P79 Head Stuck to Block, Please Help!

[grannyknot]

I would go straight to having a competent welder MIG a nut on to what is left of that stud, failed attempts with vice grips can chew up what is left of the stud pretty quickly.

[Zed Head]

I spent a lot of time cleaning the area at the base of the bolt of rust so that the PB Blaster could sit in a groove and seep in.  Also cleaned up the sides of the stub and filed flats in it so that my Vise Grips would get a firm purchase.  Then, when trying to turn it, never forced it.  Once I got some movement I worked it forward and backward, to work in more lubricant and break up the rust.  I waited a lot also which you might not be able to do.  The basic message is - don't use brute force.  It already broke once.  Even if you weld a nut to the stub, you can still break it so be careful.

[NMcKe97]

Glad to here I picked the right gaskets, thanks for the affirmation siteunseen!

I'll make sure to look around and find the best quality timing kit and grab the assembly lubes you recommended, thank you for the heads up. I'll be honest I'm not familiar with when and when not to apply the lubes and sealers etc.. I believe I'm not supposed to use anything for my head gasket, but not sure about any of the other steps, I'll have to read around.

Thanks gwri8, I'm glad to finally be moving on haha. I guess if I didn't get my fill of fun with the first part I'm going to now.

I've been trying the vise grips and I've also been using pb blaster and liquid wrench with some hammer hits here and there but nothing yet. I'll make sure to be real gentle and slow as well as wiggle it back and forth.

I was considering using a Dremel and cutting a line in the bolt then using a flat head bit and wratchet to loosen it, what do you guys think?

I cleaned the surface area and jury rigged some tape as a bowl around the bolt. I then filled it with liquid wrench to soak until next weekend when I'm back. I also picked up a new propane bottle but forgot to bring the nozzle so I won't be able to try that method tell next weekend as well.

All that and lots of prayers like you're saying grwi8 is definitely what'll do it! It got my head off it'll get my bolt out!

It's definitely a good life skill to have, that was a big reason I wanted to learn all this. Plus it saves a lot on money and gives you rest of mind in the quality of the work.

There is probably a little over a cm sticking out so I'll make sure to take it easy with her, thanks for the fore warning sweatybetty! Definitely don't want to end up going down the road to drill world haha!

I'll make sure to keep an eye out for any steering pump fluid once she's back up and running, thanks for the advice Reptoid Overlords.

I'll look into local welders but in the mean time I'll keep trying, thanks for the advice grannyknot.

Yea I decided since I'm already in here I might as well go the rest of the way. I'm going to use all arp hardware top to bottom and replace or upgrade anything else I can while I'm in there. Im thinking if I can afford it new pistons and connecting rods(sell the old ones), new valves(sell the old ones if condition allows it), new oil pan, new throw out bearing, all new vacuum coolant and fuel lines, new timing chain kit if needed, and a new water pump if needed. What am I missing or would you guys recommend?

Then I need to get the transmission rebuilt(1st and 2nd bearings are going out and it feels like most the synchros are on the way out to(maybe gm synchromesh with friction modifiers will help)), all new suspension and bushings(you wouldn't believe how bad it is), some body work and then she'll be good to go, for the most part.

Yea from what I read most the mods won't make a big difference if at all until I get an independent ecu. Unfortunately I don't have money for that right now so I'm just being proactive and doing the work I can while I'm already in there.

I have the car in front of my friends house and his dad wants it moved so I'm going to see about relocating it next weekend and continue from there.

My car was previusly in pretty good running condition with smaller problems here and there. I ended up having to tear the head down due to a severe head gasket leak I got in cylinder 1.

My heater core blew out one night and over heated almost right away. I obviously shut it off right away but it still reached higher than normal tempatures. A while later I severed my coolant feed line while on the freeway when my alternator belt broke. I pulled over and turned it off immediately but it overheated again.

At the time I was much less experienced at car work so I took it to a mechanic. Not my normal mechanic either. They fixed the coolant line and pressure tested the system to check for other leaks making my head gasket leak bad enough to steam out the exhaust.

I noticed as soon as I got it back it was puffing white out the back. So this time I decided to take it to someone more "experienced", I took it to the aero automotive z "experts" in San Diego.

They tested the pressure the day I dropped it off and called back saying everything was good, they didn't warm the car up to tempature was the thing though.

They then left the car under pressure all weekend. Come Monday they decide to try and fire it up instead of drain the coolant from the block despite being told there is a headgasket leak. It almost resulted in a bent rod according to their mechanic.

After being bidded a 2200-2500$ head gasket repair bill and them trying to get me to sell my car to them at a almost guaranteed lowball offer I took my car to my normal mechanic.

He advised I try using k seal. So I sure enough try that out and it briefly worked but the leak slowly returned.

I unfortunately had to continue driving, due to life cirumstances, with the leak and eventually stopped when it reached a point I felt was going to lead to detrimental damage.

After sitting for several months I finally got it towed a couple weekends ago and now here we are.

I believe my profile has a more in-depth description about the car if you're interested. (EDIT: I guess my profile info didn't save when I made my account so I will have to re update that when I get some free time, sorry.)

