Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) 4/4 1948 Overheating after some work done......

Hello David:

Please pass this to John and tell him that thank hime for his advices.



Hello everyone:

I just wanted to give you an update on the Morgan, and to thank you all for the good answers and tips.

Today I took my afternoon off and spent some hours with the mechanic. We thought that the radiator was leaking since it was steaming, so we took it to a radiator shop, they checked it out and it was not leaking. It seems that the car had condensation between the radiator and the frame or grill, which was new (after reinstalling it, the steam went away.

After that we put the the car on 4 jack stands, and we worked on the timing, having in consideration all the advices that I got from John via David.


After looking the flywheel underneath, we found out that someone did a mark in the past, probably it was done by the previous owner or his mechanic when they rebuilt the engine at some point, since it does not look like a mark made from the factory. Then we removed the spark plug number 1 and the mechanic looked into the cylinder while I was turning the flywheel very slow to make sure that the mark was ok and the piston number 1 was at the top. We used the “ timing light gun" to doble check. Everything looked fine, so after a little timing adjustment, (since it was not so off), I went for a short ride.

Unfortunately the temperature issue was still there, and after 5 minutes going around the block the car started overheating again. So, back to the shop to start measuring the temperature of the block, radiator hoses, etc (with a laser gun). Again the dashboard instrument was very accurate and I turned the car off just before it reached 100 C.

BUT there were some findings. The temperature of the hose (Top - right side of the block) coming from radiator was at 105 C, and the temperature of the hose (down-left side of the block) was much more colder at 65 C. Obviously the water was not flowing well, which is very surprising, since the radiator was rebuilt by an experienced guy quite recently and never gave me a problem……

The other finding was that the radiator was at 105 at one spot, and 1 inch right, close to the frame, was at 85, which makes us think that the water was not flowing very well.

It was getting late so we decided to leave some tests for tomorrow, and so far this is the plan for tomorrow (please feel free to comment or add some ideas)


1) We are going to check if the overflow pipe inside of the radiator is not clogged since with the cap on, the system needs to be able to release some pressure (that is my understanding of the thermo-syphon principle)
2) We are going to disconnect the hose at the bottom of the radiator, close with a hand, fill the radiator with water, and then take the hand off to see if the radiator empties in a few seconds, if it doesn’t very fast is because, somewhere it is clogged (we might take it out again for this test)
3) We will remove the hoses from the block, and pour water with a hose on the right side to see how it flows, just to make sure that there is nothing clogging inside the engine.

Pre conclusions are:

If it is not the radiator and the block is not clogged. Then most probably the head gasket is bad and it is putting some pressure on the radiator. This would be very weird, since with the engine running hot, today we opened the radiator and looked inside with a flash light and there were no bubbles. Beyond that, I don’t have any other symptom of a head gasket problem. I hope it will be just the radiator clogged somewhere…..we will see it soon.

Well that was all, any comment will be very welcomed.

Best regards,

Gonzalo

Is the thermostat not working?

Actually it was Andy , but David is also a good friend!

Here is the advice from John in the overnight email/

Quote
G'day Andy, as before, I can't help much without knowing the car.

But a few observations:

If the problem has occurred only after the radiator was rebuilt, that is the first thing to suspect. Depending on what was done there could be gunk inside the top tank (loose solder etc) fouling the downtubes. I suggest he pull it out , upend and reverse flush it. He should disconnect the two headlight brackets on the front upper suspension cross tube holding on the headlight bar, drop these resting on a blanket or something, remove the bonnet, undo the bolts (should be one at the top and one each side at the bottom) which hold the radiator in, also the hoses, and then lift it out. At a pinch it may be removable without dropping the headlights but the lower outlet pipe on the radiator may inhibit this, also it's not worth risking damaging the fins on the fan. As well as reverse flushing the radiator, reverse flush the block.

When he replaces the radiator, refer him to the spring-loaded system for the lower bolts detailed on "Morganatica".

While he has the radiator out, check that there is no blockage (i.e. a piece of errant cloth or gunk) in the inlet/outlet hoses and water manifolds. If the overheating correlates with the engine rebuild, check the fit of the small gaskets on the top of the cylinder head for the water outlet manifold _ these can be a bit fiddly, but only do this after a test drive. Another thing is that after the engine rebuild, if not many miles up, things may still be a bit tight, causing hotter running.

