1Y cylinder head woes.

[SplendiferousII]

My 1Y engine has started to use a drop of water. Its always used a little bit but the liitle bit lost over a 4 month period which brings the light on and the temp gauge goes to full scale deflection is now lost in only a few days or 30 miles or so.

I cannot see any external leaks so I suspect it’s the head which is known to be cracked between all of the valves anyway.

Could be something else like a water pump leaking or just the rad cap needing replacing, yet I suspect the head at this moment in time.

I know I can get a Sniff test done but as I am tight is it possible to do this myself rather than have to pay somebody.

But my main question is – do the cracks between the valves on these engines usually lead to a leak path between the combustion chamber and the water jacket? My guess is yes but I am not 100 sure after all there is only the web between the valves up there unless its cross drilled. I’ve heard said that, cracks in these heads can get so bad that the valve seats fall out mine was not that bad 18 months ago.

Any idea’s

[Snag20]

If all goes well with my replacement cylinder head--you can have my old AAZ one. not sure if it is the same, and could swap over valves/lifters etc.

[SplendiferousII]

Thanks.

Supposed to be going off on holiday with it on Sunday. So am thinking to buy a whole engine that’s on ebay and shove that in on Saturday.

I can buy a sniffer kit for £42 to test the coolant for hydrocarbons but that’s another £42. I’ll empty to back at lunchtime and see if its bubbling in the header tank or even just pi$$ing out at the water pump (that would be nice to see)

Can you PM me your phone number as I have lost it.

T

[HarryMann]

From my experience - cracks so bad that exhaust gases were cross-feeding (polluting)the inlet charge - it wasn't losing water or overheating, as such.
https://club8090.co.uk/wiki/P ... urn false;

However, starting could be bad, and ultimately the gasket usally on cyl. 3 or 4 fails, and then a weep or water-loss starts.

The small cracks between the valves are Ok till they open up or start moving across to the pre-chamber or travelling down the side of the valve seats and into the ports.

[SplendiferousII]

Thanks for that Harry. It gives me renewed hope in that I won’t have to rip the head off this weekend or change the engine out. The cracks in my head were nowhere near as bad as those in your photo’s. There were cracks between the valves on all cylinders but none were gapping but one was steeped (one edge higher than the other) I’ll go outside now and see if I can see an external leak – fingers crossed.

[SplendiferousII]

I have opted for a new radiator cap. Will keep you posted & my fingers crossed.

[HarryMann]

That was my take on it, but really can't say it is generally true or gospel...

What I think did for it in thye end, was the heated and pulluted inlet charge raised cylinder temperatures to absurd heights.. oil temp^^ etc.
Quite remarkable that a new head, honed bored and some new rings and one piston sorted. I still say these are tough old units

One area you might check is all a round the front hoses from solid pipes to radiator, often had a weep there..
Some people say the overflow tanks can weep a bit too

Water pumps seem quite robust, haven't heard of them making a habit of packing up, but never say never.

Another notorious area on JX's are the plastic water outlets from the head, on the side around No. 3... known to crack and weep (someone's asking for one now on't Syncro forum).