Thanks as always for all the advice, feedback, and info! - Noah M

Edited July 31, 2017 by NMcKe97

[NMcKe97]

[Mark Maras]

 Have you turned the engine over and inspected the bores? If they look good, I'd think twice before opening up the bottom end unless, at some point in time, it lost oil pressure.

[siteunseen]

The next rainy day I can go into better detail on what I've learned about theses L motors. I've rebuilt dirt bikes and outboard boat motors, both two stroke without valves and an oil pump. Never rebuilt a car motor.

I bought a book "How to rebuild L series motors" by Tom Monroe from amazon.com for less than $20 bucks. I rebuilt the first ever without any problems. That book and help from guys on this forum and I have a great running 280Z.  Then I got into 240s and carburetors. Rebuilt a 2.4 L motor that also turned out great.

Very anxious at first but the book and the helpful folks here got me through it and I've never had to look back. I try my best to help people now from what I've learned. These motors are super easy to work on you just need some direction to get going. 

[NMcKe97]

I haven't turned the engine over yet because of the debris that fell into the cylinders when working on it, but from what I can tell the cylinder walls still look healthy, clean, and appear to have the cross hatching from the factory. It's never dropped oil pressure, atleast under my ownership, and I feel like I'd be able to tell if it had lost oil pressure, correct me if I'm wrong.

Mark Maras and Zed Head why do you guys advise/recommend against a lower end tear down? Wouldn't it make sense to replace what I can while I'm in there or are todays replacement parts inferior to the original quality?

My Z has 168k miles on it. It was originally owned by my step fathers dad then later given to my step dads brother who eventually put it in an airplane hanger for 5-8 years with all the fluids in it and a damp environment. My step dad eventually acquired it from his father when he passed away and took it out of the hanger. After a number of repairs and auto body work my step dad had it up and running mostly healthy!

Fast forward to Christmas of 2014 and that's when my step dad so graciously surprised me with my first car! It had 136-144k miles (big range sorry) at the time and was still in need of repairs here and there. Since I've owned it it has had a number of repairs done on an almost routine schedule, if it's not one thing it's another.

I try to take care of my Z, always performing routine fluid changes, only using quality products, letting it warm up, not revving it in netrual, the normal schpeel. I definitley like to "drive it" to though if you know what I'm saying, so there's imaginably a fair amount of wear the engine has accumulated since I've owned it and over the last 36 years/168k miles.

I plan on getting new, stock, flat top pistons for roughly 300$. Then I'll  clean up and sell my old pistons to make back some money. I was looking for connecting rods but didn't see any in my price range so I'll just reuse mine and upgrade the connecting rod hardware with arp bolts.

Would it be worth while and cost efficient to have machine work done on the lower end? If I have it out I'm under the impression I might as well go the whole way. If I don't rebuild the lower end what is a guestimated lifespan, 200k more miles if that? I just don't want to be redoing work if I don't have to. Plus I'd really like to learn all that I can while I'm in there.

That would be awesome siteunseen, I'd love to get the run down on the L series from somebody knowledgeable such as yourself! If you ever get the free time and are able to get around to it feel free to pm me or leave a reply on here with all your insightful knowledge!

It sounds like you got a damn good idea of what's going on in the realm of mechanics!

I had actually considered picking up that book but never got around to it. Guess I found my next read haha. Yea anxious is an understatement in my case, I was dreading the tear down pretty bad but now that I've done it I don't know what I was so worried about. Exactly like you said siteunseen, it's all pretty straightforward, just helps to have visuals and a little advice from others. 

Thanks again everyone, you guys are awesome! - Noah M

Edited July 31, 2017 by NMcKe97

[Mark Maras]

 Reply to post above. As you stated, you can still see the cross hatch pattern in the cylinder walls. If the bores all look that good, and you're not trying to up the compression with new pistons, why bother tearing it apart all the way. Using a micrometer to measure bore taper would be a good idea. If the block is out, I'd take a look at the main and rod bearings as well as the crank but I wouldn't expect to find anything wrong. More just a step to reassure myself. If, however, you do decide to tear it down, be sure to pay extra attention to the coolant passages in the block. They are notorious for collecting deposits on the walls. IMHO, all that money in a new engine when used in a daily driver could be better spent elsewhere on the car. BTW, if you really want to enjoy the car as a reliable daily driver, keep everything as stock as possible when it comes to the engine and induction system.

[gwri8]

The old saying "If it ain't broke, don't fix it " comes to mind.  You've mentioned money and tools being in short supply right now.  Your current project project is going to set you back 6-800 bucks in parts and service.  Engine builds cost. Tools cost. Time costs.  Judging by the location where you pulled the head and given the lack of garage/storage space, I don't know how you will get the block out now that you've pulled the head . I would offer that you finish what you started with the head and when it is successful,  then look at picking up a used L28, put it on a stand and rebuild at your leisure while you drive your Z.   Just my opinion.

Edited August 1, 2017 by gwri8

[newtonhubcap]

You likely have removed the broken bolt. Typically one can clean the shaft of the broken bolt and the wedge a nut on it and then weld it. Once cooled then take a 50:50 ratio of acetone and brake fluid. Start wetting the bolt and hole with the solution. It will take a bit of time for it to work its way down the threads. This has worked well on numerous broken or seized bolts.

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