Captain Obvious

And, since no car good project goes along without complication, I've found another PO caused issue with my N47 head. I had known for some time that a couple of my valve cover bolt holes were stripped out. Not the end of the world. And I also already knew that on one of them, my PO had tried to drill out the old bolt and missed. Hole was off center, half the steel bolt still stuck in there, crappy threads... The usual. Well, I decided that since I had the head on the workbench, I was going to do something about it. Mistake. I'm looking at the whole situation, and noticed that there is a chunk of brass way down in the bottom of the off center chewed up hole. I have no idea what that's all about, but I don't want it in there. So I start drilling it out. Figured out what was going on there... When he drilled (half) the old bolt out, he drilled too deep, and actually punctured through into the water jacket below. AAARRRRRRGH!!!!! That chunk of brass was some sort of plug he stuffed down into there to seal the bottom of the hole back up. So now I'm going to spend the next bunch of hours working on trying to fix that crap.

Thanks guys. I (think I) just nabbed the last 24 off rockauto. I need 12 for this engine, and 12 for my P79 when I get back onto that. So, now that it may be too late.... Same part number for both intake and exhaust?

So anyone got a recommendation on valve seals? Nissan genuine? Doesn't matter, all the aftermarkets are fine? Low profile Ford (I think?)? Viton? Anything?

Back story? Typical. I bought it a number of years ago with very little detailed info about it's history. I got a couple pictures from the PO taken during some of the work he did to the car, and a couple of the pics show the head off the engine, so I know he did that much. I also have a stack of receipts that include ONE piston and rings for said piston. So I don't know what goes wrong with an engine that requires the replacement of just one piston, but the implication is..... My PO has been into the bottom end as well. Kinda makes me wonder what kind of trouble lurks down there. All that said... I didn't buy the car for the condition of the engine. I bought it for the condition of the underside. It's pretty much rust free. To me, everything else is easy.

Thanks all for the encouraging words, and thanks also for the additional investigative work on the head thickness. I guess the bottom line is that I've got a reasonably high degree of confidence that my head was never planed. Surprising to me that the PO would get as deep into the head and NOT have it cut, but thankful for small miracles. Just one less thing to get screwed up under his ownership. Right. I saw that in the manual. The point of the pic is that so far I've taken out one of each direction so far. My PO apparently didn't know they were unidirectional and just tossed tehm in random. I will put them all in the right way when I put this thing back together.

I love the look. My guess is the only reason they made the headlight scoops a separate piece is they just couldn't form one sheet into the shape they wanted. Either geometrically impossible, or too much stretching for the metal to handle. I suspect if they could have successfully made the fender / scoop one piece, they would have.

My buddy did that to his car above. The headlights still mount the same way as stock. He just welded the scoops on. No other changes required.

So I started stripping the valves out of the head. Next chance I get, I'll post up some pics of my home-brewed valve tool, but in the meantime..... So I'm taking the valves out, and here's the springs from a couple of the valves. I never even knew the springs had a variable pitch and a "proper direction" to them, and apparently neither did my PO. The retainer caps are at the top for both of these, but the pitch direction is different between the two: I'm not sure how much difference it makes in the grand scheme of things, but just another detail that was missed.

Even though functionally it's not critical, It would be highly un-Japanese to not control that dimension from the factory. These things are running down the assembly line and IMHO it would be extremely unlikely that they were not all peas in a pod to within a thousandth or so.

Well I don't have an explanation for why your E88 is different than my N47, but I do stand by my numbers. I cleaned off the measuring surfaces and even broke out the big guns. More accurate than the springy calipers for things like this. I don't know the last time this ol' girl saw the light of day, but she's still got it where it counts: Installed the correct anvil, checked her against the measurement standard rod, and then rechecked the head. I get the same thing I got before. About 4.254 inches or about 108 mm. So I don't know if they changed the head thickness over the years, or if yours has been cut.

Who here believe it was July Fool's Day? Show of hands?

Now is a good time to just weld the sugar scoops on and be done with that gap altogether.

Well, duh.

I call BS on the original paint. For that call, I cite (in addition to the blue on the door jamb plate) overspray on the wiper stalks, hood latch, and brake booster check valve. In addition, it appears there is blue paint on TOP of the dirt on the hood hinges. I got no dog in this fight, but I call BS.

I will get a better measurement on the head thickness once I get things cleaned up. But even though I took just a quick check, I don't think I've got eight thousandths of grime on my head. There might be a little error in my 4.255 measurement, but just a couple thousandths. Plus or minus two thousandths maybe? Probably not eight. So either they made the N47 head thicker than the E88, or I'm thinking your E88 has been cut. Anyway, when I get things cleaned up a little more, I'll take a more reliable reading.

So with the incredibly generous help from @jonathanrussell, I've got a replacement cam on the way. Since they are both factory grinds, I'm hoping his cam is a drop-in.... errr.... slide-in replacement for what I have now. So with his help, I'm not out of the woods, but I should be a lot closer to the tree-line than I was before. This people here on this forum are fantastic!

