Your First Engine Job - This Is What A BAD Cylinder Head Looks Like
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- เผยแพร่เมื่อ 29 ม.ค. 2023
- We found some mysterious damage in the bottom end of our 4.0 donor engine, but found the answers when we stripped the head to start working on it.
Here's what we found, along with a rundown of how to check seats, guided and what kind of cracks you can live with and what kind spell certain doom.
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Do you even repair cars? Or you'll just a TH-camr now for the money? Great videos for the high school shop class!
I'm actually a ballerina but I face enormous discrimination in my chosen field, so I play a mechanic on TH-cam for the time being.
@@UncleTonysGarage your plié moves are so graceful, an inspiration, thank you sir.
@@UncleTonysGarage The day you appear in a tutu and toe shoes in a video, my life will be complete! Brava, Prima Dona!!
Jim.... This is why She left you...
This is why...
@@UncleTonysGarage that explains the slim look
You didn't mention one of the most important things on a straight six and that is checking the face for flatness with a straight edge and feeler gauge, especially on a engine like yours where you had tight head bolts and not so tight bolts, that's a good indicator of a warped head.
Could be stretched bolts as well. But he did make mention about doing the check In the video when he found the bolts that were not as tight as the others.
My first porting adventure led to me going through the bowl. It went into a headbolt hole. I was a kid and said run it. And it did. For as long as I owned it. About 15 years..lol
That seal checking trick is minty. I think you’ve shown that before, but I’d forgotten until you demonstrated it again just now.
That sealing trick is awesome!
Yes, but check it DRY. A bad guide will still seal if there's oil inside.
Do you have to remove oil from the guide before checking the suction?
Tony, PLEASE do a Edelbrock headed stroker 6. This would be a great video series and practical for many of us.
That's the plan for the motor currently in the jeep. This is its replacement for daily driver use
@@UncleTonysGarage Thanks, Tony, would like to know how YOU consider the cost of new, flashy, aluminum head vs redoing/prepping a stock head, intended purpose and all.
@@landontesar3070 the one he's building right now is going to be a stock replacement. He said the engine in the Jeep when he pulls it out he will build it with the Edelbrock head the guy talks about . Just read what he wrote.
That backyard trick for checking valve guides is pretty slick. I can't recall anyone else ever teaching that technique, but that's some good information to teach us beginners, thanks Tony. Other great lessons as well, but that impressed me the most. I've always said, Uncle Tony and My Vintage Iron are hands down the two best channels for beginners. David Vizard & Andy are really great too. All 4 of you guys teach a lot of good stuff. Most if not all of the other channels are more about advertising expensive performance parts. Only once in awhile do those channels show us regular guys something worthy of learning.
I would almost be tempted to redo the seats and guides anyway having taken the head to this point, not terribly expensive
You might like Vice grip garage. he does a lot of rescue/revival of older vehicles, and other stuff as well. And he's hilarious and very VERY knowledgeable about cars and the things that go wrong with them. he and Uncle Tony are my favourites, with a close runner up of 'superfastmatt'.
@@kellismith4329 machine shops have gotten insanely expensive over the last decade. I've no idea why, but I can buy brand new fully dressed up aluminum heads for less than it costs to have double humps rebuilt. Granted the aluminum heads are Chinese, but I know plenty of people who say the quality is 'okay' and the price is nothing. perhaps more to the point, I can get vortex heads from summit, ready to go pretty much, for less than doing valve guides, seals, and seats and new valves. Hell, a shop quoted me 1800 Canadian to take an already stripped block, magna flux it, steam clean it, run the usual checks, overbore, and cam bearings. And they would charge 'in addition' to deck the block. I no longer plan builds based on cores, if it's not a great running engine to my certain knowledge, then I don't want to take the chances. Gone are the days when a kid could drag a motor out of the junkyard, strip it down, get the machine work done, and build it themselves to save money. Where I live, you can buy a turnkey crate *with transmission* for less than it costs to build a tastefully designed performance 383, and the crate motor has a warranty.
It's sad. Maybe its different where you are, but recently Uncle Tony went to sa shop to get some work done, and when they quoted the price, he just left, saying the same thing: Not cost effective.
If anyone knows why this is.or any tips, I'd like to hear it... I only ever built one engine, and loved it, but I can't pay three grand for the privilege of spending hours building a motor I could buy for much less than the parts cost...
