Few R30 Questions

[OUTATIME]

some types u cant. but ive used mine (l24) twice now, all gd...

[guska]

Ah, awesome, so what tension then?

[Ghostrider]

Tightening sequence is as follows:

14 10 6 2 4 8 12

13 9 5 1 3 7 11

Procedure, as per manual is: (1) Tighten all bolts to 29Nm or 22ft/lb, (2) Tighten all bolts to 78Nm or 58ft/lb, (3) Loosen all bolts completely, (4) Tighten all bolts same as (1), (5) Tighten all bolts to between 74-83Nm or 54-61ft/lb. Run the car for a while and re tighten if required.

Cheers, D

[guska]

Cheers, would I follow that exact procedure for reusing old bolts? Or is that to stretch new ones? I would be thinking that I would follow that procedure so that the head is perfectly flat yeah? Fisrt time actually doing a head on my own, so I want to make sure I got everything sussed out. Done a few as an assistant, but never on my own. The 30 is the practise pig before I do any major work on the 31.

[guska]

Picked up an N42 head today off of a 280ZX from Blacktown Wreckers for $120. Seems to be in good nick, no out of the ordinary burn marks or discolouration anywhere. Now it's down to the machinist to test it and give it a grind. Not going to take any more off than necessary to clean the face up. If I want to give it more stomp later, I'll strap a 68deg cam to it or something down the track. But for now, stock. All I need is to get to work and back smoothly without the cloud of smoke following me up and down the mountain.

[guska]

[Ghostrider]

As it was suggested, you might have grabbed the wrong head, but first check the distance across the valves and if it's close to the 83mm bore size, your going to have to notch the bores or take it back and swap it for an N47 off a late model R30. Remember the 280ZX has an 86mm bore.

Cheers, D

[guska]

Seriously, I didn't have a whole lot of choice. I was at the "bugger it, I'll just grab a gasket and hope like hell thats all it is" stage when blacktown wreckers reared its ugly head up and happened to have one. I'll go measure.

[guska]

Shit, 86mm across the chamber. but 82mm across the actual valves. What are the chances of it working? And if I try it and it doesn't it's going to bend valves the first time I turn it over isn't it?

[Ghostrider]

Yep! and then they won't take it back. Surely they would have had 84/5 R30's out there too.

[guska]

Is notching the bores a headf**k process? If I gave the machine shop the car, could they do it easy without too much rooting around? Obviously be an engine out job, but is it a motor apart job? Time is beginning to become a factor here, I don't know how much longer this motor is going to last with the head in this condition.

Something else the guy who runs the workshop next door said, was that "it's damn near impossible to crack an L series head" how accurate is this information? Is it more likely to be a gasket than the head?

[guska]

Well, it's crunch time. Wouldn't start this morning, so after making sure all the ignition was dry, I did the next thing on my personal "why won't you bloody well start?" checklist. I pulled the plugs. 5 out of 6 of them were wet with oil, and the one that wasn't was black. Cleaned them all and scrubbed them down, making sure I didn't move the gap (done it a few times over the years now, getting good at recycling plugs). Bung em back in, turn it over, nothing. Pull a plug out, wet again. Look closer, fresh load of gunk down the side of the block coming from between the head and block. Now using my own brand of backyard logic, that, and the fact that it was blowing a butt load more smoke on friday than normal (like, I had a cloud following me that I you couldn't see though), tells me that the head gasket has had a guttfull and blown out properly and is has filled the chambers with a lovely oil/water mixture. Have now ordered a gasket and manifold gasket from Repco, which should arrive Thursday. I then get to play the "oh dear god let it just be the gasket" game.

Now... what do I use to get the gasket off of the head and block without putting huge divots in them? As machining is for the moment, completely out of the question, and the current head has to go back on as is (sans whatever crud is in the journals).

[noddle]

Now... what do I use to get the gasket off of the head and block without putting huge divots in them? As machining is for the moment, completely out of the question, and the current head has to go back on as is (sans whatever crud is in the journals).

I use a sharp 1 inch wide wood chisel, you need to be careful not to mark the mating surfaces, but it work well if you take your time and don't rush it.

Nigel

Edited June 10, 2008 by noddle

[Ghostrider]

A single edge razor blade and holder is also a good thing, you can get a box of 100 blades from Office Works or any cleaning supplier, or maybe Bunnings.

[dodgsun]

amd make sure you dont drop any gasket grud down the water holes...or any holes!!!

[guska]

Gah! Plans change too much! I'm rip[ping the head off tonight, and my mate is going to stick it in the A1 priority list, so I can have it machined and ready to slap back on by saturday. Will be alspping it on on sunday. The original head that is, not the 280 one.

[OUTATIME]

that is only if its not corroded out inside...

[guska]

Well, after a big effort by myself and 2 31 club members (both mechanically minded and experienced), we managed to snap 3 head bolts off, discover a rounded off manifold bolt, an inaccessable manifold bolt, remove the bottom shield with side cutters, get completely filthy, lose the throttle linkage split pin, lose several bolts and nuts (should be able to find them) bang innumerable fingers, make a huge mess, get wet, pull off a few hoses, become completely jealous of small Asian fingers, pull off a heat shield, and get a lot of shit in my eyes and mouth. AND THE F***ING HEAD IS STILL ON! IT SHOULDN'T BE THIS F***ING HARD! Time to get a tow to a professional to have the head removed. Let someone else get crap in their eye. Then I need to address the issue of the snapped off bolts in the block.

*runs off to go look at tool catalogs*

[OUTATIME]

lol sounds like ya had fun. should only take 1-2hrs to get the head off normally. leave the manifolds on as well, easier 2 get them off once the head is off.

[guska]

yeah we worked that one out afterwards. Going to grab a couple ballpark quotes today. Either that or I'll have another crack on Sunday.