On the advice given it seems unlikely that the head gasket has blown. There is a problem with the Standard Special engine blowing head gaskets, however. Cylinders 1 and 2, also 3 and 4, are siamised with little distance between them. This is a design fault common to quite a number of British designs, and in the case of the Series 1 and some others, it can lead to burning through of the gasket at this point. It's because with the lack of cooling this area of the engine gets hotter than elsewhere. There is considerable loss of power, but no evidence of either water in the oil or bubbling in the radiator. If he wants to he can test for this with a compression gauge, the readings should be even and around 125psi or better. Ultimately, the only solution if this problem develops is to dismantle the engine, surface grind the head and block, and glue the new head gasket down with one of the special copper-based products designed for this purpose. Note also that the new composite gaskets use a different substance to asbestos and need a rather more complicated retensioning procedure after they've run for a little while.

Interestingly, when Standard designed this engine, they used bore centres corresponding to the Flying Standard 8 engine rather than the Standard 10 unit. While both these side valve engines were fully water-jacketed, it meant the bore dimensions in the Standard Special (which uses the Standard 10 pistons) became too close together to allow it. This spare parts bin approach to engine design also meant use of the 8 crankshaft, and the one from the 10 won't fit except with modifications to the centre connecting rods, which theoretically at least is also not a good idea.

Finally, perhaps should have been first, operating temperatures for this engine are relatively high. 95 to 98 degrees C is about the norm. He could perhaps run it and see if it actually does start to go much over 100 or start to boil. If he is still worried, and everything else checks out, he might consider fitting a Davies Craig water pump. I've had one in my '49 car for over ten years now and it doesn't run over 80 degrees C. It's a bit of a juggle to fit in and needs also the control rheostat. One will also go in the '36 car, when I don't know given its funereal progress.

Can't think of anything else for the moment.

Best regards

John
Unquote

Plenty to think about there Gonzalo

Hi Andy, I am glad that you sorted out that confusion; I wasn't sure if there were two Davids and I certainly wasn't intending taking the credit for someone elses assistance!

Dear Andy, John and David too :-)

I apologize for the confusion with the names, with all the support that I got from the forum I got confused the names.

Thanks again for all the comments that John and Andy sent me.


Here is the new report:

As planned, the mechanic yesterday tested the radiator by itself, and everything looked fine, it emptied very fast. He did the same with the block, with the radiator disconnected, poured water on the right side of the block and it flowed very well, in fact it came out very clean on the left side.

So after that he reverse flushed the radiator and the block too. The radiator was flushed three times until the water came out total clean.

Then put everything back and started the car in the shop, and temperature was definitely lower.

Test drive:

At 6:30 pm I picked up the car and the temperature was definitely lower. Yesterday evening I went for one hour ride with my wife, finally! Beautiful night of 24 C. The car after 10 - 15 minutes, reached the 90 C, and stayed in the in the 93 most of the time. In the traffic lights (there were just a few on the road) the temperature went up to 98, sometimes.

I know Morgans with Standard engines, usually run hot, and as John stated very well, temperatures can be between 95-98 C. Event though I have to say that the Morgan was running with lower temperatures until I did this full maintenance with the new Mechanic in Miami. So I don’t know, it might be the different weather, but with 24 C, that should not make any difference with the previous location.

So I am not 100% happy with current scenario. I have been driving the Morgan for 20 years, and every time that I see the engine working so hot it makes me a bit nervous.


The mechanic strongly believes that is not the head gasket, but he told me that if the temperature is still high, we will check the gasket, just to be on the safe side. He has a machine that uses some reactives to detect, oil in the water, or any kind of gas, etc………..

Now I am planing to drive the Morgan this long weekend (in US), and see how it drives. I have to say that beside this concern with the temperature, the car is running smoothly as usual. I remember that John mentioned that he installed a water pump in his car, knowing that Miami weather is quite hot, I am thinking if this would not be needed in the near future. May be not now, since the temperature will stay like this until April, but maybe later will be needed…………………..


I think this is all for the time being, I will get back to you with more info during the weekend.


Thanks again for your support.


Happy thanksgiving for you and your families!


All the best,

Gonzalo

That is encouraging news Gonzalo. Happy Thanksgiving and fun filled Morganeering!

Thanks David, the same to you!

+1

These updates are great and may be really helpful to someone having a similar problem in the future.

These 4/4 series one morgans are very special cars and the thermo syphon system without a water pump is simple and effective when all is ok. Remember to allow a little expansion in the top of the radiator and antifreeze increases the boiling temperature 2015-04-07 08.14.11 by Robert & Ali Davies, on Flickr