Dat73z

Thanks Tony, attempted measuring against NPT tables earlier in the week with no result so that makes sense. Any idea of the JIS/Metric size? Otherwise will attempt once I wrap up the work week here and report back with a size.

Does anyone have any idea what size threads the tapered fittings on the factory mechanical fuel pump are? Is this a common fitting that can be purchased off the shelf? I've attached a picture of the fitting in question. Thanks!

Mission accomplished. I guess it was corrosion after all. Rocked the motor back and forth CW and CCW until it broke free. Will check timing now and ensure all is good. Thanks again all, I guess sometimes it's just the simple things. Kept second guessing everything since so many parts went into this refresh that everything was questionable.

OK, so the motor will rotate by hand 1/2 turn either way freely now (CW or CCW) then it locks up solid. There was definitely some sort of corrosion issue going on, but the penetrant and oil resolved that. Given the condition of the valvetrain and cylinders this leads me to believe something else is locking up. Time to investigate further. Thoughts?

HOLY SH)(*&)*&!! I just got the engine to turn 1/2 turn then it stopped. Soaked cylinders with penetrant and valvetrain in penetrant then glopped in a quart of 10W40. Let it sit for 10mins then hit it with a torque wrench at 100ft-lb on the crank pulley. I guess it really did seize up hard over the last couple of weeks. Going to keep soaking it until I can rotate to TDC freely. Borescope revealed that crank counterweights and pan were clear of obstructions. I locked the flywheel with a prybar and bolt as my friend torqued the crank pulley bolt to ~100ft-lb. Thanks again to all who have commented on this thread. I've built motors that sat outside for months that still turned over freely by hand when installed. I guess that's what 43 years will do. Probably need a rebuild eventually but until then this motor is getting run hard. Not out of the woods yet but getting close. Will update shortly.

Yep, just checked the cylinders, valves, and timing chain area with a borescope - everything looks fine without obstruction. Cylinder walls looks great with the crosshatching still present. Would share some pictures but apparently I need a micro SD card to do that. Going to take a quick look around the mains next then start dumping oil all over the engine! Also oil pump is new and I haven't even primed the motor yet. I should probably do that next.

Any advice on oiling the mains without dropping the pan? I was just planning on dumping a bunch of oil onto the cylinder head and timing chain area with the valve cover off. Also I just picked up a high resolution borescope. Figured I need to get smarter about this and I've always wanted one for auto/bike work. Am going to peek into each cylinder, valves, into the oilpan/crank counterweights, etc. Should be able to report back with some interesting pictures and figure out what's causing this without tearing the entire engine down.

Double post.

From my understanding from the posts above (and this may be incorrect as there is a lot of misinformation out there on the internets and even by local Z people word of mouth)...the Harada / Kameari gasket should be mounted with the metal backing facing inwards towards the head. My original mounting in post 1 was incorrect. I suck at describing things so just ran out to the garage and snapped a couple of pictures. Correct and incorrect orientations. Good timing as I've been tearing my entire motor apart due to not turning by hand.

Gah, pulled the crank pulley off which was nice and easy since I lubed it all up and threaded the bolt and washer back on then hit it with the torque wrench at 100 ft-lb. No dice. Woodruff key looks as I left it - great. Gotta start pulling more things off later in the week but need to be up early to conduct business. Thanks again to all who have contributed their thoughts. Really hoping I don't need to rebuild the motor here, just want to get it running again and go racing!

Alright, going to really zip off the crank pulley now. Probably pull the timing cover too and catch a movie inbetween while I'm at it. Will report back soon.

Someone commented on this thread earlier that lubrication goes a long way. Any comments on that? Maybe I just need to oil the heck out of the motor/head and try turning again? Still trying to avoid tearing everything back down. Probably the beer talking but I guess on the upshot if I need to drop the pan again I can take the opportunity to pull the crank, hone the cylinders, and throw on a ported head.

Alright so I pulled the transmission earlier and everything looks great. Motor is still absolutely stuck. Torque wrench set at 100 ft-lb on the crank snout will not turn it. Going to throw on the new OEM trans mount and powdercoated bracket then start tearing back into the motor.

So just inspected the timing cover again and it's definitely not jammed. Also I do recall turning the motor over by hand after the crank pulley torque/install. Attached a pic from inspection just now. Going to start pulling the transmission. Not an ideal scenario, but usually it's spend an hour in the garage listening to music while drinking beer and 20-30 mins to actually pull a trans. Will report back soon.

Going to go zip off the crank pulley now and take a look. I do recall inspecting the woodruff key and channel when I did the front timing cover, everything looked great. Pulley went on smoothly as well. I turned it in by hand first before applying torque.

I should also note that prior to replacing the front timing chain cover I checked the chain stretch per FSM by rotating the engine by hand to the marks on the cam gear. Everything was in spec. This was like a month or so ago. Am going to start pulling everything apart here after this beer. I am completely stumped! Only things I can think of are: 1) Engine massively seized after sitting for a couple of weeks (maybe unlikely?) 2) Something binding somewhere (more likely, but what?!)

