Captain Obvious

Yes, the stock system used bolts everywhere. I found that same thing on the 83 motor I'm working on in parallel with my blowed up one from my 77. My PO already deviated from stock by installing stainless studs instead of the stock all bolt system. And ignoring the questionable length of the studs he had in there, it worked and I am (at this time) satisfied with that concept. I am NOT, however, satisfied with his choice of nuts that he used on the aforementioned studs.

Yeah, I know if I use self locking, it's likely that it will pull the studs out next time. Don't care. I'll deal with that next time. Thanks guys. Two votes for copper.

I took some quick ballpark measurements off my stuff and I'm off by about .100. Might be close enough that the original stuff would rock to take care of the misalignment. Haven't looked at it that closely yet. So gundee, how far apart are yours? What's the two dimensions you're trying to match up?

So here's a question for today... What do I want to use for exhaust manifold nuts? I'm looking ahead and I want to use something better than the mix-n-match of nuts my PO used. Of the eleven nuts I took off the exhaust... Ten of them were 1/2 inch, and one (just one) was 9/16. In addition, two of them were stainless (really really bad idea to mix stainless on stainless) and the rest were carbon steel. Anyone got a part number for something self locking? Distorted thread? I would really like something 12mm instead of the 1/2 inch nuts I took off. I would really like a set of matched, 12mm wrench, self locking nuts. And BTW, I discovered that my intake manifold is thicker than my header flange, so that might help explain all the exhaust leaks. Another thread popped up here: https://www.classiczcars.com/forums/topic/62535-thick-manifold-washers-notched-wanted/? I'm soliciting input along with the original poster over there.

So I've recently discovered that I have the same issue and was considering taking some material off my washers to compensate for the difference in thicknesses. gundee, How far are yours off? Is this an "accepted" fix? Anyone have pictures of said modification?

You could try something like this without nuts on both sides of the head, but I don't think you would like the results. I think it would be unstable and fiddley. I've called what I did a contraption, but in reality it's an extremely stable, predictable, and reliable system. I poked a little fun at it because it's a little unusual, but it's actually quite viable.

My pleasure. Glad to help!

Looks right to me!

LOL. It never stops. You just have to keep the voices at bay. BTW - I did not use a milling machine to fabricate my valve contraption.

I had mentioned my homebrew valve removal / installation fixture before, but didn't post any pics. Not sure I'll be ridiculed for the contraption, but here's what I made. Here's all the bits and pieces. Some all--thread that I feed through the holes in the head where the head bolts go. The blue stuff is just masking tape on the threads so they don't cut into the soft aluminum of the head. And the black washers are nylon so I don't take the chance that I'll mar the surface where the head gasket seats: Feed the all-thread through the head with a nylon washer, metal washer, and nut on each side: Then I place a Delrin cup (that I made on the lathe) over the valve spring retainer: And then I use the pieces of steel plate in a configuration like this: Put on the other place and once everything is in place, I just tighten down the nuts until the spring is compressed enough to remove the retainers: I used tweezers: Once the retainers are out, just loosen up the nuts to decompress the spring and everything comes out: Yes, it's slow, but there's pretty much zero risk of springing a retainer across the shop. It's very low mental stress and I'm happy with that trade off for speed. Re-assembly will be reverse of dis-assembly.

Oh, and all the exhaust studs also came out easy-peasy, so I was able to cut down the super long ones and even up the ends on all the rest as well. Most of them had burrs on the first threads on each end from the PO grinding them after using a hacksaw. The studs are all cleaned up now. Here's the super long ones all out. Thankful for small steps that go well:

No, it is not correct. I don't have a pic showing the correct routing, but one thing I do know for sure is that the elbow with the small diameter stub sticking out of it goes on the left side. The air vent should point at the driver's left knee.

Fantastic! Boat anchors for the win!! And great pic of those winners. Congrats guys. Congrats to all involved!! I miss you guys!

Wow. I need to talk to my neighbors more. Very well done. And I agree with some of the sentiment above... If you have any doubt at all that you're just going to drive it, then I wouldn't even clean it. I would leave it just the way it is and contact BAT.

An update to the project... I've got all the valves sorted out and cleaned up waiting to be reinstalled. I cleaned up all the burrs and distorted metal in the holes on the head and cam towers where the alignment dowel rings go. This allowed me to test fit the cam towers and my "new" cam. So far so good!!! Spins easy with two fingers! And that was even without a whole bunch of fiddling with the towers and the bolts. @jonathanrussell This. Just. Might. Work!!!! Some of the alignment rings for the towers were bent and mangled beyond use, so I need to get some of them on order. That and a head gasket.

