Head Removal questions

[red_dog007]

Well, today I started getting into my Datsun. Taken some of the accessories out and the radiator out as they all are getting upgraded. Now, I need to take the head off to replace a gasket.

The manual wasn't very clear about it so how abouts do I go about doing it?

Can I leave the carberators on or do they need to come off first?

Where do I discount the throttle linkage?

What am I supposed to do with the timing belt? How and where does that come off?

Are the head bolts under the Valve cover?

Then tensioner for the drive belt, show I replace that while I am in there. I am going to be replacing the springs, rockers, ect. and upgrade the cam.

[240ZX]

With all due respect......If you can't figure it out by just looking at the engine assembly, don't attempt it on your own!!!! Get someone with mechanical skills to help you.

Tom

[280~Master]

What manual do you have? FSM should tell you everything you need.

[240znz]

Good advice from Tom and John.

Get a FSM as a minimum.

Timing is done by a chain. If you want to replace the tensioner, you will need to remove the front cover. If you do that, you'll need to buy a full front cover kit which includes the gaskets and seals you'll need. Now if you are replacing the tensioner, it would be wise to put in a new chain, sprockets and guides. Thought about water pump replacement, nows the time for that decision, I'd do it.

Check the front cover for corrosion around the water pump area. Get it welded up and resurfaced if it looks like it could do with it or find another in better condition.

If now you think you want to leave the front cover on, just make sure you make up a block of wood in the shape of a wedge to jamb the chain. This will stop it from dropping down which results in the tensioner popping out. Which of course means that you'd need to remove the front cover.

[Nissanman]

...make up a block of wood in the shape of a wedge to jam the chain.

I suspect that you may need to remove the front cover to renew all the cam timing parts.

Your call.

Anyhoo, here are the dimensions for DA WEDGE:classic:

[JimmyZ]

Can I leave the carberators on or do they need to come off first?

Where do I discount the throttle linkage?

What am I supposed to do with the timing belt? How and where does that come off?

Are the head bolts under the Valve cover?

Then tensioner for the drive belt, show I replace that while I am in there. I am going to be replacing the springs, rockers, ect. and upgrade the cam.

Since you're changing the cam the answer is YES. You will need to remove the intake and exhaust manifolds. Removing valves on a bench is easy... Easier when you don't have to wrestle with the manifolds and head.

I've always preffered yanking the engine and replacing all of the gaskets and seals. It's actually easier this way. If you should break a bolt/stud and need to drill it or weld a temp head on it having the thing outside the car is easier. There's also a chance that simply swapping the head will leave you with a minor oil leak. When you remove/replace the front cover the pan gasket may get damaged.

When the front cover is off you might also have debris fall in the front end of the oil pan.

To me it's a good idea to replace all of the studs for the manifolds with new ones. (At least the exhaust) The exh studs get a little brittle with age. This assumes that you're removing the manifolds.

You could feasibly leave the intake and exhaust manifolds on the head if your'e just swapping a gasket. (Which you are not) Just avoid getting any crap on your new head gasket. (Things that may fall off of manifolds)

There's a chance that you'll break a head bolt. The way the arrangement is penetrating lubricant has no way of reaching the head bolt's threads. Since they are high tensile bolts they are hardened and can't be drilled with regular drill bits. A carbide drill in a milling machine might do the trick. A trip to a shop with an EDM would probably be in order. (Electrical discharge machining = zap the bolt away) I had enough of the bolt protruding to weld a nut to the broken bolt. The heat from welding also aids in freeing the fastener.

It's only $100 to replace the timing chain set. I'd do it on any engine that had seen lots of miles. The timing chain setup is very reliable but I don't want to find out how far it can be pushed.

2c

Jim