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Head Gasket and Oil Flow Thru Engine


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19 replies to this topic

#1 steve56

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Posted 23 November 2017 - 09:48 PM

Doing head gaskets on 2005 ej25. One of  heads had a migrated  exhaust valve guide.Using a different set of known good heads.Cleaned the head surface with 220  then 400 grit sandpaper on long sanding block. Washed and rinsed the heads in utility sink and dried with compressed air.

Is that a valid head cleaning method? Also wanted to know how the oil flows from the oil pick up tube, thru the oil pump, block and heads then back into the oil pan.



#2 GeneralDisorder

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Posted 23 November 2017 - 11:38 PM

We use 150 grit cloth backed emery sheets.....

 

https://www.amazon.c...ef=yo_pop_mb_pd

 

We use contact cement to hold this to a 1/2" thick sheet of plate glass. 

 

Remember that the paper only starts out as 150 grit. Very shortly it is much finer. 

 

We do not go any finer. And the sheets last about 4 cylinder heads per sheet. 

 

100% success with this method. 

 

GD



#3 montana tom

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Posted 24 November 2017 - 09:51 AM

Like any motor, high pressure oil at the main bearings & high pressure out to the cam shafts and then gravity feed back to the oil pan. G.D. 's method of cleaning the heads is the best ... easy, cheap, fast, and it works every time.


Edited by montana tom, 24 November 2017 - 09:54 AM.


#4 Gloyale

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Posted 24 November 2017 - 12:56 PM

Like any motor, high pressure oil at the main bearings & high pressure out to the cam shafts and then gravity feed back to the oil pan. G.D. 's method of cleaning the heads is the best ... easy, cheap, fast, and it works every time.

 

I have all my heads surfaced on a precision mill made for the job.  costs $115 plus $25 for the initial cleaning.

 

i think that is just a little better than randomly scratching the piss out of em with sandpaper.  I would never do that to a set of heads that were going to be seled withan MLS gasket.

 

Maybe old EA heads with the thick composite gasket.

 

but for an EJ.....not worth cheaping out.



#5 GeneralDisorder

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Posted 24 November 2017 - 04:34 PM

I have all my heads surfaced on a precision mill made for the job.  costs $115 plus $25 for the initial cleaning.

 

This is actually much more problematic than our method. Unless the heads are fully disassembled you risk getting debris into the oil passage leading to the cams. The machine shop for the local Subaru dealer won't even CBN cut heads without disassembly due to multiple occurrences of camshafts seizing and breaking. Doing the extra (hours) work of disassembly just so they can be surfaced on a CBN mill is a ton of extra work and cost that must be needlessly passed to the customer as in most cases the problem being corrected is an external HG weepage issue and disassembly of the camshaft carrier simply isn't warranted. By doing them inverted on glass, nothing can fall into the oil passages. 

 

We aren't just "scratching the piss out of them" with sandpaper. This is a process that we take great care in performing and has proven itself in 600 HP engines and over a decade of use on and off the track. It's called lapping and when done properly results in as good of a finish as you want (or need) to put on the head. Just because it's simple and easy and anyone with a brain could do it doesn't make it wrong or invalid. Trust me this method is far superior in that you get the same end result and have less downtime, less cost, and you get to see the progression from warped or pitted to smooth which is very informative on how the HG blew and how the engine has been treated. It generally takes about 10 minutes per head. 

 

GD



#6 steve56

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Posted 24 November 2017 - 08:28 PM

Thanks for the good advice. Think I will take the cams out and check the bearings and the oil passages on this set of heads. I'm pretty sure my machine shop doesn't pull the cams and valves out unless they are pressure testing the heads, although I never ask them. I seem to always end up with a mess of ultra grey when reinstalling the  cam plates. I've only used ulta grey in the in the 13 oz tube.  Any advise on a better method of reinstalling the cam plates would be greatly appreciated. 


Edited by steve56, 24 November 2017 - 08:33 PM.


#7 steve56

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Posted 24 November 2017 - 09:13 PM

I have all my heads surfaced on a precision mill made for the job.  costs $115 plus $25 for the initial cleaning.

