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Discussion Starter #1
hi all!
i have changed the engine in my gtv gt junior 1600 for a 2 l from an early milano, with weber carbs. The problem is that the temperature gauge reads 100ºC at anytime, once the engine is running for a while. I don't kwow if the radiator is different for a 1600 than a 2L, the fan is electric but it is unable to recover the 80ºC, which as far as i know would be right.
Suggestions please, the summer comes and i want to drive my car even with high temperatures outside.
thanks in advence
alfista
 

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hi all!
i have changed the engine in my gtv gt junior 1600 for a 2 l from an early milano, with weber carbs. The problem is that the temperature gauge reads 100ºC at anytime, once the engine is running for a while. I don't kwow if the radiator is different for a 1600 than a 2L, the fan is electric but it is unable to recover the 80ºC, which as far as i know would be right.
Suggestions please, the summer comes and i want to drive my car even with high temperatures outside.
thanks in advence
alfista
Are you sure the temperature sending unit is compatible with the dash guage?
 

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Could be lots of reasons from water pump to lean running. I think the 2L motor is taller than the 1600. Are you running an expansion tank? If not there is possibility that the top of the engine is not getting cooled properly.

- Jim
 

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Could be lots of reasons from water pump to lean running. I think the 2L motor is taller than the 1600. Are you running an expansion tank? If not there is possibility that the top of the engine is not getting cooled properly.

- Jim
Yeah thats right, 1600's dont need em.
 

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Taller engines & overflow tanks

I understand the basic point - that if the head on a longer stroke engine sits higher than the top of the radiator, then perhaps coolant wouldn't reach it. But, I don't get several details:

1) Why would the presence or absence of an overflow tank have any effect on this?

2) A 1600 has an 82mm stroke while a 2L has an 88.5 mm - so the 2L is .5*(88.5 - 82) = 3.25mm = .128" taller (assuming the rod length is the same - is it?). Would 1/8 inch really matter? Seems that driving uphill & downhill would have a bigger impact on the relative levels between the radiator & engine.

3) Doesn't the waterpump pressurize the coolant, and push it up into the head? So, even if the head were higher than the top of the radiator, the pump ought to, well "pump" the coolant up there.

4) Alfa really didn't change the underhood configuration when it went from the 1600 to 1750 to 2L - sure, the radiator went from 4 bolts to 2, but it wasn't raised up or increased in height - it really couldn't be raised on the spider - the hood limits its height.

I am guessing that alfista's old radiator simply needs rodding out, or better yet, re-coring with a modern, higher-capicity core material. It was probably marginal with his old 1.6L, and just isn't able to keep up with an engine that has 25% more displacement.

Or, his sender & gauge are just off.
 

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Discussion Starter #7
Hi all!
thanks everyone for the anwsers. the water pump is new and the radiator is the old one, this pics are from the 1600 and 2l (before and after).The question is if i have to change the radiator, which one would fit?
 

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I have to admit that I've not seen an intake manifold like that before. Does it have a bleed screw on it? Where does the heater core feed come from? Is there a bypass hose on the thermostat housing?
 

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Discussion Starter #9
Hi Jim!
Are you asking me about the first pic (1600) or the other ones (2000)?
Any comments about the radiator and its possible substitution?
Thanks again
 

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Hi Sergio,
Sorry I wasn't clear; my questions pertain to the pics of the 2l engine.

As for the radiator, there's no proof (yet) that it is the cause of the hot running.
 

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Thermostat?

Hi Sergio,
have you checked the thermostat? It could be stuck, broken or just the wrong temperature range. If the gauge worked before I'd move on to the next simple solution. Just a thought, but it could save time and money!
regards
Bob
 

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My reasoning was that with the 1600 motor the top of the head is below the top of the radiator. With the 2L the head is often above the top of the radiator and can encourage bubbles of air to stay in the head rather than being flushed out to the radiator.

An expansion tank can be fitted to either effectively raise the water level of the rad and/or reduce the chances of air pockets.

- Jim
 

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Discussion Starter #13
news after checking

hi all
after checking everything you told me to do, thermostat was perfect, water flew, etc ... i decided to change the radiator for a copper one, it will have 1 litre more of capacity and copper is better than iron to evacuate hot.
pics are from the radiator and thermostat housing.
By the way papajam, the bleed screw is the one with a black cover close to the thermostat, and heater core feeds from the back of engine (sorry for the pics, they are not very clean). What is very strange is a tube, which goes from the botton of the thermostat housing and it doesn't go to anywhere because it's blocked. You could see it in the pic of the thermostat housing, the hole comunicates that tube. Maybe someone with an early milano knows what it is.
This weekend i will install the new radiator hopping to solve the problem.
 

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Discussion Starter #15
the thermo-switch for the fan is located in the left side, is the hole you can see in the botton.This is the switch.The numbers on it are 72-82 that supposedly is the working range.
 

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Discussion Starter #18
once the temperature goes over 90ºC the fun begins to work and doesn´t stop, the temperature goes to 100ºC but doesn't go beyond, so i think that the problem is the radiator, which is unable to evacuate heat because the 2L engine produces more power and temperature, am i right?
 

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once the temperature goes over 90ºC the fun begins to work and doesn´t stop, the temperature goes to 100ºC but doesn't go beyond, so i think that the problem is the radiator, which is unable to evacuate heat because the 2L engine produces more power and temperature, am i right?
Well, I'm putting my money on the fan placement. Because of the location of the fan, the radiator has a hot side and a "cool" side. Since the thermo-switch is on the hot side, and the coolant is never cooling down, the fan runs all the time.

Have you taken the car for a nice long drive on the highway? Does it cool down when you do?
 

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my two cents is.. 1) How long did the radiator sit while doing the engine change? All the junk inside may have dried out and solidified blocking it. Put your hand on the radiator, while hot and feel all areas of the radiator. Be careful!!! If there is a cool area, that is your problem.. 2) I also believe the fan should replaced/repositioned. Try the original belt driven fan with a recored or new radiator.
 
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