Engine Refresh - Studs, gaskets, etc...

[KZJonny]

Does/has anyone gone to the trouble of checking the cylinder head flatness when replacing head gaskets?

FSM for 2005 says acceptable warpage limit is 0.035mm or 0.0014". Now, that isn't exactly a lot, but I can pick up a machinists straitedge for like $100 locally (Starett, good quality stuff), and do some checking of my heads when I pull them. I should be able to find out if they are flat enough to re-use without dragging them down to the machine shop.

I don't begrudge the shop the work or money, but the engine is just over 170k kms, and has not seen any overheating in the 7 years I've owned it. No idea about before that, but it didn't appear to have been ridden to hard before my ownership.

Just curious if people generally assume that the heads need a skim every time, or if anyone bothers to take measurements first. Most of the time this kind of rebuild story involves a trashed turbo, mains bearing failure, overheat...etc... so you would almost certainly want to have the heads stripped and looked at by a shop. In my case, I'm just upgrading to head studs and replacing as many seals as makes sense while I'm in there, so I'm thinking that there isn't any reason to expect the heads to be warped beyond acceptable limits. And if they are, then at least I know and don't need to pay the shop to find our for me. Plus, then I would own a fancy machinists straitedge to use on future projects.

I do not want to do the minimum, especially on my own engine parts, but I know dealerships/shops sometimes only use the swirly scuff pads to clean up heads before re-insall, the I suspect this would be more common on failed EJ253s etc.... (For the record, I am NOT doing this....)

But if the heads are within spec, and a light sanding on a flat surface is enough to clean things up and get a good surface for head gasket mating, then it seems to me they should be good to go... The new studs should also do a much better job than the bolts at even distribution of clamping force across the entire mating surface, etc...

Edited March 24 by KZJonny

[Infosecdad]

The last time I did head gaskets/timing, I measured the heads and block with a machinist's straight edge to ensure they were good because I didn't want to take them in to be decked unless they needed it.

[KZJonny]

2 minutes ago, Infosecdad said:

The last time I did head gaskets/timing, I measured the heads and block with a machinist's straight edge to ensure they were good because I didn't want to take them in to be decked unless they needed it.

Well. If you did it, that’s a big vote of confidence, for sure.

What was the verdict in your case? Did it save a trip to the shop and a skim?

We only get 0.3mm of total cut before presumably needing thicker head gaskets or heads, so saving that for when it’s actually needed is part of the goal here.

[Infosecdad]

48 minutes ago, KZJonny said:

Well. If you did it, that’s a big vote of confidence, for sure.

What was the verdict in your case? Did it save a trip to the shop and a skim?

We only get 0.3mm of total cut before presumably needing thicker head gaskets or heads, so saving that for when it’s actually needed is part of the goal here.

Yes, they were within spec so I didn't take them to a machine shop.  It's been 18 months now and still going strong.

[KZJonny]

Awesome. Machinists straightedge should arrive in a few days. Plenty of time to get started cleaning everything up and getting the heads off.

[KZJonny]

This is kind of doubling down on the "20 year old Legacy + ECM" post, but what the hell. Removed heads and cleaned everything up. They look okay but the tiny spot where the combustion gas was getting past the fire ring on the head gasket had just a little more damage than I felt comfortable remedying with a light sanding, etc... So heads are at the shop as of this morning for a minimal skim + the flywheel is being resurfaced.

While I had the heads apart and being manuall cleaned up as much as I could, I figured I would do a basic test to see how the valve sealing surfaces were doing. It's been years since I did a compression test, which was fine at the time, but having the heads right in front of me made me curious. The single valve out of all 16 that was out of spec when I meaured, did indeed let some liquid pass when I filled the head with combustion chamber cleaner to soften up the little bit of build up carbon.

So, I pulled it, gave it a quick cleaning and also hit the valve seal with some cleaner and a rag. Seems to be much better now, and doesn't drip liquid. Maybe if i am lucky, it will be in spec on reassembly and I don't need to do any swapping of valve buckets, we will see.

