The V8 Owners Forum -

I would think if water temps were actually over 115degC, you're into engine damage territory. 135degC and it would be cooking.

Could not be at 135C - that would require a system pressure over 2 barg

Most caps are rated at 10-15 PSI Max - 1 barg which will allow for an absolute maximum system temp of 115-120C and even then localised boiling and pump cavitation will be taking place.

Question here
Could said gauge be reading in Farenheight?
135 or about 70 C which is about right with a cold thermostat!

Ian

Stevie - I entirely agree. To me 135 C is in the realms of cuckoo land. That damn gauge has to be reading wrong when over 100 C. It was checked in boiling water and it read 100 C exactly what I would hope for and got. However that doesn`t mean the gauge is good over 100 C. and I am prepared to accept that fact.
The Ford gauge is also connected and I am using the Ford sensor that was fitted in the 2.8 V6, this is a separately wired system and this reads well into the red. The sensor is fitted where the Rover one would have in the Performer manifold.

Ian, yes it is in C not F ( how I wish it were !!! )

The release of the pressure cap ( taking the full safety precautions of course ) may remove a stubborn air lock if there is one.
A laser temp gauge pointed at the top & bottom rad hoses shows a difference of 10 - 12 degrees when engine hot so the rad is doing some work.
Nevertheless I am constantly recording higher temps than what is considered normal.
It certainly gets hot under the bonnet. You Stevie would know more about how air flows through a Granada Mk2 engine bay than most on this site. By that I mean the space that is available under the bonnet. There isn`t many cars you can fit a V8 into without altering the bonnet, firewall, wings or even the transmission tunnel therefore air flow must be at least reasonable.

Thinking out loud;

I am also using a header tank ( pressurised ... so header tank ) that is connected thus: The bottom is connected via a "T" to the bottom rad hose, 15mm ID "T" to tank. The top connects direct to the top of the rad on the drivers side the hose size needed for this is 12mm I.D.

12mm ID is too large. That hose is only a vent pipe from the top of the rad to the highest point in the system (your header tank). Are you getting coolant flow through this pipe? if yes this is flow which is bypassing the rad. try restricting it.

How is your thermostat bypass plumbed in? It this flows too much this could also be coolant bypassing the radiator.

Also is the engine tuned correctly? Timing and fuel? and obviously your fan belt isn't slipping?

Tom.

Hi Tom, Thanks for your comments.

I see where your at with the 12mm top header tank hose - yes there is circulation here.
I will have a go at slowing it down.

The bypass system is the common Edelbrock performer manifold setup.. Here I am using a P6 type water pump (space is tight ) a hose of 15mm ID is used from pump to manifold, as bypass, the circuit continues through the system, out the rear of the manifold into the heater then returned to the pump at a different pump connection. That is how the system was shown on the diagram when I bought the manifold. The 15mm ID hose is the correct size at this point - as per diagram and pump & manifold available connections.
I didn`t like that as I could see some of the coolant may never reach the radiator so at one stage I connected the return to pump connection from the heater to the top rad hose of 38mm ID via a "T". Obviously blocking the connection at the pump. This system made little difference if any so it was returned to its previous connections.
What I cannot understand is the total coolant when full and without air locks never seems to have the amount specified in other Rover V8 engine systems, i.e. 19,5 pints for the SD1. I couldn`t possibly get that amount into my system - hence the header tank to give it a little more - well that was the idea.
The answer may well be an electric fan of 16 inch the largest I can fit in the rad shroud.




The engine tuning appears crack-on, a strobe light, spark plug colour, no pinking, mpg at 27 with a very light foot and not to low readings at the M.o.T. Starts first kick - well pleased with it.