SD33 hot water bypass?

[Rosey55]

G'day all,

anyone know what's up with the 'U' shaped hose which runs from below the thermostat back to the water pump on SD33? I think its called the hot water bypass hose??

Is this for when the thermostat isn't open to allow water to circulate through the block? does this bypass effect the pumps performance/rate during normal operation? I was wondering if blocking this hose and instead drilling a couple of holes in the thermostat might inprove water circulation when things heat up.

Keen to hear peoples thoughts/knowledge on this loop.

Thanks

[nellyb1]

i dont konw what a sd33 is sorry man,

But surely the bypass would be there to allow water to move thru the radiator and miss the engine. Is the thermasate is closed then no water should be moving thru the block.

So the only thing the hose would be there for is to allow the pump to still push water around. Not too sure why, maybe so that it doesnt get an airbubble in it somewhere.

Could eb way worng, but my two cents.

[Sterlo]

Rosey

The bypass is there too allow water to flow around the engine only. You will notice the t-stat will block off this passage more and more as it opens and let the flow start to the rad. This helps the engine to come up to temp and lets the water flow past the t-stat to heat it up to open.

If you block this off the t-stat will take a VERY long time to open and the water pump will be cavitating because their is no path for the water..

How to keep and SD33 cool. Well i'll be sure to let everyone know when i work it out. Keep a t-stat in it for starters. I think to this day it the head and/or head gaskets that are the bottle neck in the cooling system..

Man i could go on here,, doo a search on sd33 cooling

[pongo]

make sure you run a factory thermostat or similiar, It needs the bit on the bottom that actually blocks this part off when the stat opens.

About $30 for a factory stat

[Rosey55]

thanks guys, makes sense Sterlo

got a new radiator and high flow thermostat to go in. Grabing some falcon thermo fans on sat from wreckers

Hoping I haven't done the head, bubbling like mad, only replace the head gasket a few months ago

Also got a International Acco oil cooler to go in it, bloody massive, hopefully keep it cool

[stokedapollo]

hi guys i have sd33t and i have no probs keepin g it cool
was stuck in traffic jam 40 degrees the other day didnt go much over half way
have two big thermoes one suck one blow seems to do the trick really well

[pongo]

hi guys i have sd33t and i have no probs keepin g it cool
was stuck in traffic jam 40 degrees the other day didnt go much over half way
have two big thermoes one suck one blow seems to do the trick really well

Its not traffic that heats em up, its constant high speed high load that does it.

Hook up a heavy trailer and head for the longest hill you can find and report back, You may be lucky though

[stokedapollo]

drove from churchill to hoppers crossing bout 190 odd kays with the biggest furniture trailer i have ever seen lol
up and down hills all at bout 100 odd kays dun get hot
but my old man done stuff to the 4wd b4 so i dun know wat he has done but it keeps cool

[Sterlo]

I second what pongo said.. Not the traffic thing,, it the working it like a diesel should be worked that makes em get hot..

Rosey,, if it bubbling now mate id be pulling the head off again.. If it bubbles from a cold start it can only be compression getting into the cooling system,, a water pump cavitating wouldnt create bubbles that badly on and SD