LS1 Thermostat Type

[cobbindale]

Hi Guys,

I was hoping someone could give the make and part number for a thermostat that suits the CSR 911LS1 straight thermostat housing some of us bought from Beejay. (thanks Ben).
Better still, if someone is able to take a pic of the water pump thermostat inner secondary sealing face for the thermostat and the measurement from the housing face to the secondary seal face. (The 02 housing is 42.7mm and square edged at the hole) This would give an indication of the later LS1 and LS2 type being suitable.

I tried a standard thermostat unit which fits a treat in the new housing (54mm) but when bolted up to the water pump, it flops around like a fish out of water.
I've since found out these motors use a bypass type thermostat (never seen one before) to allow quick warm up when cold and more even cooling when in operation. The problem is that I cannot find a straight replacement with the same measurements to suit.
My '02 original all in one housing and thermostat has a total length of 43mm from sealing face to the secondary seal, and the seal has a diameter of 35mm. the '05 thermostat has a total lenght of 47mm and 37mm diameter seal.

There are 4 superseded part numbers for the LS1 pump, the latest is still used on the LS2 motor which uses a seperate thermostat and housing and I'm not crazy about spending over $400 on a new pump.

Any info would help and may stop this frustrating pounding in my head.

Cheers,

Dale.

[Gav]

Just a stock holden V8 thermostat will fit fine.
Mine seems to work fine, I have drilled a bypass hole on each side of about 5mm.
I have no pics to show, sorry.

[pneall]

Dale,

I used the standard LS2 thermostat ie the easily removable one. You can buy the thermostat and angled housing from GM for about $70.00. The thermostat itself is not available separately.

I then machined (or at least Mike did )out the back of the straight thermostat housing to accept the thermostat. Seems to work OK.

Regards,

Phil

[Beejay]

I think I am using the standard thermostat.

The housing needs to be slighlty machined to fit, and a little section taken out.

From memory Plums found another thermostat that might have fit without mods.

Ben