 

i think that is just a little better than randomly scratching the piss out of em with sandpaper.  I would never do that to a set of heads that were going to be seled withan MLS gasket.

 

Maybe old EA heads with the thick composite gasket.

 

but for an EJ.....not worth cheaping out.

That is sound advise. I'm using non mls Subaru oem head gaskets. SSI commented that my bigger issue was debris falling into the oil passages leading to the cams. I thought hot water, dawn and good rinse in utility sink would get rid or all the debris. However I've never tried  this method  before.Yes, my method seemed a little sketchy, that's why I posted the topic. 



#8 GeneralDisorder

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Posted 24 November 2017 - 09:32 PM

You can't get any debris out that goes into the camshaft oil feed passage without complete disassembly which is time consuming and generally unnecessary as the carriers rarely, if ever, leak. The cam seals are viton so we just leave those be also. 

 

If your machine shop did not disassemble the heads prior to CBN milling then there is a potential for camshaft and cylinder head damage. And there's no way to insure this doesn't happen without disassembly once the deed is done. 

 

The Subaru head gaskets are MLS. But surface finish hasn't proven to be an issue. I used to go to 400 grit back in the day and then 220 grit.... And now the paper we use starts as a 150 and then shears down to a fine grit shortly after the first few passes. It's a very high quality cloth backed emery product though that continues to function through surfacing several heads. I would say the end finish is probably around a 400 grit. In any case we have literally millions of miles on this process with zero failures. If you're concerned about surface finish go ahead and take it to 5000 grit and then hand polish them to a mirror finish if you like. You can go as far as you like with this method, but the paper I use is 150 and has worked for me for many years. We DO NOT have repeat HG failures of any kind. I have had one HG failure in 10 years and it was because an intern mixed up a DOHC head bolt on a SOHC engine and the threads pulled out of the block shortly thereafter. That was the last job he performed for my shop. Attention to detail is not optional on my watch. 

 

As for sealant, we use exclusively Three-Bond 1217H. We get it from Nissan - it's half the price Subaru wants for the same tube. You need a special Permatex mini caulk gun ($5) to dispense it. 

 

GD


Edited by GeneralDisorder, 24 November 2017 - 10:20 PM.


#9 steve56

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Posted 24 November 2017 - 10:25 PM

You can't get any debris out that goes into the camshaft oil feed passage without complete disassembly which is time consuming and generally unnecessary as the carriers rarely, if ever, leak. The cam seals are viton so we just leave those be also. 

 

If your machine shop did not disassemble the heads prior to CBN milling then there is a potential for camshaft and cylinder head damage. And there's no way to insure this doesn't happen without disassembly once the deed is done. 

 

The Subaru head gaskets are MLS. But surface finish hasn't proven to be an issue. I used to go to 400 grit back in the day and then 220 grit.... And now the paper we use starts as a 150 and then shears down to a fine grit shortly after the first few passes. It's a very high quality cloth backed emery product though that continues to function through surfacing several heads. I would say the end finish is probably around a 400 grit. In any case we have literally millions of miles on this process with zero failures. 

 

GD?

Thanks GD. What would you recommend for this set of heads. Bring them in and have them disassembled cleaned and milled or finish doing the heads myself? I'm still a little confused  on what I need to clean on the heads if I finish the job myself.

I've used the same machine shop for yeas and never asked if they are taking the cams out before resurfacing them. I will be verifying their procedure on Monday. 



#10 GeneralDisorder

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Posted 24 November 2017 - 10:35 PM

You must use glass (thick glass), and do the lapping with the head surface down (glass stationary). I do all my own head work unless I need seats cut or heavy surfacing due to warpage, etc but the decision is yours. If they aren't disassembling them then you are much better off doing them yourself. 

 

GD



#11 steve56

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Posted 24 November 2017 - 11:04 PM

You must use glass (thick glass), and do the lapping with the head surface down (glass stationary). I do all my own head work unless I need seats cut or heavy surfacing due to warpage, etc but the decision is yours. If they aren't disassembling them then you are much better off doing them yourself. 

 

GD

I meant with this set of heads. I've already block sanded them..Can I remove the debris  from the block sanding myself or do they need to go to the machine shop?