The back of the valve also has to allow the air fuel mixture to FLOW into the Combustion chamber and a clean back valve flows far better than a dirty valve.
As an owner of the 4.0 this is becoming very helpful:) mine runs great at 200,000. But there will be a time that I'm going to have to do this! So thanks! Very informative video:)
400.000 klm they are only just run in. lol good old jeeps.
I got a good laugh when you remembered the cleaning of the valves. Getting more vintage doesn't help the memory either, I know! Great video!
He’s really good on explaining things thank you …
Every Caterpillar 3406E of C15 cylinder head is designed to crack across the intake valve area. There's no water in that area, you never see, or notice it until the head comes off. If that crack goes north of the valve seats it can be detrimental due to the the valve seats falling out and causing catastrophic damage, or it could extend up to a water passage. These heads are north of 600lbs and cost 4,000 bucks plus.
Okay...
I'll be perfectly honest:
Even I never thought about that hot intake valve issue, because I always relied on the heat inside intake manifold for that.
Since I have been planning on building an intake system which would never get that hot, I would have found myself wondering what was not working.
But now that I have seen this, I know that I have to make changes to my design to ensure I get proper fuel vaporization.
That's crazy how deep u have to search deep to find out issues keep it coming man learning so much thanks 👍
"Just taws the thing!" Tony's words of wisdom.
I work in a machine shop and do all the mag checking on the cast iron heads we have come in. Most of the time what I have seen is the heads crack through the exhaust seat into an EGR passage. They're junk once that happens.
One thing you should talk about is if the keepers have mushroomed out the metal where they lock into the stem. The stem gets a little ridge that prevents you from pulling the valves out. Having a good small file is very handy when that happens. I find that the case on a fair amount of older Chevy 350's that come in. Chryslers don't have that problem because the keepers have rounded teeth that lock into the stem. While the Chevy keepers have the square cut grove for the keepers.
Im excited to see the 4.0 stroker build, Ive got a 258 crank and rods in a box and keep thinking "someday"
The 2.2 and the 2.5 crack between the valves. I have put many back on with no problems.
4.0 heads respond pretty well to very minor port and bowl work. I have one that picked up about 30% on the bench without doing anything crazy... and since you have one to cut up and inspect, you _could_ go crazy if you wanted.
Just some food for thought before you decide to just bolt on your other stocker.
I had a 92 Mitsu Eclipse GSX that broke it's balance shaft belt and fell into the timing belt. Happened just as I was parking it.
I had it towed home and pulled the head off, and checked the valves seal like you did. They were fine - no bent valves.
I cleaned up the back of the valves and the ports and combustion chambers and reassmbled.
I was REALLY surprised how much better it ran after that - until the valves got coked up again.
Thanks for explaining why it ran so much better after cleaning up the back of the valves.
Love hearing this, like I'm back in apprenticeship
Yeah, once you overheat a 4.0 head, alot of the time it's scrap iron. Especially late 99 to 2001 cast heads.
If you know you are going to get a different head, be sure you know about the problems with a couple casting numbers and cracking under the valve cover. There are quite a few sites with people posting questions and answers to find which is good and which is taboo. I had this happen to my 2002 TJ. I found a complete head - new- at just over $300.00 about five or six years ago and it was the last one. I had pulled the valve cover to inspect for a crack because I kept loosing coolant. It kept getting worse and on a warm day, the temp would go up. When I pulled the cover, I saw water on the head between cyl. #3 and #4. I removed the head and never found the crack until after I cleaned the residue off the casting, let it set in the weather and finally it rusted at the crack. Only thing I did not enjoy was the intake and exhaust manifolds due to having headers and they reduced access to the bolts and nuts holding it in place. Swivel sockets, Wobble extensions, almost did not have enough of them. Even swinging the ratchet was miserable due to limited travel and obstructions. Knock on wood, still going. Aluminum head is out of my reach.
is out of my reach due to the cost.
Been doing this kind of stuff for 40 years and still learn new tricks from you all the time, thanks!
Love the backyard workarounds over the “Official FSM” guidance!
The 1st engine I rebuilt under my Dad's tutelage was a 6 HP Tecumseh for a Go Kart & that valve stem check was one of the "tests" but with a slight twist, he'd pull the valve out & then gage by ear the "pop" it made when the stem came clear.
I clean also polish the valves while they're out just so no cust builds up in the future and I also upgrade the valve stem seals cause oil leaks on the valve stems can aid in the build up of crust on the valves as well
Tony! I remember that valve guide test for your early days, and I used it on my Ford I6 300! It makes me a little misty eyed thinking of how far you have come and how much I miss the stunt carb!
