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Last time I saw an OEM style head gasket in a aftermarket gasket kit a lot of the ports and holes did not line up at all.
I'd recommend getting a genuine Toyota head gasket.

A word of advice from a mistake I made a long time ago.

At the minimum compare the new one with the old to see if they match up right.
Save you from some headache maybe...
 

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Discussion Starter #22
Good advice. I pulled the head gasket off the head a few hours ago and will be comparing them. It looks like a Toyota gasket.
 

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Discussion Starter #23
Well, I did the air pressure test where you fill the valve squish area with water (put a spark plug in to hold water) and blow air against the valves through the ports and several leaked bubbles. Surprised by that as there was a receipt in the car we go the head from that showed it was just machined a few thousand miles before that donor car ended up in the wrecking yard. I'll bring it to the machine shop and see what he says - perhaps that prior shop did a poor job on the heads, or my test was too stringent.

In other news, I measured the oil pump journals and both were as new - at the larger end of the allowed size range according to the factory manual. So that's nice - don't have to mess with those pressed in bearings.

Once this head/valve thing is settled, I'll be done with the measuring and such and then assemble the block. Really looking forward to seeing it come together as the block and oil pan have been painted for over a year. Satin black and the clean head atop it will start looking like an engine.
 

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Discussion Starter #24
So, machine shop doesn't do valve grinds anymore - just full valve jobs cutting the seats, and on engines like this there are the shims to deal with. So pretty big money at just under $500 with tax. Instead, I'm going to pull the cams, followers and valves and hand clean them. It looks like the donor engine was burning oil as there's quite a bit of carbon on the valve seats and sealing surfaces. No way to know if it's going to burn that out in operation with this new tight engine and perhaps a cleaner run through it, so this will tell me. I picked up an $11 valve spring compressor and will get on it.

In the meantime, I used oven cleaner to clean the head and it worked quite well.

The block is ready to be assembled, so I'll chase the head bolt holes and then give it a final cleaning before bringing it in for the crank/bearings/pistons and new rings. Then I can stow it out in the cold garage until I get the head stripped, valves and seats cleaned properly and I think my kit may have even come with valve seals. Better go check.

Here's the oven cleaner working. Did not seem to even change the aluminum's appearance despite some internet chatter about harming aluminum. I'd do it again - cut way better than other products I've tried.

255572
 

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Discussion Starter #26
Well, crud - bad news. I pulled the cams this evening and they look terrible - the bearings are scored. We are in N. Idaho so if anyone has a used head, please reach out.

I'm chagrined that this head had a receipt it was recently worked on so I had not a care it would be an issue when I found a Supra in the U pull a couple years ago and snagged it. Argh!
 

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Easy! Amazing as this is going to sound. That is actually NORMAL on the 7m heads.

Now check the journals themselves and see how bad the scoring is.

Are we talking nail get caught scoring?
 

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Discussion Starter #28
Yes, would catch a nail on the cams - the cams don't have a spot of gloss - like they spun in 80 grit. Worst at timing gears of course, but progressively better rearward. The head bearing surfaces are usable but I only glanced at the bearing caps and they did not look good. Someone knowledgeable pointed out the caps take the wear so I will look at them more closely but suspect they are pretty beat up. Any pics of cams/head/cap damage that were successfully run would be very helpful. The head is perfectly flat on the cylinder face and both cam journals. The shop I went to has a round flatness bar and a normal one and the owner pronounced this aspect very good.
 

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Discussion Starter #29
Well, Figgie. Your comment made me do a little research and indeed it appears the 7M eats cams/bearings over time and most of them running right now probably look about like mine. So, I'm going to clean up the cams and bearings and run it. I went to a friend's shop and put the cams in a lathe so I could clean them up a bit. My goal was merely to smooth the myriad ridges so they won't eat the bearing caps too quickly.

I used WD40 as a lubricant, and 500 grit sandpaper held against the spinning shafts with a piece of aluminum plate my buddy cut for me to size. I did 3 sessions of about 5 seconds each on each bearing with 500 grit. Then switched to 1200 grit and repeated the process but twice (6 sessions). After each session (once on each bearing surface on the cam) I wiped the cam, relubed andused a fresh piece of sandpaper.

This unscientific approach was intended merely to smooth the damaged surfaces so they'd be more friendly to an oil film by knocking down the high spots, and reducing point pressures from those high spots on the bearing surface when reinstalled. To remove the grooving would take off too much material from the cams.

It accomplished what I wanted, with the cam surfaces going from a "gritty" feel to feeling properly smooth, and a fraction of the smallest grooves were removed - perhaps 7% of them. I may go back over them with finer grit before this is done but I can feel I made them much more friendly to continued spinning.

