It’s nice to know Migge that a 74C thermostat exists but as explained everything had been OK until two weeks ago. So something has changed for the worse. Once we have sorted the fault maybe a 74C unit could replace my 82C with the extra hole.
Peter C
Over heating Rover V8
Re: Over heating Rover V8
You said previously that you checked the hoses for kinking etc. It is possible that your newish hoses have softened over time. It is possible for the bottom hose to be sucked closed by the water pump, there are stainless steel springs available that you insert into the hose to stop this happening.
I would keep looking around a while yet before pulling heads, and definitely get a coolant test done first to check for combustion gasses in the coolant.
I would keep looking around a while yet before pulling heads, and definitely get a coolant test done first to check for combustion gasses in the coolant.
Re: Over heating Rover V8
I inspected all the hoses whilst the engine was running and specifically the bottom return hose. It’s made up of two hoses with a substantial amount of Ali tube joining them. None of the hoses had any kinks or reductions.
As already said I have a coolant pressure test booked for Tues next. If that suggests all is well ( which I doubt) then I will drain to inspect the pump.
I am very reluctant to pull the heads off when the engine remains in the car. I found it rather awkward getting the final few degrees of turn which may possibly be the problem now.
The engine is already booked in for top hat liners so I’m not about to go the expense of changing the head gaskets for 3 months of use.
Yes, it will be a big let down for what will probably be a good Summer.
That’s life.
Peter C
As already said I have a coolant pressure test booked for Tues next. If that suggests all is well ( which I doubt) then I will drain to inspect the pump.
I am very reluctant to pull the heads off when the engine remains in the car. I found it rather awkward getting the final few degrees of turn which may possibly be the problem now.
The engine is already booked in for top hat liners so I’m not about to go the expense of changing the head gaskets for 3 months of use.
Yes, it will be a big let down for what will probably be a good Summer.
That’s life.
Peter C
Re: Over heating Rover V8
Hi Peter
Sorry to hear of this problem, I think the manifold is useless but I have controlled my overheating by remove thermostat internals so installing just the casing of the thermostat which reduces flow and seems to keep temperature higher. I also installed a variable fan temperature controller and now temperature doesn’t go off the scale. So not really a fix but bodge. Fix I think is to try a new manifold but that’s too much bother.
I have the system pressure tested too all was ok, also put smaller pulley on to speed up water pump and restricted water flow return from mg v8 radiator to header tank.
Of course none of this helps you, sorry. Maybe just buy a ford engine complete and tested ! Ha
Sorry to hear of this problem, I think the manifold is useless but I have controlled my overheating by remove thermostat internals so installing just the casing of the thermostat which reduces flow and seems to keep temperature higher. I also installed a variable fan temperature controller and now temperature doesn’t go off the scale. So not really a fix but bodge. Fix I think is to try a new manifold but that’s too much bother.
I have the system pressure tested too all was ok, also put smaller pulley on to speed up water pump and restricted water flow return from mg v8 radiator to header tank.
Of course none of this helps you, sorry. Maybe just buy a ford engine complete and tested ! Ha
Re: Over heating Rover V8
I had considered changing to a Ford a while ago but that would be circa 10k judging by advice from other members bearing in mind new gearbox and front springs etc. Converting my current engine to be 4.7 was half that. Of course that cost was before the obscure over heating problem and also discovering that the exhaust needed to be a bigger diameter for the current 4.6.
Rad has now been pressure tested and checked for flow. Tried to do a coolant gas test but it got engulfed with coolant as a burb of air went up and out the overflow bottle.
Dismantled the top end but the gaskets showed no sign of any leaks. Heads well carbonised for such a short usage since modification bearing in mind it was put on the rolling road specifically to check the carb settings. For reference on a Rover the water transfers between head and block via holes at each end of the block and not between bores.
Changed the water pump but that showed no signs of leaking but bearings/ seals sounded squeaky despite only being 4K miles old.
Oil level has not gone up so no coolant in the oil and as already mentioned rocker covers nice and clean.
One thing I did get wrong and that is the temp of boiling water at 15psi. I was convinced it was 105C but apparently it’s 120C. So you could say I might have had boiling water but then the top hose didn’t seem that hot.
As a precaution I have re assembled without the stat in an attempt to keep the temp down.
It’s now a question of waiting till Oct for V8Developments to strip and rebuild which I had booked back in January. Just got to accept that the remainder of summer is without the Cob.
You may wonder why I have rebuilt the engine when it is due for stripping in Oct. Well the exhaust guys need to start the engine to test their work. I had hoped to check what power gains I got from a correctly sized exhaust but clearly that’s off the cards with a sick engine.
Peter C
Rad has now been pressure tested and checked for flow. Tried to do a coolant gas test but it got engulfed with coolant as a burb of air went up and out the overflow bottle.
Dismantled the top end but the gaskets showed no sign of any leaks. Heads well carbonised for such a short usage since modification bearing in mind it was put on the rolling road specifically to check the carb settings. For reference on a Rover the water transfers between head and block via holes at each end of the block and not between bores.
Changed the water pump but that showed no signs of leaking but bearings/ seals sounded squeaky despite only being 4K miles old.
Oil level has not gone up so no coolant in the oil and as already mentioned rocker covers nice and clean.
One thing I did get wrong and that is the temp of boiling water at 15psi. I was convinced it was 105C but apparently it’s 120C. So you could say I might have had boiling water but then the top hose didn’t seem that hot.
As a precaution I have re assembled without the stat in an attempt to keep the temp down.
It’s now a question of waiting till Oct for V8Developments to strip and rebuild which I had booked back in January. Just got to accept that the remainder of summer is without the Cob.
You may wonder why I have rebuilt the engine when it is due for stripping in Oct. Well the exhaust guys need to start the engine to test their work. I had hoped to check what power gains I got from a correctly sized exhaust but clearly that’s off the cards with a sick engine.
Peter C
Last edited by peterc on Wed Jul 12, 2023 6:41 pm, edited 2 times in total.
Re: Over heating Rover V8
A word of caution to anyone contemplating re installing cylinder heads whilst the engine is still in the car. I’m sure this would apply to both Ford & Rover V8. To get the socket sitting correctly down onto the head of the bolt you will need a universal joint which in turn makes the rotation unstable when exerting such high forces. It’s a two man job!. One to ensure the socket stays in the correct place and the other to do the tightening.
I had to purchase a longer 30” Tommy bar to get the purchase needed. OK I’m probably not as strong as I was 20 years ago but crickey it was a big effort.
Peter C
I had to purchase a longer 30” Tommy bar to get the purchase needed. OK I’m probably not as strong as I was 20 years ago but crickey it was a big effort.
Peter C