Any ethylene glycol coolant will do. Doesn't have to be expensive OAT stuff, any bog standard glycol coolant is fine. The design of the engine is from the 1950's when coolant was just coolant!

My manifolds smoked like crazy the first time, but I wrapped them with heat wrap stuff, and that smokes a LOT the first time it gets hot. The tappets should quieten down once the oil has got round.

This is great stuff!
 
nothing wrong with running it for a while with water & always getting ot properly warmed up so you can find any leaks. Then after sorting those, drain & replace with proper coolant.
 
I'm assuming there'll be plenty of air in the system that needs bleeding, I'll drive the front wheels up on my small ramps - hopefully that'll be a good angle to get the trapped air out.
My heat wrap hasn't arrived for the exhaust manifolds yet - is there any harm in running the car without any heat shield for a while?
 
blue_cheese said:
I'm assuming there'll be plenty of air in the system that needs bleeding, I'll drive the front wheels up on my small ramps - hopefully that'll be a good angle to get the trapped air out.
My heat wrap hasn't arrived for the exhaust manifolds yet - is there any harm in running the car without any heat shield for a while?
Click to expand...
Maybe not a good idea, don't forget they put it there for a reason.. Although your choice 🤔
 
I should clarify - when I say 'a while', I mean for today while I check for any leaks. The wrap will be arriving tomorrow and will go straight on
 
Update:
Left it running with the radiator cap off, but coolant starting gushing out after a few minutes. Not sure if that's expected?
Put the radiator cap back on and let it run again, temp needle went in to the red 🔴.
In terms of leaks, found this tiny hiss from the radiator top hose:

Not sure what that small wire is for, it leads to this unknown device:
20250403_164351.jpg20250403_164355.jpg.
Only other thing I noticed was blowers were quite cool even though they were set to max temp.

Any ideas what could be causing the temp to spike?
 
blue_cheese said:
Update:
Left it running with the radiator cap off, but coolant starting gushing out after a few minutes. Not sure if that's expected?
Put the radiator cap back on and let it run again, temp needle went in to the red 🔴.
In terms of leaks, found this tiny hiss from the radiator top hose:

Not sure what that small wire is for, it leads to this unknown device:
View attachment 338339View attachment 338340.
Only other thing I noticed was blowers were quite cool even though they were set to max temp.

Any ideas what could be causing the temp to spike?
Click to expand...

Sounds like the system is airlocked.
It looks like there is a mod to use the aircon fans or an additional electric fan for cooling. The first photo shows what looks like an adjustable thermostat.
 
blue_cheese said:
Update:
Left it running with the radiator cap off, but coolant starting gushing out after a few minutes. Not sure if that's expected?
Put the radiator cap back on and let it run again, temp needle went in to the red 🔴.
In terms of leaks, found this tiny hiss from the radiator top hose:

Not sure what that small wire is for, it leads to this unknown device:
View attachment 338339View attachment 338340.
Only other thing I noticed was blowers were quite cool even though they were set to max temp.

Any ideas what could be causing the temp to spike?
Click to expand...

That doesn't look standard and, the wire has deformed the hose causing the leak, could also be drawing in air.
 
Let's hope it is an airlock then.
Are they a pain to clear? I don't want to let it idle for too long if the temp keeps spiking.

As for that device - there aren't any extra fans that I can see (around the rad anyway), I'll have to try and follow the wiring
 
I'd just follow the refil proceedure from RAVE. That's how I've always done it... with maybe a bit of squishing the top hose to burp any air round the system...

Screenshot 2025-04-04 at 01.08.04.png
 
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blue_cheese said:
Let's hope it is an airlock then.
Are they a pain to clear? I don't want to let it idle for too long if the temp keeps spiking.

As for that device - there aren't any extra fans that I can see (around the rad anyway), I'll have to try and follow the wiring
Click to expand...
The mod will operate the aircon fans.
 
Afternoon,
I've had another go at filling the coolant.
I drained as much as I could from the radiator, and made sure the bleed hose was clear.
Filled up until it was at the neck level, then started the engine.
Filled up a little more after a minute, until it was fairly steady on the cold level line.

How long should I be waiting for the thermostat to open? I waited about 7-8 minutes, until the top hose was quite hot, by that time the coolant started gushing out of the expansion tank so I shut off the engine. Is that supposed to happen?

Also noticed the interior blowers weren't that warm either.
 
blue_cheese said:
Afternoon,
I've had another go at filling the coolant.
I drained as much as I could from the radiator, and made sure the bleed hose was clear.
Filled up until it was at the neck level, then started the engine.
Filled up a little more after a minute, until it was fairly steady on the cold level line.

How long should I be waiting for the thermostat to open? I waited about 7-8 minutes, until the top hose was quite hot, by that time the coolant started gushing out of the expansion tank so I shut off the engine. Is that supposed to happen?

Also noticed the interior blowers weren't that warm either.
Click to expand...

Was the rad hot all over or still cold at the bottom ? Did you have the heater controls open ?
 
Just ran it again until it started going in to the red.
Coolant still gushing, heaters on full blast max temp.

Noticed that radiator feels cold all over - no hotspots on the top or bottom (from the limited places I could feel it anyway)
 
radiator will be cold at the bottom if its doing its job. its a petrol so you have the themostat 'heart' at the bottom of the radiator, do the pipes going to this get warm? does the cabin heater blow warm? the cabin heater always has flow regardless how the temp dial is set
if its going into the read the its already way too hot, in my opinion, you dont want to let it go that high. the thermostat should open as the needle moves to the middle.
have you tested for exhaust gases again?
 
Just tried to test for exhaust gases again.
Coolant started to get pushed up through the device before I could give it enough time to let the liquid change colour. Something is causing the coolant to overflow pretty consistently.
Cabin heater still not blowing warm.
 
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