in compression test but cause problems while engine turns fast enough. Where compression tested ok hopefully just spark timing issue. With aftermarket cams always want to use proper valvesprings for the cam, and good to index cam/verify cam timing when installing them. I Hope this helps man. I remember researching engine swaps/stroker mods for tjs, and i determined it wouldnt be worth it to me personally to put the effort in to modding a 4.0. They are reliable but heavy, underpowered, and not very fuel efficient. Make sure to get ecu tune too. I did the 12hole bosche fuel injectors swap on my previous tj, never tracked mpg but i found it started faster and seemed to idle smoother, got them off ebay under $100 for the 6 i think. If i had a mint tj wrangler i would consider an LS swap someday, even a 4.8 would be much more powerful and better mpg than a 4.0. VW tdi swaps are cool too but might as well do an LS, especially with diesel prices and less available engines. Gm 4.3's are another swap i think. Advance Adaptors and Novak Conversions have interesting swap info. Battling body rust on my 04 rubi, joys of new england🙃. Not bad yet but i need to address it soon, it's like they designed the tj to rot out🙃. Oil undercoating is a must imo. NH oil undercoat is what i use.

[@tonyc223]

@@dalton456 Try a new crank sensor.

[@papilloncycles3463]

I use castrol gtx high mileage which contains 800ppm ZDDP seems to work great!

[@andrewkelly1225]

I would add what I didn't see mentioned in at least the first few comments. A .904" lifter helps too! But I would agree that even the small chevy lifter is fine with modern diesel oil (after proper break-in) if it is a stock or mild lobe profile and moderate spring pressure.

[@rustedhorsepower5132]

I was just thinking about this because I've heard off the shelf oil is being formulated for modern direct inject engines

[@bronsonjones4623]

When I was younger the shop I worked at had a 93 Chevy 1500 since new only got shell rotella oil. I thought they were crazy but it was dead nuts reliable with 475k miles. Since seeing that if it has flat tappets it’s getting shell rotella

[@rollin19]

My family owned jeep for 25 years straight. The best ones were made to 96. The 97 and newer rot away,they have electrical issues. The 2 door 5 speed cherokee sport was so fast.