They all crack. I have a 200k mile EJ205 with four radial cracks at every spark plug hole, they are fine. Subaru has a raised area at the plug for combustion chamber shape reasons and this area runs a lot hotter because it is so far away from the water jackets, which is also why it is generally a non issue. It does look really scary though!
Driving on valve seals with a six or 12 point socket when I ran a cylinder head rebuilding department in the 90s. Was a nono. The flats can cut the edges of the seal boot. Causing excessive oil consumption later. I also lube my valve stems with staylube moly graphite assembly lube. With a pocket of that lube under the valve stem seal as a reservoir. Oil leaks out leaving a dry stem. I used to hot glue 3/8-16 nuts to the valve head to work with my old lapping spindle with a worn 9/16 socket wedged on instead of a vacuum cup. A magnet hot glued in the socket allowed me to lift the valve. I miss that job.
Greetings from Scotland. This machine shop is like the one local to me, in the respect they can literally fix anything that looks beyond its best. Incredible skill and machines. Nice to see another Subaru engine saved
For these cylinder blocks it is wise to use a torque plate because due to their small dimensions they ''flex''. Cylinder dimensions are different when cylinder head is torqued in place and when is taken off. Greetings from Greece
You reminded me of the first Subaru engine that I rebuilt it was a 1970 FF1 4 cyl. It had plugs at the front and rear of the block to access the wrist pins. 40 years later I still have the tool I made from a bearing race puller.
I had a 1986 Ford Taurus XL that I bought new with a 2.5 four cylinder. It started running bad and overheating at around 8K and the dealer determined it had a bad cylinder head and replaced it under warranty and again at about 15K and again at 20K. all had cracked across the valve seats thru to the water jacket. After the third head I traded it in on a new one with the 3.0 V6 and never had a problem with that engine in the next two Taurus's or a Ranger that had the same engine.
Big tip. The 2jz has shim over bucket and most cams need to be re shimmed. The best and i mean BEST way i did this was spreadsheet. Measure what i pulled out and tickenes of the bucket to valve spot. tada excell does the math for you.
I wish you guys or Thirlbys had a weekend crash course in this stuff. I could learn a lot from you guys. Ive never measured spring strength or used blue when lapping valves. Thanks for posting your work Davin!
A Master Class on all variety of engines would be cool. You could download and refer back to it before you start a rebuild...always have it on tap to use on your computer.
With bucket shims you can compute what the ideal shim thickness should be based on the first feeler gauge measurement. In my experience, this works pretty much every time, unless you make a mistake with the math, or location of the shims..
It wouldn't be a big deal for a good welder to fix the heads up. Problem is it's often cheaper to replace them than pay a skilled welder to fix up common parts.
The valve adjustment system is similar to many motorcycle engines. As the valves seat the clearance will decrease, set the valves to the high end of the spec. Remember that a slappy valve is a happy valve.
I'm sure it'll be fine as in, it'll run and whatnot. But this is a demonstration in how not to machine a Subaru. These blocks are very light and thin, they distort with the head torque. So you need to bore and hone them with a torque plate on the head surface. This will have significant bore distortion once the heads are on and torqued up.
I admit, I know nothing about rebuilding engines. But it’s crazy to me that cracked heads are acceptable. I’d be less worried about whether it’s a problem now, and more concerned whether it would lead to a future problem. 🤷🏻♂️
Those heads would not get used by me, good used heads or new correct rebuild practice, been do this stuff to long to start cutting corners! Davin you know better!!
Tracking down a set of new or uncracked STI heads will lead you down a very expencive and time consuming path.... as Davin said make do with what you have
I had a 50cc 2 stroke air cooled dirtbike, one time, just after a rebuild it blew the head gasket and me not knowing better removed the head without waiting for the engine to cool down, so I burned my fingers and dropped the head, it cracked in 2 straight down the middle, only the spark plug held the 2 halves together, replaced the new blown gasket with the old one it had before the rebuild and it ran as if that crack was never there.
I mean hey at the end of the day it’s a Subaru anyways, the heads, let alone the whole engine will be out in a month for new head gaskets, regardless of mileage, like clockwork, until the end of time.
I know this video is already 3 months old and so this comment won't be relevant to this specific build but could be for other viewers who want to do the same process: It's a real shame in my opinion going through ALL that hard work of disassembly, machining, honing, measuring and then reusing factory\worn parts. The minimum would be to upgrade to STI rods and pistons. I know a lot of Subaru owners who are actually waiting for an excuse to rebuild their engines and once the engine is opened for a refresh, it's the perfect time! In any case, I think the job you're doing is amazing and it's always inspiring to see someone walk into a project and learn new things as they go. Wonderful to see the attention to detail!
On my 2000 5S-FE head, after recutting the seats, the valves would be too tight. Rather than messing around with the additional time and cost of swapping spacers, they put the cams in, measured the error, then ground the top of the valves to adjust the height. Since they're pretty good at what they do, they only had to install and remove the cams twice (once to measure, then once to verify). What's annoying is the head bolts are under the cams, so I had to install and time the cams once I had the head on.
Honing should be done with the block halfs torqued. Subaru specialists do the rebuild process a bit different from what you did, I hope you won't run into trouble.
How come honing has something to do with block tightening? Honing tool is free hand on a few universal joints, so it basicaly ads sufrace finish for oil film to hold on. And andy from subieperformace also does not join block halves for honing
I would suggest getting the crack laser welded. It's usually quite cheap compared to a new head and the new weld is also going to rearrange the Atoms leading to a newly formed grid. It is probably going to crack fully if you leave it like that.
It is hard to weld it properly to last, and yes crack will grow but there will be no catastrophic failures. If he will not run to much power and control exhaust temperatures it will live happy life for long time. Weld will also crack. It comes down to how hot chamber will be, how quickly and frequently temperature peeks are happening when pushing it and quality of the head when it was poured. If you can get uncracked head that is best way to go, meaning use this one until you find one that is not cracked. To find one without cracks is hard and expensive, and it is better to get used head without cracks, then new. Not sure if new are available at all.
A new head in general for an EJ205, EJ255, or EJ257 is roughly $600 USD +/- and I would gladly spend that over having a crack repaired only to have to tear down the long block down the road. Subarus are finicky to begin with so do it right the first time or don't do it at all is what I believe in.
Hi there. In Australia I remove the inserts weld the cracks retap and reinsert. Guarantees the insert stays in place especially in big horsepower engines.
You're supposed to do that with all blocks I think, it doesn't get done most of the time. Some Ford engines they even specify which head you're supposed to torque down first.
They also need a proper align hone for the mains. Its super critical on a Subaru rebuild and the reason why so many rebuilds dont last as long as factory builds.
@hagerty was pretty shocked that you guys didn’t use torque plates when boring out the engine. Then you proceeded to explain why cam timing is so important because the intake valves could crash into the exhaust valves which is physically impossible unless you broke a valve spring. Timing is important so that the valves don’t crash into the pistons
It is not impossible if the timing belt breaks they could definitely hit each other. Or if you really fucked up putting the timing belt on they could also hit each other and piston!
Even if you folks don’t end up doing it, I’d like to hear what options there are for dealing with a cracked head if throwing it away and finding another one isn’t an option. Also, thanks for seeing this build through. I’m sure it hasn’t gone to plan, but it is an interesting engine and I am enjoying this series. Even if it never makes it back into a car, I’m looking forward to seeing this one light up again on the test stand!
For a shop that lacks a laser welder, they would remove the valve seats, then start grinding the crack until they find the end. Then they would fill the crack by TIG welding. After that, the head would be decked, machined for new valve seats, new valve job, and the ports and combustion chamber cleaned up. Very expensive
@@Levibetz Ive done it with the engine in. So easy and quick. Its easier when u have a buddy that can compress the springs and u manage the magnets thou.
The heads are fine. I've reused EJ20 heads with cracks before with zero issues. You've gone above and beyond by checking for leaks within the coolant passages. This is a practical build. It's an ej20. Just get it back on the road and driving. It's never going to be a torque monster.
I read that the when the plugs are in on these, they leave threads on the plug hole open to the combustion flame 🔥 (I.E the plug sits recessed) - which may cause the cracking?. When machining them - some folk therefore cut the plugs a bit deeper so it sits flush in the chamber.
Please do mil port and smoothen the oil galley for crank journal no.3 oil supply pathway... Thank me later by saving your no.2 & no.3 conrod Also port the 11mm oil pump outlet... Im serious.. not playing around
I heard that a proper align hone for the mains is super critical to a Subaru rebuild and the reason why so many rebuilds dont last as long as factory builds.
Great idea to do a Subaru engine, I've never seen this type rebuilt before. Your attention to detail is quite impressive, and well taken. Certain techniques can only be learned from experience, you have a way of explaining them so anyone can benefit. Keep on posting, thanks.
@@dirkmohrmann8960 - its here because Rockauto discovered 30% of their sales are to WRX dorks who've blown up their 150k mile beaters and are now attempting full rebuilds in their driveway. : D
Proof to not rush perfection 👌. It's a wonderful piece of engineering in apon itself. Then with modes use doing it making it perfect for your, and shouldn't be rushed. Sry. Perfection takes time. Patience.
New valves, 020 overbore with pistons, new rings and bearings and new head bolts. All time and money down the drain, your heads are cracked. You put boost and heat into a cracked head, they don’t heal themselves. You mentioned a “stove bolt” head having cracks and going with it. A 75 year old straight six with 7.5 compression ratio and all cast iron is nothing like a turbo all aluminum four cylinder. You can still buy new casting from Subaru, probably less money then spent on manhours “rebuilding” them
Hey that's the great thing about aluminum heads. If they have any damage you can weld them then machine it back down. Seen it done. Done properly its hard to tell they were ever welded. There's still time. Go do it please.
Ah yes the joys of performing valve lash adjustments on DOHC engines! 🤦🏻♂️ this gives me nightmares and flashbacks to when I had to do the same job on my Yamaha R6.
It's a shame there are no performance parts going in here. With all of the Subaru specialists out there especially where these guys operate I would have expected a closed deck build, torque plates, forged pistons and rods and good bearings. That engine could have been a monster. Instead it's being set up for failure.
That would be a completely different engine though. There is not much point in adding heaps of power to a non Sti engine, It's ok to rebuild this one, but I would have liked to have seen a torque plate being used at least, the machining looks sub par
@@nzuncovered1845 I think their machining is fine, its just that they are clearly not used to, or experts on Subarus flimsy engines, and you are totally correct, when boring/honing a torque plate wouldve been needed to get the best end result. With that said, I believe this engine is not meant to make any more power than oem, its meant to be rebuilt and keep it as a nice, stock, fresh engine that will be used accordingly. BUT, sadly I dont trust rebuilt subaru engines, imo when the oem goes to the shitter, as they always do, its best just to get a block from IAG and have peace of mind.
@@Hanschepu Yeah I would if was rich enough for an IAG block, that would be the dream. EJ's aren't too bad it depends how they have been treated and if it has been serviced correctly. I had a EJ20G turbo in a GF8 WRX which had 280,000km on it, it ran hard with a VF30 turbo, fujitsubo 3inch exhaust, Perrin uppipe, upgrade I/C and a few other mods, until it was stolen from outside my house and crashed. When I got car back from impound I pulled apart the engine because it got broken cam pullies in the crash, when we pulled the heads my mechanic said it showed no signs of ever been taken apart with OG head gasket, the heads and pistons/cams etc all looked new. My view is EJ20s are okay if they are a JDM engine and EJ25s are the ones to avoid due to less room between cylinders, not as strong as EJ20. The EJ207 engine is the one to get as it has semi closed block, also original Legacy RS and WRX STi Versions 1 and 2
I honestly didn't even realise how prone these heads are to cracking. I've done heaps of head gaskets on these, and I just walk them across to the machine shop. We always get the head's pressure tested on any engine.
Done hundreds of these myself in automotive machine shops. Rarely see one not cracked. Never had one leak during pressure testing and never had one come back.
Maybe I am not getting the purpose of the build, but if your going through all this work, why not upgrade stuff along the way? Upgrade the Rods and Pistons, the valve springs/retainers, and what not. That way, IF one day you want to add more boost you know the block and heads can take it? Just my thoughts.
There's no cooling passage between the spark plug and the valve seat, the issue will be the seat can fall out as it s no longer properly supported by the surrounding material. SBI recommends a .007 press fit. Put it on a flat clear plate with a rubber seal and pressurize the cylinder through the spark plug hole and see if that leaks. This would leak compression, not coolant. I don't know why they're lapping valves when they have a seat and guide machine. Not needed. Dykem the valve and spin it in the seat and check for contact, simple and fast.
The one thing I want to know is where Thrilby's purchased the sanding tapered cone that they used to take the edge off the top of the cylinders after boring and honing. I haven't been able to find one, and I've searched on and off for about a year for one of those.
I live just south of TC, I would literally drive up there and give you any info you'd ever need on that engine. It hurt seeing the pistons and rods coming out at the same time lol
A huge selection of shims makes it faster, but that is not needed. When I adjust the valves on my BMW motorcycle, I know what shims are in the from the last adjustment and all I need to do is measure the lash and enter that into my spreadsheet. The spreadsheet then calculates what shims I need to get everything back in spec, subtracts out the shim sizes I already have and then tells me how many new shims are needed and which size shims. I then place my order and get exactly what I need. Easy peasy, just takes a couple of weeks for BMW to get the shims to me.
Hi David, wouldn't it have been convenient to repair the fissure due to the risk of a cap falling out?I send you a big hug and blessings for you and your family from Buenos Aires Argentina
Could it have been an option to weld the crack, retap the treads and the valves seat??? I mean you probably went over this option so why you chose not to go with that solution???
You might want to check the Crank bore I heard they change ever time you take the block apart when putting it back together the bore is not true any more and has to be line honed
Subaru Project Description: "Davin is on a five-year mission: to explore strange new worlds. To seek out new life and new civilizations. To boldly go where no man will ever want to go again!"
Odd to me that the cracks were left just as is. Isn't there a risk of the cracks continuing after reassembly and the pressures of a running motor? Why not have a welder attempt to repair the cracks, and barring that, why not opt to use a set of heads that aren't cracked? Seems like a problem waiting to happen later on down the road, or am I blowing that way out of proportion?
Hello, this cracks between sparkhole and exausthole get it from a cold engine who musst spent full power at a time she is not warm enought for running fast, with the 914 Porsche Motor it has often cracks in the zylinderheads, same reason and one more, she don't like fullgas of long distance, watercoold engines are better.
can't you just grind it on the CNC GRINDER and make it a mirror finish on the cylinder bores? honing is creating wear for the future bores if I'm not wrong? not sure about cylinder stuff
Why would you use cracked heads? Cracks don't get better over time and coolant leak is not the only consideration. Weld the head and replace the seats if you must use these heads.
6:09 not a good day at all. That is why you must know if your car has a timing belt. If it has one, know when to replace. Nobody in my family knew, until a belt went boom in 1994. It was in mom's 1985 Nissan Maxima. I felt very bad to see that car gone. Ever since I could legally drive, I looked for timing chain engines when buying a car. My dad simply refuses to buy anything with a timing belt.
Davin, you did not explain the how and where from, but looks to me like you just happened to have a box of different sized shims lying around which is not what joe public would have access to...
14 or 15 automotive machine shops in my area and we are all super busy and backed up. Just depends on the area. Or maybe their rep is keeping them from growing.
They all crack. I have a 200k mile EJ205 with four radial cracks at every spark plug hole, they are fine. Subaru has a raised area at the plug for combustion chamber shape reasons and this area runs a lot hotter because it is so far away from the water jackets, which is also why it is generally a non issue.
It does look really scary though!
Driving on valve seals with a six or 12 point socket when I ran a cylinder head rebuilding department in the 90s. Was a nono. The flats can cut the edges of the seal boot. Causing excessive oil consumption later. I also lube my valve stems with staylube moly graphite assembly lube. With a pocket of that lube under the valve stem seal as a reservoir. Oil leaks out leaving a dry stem.
I used to hot glue 3/8-16 nuts to the valve head to work with my old lapping spindle with a worn 9/16 socket wedged on instead of a vacuum cup. A magnet hot glued in the socket allowed me to lift the valve. I miss that job.
Brilliant idea using the drill press to press the valve springs in to assemble!
Greetings from Scotland. This machine shop is like the one local to me, in the respect they can literally fix anything that looks beyond its best. Incredible skill and machines. Nice to see another Subaru engine saved
For these cylinder blocks it is wise to use a torque plate because due to their small dimensions they ''flex''. Cylinder dimensions are different when cylinder head is torqued in place and when is taken off. Greetings from Greece
You reminded me of the first Subaru engine that I rebuilt it was a 1970 FF1 4 cyl. It had plugs at the front and rear of the block to access the wrist pins. 40 years later I still have the tool I made from a bearing race puller.
Hope I get to drive an FF1 someday. Cool cars.
I had a 1986 Ford Taurus XL that I bought new with a 2.5 four cylinder. It started running bad and overheating at around 8K and the dealer determined it had a bad cylinder head and replaced it under warranty and again at about 15K and again at 20K. all had cracked across the valve seats thru to the water jacket. After the third head I traded it in on a new one with the 3.0 V6 and never had a problem with that engine in the next two Taurus's or a Ranger that had the same engine.
AFIK that block is going to be trash. Subi engines require torque plates for bore and hone operations.
Jup. They definetly need those!
Big tip.
The 2jz has shim over bucket and most cams need to be re shimmed.
The best and i mean BEST way i did this was spreadsheet.
Measure what i pulled out and tickenes of the bucket to valve spot.
tada excell does the math for you.
I wish you guys or Thirlbys had a weekend crash course in this stuff. I could learn a lot from you guys. Ive never measured spring strength or used blue when lapping valves. Thanks for posting your work Davin!
A Master Class on all variety of engines would be cool. You could download and refer back to it before you start a rebuild...always have it on tap to use on your computer.
With bucket shims you can compute what the ideal shim thickness should be based on the first feeler gauge measurement. In my experience, this works pretty much every time, unless you make a mistake with the math, or location of the shims..
Or the clearance is closed completely
Hello Davin, the cracks are also there on most audi 2.2 20v heads, greets from France.
Now there's another car they could tackle at some point, late 80's Audi with 5-cyl engine.
It wouldn't be a big deal for a good welder to fix the heads up. Problem is it's often cheaper to replace them than pay a skilled welder to fix up common parts.
The valve adjustment system is similar to many motorcycle engines. As the valves seat the clearance will decrease, set the valves to the high end of the spec. Remember that a slappy valve is a happy valve.
I'm sure it'll be fine as in, it'll run and whatnot. But this is a demonstration in how not to machine a Subaru. These blocks are very light and thin, they distort with the head torque. So you need to bore and hone them with a torque plate on the head surface. This will have significant bore distortion once the heads are on and torqued up.
I admit, I know nothing about rebuilding engines. But it’s crazy to me that cracked heads are acceptable. I’d be less worried about whether it’s a problem now, and more concerned whether it would lead to a future problem. 🤷🏻♂️
Those heads would not get used by me, good used heads or new correct rebuild practice, been do this stuff to long to start cutting corners! Davin you know better!!
Tracking down a set of new or uncracked STI heads will lead you down a very expencive and time consuming path.... as Davin said make do with what you have
It's not a passion project for them obviously. This is a click/view count project.
I had a 50cc 2 stroke air cooled dirtbike, one time, just after a rebuild it blew the head gasket and me not knowing better removed the head without waiting for the engine to cool down, so I burned my fingers and dropped the head, it cracked in 2 straight down the middle, only the spark plug held the 2 halves together, replaced the new blown gasket with the old one it had before the rebuild and it ran as if that crack was never there.
I mean hey at the end of the day it’s a Subaru anyways, the heads, let alone the whole engine will be out in a month for new head gaskets, regardless of mileage, like clockwork, until the end of time.
I know this video is already 3 months old and so this comment won't be relevant to this specific build but could be for other viewers who want to do the same process:
It's a real shame in my opinion going through ALL that hard work of disassembly, machining, honing, measuring and then reusing factory\worn parts.
The minimum would be to upgrade to STI rods and pistons.
I know a lot of Subaru owners who are actually waiting for an excuse to rebuild their engines and once the engine is opened for a refresh, it's the perfect time!
In any case, I think the job you're doing is amazing and it's always inspiring to see someone walk into a project and learn new things as they go. Wonderful to see the attention to detail!
Thanks 👍 Real team of engineers. Scrupulosity, honestly and good explanation all the time. All the best to you!
Japanese bikes have used shimmed ohv for years and years the expensive part for a home shop is buying a shim assortment kit.
On my 2000 5S-FE head, after recutting the seats, the valves would be too tight. Rather than messing around with the additional time and cost of swapping spacers, they put the cams in, measured the error, then ground the top of the valves to adjust the height. Since they're pretty good at what they do, they only had to install and remove the cams twice (once to measure, then once to verify). What's annoying is the head bolts are under the cams, so I had to install and time the cams once I had the head on.
Never seen Davin less enthusiastic about a rebuild...
You are very good in this field so don't be too late to share these videos we appreciate you so much man..
Built my ej205 with 3 or 4 cracks just like that in every spark plug hole. No issues 80k miles later
Honing should be done with the block halfs torqued.
Subaru specialists do the rebuild process a bit different from what you did, I hope you won't run into trouble.
How come honing has something to do with block tightening? Honing tool is free hand on a few universal joints, so it basicaly ads sufrace finish for oil film to hold on. And andy from subieperformace also does not join block halves for honing
@@vilbenasvienuolis I'm not saying joining the two halves, torque plate is something to simulate the head.
@@PedroFTeixeira now i understand, sorry, my bad, u are right
@@PedroFTeixeira true most people use torque plates to simulate the head and torque to spec.
I'm sure their work isnt "bad" but they do a lot of things as if its 1960 cuz thats probably how they've always done it.
I would suggest getting the crack laser welded. It's usually quite cheap compared to a new head and the new weld is also going to rearrange the Atoms leading to a newly formed grid. It is probably going to crack fully if you leave it like that.
It is hard to weld it properly to last, and yes crack will grow but there will be no catastrophic failures. If he will not run to much power and control exhaust temperatures it will live happy life for long time. Weld will also crack. It comes down to how hot chamber will be, how quickly and frequently temperature peeks are happening when pushing it and quality of the head when it was poured. If you can get uncracked head that is best way to go, meaning use this one until you find one that is not cracked. To find one without cracks is hard and expensive, and it is better to get used head without cracks, then new. Not sure if new are available at all.
A new head in general for an EJ205, EJ255, or EJ257 is roughly $600 USD +/- and I would gladly spend that over having a crack repaired only to have to tear down the long block down the road. Subarus are finicky to begin with so do it right the first time or don't do it at all is what I believe in.
What a labor intensive drill!! I guess it's a labor of love. Makes the US engines look somewhat simple. Thanks for sharing, and good luck!!
Hi there. In Australia I remove the inserts weld the cracks retap and reinsert.
Guarantees the insert stays in place especially in big horsepower engines.
From what I understand, subaru engines need to be assembled and torqued with a deck plate for boring.
You're supposed to do that with all blocks I think, it doesn't get done most of the time. Some Ford engines they even specify which head you're supposed to torque down first.
They also need a proper align hone for the mains. Its super critical on a Subaru rebuild and the reason why so many rebuilds dont last as long as factory builds.
@hagerty was pretty shocked that you guys didn’t use torque plates when boring out the engine. Then you proceeded to explain why cam timing is so important because the intake valves could crash into the exhaust valves which is physically impossible unless you broke a valve spring. Timing is important so that the valves don’t crash into the pistons
It is not impossible if the timing belt breaks they could definitely hit each other. Or if you really fucked up putting the timing belt on they could also hit each other and piston!
I found it fascinating to see that he dressed the valve seats with the same rubber suction cup tool I used 50 years ago.
Even if you folks don’t end up doing it, I’d like to hear what options there are for dealing with a cracked head if throwing it away and finding another one isn’t an option.
Also, thanks for seeing this build through. I’m sure it hasn’t gone to plan, but it is an interesting engine and I am enjoying this series. Even if it never makes it back into a car, I’m looking forward to seeing this one light up again on the test stand!
Subi-Performance has figured out a solution - laser welding the head and machining back. They have a laser-welder and 5-ax-cnc tho...
For a shop that lacks a laser welder, they would remove the valve seats, then start grinding the crack until they find the end. Then they would fill the crack by TIG welding. After that, the head would be decked, machined for new valve seats, new valve job, and the ports and combustion chamber cleaned up.
Very expensive
We toss them, but some of these heads are super hard to find because they all crack.
Thanks for the info folks!
Did I not see a torque plate?
I dont think you needed to remove the cams everytime to do lash. U could compress the valve with a tool and use a magnet to pull out the shim.
You wouldn't ever do it with the engine in the car, just pull the cams. My car has 190k miles, zero lash adjustment. You set it and forget it.
@@Levibetz Ive done it with the engine in. So easy and quick. Its easier when u have a buddy that can compress the springs and u manage the magnets thou.
The heads are fine. I've reused EJ20 heads with cracks before with zero issues. You've gone above and beyond by checking for leaks within the coolant passages. This is a practical build. It's an ej20. Just get it back on the road and driving. It's never going to be a torque monster.
I read that the when the plugs are in on these, they leave threads on the plug hole open to the combustion flame 🔥 (I.E the plug sits recessed) - which may cause the cracking?. When machining them - some folk therefore cut the plugs a bit deeper so it sits flush in the chamber.
They sit normally as long as you use the correct plugs, at least in these ej205 heads.
Please do mil port and smoothen the oil galley for crank journal no.3 oil supply pathway...
Thank me later by saving your no.2 & no.3 conrod
Also port the 11mm oil pump outlet...
Im serious.. not playing around
WHERE'S THE TORQUE PLATE!?!?!
I heard that a proper align hone for the mains is super critical to a Subaru rebuild and the reason why so many rebuilds dont last as long as factory builds.
An align hone seems least of concerns here considering the rest of the dodgy bodgy practises on this half arsed rebuild
- Knock -knock!
- Who's there?
- 4th cylinder
**Subaru's classics**
🤣😂🤣😂🤣😂 or Tick tick tick tick *I'm a time bomb*
Great idea to do a Subaru engine, I've never seen this type rebuilt before. Your attention to detail is quite impressive, and well taken. Certain techniques can only be learned from experience, you have a way of explaining them so anyone can benefit. Keep on posting, thanks.
Davin's contempt for this car is the only reason I'm watching... : D
I bet we never see another suburu on this channel.
Same! And really how can you blame him. I don't get how this engine is considered legendary, it's a mess and full of problems
@@dirkmohrmann8960 - its here because Rockauto discovered 30% of their sales are to WRX dorks who've blown up their 150k mile beaters and are now attempting full rebuilds in their driveway. : D
no torque plate ?
Proof to not rush perfection 👌. It's a wonderful piece of engineering in apon itself. Then with modes use doing it making it perfect for your, and shouldn't be rushed. Sry. Perfection takes time. Patience.
New valves, 020 overbore with pistons, new rings and bearings and new head bolts.
All time and money down the drain, your heads are cracked.
You put boost and heat into a cracked head, they don’t heal themselves.
You mentioned a “stove bolt” head having cracks and going with it. A 75 year old straight six with 7.5 compression ratio and all cast iron is nothing like a turbo all aluminum four cylinder.
You can still buy new casting from Subaru, probably less money then spent on manhours “rebuilding” them
Hey that's the great thing about aluminum heads. If they have any damage you can weld them then machine it back down. Seen it done. Done properly its hard to tell they were ever welded. There's still time. Go do it please.
