First start, very hot....

mtb_tuli

mtb_tuli

Active Member
ok, after the top end rebuilt everything ready this afternoon. Static ignition timing to TDC, new Hüco fuel pump (very quiet !) fills the carbs. Choke, starting and after 3 or 4 secs kawoum, perfect running. Oil pressure goes up to nearly end of scale. Running in the cam at 2000 rpm. So far so good, but after 10-15 minutes temperature goes close to red zone (electric fan running correctly). Stop engine, check visually, every thing dry except (...) inlet manifold (rear side of rh side) blows out water. I was alone, so checked water level, filled up some water, everything was "blubbing" but all hoses hot (thermostat with hole at the top...). Start again, running fine, but temperature again rising and oil pressure hot dropping to 20 psi at 1500 rpm. Now smoke from the heater box. Ok, stopping again and found heater matrix blown. Have a 15lbs radiator cap, this should be ok. At low revs heard some bad (knocking) noise for 1 sec. There must be very high pressure on the water system, even the thermostat housing gasket shows some bubbles when hot. Ok, need a new valley gasket (used a tin one) and will bypass the heater.
Damn.....
 
That's a real bummer, Tuli; here's hoping everything turns out ok..... oil pressure doesn't sound out-of-line - mine runs the same.....
 
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15psi is twice what most classic systems would work at. If you have a weak spot it will likely find it but that's too extreme sounds like the cap hasn't vented at all.

You did purge the air from the system (point uphill)?
 
I should have wrote, 15 lbs cap supposed to be the right one....
If not, it would explain it a little bit :confused:
Ok, I must say, I (I like idiot) did "test" the heater matrix with water filled, but not with pressure (...) before I refitted the heater unit. Made a bypass with some soldered copper pipes now and If I can see it right, I can take out the matrix without take off the complete heater unit. Just bought a new compound valley gasket here at a classic dealer, wow, impressive prices.
At the moment I struggle with the manifold to get it off, I used a special silicone added to the tin gasket (for engines, not for bath rooms) and it makes a good job. Noticed that the clamp for the dizzy was not tight enough, maybe the dizzy could move to "early" position while running.
I cannot see where I should purge air from the system without loosening a hose...
Definitely no time for heroes.
 
mtb_tuli said:
If I can see it right, I can take out the matrix without take off the complete heater unit.
Click to expand...

Even though ISTR reading on here somewhere that someone had managed to remove the matrix from the heater without removing the heater unit itself, I remain sceptical, but even if that is the case, I think it would be a lot more difficult than removing the unit.
 
First I will refit everything with the bypass pipe I made, than I will see if it´s easy to get it out. If not, I will leave it as it is and do this job (what I have done recently....) again in winter.
Does anybody know, what´s the correct pressure rate for the radiator cap ?
 
Thanks, Harvey. My radiator cap shows 15 lbs, a force unit. Not clear to me, why.
If the cap works on, let´s say 2 square inch, then it would be like a 7,5 psi cap. Maybe it´s too late now (have reinstalled everything...), but seems that this cap did not overpressure the system.

Before restart I have to go the gas station with my 5 ltr can (several times). Have added a fuel additive when storing the car and thought, tank is full. Was not full, so I have now oily film in the intake ports :mad:
 
I know people do remove the heaters & refit them without having the matrix cleaned out & properly checked or use an equally unchecked replacement matrix.
But it's not something l would do.
 
You are right, I would not do that either, but I had the heater out of the car and refurbished it. The matrix looked ok, but I did not pressurize it. The car had water in the passengers side, when I bought it, I thought it came from a missing front screen lower seal, but now I think I have found the reason...
In summer I will not need the heater, so I will try to remove it and bring it to a radiator service
 
Hi sorry to hear your problem. I have just replied to offer support to you as you did for me with my problem. I have tried both valley gaskets although I prefer the look of the tin one which did seal very well I now have the later type one as supplied by V8 Tuner with the camshaft parts I bought from them. I still have fuel evaporation when hot but am going to fit an auxillary electric fuel pump now all the bits are here. Good luck and I am sure you will succeed.
 