 

I am pretty sure the results of the 'test' are good, but once the heads were clean, I filled all 4 combustion chambers with ATF and stuffed paper towels in the ports. Two of eight had a very small amount of ATF leak by over and entire evening... like 5-6 hours. I am of a mind that this is fine, since the head is cold and not assembled to the block, and ATF is pretty good at penetrating things, and is also has a lot of detergent action (which is why I used it for this "test"). I figure that less than a few drops of fluid making it past that valves over the course of hours is fine. BUT if that is NOT okay, then I wanted to ask here. I'm not a  machinist or an engine builder, but I've done this kind of thing a few times. It never occured to me to check like this before, so it's my first time interpreting the results. There isno indication of that valves every having made contact with pistons or anything at all like that, or I expect they wouldn't sit properly in their seats and hold a fluid so well.

 

OR, I am over thinking this, and I just need to get back to work cleaning the block side and prepping it for reassembly. LOL!    

[RumblyXT]

While you are at it, you might also want to check the Cylinder block out-of-roundness.. The turbo motors hold up better since the H/Gs are MLS, so I don't expect it to be uneven, especially if the engine has not been abused, but after so many heat cycles and mileage, who knows.. 

Back when I overhauled my first ej251, besides machining the heads, my Cylinder block was also bent a little, I think 0.0003" were going under the straight edge back then.. Believe it or not, I fixed it myself at home with a square piece of counter granite (which I first made sure it was totally straight using the same machinist straight edge). I removed the 4 alignment dowels with a bolt of their ID and used a combination of different grit sand paper glued on to the counter granite with the help of some WD40 to slide it, just using the weight of the granite block passing it back and forward till the block was straight. I took the risk, but It actually  came out great lol

In the end, from the original 0.0003", only the 0.0001" gauge went under and with difficulty. When I put everything back together using Six Star MLS H/Gs, that sucker never leaked again.

 

[KZJonny]

That is similar to how I flattened the heads on my EJ253 last summer, only I glued the sandpaper to a section of glass and moved the heads around on that rather than the reverse. I have my fingers crossed the block itself should be flat within tolerances, since I never had an overheating event with the car, and the head were pretty good aside from where the head gasket had begun to fail.

The chunk of granite is a good plan tho. I just kissed the block side of the Outbacks mating surfaces with a 750 grit sharpening stone with the corners rounded a little. I am 100 % sure the job was NOT done within 0.0001" or whatever that is in metric... (0.003 mm?). Also, it was not until I had totally finished the job that I realized I had tighened the head bolts in the reverse order!!! Real dumb. I had the diagram for dissasembly in front of me, not the re-assembly page. On the other hand, it has been a year, and nothing leaks at all, and the engine runs better than it ever has. I think the MLS gaskets are a little more forgiving that the single layer coated ones, but we shall see. Maybe they'll fail before too long, tho I kind of think that clamped and sealed is just that.... I will not make the same mistake on this rebuild, and it is head studs in any case, so no need to the whole silly tightening sequence..... 30 ft/lb, 60 ft.lb, 90 ft.lb done!

 

On another note, I just went and picked up a box full of VF52 parts! So, big thanks to @RumblyXT!!  I'll have JMP take a look at everything and decide if it is a candidate for a Custom rebuild. Scope creep is a thing.... Sigh....

[RumblyXT]

I doubt that block is warped then..
The biggest challenge I had was removing the block alignment dowels without damaging the mating surface of the block.

The sand paper method, even though it may seem a bit rudimentary, works really well.. and to be honest I think I ended up using much finer grain than 300.. it was more like 500, 800 and 1,000. The most important thing is making sure it’s truly straight and the straight edge assures that.

Looking forward to seeing how that VF52 turns out for you. 

Edited March 22 by RumblyXT

[KZJonny]

So this whole thing is snowballing on me (of course it is...) and not I'm messing around with flattening all the mating surfaces I can with the sharpening stone and some 400 grit paper wet sanded with oil, etc.... Just wanting to make sure that everything buttons back up nicely when the time comes to put it all back together.

