C4VetteLS1

I got a guy telling me that my radiator hoses on my ls1 swap are backwards.

The thermostat housing (passenger side of block) is ran to the top drivers side of the radiator, and that bottom passenger side of the radiator runs across and up to the water neck on the top/center of water pump


Can i run the radiator hose from the thermostat housing to the bottom of the radiator? I thought it had to come off the top, if i did this it would clean up some of my hoses running so long.

Speartech

iTrader: (14)

You have it wrong. The thermostat housing goes to the lower radiator hose.

LS1swap

Hmmmm are you sure???? that doesn't make sense. Shouldn't the feed come from the bottom of the radiator? The thermostat is the outlet not the inlet. If you ran it that way and it became low on fluid it woud start sucking air. <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" /> <img border="0" alt="[USA]" title="" src="graemlins/patriot.gif" />

<small>[ March 31, 2003, 09:36 PM: Message edited by: LS1swap ]</small>

Speartech

iTrader: (14)

The thermostat housing is the INLET not the outlet!! That why these engines usually run 10-15 degrees warmer than the thermostat temp rating. Water comes IN over the thermostat, warms as it goes thru the engine, and then returns to the radiator.

They have been doing it like that since the LT1 back in 1992. It's not like an old small block Chevy.

John

LS1swap

I knew the lt1 had reverse cooling, but I thought that meant the heads were cooled before the block. I am not arguing because I will be the first to admit I don't know, but I still don't know how this makes sense. It would seem to make a poor way of controlling the temp. The only water flowing is what is going through the heater core. This would be the only water flowing over the thermostat to open it. The water entering this thermostat would quickly cool the thermostat and close it again. Pulling the water off the top of the radiator also makes no sense. <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

Speartech

iTrader: (14)

That IS what reverse cooling is; the heads are cooled first, then the block. That's not what I'm talking about.

These engines use dual stage thermostats that do a nice job of mixing the radiator water with the engine water as needed to maintain a constant temperature. Most newer designed GM engines do it this way (Northstar, etc.).

I've probably processed 25-30 of these engines thru here in the last 3 years, so I've gotta know a little about them <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> , but don't take my word for it; pop the hood on ANY 93 and later Z28 or 92 and later LT1/LS1 Corvette and look at the hoses. The thermostat housing is the inlet.

You are the only one that has talked about pulling water from the top of the radiator. That certainly would not make sense. The lower radiator hose goes to the thermostat housing, because that's where the water is drawn in. Water is returned to the radiator thru the upper hose, as always. It's just that on these engines (as well as others), the upper hose does NOT go to the thermostat housing.

John

LS1swap

Hmm I get it now... It just takes me a while sometimes LOL. I guess it just took me a while to get over that the thermostat is not the outlet. <img border="0" alt="[bang head]" title="" src="graemlins/gr_banghead.gif" /> This also means that a ls1 is not reversed cooled. for the top holes go to the heads. Which are plumbed to the outlet. so the block must be cooled first like a gen I SBC. Learned something new today <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />