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I'm wondering if the valves rotate under tension while the motor is running. I had a leaky intake valve, turned it 180 degrees and now it's tightly sealing. When I put that head back in use will that valve possibly rotate in relation to the valve seat? Thanks

They all sealed up tight except #2 intake leaks a little. I'm about to do something stupid I know. I'm going to lap it without pulling it back through the valve seal. Q tips and patience hopefully will work.

That's very similar to what is on my 240 from Cullman, AL. Have you ever dealt with Paul's Auto Shop, Green Cove Road Huntsville, AL? I have receipts from where some other work was done from there in 2000.

That's really interesting. I found something that is close to what you have. They think the chain on the clutch disengages the cruise control. https://www.reddit.com/r/Datsun/comments/38shj5/what_the_hell_am_i_looking_at_1978_280z/

It's one of those things you just have to do to know what I mean. When I sat a new valve seal next to a bare valve guide I could judge where it should end up on the guide. Then using that other guys measurement of .550" from the top of the metal "barrel" base of the seals to the outer spring landing I had another reference point on the valve guides. The neat thing is both of those measurements hit at the bottom edge of the locking groove in the guides. So after lubing EVERYTHING, I pushed the valve through then put a cut in half "condom" over the valve tip. Put the lubed up seal over the end, holding pressure with my finger against the seal and valve tip I barely twisted the valve and it popped right through the rubber hole of the seal. Twisted it down onto the guide with my fingers as much as I could then with a 12mm deep well, I used a 13 the first time but the 12 was perfect, I started tapping until it covered the locking groove on the guide. Then went around the gap between the bottom of the barrel and the inner spring seat with angled feeler gauges, 026, 025, 020, 019 for 090" total. They are perfect I must say. They will stay up by themselves but if you tap the 2 that are next to each other on each cylinder they will do a slow motion styled fall until the valves hit the cardboard the head is sitting on. It's really easy once you get your feet wet.

Measure twice, cut once. That was so easy after I did some measuring. They look great and all drop at about the same rate, not staying up like the first two, too tight of a seal. .080" all the way around the seal bases and the inner spring seat. Thanks for the feedback, it gives me confidence. 8^)

Well I have a benchmark now, I read all the other pages of the thread on hybridz about those seals. I don't have an attention span. "I installed so the top of the steel barrel was about .550" above the height of the naked outer spring perch. This seems to leave plenty of room inside."

I'm glad you said that Blue, I couldn't figure out what he had. Is it a four barrel conversion?

Great! I love this forum. I actually thought about cutting a couple of flat washers last night. I can call some body shops and see if I can get one, or maybe the chain stores may have them? Thank you both! I'll get on this as soon as I can calm myself down enough. That's about the most nerve racking thing I've done in awhile. This is an educational endeavor for me, the E31 is next. EDIT: Hooray, the chain stores do have them. I would probably loose some blood if I tried to make my own.

The E31 & E88 came with the one on bottom, I think. The N42 had the newer design, the one on top. I bought an N42 that had been changed over to internal oiling cam and block off plates on the cam towers. Spray bars are prone to failure, so as Captain Obvious says "CHECK YOUR SPRAY BARS". Great looking motor you have there!

Those aren't made for an L head and if you drive them down too far the valve guide will cause them to "bulge" out between the little spring and the metal base of the seal. You can see the gap at the very bottom between the inner spring seat and the metal base of the seals. I'm worried I went too far. I'll put another, uninstalled one beside these and take a closeup picture to help judge, my eyes are finally showing their age.

If you can get $50 dollars worth of stuff from Advance Auto, put TRT30 in the coupon code when you check out and you'll get 30% off. Pick it up at your local store, no shipping charges. The good carpet is made by ACC and the best price I've found was on ebay.com. Rockauto.com is good, they may have the ignition switch? I got my rubber kit with a project car I bought. It came from from MSA as a whole kit, I've read they don't sale the kits anymore you have to buy it it in pieces like the hatch kit, the doors etc. I'm not 100% on that though. I've had my best luck with amazon.com, overall. Spend some time online, get the part numbers you want and google them for the best prices. In my experience.

