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IZU069 wrote:The only Piazza work I have recently done is supply the turbo water valve mechanism to Barterman along with a description of how I thought it worked. (Good ol' Isuzu designed it as a fail-safe mechanism - it should fail "open" so that water/coolant is NOT restricted. In fact it seems a few Piazzas have bypassed the whole thing with a plain hose; this should merely mean that that turbo takes a bit longer to warm up.) I could submit the "article", but I'd like to confirm my understanding of what it does, and it would be nice to know what controls it - is it merely engine-temp controlled, or is there more to it?

Cheers,
IZU069

So how the heck does it work??? Do tell all Peter.

Heres my thoughts/experiences so far.
As far as ive worked out my (i wont say all coz im not sure, but i have my suspicions) Manual Piazza had a oil only turbo on it.
The goose i bought it off fitted up the oil and water turbo off the auto and didnt hook up the water to the turbo. Broken shaft and i would think it would have happend in the first day of driving too.

The new turbo i got to replace it is water and oil. I was told when shopping for a reco on my turbo that you can only buy oil and water cores now for the RHB5.

Since the new turbo came with all the water tubes attached to it, i hooked them all up. Theres two points of feed and two of return. Or is that one of feed an two of return i can remember exactly and for the skinned knuckels it cost me when fitting it up with new stiff as hose im not even wanting to look at it. lol.
One (maybe the only) feed comes out of the std drain bung in the block (lower left side of the block behind engine mount/lower radiator hose tube.

One exit goes into the steel lower radiator hose tube, which would exit hot water into the block with the flow of cooled water into the engine from the radiator. (note: water is constantly flowing thru the block even if the thermostat is colsed, it flows thru the heater bypass circuit at the rear LH side of the block)
The other exit is meant to go thru the gizmo valve and into the filler neck of the radiator. I wasnt aware of the gizmo when i fitted the turbo to the motor and would be interested in fitting it if the auto car still has it under the hood.

Am i lost and confused????

Bob.

Might be abit over-simplified but my understanding of it is that it works on the same principle as a thermostat. AFAIK the water in a water/oil core is only used to cool the temperature of the core down. Thermostat closed to bring engine and turbo bearings upto temp, then open to allow the water/coolant to bring the temp to a stable level. I dont see why a normal hose for a feed wouldnt be a good idea?

Nick-

A couple of years ago mine broke. When i took it to the mechanic he said that the thing needed to be there. So it was a nightmare trying to get hold of another one as the part isnt listed in part books at most places.

I only spied R-Bob's request recently... (Better late...?)

It's the original May05 version (with a minor edit Oct08) and was done so a Piazza owner could simply bypass their broken solenoid.





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