Hi Neil, thanks for it. I´m sure, we will succeed ;)
Today I got my new radiator cap from a Brit Car specialist. Unpacked it, happy happy, 15psi ? No, 15 lbs again :confused: Ok, now I have two of them. Maybe I will start a thread about 15 psi or 15 lbs caps....
Good good, I had to change my valley gasket again yesterday (now then later one) and due to the thicker gasket I could not bolt down the manifold on one side, the halfmoon brackets collided with the (Range) manifold :mad:. Off with the brackets, hurry up, Hylomar gets dry. After that, I grinded the halfmoons, it was late and I had to do it manually, then back with them.
This evening, after carrying 3 tons of pellets in 15 kg bags, I finished the work, filled up the radiator again, filled in 100 oct fuel and fired it up. Kaboum, but now I FOLLOWED THE RED STICKER FROM THE MOTOR BAY. Off with the radiator cap and with fast idle 1500 rpm waiting until the thermostat opens, then watching the water dropping, filling up again. Then running the engine and watching the crossflow of the water :p
Then watching, watching, and then the engine spills out again some litres o_O
Again filling and closing the (right ?) cap. Temperature stays mid green (a little bit more than mid...).
Regarding the blown heater matrix my bypass with soldered copper pipes works. Have tried to get the matrix out with the heater box in, but you cannot reach the bottom screws for the panel in front of the heater matrix. Ok, again out with it in winter.
Tomorrow timing and (Schliesswinkel, contact gap or so...) and basic adjustment to the carbs, although idle is fine after the carbs rebuild with basic settings.
Thankfully I followed Harvey´s advice not to use exhaust manifold gaskets (like the original does not use) and only used some grease. Everything quiet, just be prepared of the smoke from the grease.
The OEM followers, tappets etc are very quiet, no problem up to now. Ok, 20 minutes..
Today my safety relay for the electric fuel pump arrived. I think, it´s a good thing. It´s not a real relay but a transistorized unit which uses terminal 1 from the coil (or a pressure sensor if you have an older injection). It has a delay time, after 2-3 secs with ignition on but motor not running it cuts off. So you can start but only with engine running the fuel pump is running.
 
the generic structure of some Germans (must be careful as there are some more G´s on this forum) is more complicated than you will ever dream of. I think, psi is a pressure related to a certain surface rate, lbs is what I have too much in relation to my body length.
I will think about this night.
 
mtb_tuli said:
Off with the radiator cap and with fast idle 1500 rpm waiting until the thermostat opens, then watching the water dropping, filling up again. Then running the engine and watching the crossflow of the water :p
Then watching, watching, and then the engine spills out again some litres o_O
Click to expand...

Hi Jörg,

The reason for having a radiator cap is to prevent a change of state from liquid to gas when the temperature of the coolant reaches 100 degrees C. The thermostat will open to allow coolant to circulate once the average temperature of the coolant has reached in the order of 82 degrees C, if using an 82 degree thermostat. Now, the temperature of the coolant within the cylinder heads is far more than 82 degrees C, especially in close proximity to the exhaust valves. So even though it appears that the coolant is circulating nicely with the radiator cap off, when you see the temperature gauge in the green, it is in fact boiling in the cylinder heads. So in an attempt to eliminate air from the system, bringing the coolant temperature up with the radiator cap off is very counter productive, not least of all due to the potential to result in head damage. It is all based on the laws of physics, which apply without reservation in situations such as this.

Fill the system with coolant, top up right to the brim and then refit the cap, well before the temperature is sufficient to result in the thermostat opening. Drive the car, switch off and leave it till the next day. When you remove the cap, the coolant level will have dropped significantly. The is a result of coolant now displacing the air that was previously trapped within the confines of the engine cooling system. Start the engine and fill to the brim or very close to. Refit the cap and you're done.

Ron.
 
Thanks guys. If you spend a lot of time in your engine (and it´s only the top end...), a simple radiator cap can speed up your heart rate.
I have thought about why the heater matrix was blown and one coolant connection from manifold to head blew bubbles.
Think, the one thing is independent to the other. The matrix I had simply not checked pressurized when working on the heater box (and the car had rust under the heater, thought it came from a missing screen seal, maybe altogether).
The manifold (not original, but from a RR) collided with the halfmoon brackets. As the first valley gasket was tin type, I could bolt it down but suppose at the rear end the manifold could not fully press against the head. With the next valley gasket, the thicker black one it was then impossible to set the bolts correctly on one side. With all this experience, a radiator cap makes you wake up in the night ;)
 
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