Ferret thermostats adjustable?

[LRDG]

Ive got the t/s opening at 155F based on a strip of 0.001" shim stock trapped under the valve coming free. The trouble is I had to screw the disk down about 1/8" which extends the bellows 1/8". This means there is now only 1/4" of free movement before the top of the bellows hits the brass housing, down from an original 3/8" so the maximum flow area is reduced by about 1/3rd. I am going to run this in the short term but a new t/s is in her future.

Malcolm

[Lynn Eades]

Malcolm, have you the space underneath to undo the screws on the side and slot the bellows frame down further. this would in theory at least give you a new start point.
I do think a new one is the answer though.

[LRDG]

That's a good idea, Lynn. I'll try that.

[Robin Craig]

Great information and suggestions all with great reasoning.

Thanks

R

[LRDG]

I unscrewed the 4 screws securing the bellows to the t/s body and elongated the screw holes. (They were already slotted so are part of the original setup by the OEM, I guess.) That got me a bit more flow area.

I did a calc of the final fully-open curtain flow area at the valve opening and it is now equivalent to the flow area of the port under the valve, so my anal engineering mind is now satisfied. Of course, the real test will be what temp she runs at.

[Lynn Eades]

Well done for having a go!.
The carriers have a radiator pressure cap that is adjusted then soldered, as is the oil cooler bypass valve.

[LRDG]

Since you raised the issue of rad pressure caps, I have some questions.

The pressure relief valve is a semi-permanent attachment to the top of the rad. Semi-permanent in the sense it is not just the standard screw-on cap. From the manuals, its setting is 10 psi.

The Ferret I am working on also has a "rad cap" on the filler opening in the line between the t/s outlet and the top of the rad, with a spring-loaded relief on it rated at 7 psi. I've tested this cap and it lifts at 6 psi.

So was the Ferret originally fitted with a non-relieving filler cap, leaving the rad-mounted relief valve to lift at 10 psi?

If I pressure test the whole system at 10 psi to check the system integrity and confirm the RV lifts, do I run the risk of finding it won't reseat, leaving me scrambling for a spare? It seems it has a soft rubber seat seal and who knows what condition it's in. (I think I know the answer to that question.)

I guess I run the risk of lifting the RV no matter what pressure I test at.

Is there a real risk of causing the pump shaft seal to leak in an unfixable way? It's a mechanical seal, and I know they can just let go if the rotor pops away from the stator and sticks open..