vn s1 n s2 cooling system diagram

[Alan22008]

need a cooling system diagram of v6 s1 and s2 engine
which way the water flows through intake manifold and out of the timing cover
the flow of the pipe that comes outa the timing cover that feeds the heaters
and the flow of the pipe that comes out of the front of the manifold
the two pipes end up being right next to each other under the power steering pump

any help would be appreciated

 

[Immortality]

it's fairly simple really. cool water flows from the radiator into the waterpump. the water pump forces it through the engine block and up into the intake manifold to the thermostat housing. from the thermostat housing it goes back to the radiator to be cooled and start the process again. for the heater, the pipe coming from the intake manifold is the hot feed and the hose going into the timing cover feeds back to the waterpump (this creates the suction for flow). there is also a hose going directly from the intake manifold to the waterpump, this is a bypass that allows coolant to circulate when the thermostat is closed. (ecotecs don't have this). the heater hose from the manifold goes to the heater tap, then it goes into the cabin to the heater core, comes out back to the heater tap and then goes to the timing cover/waterpump. when you have the heater knob set to cold the heater tap closes and prevents hot coolant coming into the cabin and cycles it directly back to the timing cover/waterpump.

on the s1 there are 3 lines going to the reservoir. 2 small lines. one coming from the intake manifold and one from the radiator. these are bleed lines. there is one large line going into the waterpump. coolant cycles through the reservoir and the system is self bleeding. the s2 setup eliminates this and uses a more traditional style overflow system with a pressure/bypass cap and expansion tank

 

[Alan22008]

cheers dude

 

[Nevyn]

I'm fitting a S1 engine into me VN that has a modified S2 inlet manifold.....in regard to the cooling system, what will I need to change?

 

[Jxfwsf]

put a s2 radiator in, easiest simplest option... how did they modify the s2 inlet manifold? it bolts straight on, the mod needed is to drill 2 holes (1 in each head) so the pcv system works, also remove the pipe going from the rocker cover to the tb, s2 has that straight from the inlet manifold to the tb (alternatively put a bung on the hole of the s2 manifold).

use a s2 inlet manifold gasket and sit on a s1 head, drill a hole (best done with head removed from engine to avoid getting lose metal in the engine)
you can see the old outline of the s1 gasket in the pic.

top left shows hole drilled, bottom left arrow points to where the other hole should be, alternatively put s2 heads on the s1 block to suit the s2 manifold.

when i did the above to a $10 ebay special engine that someone had just shoved a s2 manifold onto a s1 engine *shakes head* (i think i know why it cost $10 as it probably ran like crap and spat oil out the dipstick tube and anywhere else that had a chance to leak to let the crankcase buildup escape, i never started it unmodded), i drilled the hole so it was at the bottom and any oil that manages to make it into the manifold can drain back into the head and not be trapped as per the rough outline below, it's only to allow ventilation and didn't have a big enough drill bit on hand to make it the same size as the proper hole.
View attachment 153325

 

[Immortality]

You will need to set it up as per a series 2 cooling system. Basically, you remove the s1 coolant reservoir and fit a series 2 type, with the correct radiator etc.

Personally, I don't know why Holden reverted back to the radiator with cap/overflow system on later VN's, the original VN system is better. Have a look at any late model Commodore and Ford, they all use the same type of system that the original VN's had