Series 3 Pressurising Coolant?

I have looked through the previous threads and no-one has answered the issue I may have, I have got the 2.5 N/A up and running in the series 3 rebuild and left it idling today to see if all is well.
It has the original coolant system and the temp gauge is wired up but probably not accurate as its the 2.5 one and not 2.25 as the binnacle gauge wants . It does register temp but seems to say its cool when the hoses are hot. It looks to me like the hoses are bulging slightly, is this normal, its got an 88 deg thermostat and that seems to open ok and it doesn't overheat, no head problems etc.
Any ideas welcome..........

It's normal for the coolant to be under pressure, look at the rad cap, it will say what pressure it is set for. Hoses bulging slightly, again probably normal unless they are getting soft with age in which case replace them with new. Excessive pressure will cause the coolant to be violently ejected, this is usually a leaking head gasket, a faulty thermostat or possibly a cracked head.

The reason for the coolant working under pressure: the higher the pressure, the higher the boiling point.

Get one of those infra red thermometers, they're only about a tenner. Find out what the temperature of your engine is, in your case it should be about 88 degrees, (the 'stat temperature).

Ok thanks for that, I thought it was ok but just wanted someone elses thoughts.

It should only pressure up to the rad cap pressure. If it goes any higher the rad cap will allow it to vent to the expansion tank. Once cooled it should suck back into the rad. Its not a huge pressure either. If its going too high replace your rad cap and check the overflow from expansion tank to floor (the one with the very tight bend in it). This can stop the pressure being released from your tank and building up in the system. It shouldnt be enough to bulge the hoses.

I recommend that everyone driving an older Land rover fit a capillary temp gauge with the reading in numbers on the face and know what temperature their motor is running at.

tottot said:

I recommend that everyone driving an older Land rover fit a capillary temp gauge with the reading in numbers on the face and know what temperature their motor is running at.

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Durite ones are good and are pretty cheap aswell

Any temp sensor can only tell you how hot one spot is. Getting to know how the gauge reacts and knowing how the engine runs in different circumstances is more important to me.
I don’t have a block sensor at all but have a readout of the coolant temp. Accuracy is unimportant as long as my reading stays consistent. The sound, smell and feel of the engine alerts me to the gauges to see if things are overly hot.

Good old seat of the pants stuff Bobsticle,you are right.Trouble is most today do not know what to feel for as the drivers of modern cars are so insulated from the engine bay.
Had a starter keep running on my tractor the other day,only found out when I stopped the engine. Would have known straight away on my series.

Bobsticle said:

Getting to know how the gauge reacts and knowing how the engine runs in different circumstances is more important to me.

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Thats my thinking as well, I have however ordered an infrared temp gauge off tinterweb so if its getting too hot I will know.

Read an interesting article recently - I'll see if I can find it. jist of it was that one of the US car makers always fitted rad caps that had the vent without a spring so the cooling system only pressurised once there was an outflow. Appearerntly now 40 years on these systems are lasting better than the ones that had a sealed type cap.

Bobsticle said:

Any temp sensor can only tell you how hot one spot is. Getting to know how the gauge reacts and knowing how the engine runs in different circumstances is more important to me.
I don’t have a block sensor at all but have a readout of the coolant temp. Accuracy is unimportant as long as my reading stays consistent. The sound, smell and feel of the engine alerts me to the gauges to see if things are overly hot.

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Smell is a big thing, too hot metal and oil has a very distinctive smell.

Good tip this.