#12 Gloyale

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Posted 25 November 2017 - 02:34 PM

I always disassemble all my heads before I drop off at the machinist, and then reseal them completely.  I also use this opportunity to reset valve clearances.  Seen lots of them leaking at the Cam case seam.  Yes it takes time but it's the very best way and that is all I give my customers.....The very best work.

 

Soooo.....GD, let me get this straight, you "do headgaskets" on customer cars by simply popping new gaskets onto an assembled head, without surfacing them   (i would contend your method is not surfacing, but debris removal, Get's the surface nice and shiny a kinduv uniform......But it's not a "true" plane.  ...It's how I prep intake surfaces but not the head or Deck)  

 

And then reassemble?  do you even bother pulling  them to do Seperator plate?  Do you do Oil pump re-seal? Do you clean carbon from pistons?  Do you re-ring the pistons?  Why do all that wonderful work but NOT disassemble and surface the heads?  If it's a time,at the machinist,I think you are trying to service too many cars too quickly.

 

What do you do for Dual Cam heads?  Gotta take cams out just to get the head bolts.  So what's the reasoning there?  Those heads leak INTERNAL and MUST be a perfect surface or they won't last.

 

Just trying to understand how you can be such a wonderfully knowledgable and competent mechanic but be against the advise of Machine surfacing.  You are usually a do it right or not at all kinda guy.


Edited by Gloyale, 25 November 2017 - 02:36 PM.


#13 Gloyale

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Posted 25 November 2017 - 02:40 PM

The cam seals are viton so we just leave those be also. 

 

 

WHAAA!!!???? Just read this.

 

Even without disassmbling the carrier you can pop new seals in there in seconds.  they are like $7 bucks a piece.  So cheap why would you not do them?

 

Viton seals DO Leak.  I won't do a HG or Timing belt job WITHOUT replacing those.

 

C'mon man......sounds too much like cutting corners to me.



#14 GeneralDisorder

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Posted 25 November 2017 - 04:15 PM

You would contend incorrectly if you don't think our method IS resurfacing. You manifestly don't have the experience doing it this way to understand what the end results are. It is a truly flat surface and you can really only learn this by the experience of seeing many different heads and how they progress from unfinshed to fully surfaced using the same glass each time. When you have done hundreds of heads and seen everything from heads that surface easily in one or two passes to heads that have severe low spots and fire ring pitting you begin to get a feel for how flat of a surface it creates. Every head is different and it's pretty obvious once you have done a few that the process produces an extremely flat surface with excellent finish. We have an excellent relationship with Rick's Cylinder Head who is nearby to us and the owner has seen and approved of our method. In fact he thought it was quite ingenious and effective for our purposes. 

Heads and many other things have been surfaced using this method for hundreds of years before the advent of milling machines and Blanchard grinders. We used this same method (all the way to 1200 grit) on disc valves when I worked industrial machinery - we would then leave them filled with solvent overnight and the flatness was such that the mirror finish from 1200 grit on glass would seal off mineral spirits between two lapped surfaces held together with a very weak spring.

As for the cam carrier or cam seals leaking.... never seen it unless someone had messed with them. None of the HG jobs we do ever leak there. Like the Viton rear main seals - leave them alone. The rear cam plugs do leak and often need replaced as they are Buna-N. There are cases where the carrier needs to removed for inspection such as bottom end failures, or previous incorrect work, but the vast majority of engines are just fine to leave these alone.

You clearly haven't experienced the 10mm Allen camshaft sprocket bolts yet. Once you experience that BS you will think twice about replacing viton cam seals that aren't leaking. Half the time we have to weld axle nuts to them, and sometimes the sprockets get broken in the process.... Viton lasts virtually forever unless there is engine contamination, shaft damage, or have been installed improperly.

We do rings in about 90% of cases. On pre-2006 engines I knurl the piston skirts (on my Perfect Circle Nurlizer).

