Hey gents... Installed a custom closed cooling system in my 91 Sunsation Rocket with a 454 gen iv... The heat exchanger (H/E) is a seakamp and also installed a factory circulating pump... Got everything installed and plumbed, incl a new 160deg tstat... When I bought the kit from a forum member this is the tstat housing that was included...806235A And below that image is the diagram I used to setup the plumbing, the only difference is explained below, with the exhaust manifold lines and the larger hose from the tstat housing going into a Y into the H/E since this H?E did not have 2 return fittings,
[ATTACH=CONFIG]523055[/ATTACH]
[ATTACH=CONFIG]523057[/ATTACH]


Once I got the whole system filled I started it up and everything ran great and kept cool around ~125deg, but thats too cool??

The way that tstat is designed water flows from the intake manifold, into the housing where the sleeve is and has bypasses, that go directly into the one larger outlet that goes directly back to the fill/cap and into the heat exchanger, which in turns cools off and goes back in the circ, pump. The 2 smaller outlets only flow once the tstat open up, which go to the exhaust manifolds, which then go into a Y fitting back to the heat exchanger. Since the temp never comes up to 160, I wouldnt think the tstat is opening at all and the exhaust manifolds wouldnt get any cooling flow.... That said it felt like the hoses were hot and had flow?

Either way, its not coming up to temp any higher than 125deg... Is this the wrong tstat housing for a closed cooling system? I need one for (2) 1" hoses to the manifolds and (1) 1.25 or 1.5" hose to the fill/cap that goes back to the heat exchanger. To me it seems the flow to the fill/cap/HE should be restricted by the tstat, not the manifolds?? The only other thing I can think of is I do not have a bypass from the circ pump to the tstat housing like in the diagram, could that help it to heat up?

Otherwise I may just take out the tstat and maybe put in a water outlet restrictor to slow the flow down so maybe itll build some heat. The motor is tuned now anyway for the 120deg tstat that was prev in there

Thanks for the help and suggestions if you have any! Chris

[ATTACH=CONFIG]523058[/ATTACH]

What is most important is the correct oil temp. You want your oil temps to periodically get above 212F so the condensation will cook off. Any oil temp below 260-280 +/- is good. Our water temp never exceeds 110F, many don't even bother with water thermostats.

Thanks, that makes me feel a lot better... Esp since the oil cooler is plumbed into the raw water prior to the H/E, no different than the cross over system where it was prior to going into the motor

in closed cooling systems the thremostat goes back where it was orig supposed to go. that is a raw water housing with t-stat up high. i think buying the correct housing and plumbing correctly would be a good idea. you can get engine temps up where they belong with closed cooling.

Thanks sir... can you tell me which housing is the correct one or if there is an aftermarket one I can use??

TIA - Chris

i will surf ebay and get u an item number.

That is correct. The T-stat sits up off the intake manifold floor sitting on a spacer. That way in the open system, when t-stat is closed it redirects water coming out of engine/intake manifold back to the inlet of the reciculating pump.

So, furthermore, in open system with that t-stat housing:
When t-stat is open, it lets water exiting intake manifold go straight to the two smaller outlets and then out the exhaust.

There are small holes in the tstat housing connecting the inlet water (the big nipple) cavity to the two small/upper outlets so the exhaust gets constant water.

Thanks buddy. I appreciate it as im not sure whatvthe one I needs even looks like...

go to ebay and put "
thermostat housing closed cooling in search box. 7 come up. all essentially the same.