 

I am also getting a little OCD about cleaning up the outside of everything, and trying to remove a lot of the crud that has built up over 20 years of use. To that end I picked up a soda blasting canister, and it's in the mail. I know how good they can be for cleaning up old carbs and the like, but has anyone here used one to blast the outside of heads, cases etc....? I mean, I'll have a go and see what results I can get, but I'll take any advice that anyone has as well. My first thought has been to get a vapour blasting cabinet, but at a little over $2K USD, I figure I could just get a new short block with the money, and it would be plenty shiny.

I may yet consider it if there is any demand in my area for vapour blasting/honing as an occasional weekend cash earner, but I'm kind of lazy as far as promoting that kind of thing, and don't use social media, so I suspect it would really be an excuse for me to pull the trigger on a cabinet. 

 

Thoughts always welcome. Taking a break from the 3 hours I've spent cleaning up ONE TGV SIDE. Ugh. But it looks a lot better than when it started, and the butterflies are gone now. I know it doesn't make much of a difference, but at least if the motor fails in the shut position, the car will at least still run fine, and not be a brick.

[KZJonny]

Picked up the heads the morning.

7 thou off to flatten them up, so I have one more skim more or less before I need to either go to thicker head gaskets or swap to a new set of heads I guess?

One more thing to start packratting I suppose. Guess I'll be heading to the scrapyard to pull the heads ouf of the 05 sedan there. Can't have too many, and more valve buckets it always a good thing.

[RumblyXT]

On 3/24/2024 at 1:26 PM, KZJonny said:

So this whole thing is snowballing on me (of course it is...) and not I'm messing around with flattening all the mating surfaces I can with the sharpening stone and some 400 grit paper wet sanded with oil, etc.... Just wanting to make sure that everything buttons back up nicely when the time comes to put it all back together.

 

I am also getting a little OCD about cleaning up the outside of everything, and trying to remove a lot of the crud that has built up over 20 years of use. To that end I picked up a soda blasting canister, and it's in the mail. I know how good they can be for cleaning up old carbs and the like, but has anyone here used one to blast the outside of heads, cases etc....? I mean, I'll have a go and see what results I can get, but I'll take any advice that anyone has as well. My first thought has been to get a vapour blasting cabinet, but at a little over $2K USD, I figure I could just get a new short block with the money, and it would be plenty shiny.

I may yet consider it if there is any demand in my area for vapour blasting/honing as an occasional weekend cash earner, but I'm kind of lazy as far as promoting that kind of thing, and don't use social media, so I suspect it would really be an excuse for me to pull the trigger on a cabinet. 

 

Thoughts always welcome. Taking a break from the 3 hours I've spent cleaning up ONE TGV SIDE. Ugh. But it looks a lot better than when it started, and the butterflies are gone now. I know it doesn't make much of a difference, but at least if the motor fails in the shut position, the car will at least still run fine, and not be a brick.

I did what I could with just degreaser and a brush, covering all the head ports as best as I could.

Will you be replacing the Piston rings as well? Why not do so since you're already here? If you're going to though, just make sure they end up with the correct ring gap (very important).

This was the end result after cleaning the block with degreaser and a brush as much as I could..

For the pistons, this chemical I used and a wire brush worked great.

Berryman Chem-Dip Carburator Cleaner (great chemical for removing the carbon deposits off the pistons).

Before..

After the Chem-Dip

 

 

Edited March 25 by RumblyXT

[RumblyXT]

6 hours ago, KZJonny said:

Picked up the heads the morning.

7 thou off to flatten them up, so I have one more skim more or less before I need to either go to thicker head gaskets or swap to a new set of heads I guess?

One more thing to start packratting I suppose. Guess I'll be heading to the scrapyard to pull the heads ouf of the 05 sedan there. Can't have too many, and more valve buckets it always a good thing.

Oh wow, that much eh? I thought they'd remove something like 2-3 thousands.. hmm

In that case, I'd think a thicker MLS H/Gs would be better to compensate for the material removed. I swear by the SixStar MLS I used, they were great.

Hope you don't mind me photo bombing your thread, but a pic is worth a thousand words lol

Edited March 25 by RumblyXT

[KZJonny]

Don’t mind at all man.