We don't reseal the oil pumps if they have a 10mm. Those o-rings haven't been a problem on the newer EJ's thus far. For that matter there are three more of the same part number o-rings used between the case halves so if they were a problem we would be seeing those fail also.... Usually we are swapping out the 7mm and 9mm pumps for 10's because the small pumps have a lot harder time on older engines supplying enough volume to the rods. Yes I have seen the failures of that o-ring - but it's usually on older 90's stuff, and it's pretty rare. I pull off 7mm and 9mm (and 10/11 on turbo engines) all the time and can't remember the last sucked in pump o-ring I saw. Probably better oils not doing so much damage to them. Or maybe improved machining tollerances putting more accurate clamping force on them.... In any case it hasn't been a problem in our experience since the 90's models and we almost never work on stuff that old. 

I've been doing this a LONG time. And each job is unique in some respects. But these are the methods that work and produce excellent customer satisfaction. One need only consult my reviews if they have any question about my customer satisfaction with our methods.

GD


Edited by GeneralDisorder, 25 November 2017 - 07:19 PM.


#15 Gloyale

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Posted 26 November 2017 - 12:33 PM

You would contend incorrectly if you don't think our method IS resurfacing. You manifestly don't have the experience doing it this way to understand what the end results are. It is a truly flat surface and you can really only learn this by the experience of seeing many different heads and how they progress from unfinshed to fully surfaced using the same glass each time. When you have done hundreds of heads and seen everything from heads that surface easily in one or two passes to heads that have severe low spots and fire ring pitting you begin to get a feel for how flat of a surface it creates. Every head is different and it's pretty obvious once you have done a few that the process produces an extremely flat surface with excellent finish. We have an excellent relationship with Rick's Cylinder Head who is nearby to us and the owner has seen and approved of our method. In fact he thought it was quite ingenious and effective for our purposes. 

Heads and many other things have been surfaced using this method for hundreds of years before the advent of milling machines and Blanchard grinders. We used this same method (all the way to 1200 grit) on disc valves when I worked industrial machinery - we would then leave them filled with solvent overnight and the flatness was such that the mirror finish from 1200 grit on glass would seal off mineral spirits between two lapped surfaces held together with a very weak spring.

As for the cam carrier or cam seals leaking.... never seen it unless someone had messed with them. None of the HG jobs we do ever leak there. Like the Viton rear main seals - leave them alone. The rear cam plugs do leak and often need replaced as they are Buna-N. There are cases where the carrier needs to removed for inspection such as bottom end failures, or previous incorrect work, but the vast majority of engines are just fine to leave these alone.

You clearly haven't experienced the 10mm Allen camshaft sprocket bolts yet. Once you experience that BS you will think twice about replacing viton cam seals that aren't leaking. Half the time we have to weld axle nuts to them, and sometimes the sprockets get broken in the process.... Viton lasts virtually forever unless there is engine contamination, shaft damage, or have been installed improperly.



GD

 

I used to polish glass.  I know what a proper surface is, and a few passes of 150 grit don't get you there.  Glass is not a perfect plane, and 150 grit leaves DEEP scratches that themselves are deeper than the .02mm surface prep spec.  And even if it is perfectly "flat"  it may not be truelly parallel plane to the crank centerline/ Perpendicular to the bore.

 

Glad it's working for you.  But If I told my customers I was gonna use sandpaper to refinsh their heads, they would run....rightly.

 

I remember when you "developed" this method and YOU YOURSELF titled the thread "post apocalyptic" machine techniques.  Now it's a totally normal professional accepetable method that others should trust paying you thousands of $ to do to their cars?

 

And I took the Cams off of an 05 Baja Turbo just last week.  Proper tools.....no Problem.

 

Not all Subarus use Viton seals either.  Many non-turbos use black Buna-n seals.

 

And many of my customers cars have been apart and screwed off by others, so I have to double check and re-do shoddy work all The time.  Cheap-o cranks seals, timing belts sets, HGs  seen it all.



#16 GeneralDisorder

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Posted 26 November 2017 - 02:26 PM

I used to polish glass.  I know what a proper surface is, and a few passes of 150 grit don't get you there.  Glass is not a perfect plane, and 150 grit leaves DEEP scratches that themselves are deeper than the .02mm surface prep spec.  And even if it is perfectly "flat"  it may not be truelly parallel plane to the crank centerline/ Perpendicular to the bore.