Next will be the cam journal caps. Same goal - just get rid of the abrasive feel to them so they may support more of an oil film. They are truly sad feeling and I wish some would post pictures of theirs as it may give others heart to know just how bad something can look and still operate. These journals look rough. I can see tiny divots here and there with raised edges that were trapping dirt and making the surface a source for further abrasion. Even some embedded contaminants. Goal again is to knock down the high spots and try to create a more uniform surface that will support an oil film. I have a couple bits of good advice on doing this. Tomorrow my buddy is going to show me a 3M polishing dremel product I was not aware of. Likely the final process will involve some Rube Goldberg apparatus to hold either my Dremel or that extension Dremel accessory centered in the empty head journals and a polishing operation. Will update on that - still cogitating.

I'll also be looking at increasing my stock pump's oil pressure by reading the threads on what others have done. Seems like idle pressure is the issue. Likely jump up an oil viscosity once my new bottom end bearings are broken in as well to maximize whatever oil film I can achieve here on the top end.

Input welcomed.
 

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I'll also be looking at increasing my stock pump's oil pressure by reading the threads on what others have done. Seems like idle pressure is the issue. Likely jump up an oil viscosity once my new bottom end bearings are broken in as well to maximize whatever oil film I can achieve here on the top end.
While I have no first hand knowledge of the product, Driftmotion sells an overdrive oil pump drive pulley that will help with idle pressure. It's a small enough change that the stock belt tensioner can be used. I've done the same concept but with a much larger overdrive that's not a simple bolt on.

Another key thing to consider is the filtration. Some oil filters have a bypass valve that opens as low as 8psi, meaning not all of the oil is getting filtered. I always try to find a filter with a higher bypass pressure (~22psi) for my daily and the fast car has a no bypass filter.
 

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Discussion Starter #31
Thanks for the tips and the driftmotion site. On filters, I'm a Wix Gold fan but will see if they have a spec on the bypass psi - that's a great thing to know.

So. The Head. I put the polished exhaust cam on the head this evening just to see what had been done. Just laying it there without the caps and of course no valves so I could feel it spin. They haven't been in the head since I disassembled. What's this? The cam rocks as if the head is bent. I could feel which cam journal it was (just rock the cam and push down on each journal. When you find one you can press hard on and it doesn't stop the rocking - that's the high one). So I removed the cam and got a bright light. A chunk of hardened chrome plating half the size of a small grain of sand. From when the engine it was on destroyed a crank and it looks like bits of the crankshaft's journal got into the oil. Luckily it did not run long (!). Anyhow, the bit was slightly embedded in the aluminum. Got a dental pick and popped it out. Then spent an hour going from journal to journal in the head finding 1 or 2 in each. Amazing. Cam still has the tiniest bit of rocking which I will get handled in my polishing process. And I'll have to do the same thing on the cam caps as they will have bits as well. After I do this new step (3 steps forward, 2 back on this project so far), I can polish it. Otherwise, I'd be polishing aluminum and that hardened steel would not budge. My buddy lent me a sweet industrial grade dremel device with a cable drive and a super fine foot pedal control. Can't wait to get into it.

I've been watching an incredible series of videos online by Faye Hadley and Danny, the owner of a nearby shop, where he's working on her 7M and letting her film his work. It's amazing what you can do on the cam journals with polishing, using blue machinist's dye, and being a sensei-master machinist! And if you're VERY astute a hammer is even used. I'm amazed - I have gained serious confidence through watching this gifted gentleman massage and hand form her bent head and rough journals into a smooth set up with Brian Crower cams in it without ANY machining beyond a simple shop. I'm literally just following his recipe and honestly this video series is a total gift to the 7M world.

So, tomorrow I need to pick up some 3000 grit sandpaper as I'm going to wrap a right size socket and carefully hand hone the caps/journals and then polish them. I feel the socket will immediately attack the high spots and possibly identify any bits of embedded steel I missed (I know, I know...) where the polishing device is soft and will go around them. The blue dye will then guide me.
 

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Discussion Starter #32
Thought you might enjoy a picture of this week's focus. The blue is a machinist's dye so I can see where the cams are dragging too much on the journals in the head. A few rounds of polishing to relieve the pressure and then they'll spin more easily. At the moment, you can see the intake journal (picture's left) in about the picture center has too much contact with the cam.


255769
 

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Discussion Starter #33
Had a hare-brained idea at the last minute before I actually started removing material. The head and block are rarely even close to the same countour. Call it flat ish. But when bolted together, the block will win and bring the head into its contour. So I thought "Hmm, I should bolt them together and THEN check the cam alignment." But I don't want to mess up the head gasket. Hmmm - just metal on metal? I literally called every wrenching buddy I know to see if anyone thought it unwise (crack something, etc) and nobody could think of a reason not to.