I’m not planning on splitting the cases, no. Or removing the piston. I’ve already signed up for enough work, hah!

We don’t get the Berrymans stuff here in Canada, but I’ll go looking across the border next time I’m over.

And that block looks really good dude! If it was less cold here, I would consider it, but using a liquid degreaser + brush etc here right now…. *yeesh*

I can’t afford to actually freeze my fingers off. Hah!

[RumblyXT]

Actually, you don't have to split the block to remove the pistons.

But yeah, I'd definitely not split the block unless absolutely necessary, unless it had been through some bigger damage like a spun bearing, which then would require a lot more work. Best to leave it that way then. Just reassure yourself with a compression test before mounting in on the car, it's much easier off the car than on it.

I hear you on working in the cold.. the warm temps down here definitely help a lot in that sense. But you hate FL anyways haha 

Edited March 26 by RumblyXT

[KZJonny]

I will be doing all those things as a quick check. Compression numbers will of course be low on a cold engine, but they should at least all be about the same. So, that is the place I will start.

Got the heads back from the shop, and the more I think about it, I figure I am going to pull the valves, clean the backsides of the exhausts which have a little build-up, and replace all the valve seals. I've got 2 months, more or less before I *really* need this car on the road, so why not go all in on the head work while I have them off. sigh...

 

On the other hand, the soda blaster arrived yesterday, and it looks surprisingly decently made for the cost. I am sure someone in China is proud of their work, but whatever. So far I have given almost everything a bath in the ultrasonic cleaner except the heads themselves, which *just* didn't fit. If I were to do a job like this again, I would certainly consider getting a bigger ultrasonic cleaner to just shove them in there whole. Mine is a 15L model, and they make a 20L which would hold the heads. Or, I could go all in and get a 30L and probably be able to do case halves!! 

In any case, between my blasting cabinet with walnut shell media and the soda blaster I will see what I can do about cleaning everything up some. As well as taking before and after pics of everything. Hopefully I can bring a little shine back to the old girl. We will see. It ain't the chrome that gets you home, but having everything be neat and tidy feels good anyway. Makes it easier to find leaks as well.

Edited March 26 by KZJonny

[RumblyXT]

Dude, I love Ultrasonic cleaners, they leave parts so clean! A 15L one is great, I can't imagine a 20L one.

I have seen people create one from one of those Costco big plastic animal cookies containers and attaching the cap with Velcro to a cheap buffer machine from Walmart, leaving it hanging while it vibrates lol They actually work really well. I know those machines are not cheap at all.

Definitely replace the valves seals while you're here. And make sure you blow a lot of compressed air through all the holes/ports of the heads. You will be surprised how much junk/metal shaving probably fell in there while they were being machined. At least this is what happened to me.

[KZJonny]

28 minutes ago, RumblyXT said:

Definitely replace the valves seals while you're here.

Yeah, I think I hate having free time enough that I'm going to do this "while I am in there".

+ clean and polish valves
+ lap any that are even the tiniest bit not perfect looking, or that do not pass the liquid test onve they've all been cleaned.

 

And a massive +1 to having ultrasonic cleaners at your disposal. I have one at work, and it was my first experience with them. Awesome. Then I decided to get one for home, and I bought one big enough to put my 4 carberettor rack into for my KZ... Hence the 15L. Which, ironically I ended up breaking down the whole rack anyway and totally rebuilding those.

I was completely sold when the carbs, which I had totally cleaned just the season before, with carb cleaner, hot water, dish soap and a scrub brush, etc.... went into the ultrasonic with some HD Simple Green..... after a 15 minute session in the US cleaner, there was SO...... MUCH......JUNK at the bottom of the machine, I could hardly believe it. Once I got those things back together after replacing all o-rings and polishing all the needles, jets + rejetting them anyway.... The bike has never run better. That and swapping in a AGM battery are the best bang for buck things I have done on that bike.