I agree anything clean on an engine will benefit! The 345 IH intake valves had more than a quarter inch of carbon.
Tony, as a rule of thumb with purchased heads, with valves installed, I always check the seats for lap-in and check for burrs in the intake and exhaust ports. It seems like a waste of time for the average guy, but several ruined valves and heads later, it pays off! Of course, you know this, but some don't and to help them not have problems, check everything!
Yep. It's very common to find cracks between the valves on the 2.2/2.5 4cyl engines.
On those engines, if those are the only cracks, you just ignore them and finish building it out, even on the turbo ones.
I have a bunch, the only one I had that wasn’t cracked like that was a new casting from Alabama cyl head
These videos are great ! I'm learning allot . Thanks from posting them .
Great video, learned a lot thanks for sharing all your knowledge.
That vacuum seal check on the valves is a nice tip! Thanks as always.
Great video about cylinder head inspection. I was wanting a little clarification on the crak you found. I understand that is a water jacket and not casued by an inclusion in the Cylinder heads casting. The Slant 6 video you did on the deck having the inclusions had me thinking. Also i will be adding that Valve seal check trick to my knowledge for sure. Thanks
Thanks for this series. I am about to do my first engine breakdown on a mercruiser at the age of 62 and this is just what I needed. Thanks for the details.
So use that head to practice porting or other grinding work. For those of us that have never tried doing it before anyway. :)
Just wanted to thank you for this series. I've seen lots of videos of people explaining how to put an engine together, but no one else seems to explain WHY you take certain steps. Your experience really shines through, very informative. Thanks again!
Finger over the guide is great information. Thanks again Tony.
Uncle Tony truly is awesome!
Perfect test subject for doing some port work. Those engines really respond to minor work and you have a head you can cut up and go wild with to see what you can really do
Dodge Magnum heads are like concrete, which comes in 2 types: concrete that is cracked, and concrete that is going to crack. And as UTG says - there are cracked ones running around doing just fine.
I have commented on this before, but that’s why the injectors spray pattern is important on these Jeep engines.
They run a single hole injector that gives a solid squirt of fuel straight at the top or back face of the valve and clears it up and like you said the heat atomised the fuel for better burn.
Like I said it would be good to dyno your old injectors to see patterns.
Benjamin, is that what supports the thinking for these massive intake plenum manifolds with fuel injection on 90's Dodge/Jeep?
The built up carbon absorbs raw fuel like a sponge besides insulating from heat . This causes emissions problems. Where I currently reside we unfortunately have to get tested to purchase new license plates. We used to have lots of trouble with the last of the Oldsmobile V8s passing unless we ran a bunch of sea foam through the carb until it flooded out then let it sit all day and soak then fire up at the end of the day and run the dog crap out of them before knocking the ignition timing back until it would hardly get out of its own way then take back to the test site to retest.
Thank you. Good video.
Clean the port and fix the crack. With JB-weld or silicon bronze braze it will run "just fine" under low stress.
Awesome informative content 👏👍
I just rebuilt a VW 1.6 diesel a couple years ago. I was concerned when I found that each combustion chamber had a small crack between the bowls. Then I found out this is a common issue and unless it's excessive, like going into a bowl, it's not a problem. They say if you can get a fingernail in the crack grind it out and run it. Otherwise leave it alone.
Are you gonna put a mild RV cam in it before you button it up? I'm sure your gearhead go-fast senses will at least allow you that one luxury in the build 😉
I remember hearing about sewing cracked-rare cast iron heads, before the aluminum ones were available. Alot of talent lost, but alot of performance gained.
The backside of the valve cleanliness... or swirl polished, and under cut head, at least a 3 angle valve job. Gettin into race talk now, but it does free up power to a point.
8:04 "Like I sez..." :) 13:50 Very interesting, never heard that. I know it's true that the intake valves are cooled by the incoming fuel, so they can live nearly forever, whereas exhaust valves just get brutally hot... and stay hot, slowly eroding themselves, the seat and guide.
thats why its important that they have a good seal, not only to hold the combustion pressure from being wasted but also because a good seal has more surface area to transfer heat to the head away from the valve
Thank you.
This crack often happens when the engine runs with too low coolant level ! Most of the time head cracks between valves on the the furthest cylinder away from water pump !
