Morris Minor Owners Club

Help!

I am just about to install an Ital 1300 engine into my moggie, but want to upgrade the cooling system with a more modern radiator (with higher pressure cap) and Feed & Expansion tank etc.
Has anyone done this please? and can you tell me what will fit?
Can't find anything on this other than Owen Burton's recommendation to use an allegro rad etc. Try finding one of those.
Any help would be most appreciated.

No need - the standard Minor radiator is more than big enough - and higher pressure is just a mistake. Add a catch tank to the overflow if you wish - and with the correct cap it will suck any water back in when it cools.

Many thanks bmcecosse. I may well go down that route. thank you.

In our 1380 we ran the original standard radiator, with no expansion tank, until about 5 years ago, when age caught up with it (~50 yrs old!) and it was time for a re-core. I did take the opportunity to have a 'modern' core put in (still no expansion tank) and also a neck to use the later, shorter, pressure cap as there are more options available. I used a 7lb cap on the original and a 10lb cap now, as I believe that a little more headroom until it boils is no bad thing.

I agree that a standard radiator is more than adequate for even a modified 1275, and much easier to fit than something 'foreign'. Our 1380 produces 3 times the power, thus heat, of the original 948 engine, so the original radiator has loads of spare capacity!

We were travelling very slowly, often stationary, along the M25 in August 2003 (with the original radiator) near Heathrow when the temperature hit 100°F (~38°C) - lots of 'moderns' on the hard shoulder, but the Minor kept around 95°C with the electric fan running continuously.

Over the temperature range around the boiling point of water (100°C), for each lb/in² above the ambient pressure, the boiling point increases by approximately 1.7°C, decreasing to 1.3°C at 15lb over. This means that with a 4lb cap the boiling point is 107°C, 7lb is 111°C, 10lb is 115°C, 13lb is 118°C and 15lb is 120°C.

Very many thanks for your input IslipMinor. Could you tell me which fan and thermostat you used please?

The thermostat is 82°C year round and the fan is a Spal 9" fan VA07-AP12/C-58S (Soffiante/Blowing). The fan is 52mm thick and attached to the front of the radiator with a standard Spal 'pin' kit. It fits very neatly in behind the grille - you can just see the label on the fan in the signature photo! After disconnecting the fan electrics (2 wires), with care the radiator and fan can be removed in the normal way.

The fan is controlled by a thermo switch in the radiator (boss was soldered into the header tank in 1998) - it cuts in around 90°C and out around 80°C. The thermo switch operates a relay that switches on the fan - it is fed from a fused 'permanently on' supply. In normal use the fan does not come, unless in slow moving traffic, but once the engine has stopped and the hot water rises to the top of the system, that will often start the fan running while the car is stationary and no engine running.

No mechanical fan is fitted, but a spare blade is kept in the boot!

So Mr Islip, to be sure I understand you properly, a 7lb per sq in cap is suitable on a normal 1098 engine, radiator, pump, heater and pipework without fear of leaks etc. Like you I like a bit of temperature headroom and I'd like a bit more because I fancy raising my 89C thermostat to a 91C or thereabouts.
Regards, MikeN. (With apologies for the intrusion to Mr Slugger.)

Mike,

I ran a 7lb cap on the original 948 engine for 20+ years with no leaks, and after the restoration ran a 7lb cap on our 1380 initially, then with the re-cored radiator a 10lb cap for the ~last 5 years. Again no leaks.

I don't know the condition of your hoses, heater, radiator, water pump etc., but if they are all in good condition, then there is no reason why a 7lb cap should not be used.

I have never run a 90°C+ thermostat, so cannot comment on that, but am trying an 88°C at the moment to see if all OK. So far so good, it has been used on two track days, and temperatures of water and oil were both normal, and this last weekend we were in a classic car parade around Wem that moved at a snail's pace for about an hour - water temperature stayed constant at 88/90°C with the fan on, so I am going to leave it in.

There is absolutely no need to upgrade the radiator when fitting a 1275cc motor.
Attached is a picture of my Minor when fitted with a 1400cc competition motor and you can see that the radiator is standard Minor.
There is more than sufficient spare heat exchange capacity in the Minor radiator to cope with a standard 1275cc engine.
The radiator cap was a plain cap with no spring (Mini Spares Pt No: GRC126). The car was fitted with a expansion tank which had a 13lb radiator cap (Mini Spares Pt No: GRC1111).
The Minor radiator in good condition is more than capable of accepting a 13lb radiator cap.
The thermostat was removed and a thermostat blanking sleeve fitted (Mini Spares Pt No: 11G176).
The car was run on the road with a tuned 998cc motor (and same cooling set up) giving about the same power output as the standard 1275cc engine and never gave any problems even without the fan blades fitted. If the car engine started to get warm the heater was activated to provide additional cooling.
Again there is no need to upgrade the radiator.
Phil[frame][/frame]

Thanks for all the input guys. It's been really useful. I shall definitely stick with original rad, albeit re- cored. Much appreciated.

G,day all
Slugger - if you are going to have your rad re-cored you might consider having them install a short neck filler in place if the tall one. This would mean you could revert to a recovery system if you wished. Recovery caps are not availamle here in oz for tall neck fillers.
Cheers Bob

I see no point in fitting a 'high pressure' cap - I certainly don't want my engine running at anything over about 90C - and certainly not 100C...so a simple 4 psi cap to keep the water in is plenty for me !! If it's getting that hot - I would be finding out why - and pulling over to cool off if necessary. High pressure increases the chances of leaking hoses / leaking radiator/ blown bypass hose/water pump seal leak quite unnecessarily!

Some Minis were fitted with a 15lb pressure cap and their engines ran ok and did not suffer water leaks.
Mini Spares Pt No: GRC207 & GRC1110 are the 15lb caps used.
If you suffer coolant leaks the leaking parts were due for replacement anyway - you cannot always blame coolant leaks on the fitment of a high pressure cap.
I have never had a hose or water pump fail because I have used a high pressure cap and I have always used standard O/E hoses - I have always carried out a good inspection and maintenance regime though. Prevention is better than cure,
My Minor has always had a temp gauge fitted when running with a high pressure cap and the engine temp has always remained fairly stable. If stuck in a traffic jam and having noticed the temp gauge start to rise I have put the heater on to act as an auxiliary radiator/heat exchanger and the temp soon comes back to normal again.

Minis had tiny radiators... I just don't see the need or the point ! The radiator is huge !!

Blownmm : Thanks Rob. Point taken.

Phillthehill : Looking at your rad, it would appear that you have had the top hose outlet adapted to go straight out at 90 degrees from the rad? Did you get that done by a radiator company? If so who would you recomend. ALso, do you happen to know exactly which hose you used please?


Slugger

A cut down bottom hose will fit on the existing angled inlet.

As far as I can remember (and it was the mid 1980s) the radiator top pipe remained standard and as panky advises it could have been a cut down bottom hose. I would not have cut the radiator pipe as that would have lost the raised bezel which helps to retain the hose pipe.

Okie Dokie. Thanks guys.