Just my luck due for rego in a couple of days :(
Last week I had blown the head gasket pretty bad well I think,
So today I stared doing the head
Need some help the car is a 81 b310
Just some info is this all normal stuff?

All 4cyl where full of water when removing head?

At the back of the head near the firewall there is a 90 degree water outlet
(Going to the heater unit inside the car)? I think? This was blocked
The head gasket had blown out on the cyl that is closest
To the firewall next the to blocked outlet, could the blockage have
Caused the blown head gasket?

If what I'm talking about is the heater unit, will it now be busted?
Or fully blocked up?

Also any ideas on trying to get a snapped head bolt out?
Without pulling the motor out and taking it to the shop.
Snapped in the middle of the head closest to the intake
Snapped bolt is hanging out 10mm

Any type of help will be awesome I'm in a bit of a rust to get this done for rego :(

Cheers shaun

Sounds like you've had some crap luck, I hope it turns around soon :/

To answer your questions...

Yes, the 90 degree fitting behind the head is the outlet for the heater core. It shouldn't have caused the crack in the head as you can plug this and run without a heater unit no worries. If it looks blocked now, chances are it's clogged up the heater core, so I'd suggest pulling it out and giving it a good clean along with the heater cock and other hoses. The unit should work fine once it's clean and put back in.

To get out the snapped head bolt, my first attempt would be with an Easy-Out. Failing that, if you were skillful with a welder and you had enough bolt exposed, you could weld something on the end and use that to remove it.

Good luck!

The heater outlet can be plugged with no ill effects. In fact, Datsun plugged it at the factory for cars that did not have the heater option.

To remove the bolt, first remove the cylinder head. With that off, you can get vice-grips on the bolt and turn it out.

With water in all four cylinders, you may have a warped head. This happens if the engine severely overheats. Severe overheating causes the head to warp severely, and if so the head must be replaced. A minor overheating won't damage anything. In any case when you get the head off, place a straightedge on the face of it, and see if a 0.004" feeler gauge will fit in between the head and the straightedge. If not, the head is good as is.



Changing Head Gasket

Ok heater unit is blocked right up, head is being overhauled
Now for the bottomend, may as well get the shop to pull the
Snapped bolt,
While they are at it drop in a fresh regroud cam

How agessive can I go with a regroud cam?

Will be running 4in1 extractors
Dcom 40 single sidedraft weber with 28mm chokes
With a fresh rebuilt head

If you do the cam, don't forget to have the cam followers refaced at the same time.

Yes, new or refaced lifters are very important, otherwise the new cam won't last very long.

You can go as aggressive on the cam as high as you want to rev the engine. If you do not want to rev it over 6000 RPM, just keep your original cam.

Ok cheers guys i mite start a build thread for some ideas, I've been smashing up the wiki
But head is about to explode I'm not the best with this engine building stuff, will be a first time thing,
But keen as to get it done and finished
And while the motor is out I wouldn't mind doing some work hear and there to improve its perforence and get that auto gear box up and running.
20km/h foot flat up hills atm