Now I can't sleep knowing I have crud on my intake valves! I was happy just blaming it for "being a Dodge", haha... Always learn something; all the best from here!
Our timing is off. I would've sold you my wife's original cylinder head cheap that she's using now as we are replacing it with the Edelbrock one this spring. Already purchased, too cold to pull right now outside. I still need to buy some rockers but we have the head already. Her original was very well rebuilt 25,000 miles ago and will go to someone in need for pennies on the dollar to help our fellow Jeep enthusiast. All cylinders still over 150 on compression but those iron heads stink. Picked up the 4.2 crank and installing that with fresh pistons. She's gonna love it. Hope her tranny does too.
Sounds like a beautiful plan
Sounds like a damn good plan going with the Hot rod an elder Brock head
That would be great if you do a stroker, looking forward to seeing it, all the best to yous and your loved ones
Early amc 258’s had umbrella seals. And would accumulate a large golf all sized carbon lump on the valve obstructing flow.
Been loving this series uncle Tony very nice work!
Dropping some serious coin for that Eddie Head and talking up a stroker ?
5 liters or bust !
I dare ya !
Nice trick for checking valve guides , btw .
I had a machinist show me that one a long time ago and had totally forgotten about it until now .
UTG speaking of aluminum heads for his own use? Something supernatural happened after the encounter with the cyborg from Canada who claims there were appendages missing…
Thank you Uknie Tony you have taught me a lot since 2018. Came for the Mopar knowledge but stayed for the tech....
Exactly my situation!
I'd also think the carbon buildup would lean out your mixture as the carbon would absorb the fuel on a cold engine.
Just like cast iron intake manifolds, cast iron is porous and can absorb fuel just like oil?
would love to see some vids on different hemi engines, parts interchange, evolution, and hot rodding would love a 392 in my dragster but an old 354 would be cool also, love the nitro funny car vids you have done
As a certified TAVO, I'd do the same, build one good engine out of the two. Aussie Hemis are notorious for flogging out valve guides. A high mileage engine would almost take .005" O/S stems right out of the box.
This engine may have been overheated, sure. That's a pretty bizarre way for that head to crack. But the skirt failure was almost assuredly not related. Neither of the 4 liters I had piston skirts fail in an almost identical fashion on were ever overheated, its just something that happens. I had one fail at about 220k, and another at about 250k. Buddy of mine had one fail on a 130k mile 4 liter that had been babied its whole life. All 3 were XJs. My guy at the machine shop told me he's seen 4 liters with as many as 5 out of 6 pistons that had skirts with chunks missing. For whatever that's worth. It was a design or manufacturing oversight, something to do with making them lighter for fuel economy as well as cheaper.
believe replacement piston sets, stroker or not, have different skirt designs
The cracked cylinder head is actually good news. Since you are putting parts in you can justify putting a 258 crank and rods in there (we all know you want to).
I like the valve guide trick
I have seen a few Jeep heads crack in the bowls. Make sure your replacement head is the same casting number so you get the same intake ports... They changed them repeatedly over the years..
Where will the hot rod 4.0 go? Would it fit in one of your smaller cars, valiant or dart maybe?
Can’t wait to see and hear the hot motor… how about pushing the Jeep 4.0L to Hudson 5.0L (308)?
Good job! Aluminum aftermarket heads for a Mopar inline? Why am I playing with a sl6 again?
Interesting that it cracked on 1. Depending on the casting, it was more typical between 3 and 4 on the 4.0s and that was in the '00 and '01 year range due to a casting defect.
The Edelbrock head for the Jeep engine was absolute junk. I say "was" because it has been discontinued. That head offered zero advantage over a stock casting in terms of power potential or efficiency. It came with smaller than stock ID valve seats and it could not be ported as thoroughly as a stock head. The primary issue was an incredibly thin aluminum casting. Cast from a weaker material and yet, thinner than stock. If you truly ported that head, you would break through, or it would crack as soon as you torqued it down to the block. If your engine is a distributor engine, you need a 7120 casting, if it is a coil on plug engine you need a TUPY casting.
Nice content. I’m thinking of using the casting #0630? 96-99 casting 4.0 cylinder head on a old AMC 232; why? as the AMC/jeep guys say those years flow best with no modifications or other work. Do you have any experience with the 630 head?
Anyone who's played with VW IDI diesels knows it's ok to run a cracked head😃
I've seen a few but never had any of mine do it.