Wow. Well done. I absolutely cannot understand the reasoning behind the whole situation, but it sure does look like that could very well be a 350 mile car. So where / how did you find the car? Craigslist? Word of mouth?

Not wanting to start a religious war over gasket brands, I've had two high annoyance gasket failures with Fel-Pro. First was a head gasket on an Acura Integra, and the second was an oil pan gasket failure on a Honda Civic. I'll use simple paper gaskets from them, but the complicated stuff doesn't seem to work for me. I'm just cutting my losses.

Double check the FSM for the direction of that fresh/recirc actuator. I'm fairly confident I got it right, but not 100%. Want another idea? A local buddy of mine @GGRIII ran a cable from the fresh/recirc linkage over to a push/pull knob that he placed where the cigarette lighter normally goes. Now, with a pull (or push) of a knob, he can choose fresh or recirc at any time regardless of what else is going on with the system. I think it's pretty slick. As for Zcon, no, unfortunately I couldn't make it this year. Are you there?

So I've got those Sealed Power valve seals on order, but Rockauto's inventory quantities were screwed up and the order was delayed. Won't be here until next week sometime. No biggie. So todays questions: I need to get a new head gasket on order. I won't use Fel-Pro. Anyone have other suggestions they think is the best way to go? And I think I've already got an intake/exhaust manifold gasket around here somewhere... Have we definitively determined does the metal faced side go against the head, or against the exhaust manifold? I know it's been discussed, but I don't remember if it has been 100% confirmed. Looking for guidance there.

Well you're going to have to accept it because I'm not going to measure it. I like the small bore gauge in that video. I don't have one of those, but I should.

Thanks for the part numbers. I know the head gasket changed a whole bunch of times over the years, and I've heard that the final version of the gasket was actually supplied to Nissan by Stone. And from the pic you posted... Based on all the round holes for the head bolts, that looks like it. For comparison, here's the head gaskets I recently pulled from two motors. One is an aftermarket gasket pulled from my 77 - Has "BC380" stamped in it, which I believe is from Payen. The other is a Nissan genuine gasket pulled from my 83 - Has NISSAN 15A stamped in it. Here's the two side-by-side:

1) What he said. The mode flapper doors rarely form a totally perfect seal, even with new sealing foam. It's not unusual to get a tiny bit of air still flowing through the heater core even when the control in in the VENT position. 2) No, and no. With the stock system, the only way to get recirculated air is with the control in A/C or REC HEAT. When you switch it to VENT, it always uses fresh intake air instead of recirculated. And as for connecting the intake door actuator to the intake manifold... I didn't study things extensively, but I believe that's backwards. I believe when there is vacuum present on that actuator, it pulls the door to fresh intake. So the point is... Just disconnect and plug the vacuum line to that actuator and I think it will always pull recirculated. I think.

Cool. Neat find. based on the pin numbers and similar use in the schematics, I would concur that there are a lot of similarities. Good luck with the repair. Sounds like you're almost done!

All of the valves wiggle a little bit, but yes, I've found that the exhausts wiggle more than the intakes. I'm not going to measure them, because then I'd know. I did measure the lengths of all the exhaust valves though, and found one that was twenty thousandths shorter than the rest. No idea why it's like that, but that one did not make my set of the six best exhausts.

No. That's exactly what they would they expect me to do. What I'm doing instead kinda goes like this. Under magnification and with the use of some sharpie marks on the sealing surfaces, I've tried to match up the correct valve with the correct cylinder. And then after that, I'm lapping them to match the seats. For example... Here's one of the seats before I've done much of anything to it. The valve that WAS in this location wasn't even close to making contact on most of the seat. I managed to find one of the other exhaust valves that was pretty close. Here's what I'm starting with: Here's my handy-dandy valve lapping "tool". I use double back sticky tape to hold the valve to the "tool": Some 800 grit lapping compound: And I work the pair: until I have something like this. Smeared contact markings over the entire seal: Yes, there are still a few pits on the valve seat, but I'm not looking for perfection here. I'm just looking to be able to drive a little bit more on this engine until I finish the F54/P79. What I'm ending up with is 1000 times better than what I started with!!