Ah yes the joys of performing valve lash adjustments on DOHC engines! 🤦🏻♂️ this gives me nightmares and flashbacks to when I had to do the same job on my Yamaha R6.
can't say I'm eager to get my work done in my shop.
got an 86 silver spur with a mineral oil leak. (brake and suspension fluid)
Your comment “just like all stovebolts crack” now has me a little concerned about my stock 1941 Chevy 216!!!
Ah yes the old bucket and shim lash adjustment.... that absolutely gets done in service by the book..... can you sense my sarcasm?
Spark plug cracks on the ej20 motor are normal, they haven't caused any issues for a large majority of people.
It's a shame there are no performance parts going in here. With all of the Subaru specialists out there especially where these guys operate I would have expected a closed deck build, torque plates, forged pistons and rods and good bearings. That engine could have been a monster. Instead it's being set up for failure.
That would be a completely different engine though. There is not much point in adding heaps of power to a non Sti engine, It's ok to rebuild this one, but I would have liked to have seen a torque plate being used at least, the machining looks sub par
@@nzuncovered1845 I think their machining is fine, its just that they are clearly not used to, or experts on Subarus flimsy engines, and you are totally correct, when boring/honing a torque plate wouldve been needed to get the best end result.
With that said, I believe this engine is not meant to make any more power than oem, its meant to be rebuilt and keep it as a nice, stock, fresh engine that will be used accordingly.
BUT, sadly I dont trust rebuilt subaru engines, imo when the oem goes to the shitter, as they always do, its best just to get a block from IAG and have peace of mind.
@@Hanschepu Yeah I would if was rich enough for an IAG block, that would be the dream. EJ's aren't too bad it depends how they have been treated and if it has been serviced correctly. I had a EJ20G turbo in a GF8 WRX which had 280,000km on it, it ran hard with a VF30 turbo, fujitsubo 3inch exhaust, Perrin uppipe, upgrade I/C and a few other mods, until it was stolen from outside my house and crashed. When I got car back from impound I pulled apart the engine because it got broken cam pullies in the crash, when we pulled the heads my mechanic said it showed no signs of ever been taken apart with OG head gasket, the heads and pistons/cams etc all looked new.
My view is EJ20s are okay if they are a JDM engine and EJ25s are the ones to avoid due to less room between cylinders, not as strong as EJ20. The EJ207 engine is the one to get as it has semi closed block, also original Legacy RS and WRX STi Versions 1 and 2
Love the Victor Reinz sticker on that toolbox :D
I honestly didn't even realise how prone these heads are to cracking. I've done heaps of head gaskets on these, and I just walk them across to the machine shop. We always get the head's pressure tested on any engine.
Done hundreds of these myself in automotive machine shops. Rarely see one not cracked. Never had one leak during pressure testing and never had one come back.
Maybe I am not getting the purpose of the build, but if your going through all this work, why not upgrade stuff along the way? Upgrade the Rods and Pistons, the valve springs/retainers, and what not. That way, IF one day you want to add more boost you know the block and heads can take it? Just my thoughts.
Laserweld and done. Look up Alpha Laser!
Well, I'm glad Davin is enjoying himself, anyways...I admit, my interest in this engine is waning, however.
Here’s a formula to make setting your valve lash easier.
Measured clearance + existing shim thickness = x
X- target clearance= shim thickness needed.
Yea, doesn’t work if the clearance has closed up
There's no cooling passage between the spark plug and the valve seat, the issue will be the seat can fall out as it s no longer properly supported by the surrounding material. SBI recommends a .007 press fit. Put it on a flat clear plate with a rubber seal and pressurize the cylinder through the spark plug hole and see if that leaks. This would leak compression, not coolant. I don't know why they're lapping valves when they have a seat and guide machine. Not needed. Dykem the valve and spin it in the seat and check for contact, simple and fast.
Goodson makes 6,7, and 8 mm lock installers that work nicely most of the time and a lot faster.
Still may be able to save the block if longevity is a concern, but it'll still run. May knock and burn oil.
The one thing I want to know is where Thrilby's purchased the sanding tapered cone that they used to take the edge off the top of the cylinders after boring and honing. I haven't been able to find one, and I've searched on and off for about a year for one of those.
Are those heads forged aluminum that can be welded? If they are why not remove the valve seats, weld up the cracks and re-thread the spark plug holes?
I agree by measure of precaution, could those cracks be injected with some kind of material ?
I live just south of TC, I would literally drive up there and give you any info you'd ever need on that engine. It hurt seeing the pistons and rods coming out at the same time lol
Every Subaru cylinder head I've seen milled is low in the middle.....every one of them. New valves is a no brainer.😉
I wonder if it's because of the torque specs on the head bolts...? Middle two bolts are tighter than the outer 4.
