Edelbrock Performer erratic water temperature

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Homewood
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Edelbrock Performer erratic water temperature

Post by Homewood » Wed Oct 23, 2019 7:46 pm

Just put a thermostat (with pin hole at 12 o'clock) in my Rover V8 with edelbrock performer manifold as its running very very cold but see why it was taken out.

My mechanical water temperature gauge has gone off the scale !

Seems to run at 90 degrees when in the drive and fan on but when out on the road it runs cooler at 70-80 but then goes off the scale for some reason and the bottom hose seems very cool then.

I presume its air locks but how to remove ??

I saw this article which seems a bit drastic...

http://how-to-build-a-pilgrim-sumo.wiki ... e-plumbing

Anyone experience this issue ?

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Re: Edelbrock Performer erratic water temperature

Post by peterc » Thu Oct 24, 2019 9:40 am

Hi Tony,
Welcome to the Edlebrock Rover inlet manifold cooling problem club.
I cannot explain why some owners have apparently no issues and I ( and now yourself ) have this over heating issue.
It is true the the temperature sender sees the hot water from No2 cyl before the stat sees the hot water from the rest of the engine. Result is that the gauge goes sky high during the warm up period and also rises when ever you use a load of acceleration and before the stat can react.
I did embark on the drilling of two small holes to connect the stat area to both No1 and No 2 water outlets with the result that I can keep the temp below 95 degrees in normal driving. Ref the swarf problem when drilling I just used cutting grease on the drill to keep it all together to be able to wipe it out.
In hindsight I think that there is now a potential Venturi effect with a small hole going into the ports allowing them to suck water back from the stat area such that it takes around 10 miles to open the stat and settle the temp.
Ideally you would need to spoil the cyl end of the cross drilled holes thus preventing the Venturi effect. This is would be extremely difficult unless you have some specialist tools. I have even thought of blocking them back up such I recommend you should only do this as the last resort.
My system runs a 82 C stat with a 5 mm hole to help some water circulation under all circumstances. It runs nicely at around 85-87C but on a long downhill cruise will drop to around 80 C. Uphill it still rises up to around 90 C but then I believe Rover engines are meant to run at around 90C.
As indicated in previous postings it is very important to ensure that your water level is able to fill the system 100% and that the heater is not higher than the top hose/ water level. Check with a sprit level. To this end I have an overflow bottle connected to the header tank over flow which enables the water level to be to the very top of the header tank. When the water heats up it spills into the overflow tank and then gets sucked back in when cooling down. Just maintain 1/4 full in the overflow tank. The system is then effectively a closed system e.g. does not throw the excess onto the road as per most older designed cars.
Hope that helps.
Pete C
Last edited by peterc on Thu Oct 24, 2019 12:00 pm, edited 1 time in total.

Homewood
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Re: Edelbrock Performer erratic water temperature

Post by Homewood » Thu Oct 24, 2019 9:57 am

Thanks Peter without thermostat it ran 70-80 during summer up to 90 when hot but 50-60 in cold weather which isn't enough to warm the spitfire heater. Now with thermostat it ran 80-85 then goes off the scale quickly and quickly back so I assume air lock just raising front of car took plastic cap off mgb v8 radiator and its low so filling up then I will run with cap off expansion tank see what happens. Cheers horrible weather cycling was cancelled so car gets my time

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Re: Edelbrock Performer erratic water temperature

Post by KevinW » Thu Oct 24, 2019 6:24 pm

I'm guessing you don't need the timing light now, Tony?!
Its here if you do.

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Re: Edelbrock Performer erratic water temperature

Post by stu60 » Fri Oct 25, 2019 9:12 am

Hi Peter,
i think i might have the Edelbrock issue, as occasionally get erratic temperature reading and sometimes water being spurted into expansion tank but i dont think any actual overheating. I always switch off engine just in case and when I start it up again all is normal

1. Can I just be clear, are you saying with hindsight you would prefer not to do the the 2 hole modication?

2. do you have an overflow tank (pressure cap on Gerry's cylindrical header tank and unpressurised oveflow tank) or one where expansion tank has pressurised cap and Gerry's cylindrical tank has a fixed cap? (latter being more akin to modern systems)? I have the option of either system but just wondered on best practical results. (pics would be great if you have time)

3. do you know what radiator you are running? i was thinking of upgrading as a belt and braces approach?

thanks for any help
kind regards Stuart

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clive
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Re: Edelbrock Performer erratic water temperature

Post by clive » Fri Oct 25, 2019 12:17 pm

Can I ask where your temp sender is located?
Cheers, Clive.

(If I'm not here I'm in my workshop or on the golf course!)

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Re: Edelbrock Performer erratic water temperature

Post by stu60 » Fri Oct 25, 2019 1:34 pm

Top left (drivers side) of
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clive
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Re: Edelbrock Performer erratic water temperature

Post by clive » Fri Oct 25, 2019 1:35 pm

That looks like the thermostat.
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Re: Edelbrock Performer erratic water temperature

Post by stu60 » Fri Oct 25, 2019 1:45 pm

Hi Clive
Sorry it a poor picture but its between thermostat and top bolt of manifold. you can just make out the brass sender unit in the manifold next to where thermostat hose clipe tightening screw is
Stuart

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clive
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Re: Edelbrock Performer erratic water temperature

Post by clive » Fri Oct 25, 2019 4:18 pm

Thanks Stuart. Is that the only place you can fit the sender as it looks a bit low? On the Ford Edelbrock header there are plugs on the top of the casting at the front and back, which are easier to fit and bleed any air off. Perhaps if there are the same on the Rover one you could give that a try.

Image
Cheers, Clive.

(If I'm not here I'm in my workshop or on the golf course!)

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