L28 About To Pull The Head, Any Advice?

[2sixTZombii]

Alright so since the last I posted up here, I blew the L26, road tripped 5 hours to pick up an L28 load it into the lidless trunk of an oldsmobile and drive it back. Then I stripped it down did several new gaskets, and painted it. Threw it in the Z with DGVs and after a month of fighting with them, bought a rebuilt set of round tops, ups broke those , so after a huge debacle with them repaired them and installed them. It ran awesome but kept dying randomly, seemingly because of a gas tank issue. Dropped it had it hot tanked again, and sealed it with red kote. I proceeded to put about 400 miles of awesome daily fun on the odometer in a space of about 2 and half weeks . Blew a coolant line, overheated her, and blew the head gasket. My recently dead temp gauge helped facilitate that. Sooooooo I'm off work till the 6th, my head gasket kit is waiting, and my chain wedge will arrive tomorrow in the mail. Anyone have some especially good advice? Tips or good write ups to read? I've done a ton of searching and have read some really good stuff, but figured an update was in order regardless, and extra advice never hurts. Here's a recent pic of my baby, and a shot of how I got my engine home.

[siteunseen]

Here's the one I went by, http://www.classiczcars.com/topic/39674-77-280z-head-removal-step-by-step-photos/

 

That chain tensioner tool makes all the difference in the world.

[grannyknot]

Sounds like a bit of a nightmare, you might want to do a complete coolant flush of the engine and rad right now while it's still running, diluted CLR worked well for me. A new Nissan thermostat.

[rcb280z]

Diluted CLR? Hmm...I will have to try that.

 

Bag and label everything that can be bagged.

Edited March 27, 2015 by rcb280z

[rossiz]

you've been busy.

 

if you overheated, it's very possible that the head warped - been there. a new head gasket won't fix that. when the head comes off, you can pull the rockers out (keep them organized by cam lobe in an egg box) and see if the cam still spins freely in the towers. any resistance and your head is likely warped.

 

it's also possible that your coolant passages are filled with crud. the situation: small leak, owner tops off w/water over and over and eventually there's not enough antifreeze in the mixture to prevent rust. then a "stop-leak" additive is put in, which is gloopy stuff that plugs the leak, and happy owner drives on having "fixed" it. meanwhile the block continues to rust, and rust particles + gloop = sludge which can block water passageways - been there. when you have the head off, check the water passages and flush if needed. i yanked my frost plugs and used a pressure washer, which blew gobs of crud out of the motor. 

 

head bolts, if 40 yrs old and never been messed with, can freeze up and break when removing - been there.

you can re-use 'em, but for $60 (courtesy nissan) a new set is great insurance from having them break on the way back in. either way, use anti-seize on the threads.

 

beware the "hole of doom" - stuff rags around the timing chain to keep a bolt or tool from dropping down there, otherwise it's a loooong job.

 

when the head comes off, keep track of the locating dowels in the corners - they are pressed in to the head, but may pull out/fall out and you need them - been there.

 

i've got some threads on this, mostly showing the things NOT to do...

[2sixTZombii]

Weird thing is when it first happened it was only leaking oil into the #6 cylinder, but no white smoke. It still pulled good compression numbers, so I was thinking valve seals.but then I tried to start it and number #6 hydrolocked, I pull that plug cranked it over and shot coolant and oil everywhere. Won't know to much till the heads off, so I better get to work!

[2sixTZombii]

Well heads off, my chain tool worked awesome, but bolt number 14 broke........ spent all day today today trying to get it out to no avail. The rest came out easy, that one, put a little torque on it and snapped.

[siteunseen]

Uh oh.  Maybe it's not too deep?

[rossiz]

i feel your pain. i was lucky enough to have a bolt break with 3/4" sticking up and got it out w/a pair of vice grips.

if you need to drill yours out, be sure to tape off everything to keep metal particles from getting into the bores, as well as water jackets, oil passages, etc.

[71Nissan240Z]

It seems like if the engine has never been touched it will break head bolts. All of the heads I've pulled at the junkyard (about ten ) only one of them I broke a bolt and it appeared to be all original and never been apart.

[240260280z]

Scrape away any corrosion with a scribe then squirt a 50/50 mix of acetone and ATF at the margin where the broken bolt meets the block.

Tap on the remnants of the bolt with a small hammer. (assuming it is above the block surface).

Do this for at least a 2 hour period every 15min or so then try to grab onto the bolt remnants with tightly clamped vice-grips and turn.

Edited March 30, 2015 by Blue

[rcb280z]

I helped a friend with the same situation a couple years ago and we used ATF, heated a few times hoping it would help the ATF to penetrate the threads and then grabbed it with the monster vice-grips and that did the trick.

Good luck and keep us posted.

 

Hope you have enough of the bolt exposed to grab onto! 

Edited March 30, 2015 by rcb280z