Cracked heads on ej205 is actually a common thing, same with vf39/48 turbos having a wastegate crack. Doesn’t really affect performance
Didn't use a torque plate when doing the boring and honing? EJ case halves machine truer with a torque plate used.
First year high school teacher “oil and water do not mix”
Subaru “hold my beer”😁😁😁
Why you didn't welded these cracks?
For example there were 5 cracks in head of my super old vr6 engine, but they all were welded without any problems.
That type of lash adjustment is tedious. And you have to have a huge selection of shims!
It's easier if you measure the shim, measure the actual lash and do the math yo get the shim you need.
A huge selection of shims makes it faster, but that is not needed. When I adjust the valves on my BMW motorcycle, I know what shims are in the from the last adjustment and all I need to do is measure the lash and enter that into my spreadsheet. The spreadsheet then calculates what shims I need to get everything back in spec, subtracts out the shim sizes I already have and then tells me how many new shims are needed and which size shims. I then place my order and get exactly what I need. Easy peasy, just takes a couple of weeks for BMW to get the shims to me.
Classic EJ build quality.
Nice i like the song mt fuji too I usually work to that style of music
Hi David, wouldn't it have been convenient to repair the fissure due to the risk of a cap falling out?I send you a big hug and blessings for you and your family from Buenos Aires Argentina
Could it have been an option to weld the crack, retap the treads and the valves seat??? I mean you probably went over this option so why you chose not to go with that solution???
You might want to check the Crank bore I heard they change ever time you take the block apart when putting it back together the bore is not true any more and has to be line honed
Nothing but damn scammers
I've always read you should never loosen a nut/bolt with a torque wrench because it can throw the torque wrench out of calibration. True or hogwash?
Subaru Project Description: "Davin is on a five-year mission: to explore strange new worlds. To seek out new life and new civilizations. To boldly go where no man will ever want to go again!"
those cracks will migrate personally i would never reuse the heads
All that work, they are still cracked? Even though they don't leak yet!
Вот такой формат лучше чем был. Удивляюсь его знаниям и его пряморукостью.
I think I'd be looking for heads with no cracks. There's got to be boatloads of heads at salvage yards, surely they aren't all cracked.
Not to mention that there will be a serious hot point in the head where the crack is, and it's only gonna get worse...
I thought the same. the answer for me was no. depending on the engine and year of build, they became very prone to cracking towards all valve seats
Mike Thirlby, the most serious man I know…or not…
Odd to me that the cracks were left just as is.
Isn't there a risk of the cracks continuing after reassembly and the pressures of a running motor? Why not have a welder attempt to repair the cracks, and barring that, why not opt to use a set of heads that aren't cracked?
Seems like a problem waiting to happen later on down the road, or am I blowing that way out of proportion?
Hello, this cracks between sparkhole and exausthole get it from a cold engine who musst spent full power at a time she is not warm enought for running fast, with the 914 Porsche Motor it has often cracks in the zylinderheads, same reason and one more, she don't like fullgas of long distance, watercoold engines are better.
Wow, fuff to begin with. Nice work
How would these cracks effect specs. on bolting theses heads down with internal cracks.
Outstanding work, as usual! Thanks for the video.
Go ahead with the cracked head ? No way
Also importent to weight the pistons and rods
For eqwall and balanced rpm
can't you just grind it on the CNC GRINDER and make it a mirror finish on the cylinder bores? honing is creating wear for the future bores if I'm not wrong? not sure about cylinder stuff
We don't want a mirror finish as the rinhs won't seal and you don't need cnc to grind a bore to mirror finish.
why use a hone over a lathe to bore the cylinders?
Why would you use cracked heads? Cracks don't get better over time and coolant leak is not the only consideration. Weld the head and replace the seats if you must use these heads.
Wouldn't a crack between valve seat and spark plug holes allow leakage on compression?
6:09 not a good day at all. That is why you must know if your car has a timing belt. If it has one, know when to replace. Nobody in my family knew, until a belt went boom in 1994. It was in mom's 1985 Nissan Maxima. I felt very bad to see that car gone.
Ever since I could legally drive, I looked for timing chain engines when buying a car. My dad simply refuses to buy anything with a timing belt.
would you not Tig weld the cracks?
Great video!
It is quite common to see hairlines on this model of cylinder head.
Davin, you did not explain the how and where from, but looks to me like you just happened to have a box of different sized shims lying around which is not what joe public would have access to...
So using that machine shop and showig it on your videos have you gotten them more business? The one in my area never seems to busy.
14 or 15 automotive machine shops in my area and we are all super busy and backed up. Just depends on the area. Or maybe their rep is keeping them from growing.
I love your work.
Nice job, best wishes from Ukraine 🇺🇦
Welcome to euro cars 😁😁 shims and buckets
At 1:31...A bagel? Always thought you guys were donuts people...