So, I tapped in the new block dowels, and bolted the head directly to the engine at about 30ft-lbs and rechecked. No discernible change. Cams left the exact same witness marks. So now I know the clearances I obtain on the bench will be the same in the car. I also was happy that I could not get my thinnest shim between head and block when it was just laying there with no bolts. My slab of granite strategy seems to have produced a VERY flat block as well as head. This was also the first time I checked the cams for binding and am happy there was none. Just the slight interference on 3 central journals.

The "right size socket" has now also morphed into a much tighter fitting piece of Schedule 40 PVC pipe that I'll wrap and use to relieve the journals and then polish. I cut a piece long enough to straddle the journals on each side so that proper alignment is maintained. The socket later made me nervous in that regard as some journal contact is only on the forward or rearward edges and this new "tool" will be precise enough to relieve that by using adjacent journals.

Valves are still out in the garage poked into cardboard and waiting to be cleaned with a steel brush wheel. Then I'm doing a hand valve lapping on them to clean up the valves and seats.
 

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Had a hare-brained idea at the last minute before I actually started removing material. The head and block are rarely even close to the same countour. Call it flat ish. But when bolted together, the block will win and bring the head into its contour.
If the block isn't flat you're going to have problems regardless of the head being flat, so realistically there shouldn't be a difference on the cam journals once the head's bolted down.

But I don't want to mess up the head gasket. Hmmm - just metal on metal? I literally called every wrenching buddy I know to see if anyone thought it unwise (crack something, etc) and nobody could think of a reason not to.
Any sort of oddities in the block will imprint into the aluminum head so it's usually safer to put an old gasket in just to be safe. Since you hand lapped the block with a flat block you should be fine though.

The "right size socket" has now also morphed into a much tighter fitting piece of Schedule 40 PVC pipe that I'll wrap and use to relieve the journals and then polish.
A much better idea than a single contact point like the socket idea. I had a bar of aluminum turned to size minus the thickness of the sand paper I was using to polish the journals. The #1 journal was cut undersize for wrapping a piece of 1/16" PTFE around the rod though so I could bolt the cap down and hold the rod centered for the process. Turned out great and now I am wondering what I did with that thing.......

Valves are still out in the garage poked into cardboard and waiting to be cleaned with a steel brush wheel. Then I'm doing a hand valve lapping on them to clean up the valves and seats.
If you have the means, or know someone that has the means, walnut shell blasting works great on the valves.

Once all of the work is done on the head I assume you will be thoroughly cleaning it? If not, you really should. I personally use Simple Green Pro HD degreaser. It's aluminum safe and won't discolor the head, and it's available at Walmart and Home Depot. Also fairly cheap. If you have a big enough tub you can submerge the head in it and let it soak for a bit to help clear out all of the coolant and oil passages.
 

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Discussion Starter #35
Yes, on the relative flatness, though the gasket (traditional) is designed in part to handle minor variances in surface and certainly a head can be cracked by uneven bolt torque precisely because it compresses the gasket and flexes the head. That was a great idea with the aluminum rod and gave you some precision on the outcome, I expect.

On cleaning the head, there is a closed off oil passage used in manufacturing that has a steel ball pressed into it (I think it's at #1 on intake side). I'm unwilling to screw around with having a shop remove that (tig weld and pull it for me) so I can put a plug in. Did you mess with that? It's common that a head will have one or two closed off passages like that, so I am OK with it as a normal small source of future contamination.
 

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On cleaning the head, there is a closed off oil passage used in manufacturing that has a steel ball pressed into it (I think it's at #1 on intake side). I'm unwilling to screw around with having a shop remove that (tig weld and pull it for me) so I can put a plug in. Did you mess with that?
Don't bother messing with that, not enough can get trapped there to make it worthwhile. The soak method will loosen anything in there up and it'll rinse away or come out with compressed air. Also make sure you flush out the oil galleys on the cams well too.
 

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Discussion Starter #37
Good advice. So the head is from an engine that lost a rod, and I found little flakes of metal in it which I didn't expect. Generally, when a rod goes the engine lasts about 1 second give or take (heh). Hardly enough time to pump crud around much. However, I did not consider it took some time for a bearing to wipe out and tha's what I think is in here, thought they look like chrome, not brass bearing material. Pounded/spun cast iron from the block after the bearing parted ways? Dunno. Anyhow, that is a good idea to soak the head in a tank and blow it clean. I'll rinse it with hot water as well. Sounds like you're just trying to get me out in the Idaho cold spritzing myself with Simple Green via air hose.

In a couple hours I'm going to be spinning the cams on a buddy's lathe and doing some further cleanup on it. Thanks for the input on the plugged gallery. It's common practice to leave those alone, but gives me the heebie-jeebies a bit. I'll make my peace with it.
 

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That is really dependant on the head being annealed or not.
Most likely it will be with how old 7Ms are.

There is also a good use of it to allow the aluminum to mold around the insert instead of letting it collapse around the stud. Annealed or not, the aluminum will collapse around the stud and lose head clamping force. It is not expensive to do and definitely worth it for a 7M.
 
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