Just dropped the oil pump to check the timing chain tensioner, hard to make out in the photo but it looks tight on the alternator side of the motor to me. Slack side of the chain has some slack as well. Not sure about keeping the chain tight, was just careful to not bump anything out of place with the front timing cover off. Here is how I went about replacing the seals at the front of the motor: 1) Drop oil pan 2) Impact gun + thread on pulley puller to remove crank pulley bolt + washer 3) Remove front timing cover 4) Replace crank snout seal 5) Bolt front timing cover back in place with new gaskets 6) Bolt in AZC oil pan with new gasket 7) Lock flywheel and torque crank pulley bolt + washer back to ~100 ft-lb with loctite blue Also checked if the motor would turn CCW. Set torque wrench to 50ish ft-lb and attempted but no dice. Yeah, I drained all of the fluids from the motor due to realizing my water pump was vomiting out of the weep hole something furious. No overheating, caught it right at failure. In the process I realized that the block freeze plugs were starting to go along with everything else. This was maybe a couple of months ago (I'm a slacker), but now on the tail end of the refresh process so probably not completely bone dry but not lubricated as in I ran the car yesterday.

Thanks, just took a quick peek at the Tstat housing and bolt looks to be the correct length. Picture attached. Only running alternator belt, but it's on there finger tight (e.g. no tension) at the moment.

Alright so with the transmission in neutral and my housemate fully depressing the clutch the engine is completely locked up. Going to pull the transmission tonight and see what the heck is going on! Will report back with results. I checked for rotation every step of the way since I was mixing and matching parts EXCEPT right before I bolted my header and manifold on . Got too excited. If anyone has anymore thoughts please chime in, really appreciate it.

Ah, that makes sense. My housemate just got home so I'm going to have her hop in the car and depress the clutch pedal while I attempt to turn the engine. Will report back here shortly. In my previous post I used my cell phone video to record the clutch slave moving the clutch fork fully thus depressing the pressure plate. Have not attempted to spin the motor yet with the transmission in neutral and someone depressing the clutch.

So I need to pull my header to remove my transmission. I have not run the engine with this gasket and I liberally slathered the gasket with anti-seize. Anyone think I have a shot as re-using the gasket or should I just bite the bullet and order another?

Did not even need to slide prop shaft in, transmission output shaft rotates freely in neutral between my fingers. Removed starter, flywheel visible still no dice, engine stuck. So I suppose this leaves me with pull the transmission and inspect?

So was not the clutch slave bolts. Also filled and bled the clutch system, and set up my phone to record. Clutch fork movement is superb, no binding and functioning as intended. Pedal feels great, a little more effort than the factory 240z, but everything in the car was leaking before. Engine still won't turn. Going to slide in the prop shaft and attempt to rotate trans in neutral then onto starter. Will report back with results. Thanks for the help guys.

Thanks NewZed, I'm going to give that a shot later today to see if I can narrow this down. I'm pretty sure I used the OEM 240z or 280zx slave cylinder bolts based on the picture above, but I recall recently reading about that potential issue as well.

Hi guys, Looking for advice to turn my motor over which doesn't want to turn by hand with the spark plugs out. Also some pictures to detail some of the steps which I took in case I second guessed something. Everything torqued to FSM spec with Snap On digital torque wrench. So here is the short of the long in basic sequence of events over the last couple of weeks: Engine side (L24 Block) 1) Installed new rear main seal + front main seal + timing cover gaskets - motor turns over fine 2) Installed AZC oil pan + felpro cork/rubber gasket - motor turns over fine 3) Installed 240mm chromoly flywheel + new OEM 2+2/turbo bolts (these are thinner than stock 240) + pilot bushing - motor turns over fine 4) Installed 240mm clutch + PP (9 bolt) - motor turns over fine 5) Torqued everything down to FSM spec + blue loctite including crank pulley bolt since I could lock the flywheel at this point easily - motor turns over fine Transmission side (280zx 5 Speed) 6) Installed all new gaskets and seals - transmission rotates fine 7) Installed short turbo throwout bearing collar and new bearing + clutch arm onto transmission - transmission rotates fine Assembly 8) Installed transmission onto motor along with new 280zx starter and clutch master + slave cylinders. Clutch system is bone dry right now. Did not need to force the transmission on, just lined up the splines to slip on then torque down. After (8) engine does not want to rotate by hand in neutral from the crank pulley bolt and did not want to force it with a breaker bar so left it at that. Am I missing anything here? I should also mention that when I had the front timing cover off I'm pretty sure that I did not bump anything out of alignment in the process. I'm thinking I should pull the transmission and backtrack, but literally just got the header + intake on there and clearances are pretty tight. Have installed many a clutch, transmission, etc. over the years but have never had this issue. Thanks in advance guys, just trying to backtrack and figure out what could be causing the no turn Edit: A couple of last thoughts and points: 1) Both engine and transmission are bone dry right now and has been for a couple of months. Motor was not burning anything. Was running but water pump blew up and every seal on the motor was leaking along with 4 speed going out. Clutch was soaked from both ends due to rear main and transmission seal failures - refresh time. Last time I turned the motor by hand was 3 or 4 weeks ago? I shot some penetrating fluid down each cylinder a day ago when I discovered this (was trying to set motor to TDC to adjust valves). 2) Should I fill the clutch system with fluid and try pumping the clutch a couple of times to see if anything frees up? No idea, just trying to avoid pulling everything apart again. I'm running out of beer and patience.