It's hilarious to see folks who don't know, post in a forum freaking out about it.
Not worth taking the chance. Replace it and be done. Chances are your money and time ahead in the long run.
Not so fast - in today's day and age, you really need to check what you're getting, as the farther we go in time the more low quality work there is out there, waiting to bite someone in the ass.
But I agree with replacing here.
Trust, but still go at it with calipers and dial indicators...
That’s really to bad. When I worked in a machine shop we repaired many head cracks with King Serts and JB weld. But that was only possible if your tools could reach both ends of the crack. We. Guaranteed our work, and never had a return, but I reiterate, you have to be able to reach both sides of the crack. The idea is to prevent the crack wouldn’t spread, so the outside of the cracks were repaired first, moving to the center as the repair continued. Anything short of that, your screwed. Uncle Tony is right with these heads and this particular crack. If your not sure take it to your local machine shop and if the Machinest is worth his craft, they will tell you in short order. And as far as cracks go, they don’t charge the much to check the head for cracks, some of which you won’t see without magnafluxing or dye checking up in aluminum heads. Good luck!
A quick note on valve and seat repair. You can lap the valves at home, but the seal will not last anywhere near as long as when it was built by the manufacturer. Cutting the valves and seats with a machine like a series valve cutter will establish an interference fit between the valve and seat like it was when it came from the factory. In my mind this is a must with any performance engine or any engine that you intend to use for another 50 to 100 thousand miles. If your flipping cars lapping the valves will get the car sold. If you like tearing your engine down frequently, lap the valves.
Those heads like to crack between the two center cylinders. Having two exhaust ports side by side flashes the coolant into a steam pocket within the coolant jacket and allow the head to get to the point of cracking.
It's all in the details.
If you suspect the engine has overheated, is there a quick way to check valve spring temper or just junk them ?
Uncle Tony, send the head to uncle Vizard and he'll cut it up and figure out how to port it and then you can port one based on what he says and slap that on your souped up engine.
Plus, it's more content for both of your channels.
So you need a head, you can make a set of cheap sbc aluminum heads work with a little cutting and welding just like the videos of the Ford 300 with a set of cut and welded together LS heads on it.
If you want the details let me know, I'm happy to help.
the head on my diesel is extremely known for cracking between the valves. Doesn't seem to bother anything though so I'll ignore it if I ever have to pull the head.
I don't think I've ever seen a crack like that on anything I've worked on, usually it's the 0331 heads between cylinder 3 and 4.
I liked the 4.0 in my WJ, was a tank of an engine even as worn out as it was. Unfortunately the number 1 connecting rod let go a few days before Christmas, I think worn out may have been an understatement. At 352k I'm not gonna complain, putting a 350 vortec with a 700R4 and NP241C in to replace the worn out and blown this spring. Too cold here to pull things apart Right now and I need to finish getting the parts together.
Im sure you know this Tony but they do make cylinder head appoxy or can use JB weld and ive seen it used in a bowl.
dam tony,,, i guess i learnt something today, is it accurate the vacuum test in valve guide?
ProMaxx sells an improved casting with hardened seats, complete for a good price.
Such good information, brother. Really appreciate your knowledge and experience man thank you so much. 🙏
Gotta watch those 0331 heads!!
About cracks in heads i saw several new merces head all craked up,, I just removed the cracks between cilinders , becasue they were deep the head was compçletly "destroyed" and a guy just rebuilt it with a tig, weld.I also welped but iam not a ver y good weldeer- It worked well.
It was an aluminium head , i dont know if iron heads can have that job but i have seen too guys welding iron heads .
Like I mentioned before in another video my dad had 2 of these different jeeps late 90s both 4.0And he blew both of them it developed a rod knock or a Main bearing knock on cylinder #6 on both vehicles And I was told by some research That it's an oiling issue I'm curious to know what the real issue is..!!!??😇
I think I've learned more about rebuilding engines from Uncle Tony than just about anyone else. That quick test for valve guide tolerance is pretty damn cool.
Yep great door stop
It had a good career. Now it's a teaching tool.
the back of the valve is a probem on the 265 they nearly close the port off can be 1/2inch thick they where like it from day 1 umberla seals ..........
Is valve test done with dry stem and bore or oiled?
How does a crack in the #1 cylinder valve port lead to skirt failure in the #6 piston?
is polishing the back of the intake valve a good thing or bad?
Hotroding we never really know what we will do next