 

So... yeah. They're not cheap, but if I find myself doing more of this, I think getting a bigger US cleaner would be justifiable. It would be best if it could fit the head from the L20B in the Datsun as well.... But that is an inline 4, so I don't know if it would work. (Also an iron head, so I can just use Sodium Hydroxide without worrying about damaging the metal.....) \m/

[KZJonny]

+ valve seals (in the mail right now)

ya know.... while I am in there

 

I abso-frikkin-lutely swear that this is it for the heads. Sticking with stock springs/retainers/cams... Until I need more RPMS. 

Edited March 27 by KZJonny

[RumblyXT]

Will the VF52 be for this motor?
Post some pics.. while you’re there

[KZJonny]

In theory yes..... I figure aside from injectors, which it will likely need with the Custom VF52, I am pretty much all set up for a little more power anyway. Pump + wiring + full exhaust, etc.....

JMP VF52 + 3port EBC + maybe biggre injectors + tune. Done.

That will likely be a next year problem tho. As I said before, I've got 2 months to get this engine put back together and into the car, and all the other little things that I'm bound to find along the way that need attention. Seems like a while, but I bet it flies by. I've also got to prep to get a garden in, do a handful or renos and try to see other humans enough that nobody sends the cops along for a wellness check.

Piece of piss right?

 

EDIT: I'll grab some photos tonight of what is going on. I definitely want some before and after of the parts, assuming I have any time this weekend to put together a dust extractor for the walnut shell blasting cabinet. Valve stem seals + injector o-rings should arrive tomorrow, so I can start putting together the new fuel rails as well.....

Edited March 27 by KZJonny

[Max Capacity]

I may have missed it, but, I hope you have ARP head studs for this ?

You don't need the injectors just yet, you can always upgrade them later if money is a concern. With bigger injectors, you'll want a bigger fuel pump too, unless you have already done that.

[KZJonny]

Well, if this is your first time doing it on a set of EJ heads, I would say it takes about one afternoon to dismantle and tidy up a head. Clean valves with some scotch brite + a drill press and change out the valve stem seals.

Speaking of which, given the OE ones are meant to be sort of a pale green colour, I'm happy to have just gone ahead and got new ones, considering the price. Not the most important thing, but still. The OE rubber(viton?) was pretty stiff as well. GSC power seals are definitely viton, so hopefully will hold up to a few more years of use.

Edited March 30 by KZJonny

[KZJonny]

 

One side back together and so long as I don't see any leaks in a little bit, I will call it good to go and start in on the next set. Quite a lot of extra work, but cleaning up the seats and valves seems like a 'worth it' sort of effort. Everything is just so nice and clean and fit together well. The exhaust valves and seats weren't perfect, but did clean up well. I have neither the time nor money to have that all cut and lapped then have to get all new buckets.

There is a point where I need to stop myself and recognize that good parts in decent shape are OK. I can't afford to have these go back together with GSC springs and new cams.....

Edited March 30 by KZJonny

[KZJonny]

7 hours ago, Max Capacity said:

I may have missed it, but, I hope you have ARP head studs for this ?

You don't need the injectors just yet, you can always upgrade them later if money is a concern. With bigger injectors, you'll want a bigger fuel pump too, unless you have already done that.

Yup. That is really kind of what started this whole mess. I was lifting the heads at 17psi, so decided to go to studs so I can turn up the wick a little more.

I do have a new AEM pump installed and the 10 gauge wiring kit + STi fuel pump controller ready to go in as this all gets put back together. You're right that I don't need bigger injectors for the JMP Custom VF40. BUT I have a VF52 in the basement that I intend to have JMP perform his black magic on this summer, for next season. At that point I will 100% need more injector. Stock 550s are at their absolute limit with a normal VF52. Add in the rapid spool and overall more boost everywhere the JMP turbo can produce..... 

This is going on in another thread, but I've had 3 people tell me I will need bigger injectors, so I'm listening to those here who have all kinds more experience than I do!

 

I will also say this (in writing) here... That's it. No more bigger turbos or silliness. That is the end of the power mods. From here on out it is just maintenance and fixing the things that need fixing. Someone needs to stop me if I do not follow my own advice.

Edited March 30 by KZJonny