 

Glad it's working for you.  But If I told my customers I was gonna use sandpaper to refinsh their heads, they would run....rightly.

 

I remember when you "developed" this method and YOU YOURSELF titled the thread "post apocalyptic" machine techniques.  Now it's a totally normal professional accepetable method that others should trust paying you thousands of $ to do to their cars?

 

And I took the Cams off of an 05 Baja Turbo just last week.  Proper tools.....no Problem.

 

Not all Subarus use Viton seals either.  Many non-turbos use black Buna-n seals.

 

And many of my customers cars have been apart and screwed off by others, so I have to double check and re-do shoddy work all The time.  Cheap-o cranks seals, timing belts sets, HGs  seen it all.

 

My head surfacing works wonderfully. I've checked flatness and parallel with a machinist straight edge and height gauge and both are well within spec. It's not an issue nor is surface finish. The paper is not 150 grit after multiple passes. It cuts fast at first then shears down to a fine grit and gives a very nice finish. And again it's MOST important to consider that I've been doing this over a decade and not one head gasket job has EVER failed. You claim my method is wrong though you have no experience with it nor any evidence that it doesn't work. Only speculation and an irrational belief that because it's an arcane method it can't possibly work. If you want to disassemble all the SOHC heads so they can be milled go right ahead. It's a pain in the butt for no benefit to the job in my experienced opinion. I have a customer making 380 AWHP on EJ205 heads surfaced with my method. A fuel system issue caused an injector to clog and he detonated the engine - cylinder pressure was high enough to blow out the 257 cylinder wall like Elmer Fudd's shotgun. The head gaskets did not blow even with enough cylinder pressure to break the block casting on a semi closed deck. It split the iron cylinder liner down 3/4". 

 

All Subarus since 2000 have Viton cam seals unless someone changed them. Subaru superseded the seals on the 90's cars to the Viton seals. 

 

Sometimes the sprocket bolts come off. Sometimes they break all your tools, and the sprocket, and you have to destroy the bolts. That's why the dealer stocks them by the dozen. If you haven't experienced that, then you haven't done very many 02+ dual cam models.

 

Yes I've seen it all as well. x5 what you have seen I'm sure. Remember I'm running 5 bays simultaneously so I see 5x as many cars on an average day. I'm also pushing all this stuff to the limit and beyond. You have no idea what goes into making a 257 live at 600 HP. There are things that matter a LOT more than the method used for head resurfacing. 

 

GD


Edited by GeneralDisorder, 26 November 2017 - 03:33 PM.


#17 CNY_Dave

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Posted 26 November 2017 - 06:57 PM

You two. table. Ruler. Now.  :)



#18 Gloyale

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Posted 27 November 2017 - 02:07 PM

It's ironic that the guy with the "real" shop, who charges way more money, is the one saying to "surface" heads with sandpaper and no way to measure how much taken and from where......

 

And the "home mechanic" is the one saying that a proper milling on real surfacing equipment to a measured amount and a true plane is the way to go.

 

True irony.



#19 GeneralDisorder

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Posted 27 November 2017 - 04:26 PM

We probably do charge more. Especially given the cost of living differences between our locations. 

 

The difference is that we provide better *value* in that we spend the customer's money wisely where it's needed, and not where it isn't. Just like knurling piston skirts instead of buying new pistons. That's due to experience and knowing what truly matters for longevity and what doesn't as well as knowing how to perform tasks without incurring unnecessary labor such as disassembling camshaft carriers, etc. It allows us to charge less overall labor for the job, and keep the job in house as much as possible. That's why I bought and shipped a piston knurler from Ohio. 

 

I'm going to put this one to bed once and for all. I'm going to pull out my height gauge and granite measuring surface and take before and after measurements. Additionally I'm going to borrow or buy a surface roughness tester (profilometer) and actually measure the finish.... why not - it's a good excuse to buy another machinist tool. Pair well with my lathe and mill.

 

GD



#20 GeneralDisorder

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Posted 28 November 2017 - 09:45 AM

Surface Roughness gauge (profilometer): Ordered

GD




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