Gasket & Temp Questions

[Rob5464]

In anticipation of resurrecting the beast I have two important questions.

I am fitting an after market temperature gauge seen as the standard one has similar accuracy to that of ####ing in the wind.

What is the correct running temperature? What temperature is concerning/damaging?

I can set my gauge to alarm above a certain temp which is pretty useful.

Would it not be better to put a cheap gasket on instead of a higher quality one?
I know it sounds like a stupid question but logically speaking; if a weaker gasket is installed then its more likely to give in before the head if (god forbid) it overheated again. If it doesn't overheat again then the the gasket shouldn't let go anyway regardless if it is cheap or not.

Correct me if I am wrong?

[tweak'e]

no point in cheap gasket. it can let go even on a perfectly fine engine.
quite a few have had problems with the cheap Chinese rubbish.

[shokenore]

You do not say what you are rebuilding, so assuming it is the head, do not scrimp on ANY of the components.
Do you know the condition of the radiator?
Do you know the condition of the water pump?
If the pump or the rad are suspect then it will only be a matter of time before the coolant temps start creeping up.

[Bogus]

In anticipation of resurrecting the beast I have two important questions.

I am fitting an after market temperature gauge seen as the standard one has similar accuracy to that of ####ing in the wind.

What is the correct running temperature? What temperature is concerning/damaging? 1, 80ish 2. 110

I can set my gauge to alarm above a certain temp which is pretty useful.

Would it not be better to put a cheap gasket on instead of a higher quality one? NOI know it sounds like a stupid question but logically speaking; if a weaker gasket is installed then its more likely to give in before the head if (god forbid) it overheated again. If it doesn't overheat again then the the gasket shouldn't let go anyway regardless if it is cheap or not.

Correct me if I am wrong?

+ Wot he ( Shokenore) said about making sure the cooling system is tip top including viscous fan performance.

[Rob5464]

Thanks guys, I am doing the head, AMC one, plus too bent roads to replace so the engine is coming out. I will check the bearings too before I go ahead.

I have a new water pump and belts.

I have the rad out and from what I can see its in a reasonable shape. Any way of telling if its a Toyota one? As in the original? Part number somewhere?

Fan is off too, might put slightly thicker fluid in it as some others have done. Considering an inter-cooler too.

I got the after-market gauge so hopefully any problems that occur will be caught straight away. Not taking any chances.

Engine should be out next time I go down to the yard its at. Just whatever is underneath to unbolt/mover out of the way. I have not had a detailed look yet. Oh and some pesky wiring between the starter and the block I can't quite get at.

I was just hoping that I could design a weak point (the gasket) so it blows first as opposed to the head. Gaskets are cheap heads are not. But I don't want to be changing them like brake pads ether.

Its quite a learning experience as I have never undertaken a big job like this before. I appreciate the advice so far.

[shokenore]

As far as I am aware you will have little chance of engineering an early warning device to detect a head issue, if whatever system you devise actually works, when the damage is done you won't be able to stop it, think along the lines of an exothermic reaction, when the right conditions are met you ain't gonna stop it, you can only contain the damage.


Far far better to ensure the cooing system is in tip top condition, and the replacement parts are also quality parts.

As the classic signs of head failure are bubbling in the expansion bottle and sweet smelling exhaust, you would need to look at these.

Perhaps a high level warning sensor in the expansion bottle would give you a warning but if it is already starting to pressurise the bottle the damage has already been done.

[Rob5464]

I will make sure the pipes don't leak when everything is on, new genuine thermostat and pump have already been fitted. Viscus will be given treatment and the rad will be checked again.

I understand what you mean, but unless its very high mileage the head shouldn't crack unless it gets too hot from failure of another part. Which is where the gauge will come in handy. I am not relying on it but its a good lifeline. I can look after the cooling system but its not possible to predict failure.

One thing that has come to mind is what happened to it when the head came off.

From the beginning when I took it off the road the engine ran nice and smooth. I had someone else replace the head (the bent rods were not spotted). When it was started it ran like an alcoholic pig and made enough smoke to cripple the ozone layer. I still do not know why this happened. Originally I suspected poor timing but he assured me it was correct. He tipex marked it for when he had to put the belt on and it lines up with the engraved markings, all be it just.

I turned a blind eye to this at first but I don't want to have the engine back in then find its still ****ed.

[shokenore]

He/they didn't spot bent con rods run the fcuk away from them.
How would they have turned the engine over to set the timing?

Are you sure they are not responsible for the further damage?


Or are you sure the rods were not already fubared ?

[Rob5464]

I originally only took it to him as I was hoping it was a straight forward job and it was a good price. After the incident the head came back off and upon finding the bent rods I took it away to sort out myself.

I have no idea what they could have done, The head seems undamaged and bad timing couldn't have bent them.

I was suffering from pretty bad locking up when starting it; because of the water in the chambers. So I put it down to that.

The rods are only 2mm or so off coming up flush. I just don't see how they could have bent them from the work they carried out.

[Rob5464]

Engine is at home, making progress now.