Running Hot

[Sully2908]

[quote="dgear1984"]I had a few issues with a "hot" engine after I built up my 1275s.

I was a little worried to start that it might have been an engine build issue as it had been built up from unknown history parts and was not a complete engine before I started, (block from oz, crank from ebay, rods from miniformum etc....)

I tested the standard electric temp gauge out of the car and it seemed to be reading about right so that lead me down the garden path for a while.

In the end as I didn't have a IR gauge to hand I use some temp stickers, they change colour as a temperature is reached, that showed it didn't seem to be running that hot.

In the end I bought a second hand genuine smiths mechanical capillary temp gauge and used that. That was much easier to test, simply by putting it in a cup of boiling water with mums cooking thermometer and watching the two scales as it cooled to check the calibration. It was close within a degree or two.

After fitting the mechanical temp sensor the engine temp was running where I would have expected it to, and I had confidence in what it was telling me. So the way I had tested the electrical sensor was inaccurate and let me down the garden path.

Shortly after that the water pump started to knock. Brand new repro item less than 100 miles old. Luckily next door had a nos cast water pump he gave me so fitted that and at the same time I fitted the old plastic fan rather than the 16 blade metal one. Once again that dropped the temperature a little more. Not sure if it was the pump change or the fan that made the difference..

I would recommend to you getting a mechanical temp sensor, if only to use until your happy you don't have an issue. I think my good condition second hand one was around the £50 mark so not too expensive, and it can be checked for calibration easily and also will tell you a temp in degrees rather than C N H. With a IR gauge you'll have to keep stopping to check the temp, at least with this gauge you can watch the temp as you drive along and know if you need to turn it off when sat in traffic.

Once your happy with your engine temp issues, and if you do find its the gauge reading wrong you can always go back to a electrical gauge once you have fixed the gauge for originality sake if your concerned about that and sell the mechanical one on, i doubt you'll loose much money.

Hope that helps?

I find my car runs very cool now, very very cool, in fact it never gets even warm, mainly due to the face I have not been able to use it for close to a year now that i'ved moved to Australia and the car is still in the UK. Shame the shipping and import costs are so large.[/quote

That's good advice. Is the capillary device a replacement for the temp gauge or does it require a rewire? I am also going to as the question what is the best fan to fit to cool the rad.

Sully

[dgear1984]

The mechanical gauge is a straight swap. the gauge is the same size so fits the dash as normal. you then just run the capillary tube around to the engine and screw the bulb into where the sender goes. You might need an adaptor for the bulb depending on the thread of the nut. You can buy or make these easily. The gauge is mechanical so does not need any power. This is like the one I bought, the tube also comes in different lengths, so make sure you buy it the right length

http://www.ebay.co.uk/itm/SMITHS-Mechan ... 7675.l2557

The wire you can see is for the bulb, but you'll be able to pull the bulb straight out of the back of your gauge. That one on eBay would need an adaptor like this http://www.holden.co.uk/displayproduct. ... de=070.043

You'll see it on a lot of cars, they can be spotted by the tube which has a spring the whole way around. Careful not to damage the tube when fitting it, they are fragile.

As for fans everyone seems to to have an opinion but I was told the 16 blade metal one is not great, the plastic one is pretty good, efficient for air flow and engine power, the 6 blade export fan is the best for cooling but very noisy and takes a lot of power, and the two blade ones are very very noisy. But this only what i have been told, never done a proper test.

Here is a picture of my car before i tidied up the routing of the tube, you can see the tube clearly with the spring around it.

[gs.davies]

My 1961 850 came to me with a capillary gauge though the actual capillary was long broken and the sender hole in the thermostat housing blanked off with a plug.

Car always ran well with no actual signs of overheating even on long motorway blasts.

I eventually put a voltage stabilised gauge and a new sender from the local motor spares shop in. I wired a stabiliser across the gauge terminals and around town the temp gauge was always just below the 'N'

Motorway trips - it used to rise to just under 'H' and then of course I spent AGES chasing an overheating problem which didn't exist. I never solved it either and always suspected a dodgy gauge but back then (twenty odd years ago) forums like this didn't exist.

Still, it did make me keep the speed down to under 60

[Sully2908]

Now that's a tidy looking engine!

[Drkassler]

Beatiful engine bay!

[Sully2908]

My 1961 850 came to me with a capillary gauge though the actual capillary was long broken and the sender hole in the thermostat housing blanked off with a plug.

Car always ran well with no actual signs of overheating even on long motorway blasts.

I eventually put a voltage stabilised gauge and a new sender from the local motor spares shop in. I wired a stabiliser across the gauge terminals and around town the temp gauge was always just below the 'N'

Motorway trips - it used to rise to just under 'H' and then of course I spent AGES chasing an overheating problem which didn't exist. I never solved it either and always suspected a dodgy gauge but back then (twenty odd years ago) forums like this didn't exist.

Still, it did make me keep the speed down to under 60

I'm having exactly the same problems, new temperature gauge, new sender but it's still going way off the H on the gauge, the only thing it can be now is the wiring. I have a IR gun that says the block is no warmer than 80 degrees.
It's so fustrating

Sully

[Spider]

I have a IR gun that says the block is no warmer than 80 degrees.

Sully

Try the IR Gun at very close range on the Top Tank of the Radiator, that will be very close to the coolant temperature and I've found the most accurate place to measure it at.

[Sully2908]

I have a IR gun that says the block is no warmer than 80 degrees.

Sully

Try the IR Gun at very close range on the Top Tank of the Radiator, that will be very close to the coolant temperature and I've found the most accurate place to measure it at.

It's got a fletcher rad. Reading is about 35 degrees I think the IR sensor is bouncing off.

Sully

[Spider]

I have a IR gun that says the block is no warmer than 80 degrees.

Sully

Try the IR Gun at very close range on the Top Tank of the Radiator, that will be very close to the coolant temperature and I've found the most accurate place to measure it at.

It's got a fletcher rad. Reading is about 35 degrees I think the IR sensor is bouncing off.

Sully

Paint a blob of black paint on it and then try again. You can always clean it off later.

I have to say, I am not remotely crazy what so ever about any aluminium radiator on these engines, I know they are popular.

[madaboutcherry]

sorry to go off topic but are they standard rivets on the rocker cover plates?

[ianh1968]

Hey - I know it's a fantastic looking engine bay, but can we stop
quoting the entire post with pictures and all?

I'm starting to get RSI from all the scrolling up and down the page...


I am not sure whether or not this has storage implications on
the forum server as well, it may well do...

Ian

[mk1]

DONE!

I have the power

[Spider]

DONE!

I have the power

Control Freak!

[mk1]

YUP !!

[Andrew1967]

Apologies if this has been mentioned before but what sort of temp gauge have you got as '64 was the change year for ballasted fuel/ temp gauges and the earlier constant read out types. The sender units are different for the two types. IIRC the sender for the constant read out is red or maybe green coded not black.

Dad had similar trouble on a 64 Hornet that was cured on fitting the correct sender.

[Sully2908]

Apologies if this has been mentioned before but what sort of temp gauge have you got as '64 was the change year for ballasted fuel/ temp gauges and the earlier constant read out types. The sender units are different for the two types. IIRC the sender for the constant read out is red or maybe green coded not black.

Dad had similar trouble on a 64 Hornet that was cured on fitting the correct sender.

Nope Andrew this is a new one on me? I fitted a sender from one of the spares shops and I fitted a brand new temperature gauge so in theory should have solved the problem I currently now just ignore it although I wish I could solve it.