I am putting a 2003 5.3 LS engine in my 1986 K5 Blazer. Question- Will my factory radiator be sufficent to cool my LS engine, or should I replace it? I'm having a hard time justifying the extra expense. I plan on moving my transmission cooler to an external type, so that's less cooling the radiator will have to do.
CK5
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LS Engine Swap with '86 Factory Radiator???
- Thread starter PWagon
- Start date
It should You need to run the steam ports out of the heads into the upper rad. hose somehow as well.
All should end well.
upper steam port easy mod . see my pic .
and if you are in any kind of cold temps do not bypass the rad cooler for tranny . fluid to cold is almost as bad as to hot.
and i just got a nice griffin rad for 73-87 trucks setup for ls motor swap with both hoses on pass side but tranny cooler was moved to left. rad/cap/upgraded rad rubbers shipped under 450 from summit.
ls swap info in injection section and also my 2wd build link in my sig line below .
and if you are in any kind of cold temps do not bypass the rad cooler for tranny . fluid to cold is almost as bad as to hot.
and i just got a nice griffin rad for 73-87 trucks setup for ls motor swap with both hoses on pass side but tranny cooler was moved to left. rad/cap/upgraded rad rubbers shipped under 450 from summit.
ls swap info in injection section and also my 2wd build link in my sig line below .
Yes, depending on the engine there are two ports either at the front or back that have lines coming off of them, these are the steam ports.
Basically one school of thought is that the engines create steam in the heads and this bleeds it off and puts it into the radiator for cooling. OR the other school of though is that they are there to assist in bleeding the system of air and don't do anything once there is no air.
I use the steam theory myself, I haven't done the research on the front of the water pump steam-port install. I like the upper rad. hose method IF you don't have a radiator setup to accept it.
I'm not saying the port in the water pump is wrong I just haven't followed up on that install. For these engines you kind of have to think backwards from the old school 350 stuff. It all makes perfect sense once you get into it but it's just not the same.
Basically one school of thought is that the engines create steam in the heads and this bleeds it off and puts it into the radiator for cooling. OR the other school of though is that they are there to assist in bleeding the system of air and don't do anything once there is no air.
I use the steam theory myself, I haven't done the research on the front of the water pump steam-port install. I like the upper rad. hose method IF you don't have a radiator setup to accept it.
I'm not saying the port in the water pump is wrong I just haven't followed up on that install. For these engines you kind of have to think backwards from the old school 350 stuff. It all makes perfect sense once you get into it but it's just not the same.
what i have read over at www.ls1tech.com is
new ls stuff pushes water/coolent threw on 1 port per side of block and recives it back out other port in block . thats why there is now 2 holes / ports on each side of the water pump to block .
also there more like air bleader ports since the coolent no longer flows threw the intake like our older stuff. so the highest point is now the bleader ports .
also no matter were you put the bleader hose in pump / upper hose / rad port its all going the same place the radiator .
guys over on ls1tech do this some and no problems i have read with it in the pump . that extra flat spot is were it gets the upper hose if the pump was to be for a car aplication anyways .
and the early motors got a 4 corner bleader system . the newer / later motors got caps on the rear 2 ports and only did a front cross over with 1 barb hose fitting just under the intake . thay do say tho if heavy working with extra power adders make it a 4 port system .
also if you live in the cold belt and drive in the winter dont bypass the heated throttle body stuff .
new ls stuff pushes water/coolent threw on 1 port per side of block and recives it back out other port in block . thats why there is now 2 holes / ports on each side of the water pump to block .
also there more like air bleader ports since the coolent no longer flows threw the intake like our older stuff. so the highest point is now the bleader ports .
also no matter were you put the bleader hose in pump / upper hose / rad port its all going the same place the radiator .
guys over on ls1tech do this some and no problems i have read with it in the pump . that extra flat spot is were it gets the upper hose if the pump was to be for a car aplication anyways .
and the early motors got a 4 corner bleader system . the newer / later motors got caps on the rear 2 ports and only did a front cross over with 1 barb hose fitting just under the intake . thay do say tho if heavy working with extra power adders make it a 4 port system .
also if you live in the cold belt and drive in the winter dont bypass the heated throttle body stuff .
I took mine to the radiator shop and the took out the nipple for the heater hose and add a threaded bong for a hose barb. Cost me $10 plus the fitting.