I'm not sure if my PO had my head planed as part of the "work" he did to the engine. I took a quick look through the FSM and I didn't find a spec for the overall thickness of the head when new. Is that number known? I measured my head thickness at 4.255 in (108 mm)*. Anyone know if that's factory original thickness, or if it's had material removed? * I didn't clean the head well before that measurement, so I could be off a couple thousandths.

Wowsers!! Yes, that's exactly what I have now. Both pieces. Haha!! I measured my lobes at 1.585, so the same as what you have there. I'd love to have it! Thank you so much for the offer!! PM on it's way!

Yeah, it's unfortunate that I'll miss this one. Was really looking forward to the group meeting of the Flat Top Advanced Research and Development Society. So if I'm not there... Can I count on someone else to do something stupid in my absence? Is @siteunseen gonna be there? He'd have my back on that.

It's probably the ink from the warning label that's the problem.

And I don't think I'm going to make it this year either. It's been a good run of consecutive years, but this one is going to be a year off. For those of you that are going, please take lots of pics, mingle lots, and gather up some great stories to share with us from the event!!!

So, as a follow up to the above, I pulled all the cam towers off and found all sorts of other issues as well. Less severe than the above, but I also found: Screwdriver pry marks (and corresponding burrs kicked up) at the seam between the towers and the head because he had a hard time getting the towers off. Small flakes of aluminum smashed between the towers and the head. Presumably little pieces of material scraped off with the screwdriver used above. Small chunks of carbon junk smashed between the towers and the head. Burrs kicked up on the alignment rings from using pliers to pull them out of place. And one of them was ovalized a little bit from too much force with the pliers. So just as a quick test to see if it was possible... I carefully dressed all the mating surfaces to remove the burrs on the head, the towers, and the (salvageable) alignment rings and put everything back together. I got it to the point where the towers properly sit flush against the head and I can align them so that the two parts of the cam spin easily with two fingers. I haven't tried it with a complete cam, but it looks like this head may actually be salvageable. So... Long story short. my PO's workmanship strikes again. Not enough cleanliness, attention to detail, and understanding of what's important. Please step away from the motor, sir. Just walk away. Anybody got a Nissan "A" grind cam laying around they would part with? I think that would be my fastest route to getting back on the road for the rest of this summer.

SMOKING GUN!!! So I was messing with trying to align the cam towers by loosening them a little bit and trying to get the cam to spin smooth, but #3 kept giving me trouble. Just didn't feel right. So I decided to pull it off completely and see what I could see. And....... Here's what my Previous Owner put in there on one side to "align" the tower to the head: And it gets worse... Notice that since that threaded "thing" is so crappy, it caused the other side alignment ring to be so far off that he had to use the cam tower bolts to jack the tower down (because it was out of alignment). it caught the alignment ring on the other side and pinched it in the gap and smashed it. Here's what used to be the precision alignment ring: The ring got smashed and actually extruded a tongue of material out into the seam between the tower and the head. Pulling that damaged ring out, you can see the dent it left in the aluminum head: At first, I thought that threaded thing was a Helicoil or something, but it was just a short stub of bolt that he drilled out. I guess he lost or mangled the original alignment ring and made that instead. Here's the two pieces that were "aligning" my #3 tower: Previous Owner strikes again!!! It's beyond me how you can't tell that something doesn't feel right as you need a wrench to crank that tower down into place and crushing that alignment ring in the process. I know the hobby is filled with people of varying skill levels, but this surprises even me.

Head is off, and by some incredible stroke of luck.... No contact between pistons and valves!! So I don't know if the engine isn't interference (with the dished pistons), or if I just got lucky and the rear half of the camshaft just happened to stop in a position where none of the valves were open enough to cause a problem, but whatever the reason, I'm thankful for small victories. Here's a pic of the valves from one of the rear cylinders. They all look like this. No clean spots and no hint of collision: My beautiful camshaft. The rear portion spun really easily in the two rear journals. I just slipped it out the rear of the head: The front portion of the camshaft spins relatively easily, but not as easy as the rear half. There is also one part of the front half rotation where it gets a little tighter. Not so tight that I can't turn it by hand, but to my calibrated hands, it's a little tighter in one spot then the rest. I wouldn't be surprised if there's some sort of alignment issue with the cam journals that was stressing the shaft for the past five years. Here's the break area. I don't have any of the typical beach marks of a gradual failure. It looks like it was a one time catastrophic snap: I took the front half out to get a better pic. Here's another close-up: Next chance I get, I'm going to put the front portion of the cam back in and see if I can loosen up the front towers and get them aligned better. I suspect that if I loosen them up and tighten them down again evenly I might be able to get rid of the rotational tight spot. Just to see if I can.

What he said! So how's it running? Cold, hot? Everything stable?