Want any opinions on these seals before I go any further. Are they bulging too much? The valves will stay up by themselves so they are sealing pretty tight, I guess. I did #1 exhaust last night with a plastic piece of tubing to drive it down, bad decision. A 13mm deep socket works better, more control and the socket is perfectly even top and bottom. Thanks for looking.

Your pedals look look sorta worn, could be 160,000?

Thanks Rossiz but the seals I'm using have the metal base that can't be pushed down with your thumb. Most people use deep well sockets but I'm using a short piece of 1/2" PEX tubing. After seeing these I got the idea. Oh yeah, I've got the straw looking sleeves, cut in half, just enough to cover the stem's groove. I'm using Permatex assembly lube, that red stuff, and so far it's working great. I'm going oh so slow though.

The end that connects to the valve is smaller than the other end that connects to the tube coming out of the block. Here's a picture showing where it goes, the red line, and the block tube is covered with blue painters tape. here's another block picture with the tube sticking out,

With all the things that are missing, I wonder if the motor may be locked up? If I had a non running car I'd probably let somebody take some parts they needed. After you take the plugs out and squirt some oil in the cylinders you can put a 27mm socket on the big bolt inside the front pulley and try and turn the motor. Take the valve cover off and oil the cam stuff first though. They turn clockwise, looking from the front, towards the driver's side.

Thanks Madkaw. After a lot of reading, I can do it either way. I'm gonna measure how far down they can go without bulging the rubber at the top. Inner spring seats then the seals, valves next and so on. I had to add a new tool for the valve train work. Hands-free magnifying glass;

Clarify my rambling. Can I put valve seals on first then push the valve stems in from the bottom? Thank you!

Can I not put these viton seals on the guides then gently push the valve stems through? Seems easiest since they don't sit on the very bottom anyway. I could get the seals on first then put the condom over the stem tip and twist it through. Or should I do it the way tom monroe does the OE seals? Valves in then push the seal over the tip. Seems to me it's the same thing if the metal base of the viton fits tight onto the guides anyway.

I didn't what the heck that was. Workers polish a new sculpture in the shape of a giant oil bubble at a tourism resort built near the first drilling well of the Karamay oil field in Xinjiang Uighur Autonomous Region, China, August 9, 2015. Photo: Reuters "New sculpture in the shape of a giant oil bubble." 11 Aug, 2015Workers polish a new sculpture in the shape of a giant oil bubble at a tourism resort built near the first drilling well of the Karamay oil field in Xinjiang Uighur 11 Aug, 2015Workers polish a new sculpture in the shape of a giant oil bubble at a tourism resort built near the first drilling well of the Karamay oil field in Xinjiang 11 Aug, 2015Workers polish a new sculpture in the shape of a giant oil bubble at a tourism resort built near the first drilling well of the Karamay oil field in Xinjiang Uighur Autonomous Region.

Bottom left corner of this picture where it says "AFM connector". Some refurbished ones for sale, https://www.google.com/search?q=280z+afm&biw=1280&bih=620&tbm=shop&source=lnms&sa=X&ved=0CAcQ_AUoAWoVChMI2IS5pYWkxwIVysyACh0XJwtB&dpr=1.25

When I first got my '77 it would suddenly die when I pushed in the clutch. The BCDD was out of adjustment. It's something that lets them gradually drop in RPMs to keep from stalling. Another thing that may have happened, the EFI connector by the battery may be loose? It may have just been letting you know who's the boss. Mine does some weird stuff sometimes too, but it has never left me stranded. Gremlins.

Here's where the AFM ground goes, thanks atlanticz for the picture.

Parts stores loan those out if you need one. There's a lot of diagnostic testing you can do with one. http://www.atlanticz.ca/zclub/techtips/vacuum/