V8 Radiator troubleshooting (1 Viewer)

[lonelydriver]

Fan shroud is a must

Do you have a recommended fan size, I believe there are a few options blade designs and diameters?

 

[tmxmotorsports]

I use oem 2500hd clutch and fan

 

[MANUCHAO]

I use oem 2500hd clutch and fan

Part numbers?

 

[cruisermatt]

I don't believe in the heater outlet bypass anymore, the inside of the water pump does it for you

 

[lonelydriver]

I don't believe in the heater outlet bypass anymore, the inside of the water pump does it for you

Could you elaborate on this matt? If I don't have a bypass valve I'm always feeling hot air coming out of my vents even with the hvac lever set to cold...

 

[tmxmotorsports]

Part numbers?

Just happen to have all that here for n up and coming lsswap in a Lx450

 

[cruisermatt]

Could you elaborate on this matt? If I don't have a bypass valve I'm always feeling hot air coming out of my vents even with the hvac lever set to cold...

that sounds like your heater valve isn't closing properly. If it's original then it's time to replace it

 

[MANUCHAO]

If I don't have a bypass valve I'm always feeling hot air coming out of my vents even with the hvac lever set to cold...

I had the same issue.
Few years back I put a shut off valve (from an FZJ80) midpoint (still there), between the block, and heater valve.....
Couple of months ago while replacing my bezel I found one of the clips (right side) that hold the blue cable had snapped off.....

This didn't help the heater valve isolate properly......

Might want to look at that clip to see that it is locked in place...

Thanks for posting those #'s @tmxmotorsports

 

[tmxmotorsports]

I had the same issue.
Few years back I put a shut off valve (from an FZJ80) midpoint (still there), between the block, and heater valve.....
Couple of months ago while replacing my bezel I found one of the clips (right side) that hold the blue cable had snapped off.....
View attachment 2450658View attachment 2450659

This didn't help the heater valve isolate properly......

Might want to look at that clip to see that it is locked in place...

Thanks for posting those #'s @tmxmotorsports

Not a problem

 

[NCFJ]

The steam port dumping into a heater hose is a problem. The idea is to remove air from the cooling system. By dumping it into a heater hose it is putting that air right back into the system. The steam port needs to dump into the upper tank, top of a side tank, surge tank or upper heater hose to be efficient.

I use a bypass valve in all my swaps and will continue to do so. My personal preference is a mechanical fan. Unfortunately not all LS series motors are set up to take a mechanical fan. A proper shroud is a must! I use Ron Davis radiators in my swaps and at anything over 35-40 MPH in the middle of the summer, 95-100 degrees, electric fans do not even turn on and the trucks run around 195-200 degrees.

Keep in mind, these motors do not have common over heating issue in the vehicles from GM.

 

[Dumpolina]

@lonelydriver have you made any progress on this?
Im sorta in the same situation with an 83, a ranger and 4spd, 5.7 TBI with very very little waterpump to radiator clearance.
I was looking at fixed blade fans to eliminate the depth of the clutch but neither Derale or Flex-A-lite have available stock.
what size electric fans did you have that were not performing enough and where they shrouded?
Thanks!

 

[lonelydriver]

@Dumpolina check out this vid. Has my old and new fan. Old one is a pair of 12" spals.

New video by Kevin Chon

I have the old ones still if ur interested in a super thin setup.

Now that I redid the radiator setup a big issue I found with the old setup was the rad was sucking in hot air because there was big gaps between the radiator and the rad support. Wish I had tried addressing that first with foam to fill in those gaps before swapping fans but I was in there so I replaced fans since a bigger shroud doesn't hurt and and redid the foam.

I haven't had a chance to stress test the new setup as it's cold in LA now and truck is in body shop for a month for new paint.

 

[cruisermatt]

Just happen to have all that here for n up and coming lsswap in a Lx450

I've heard a few talking about the 2500/3500 fan and clutch as a upgrade but I looked up the part numbers and it looks like it's the same thing on all the GM trucks? 1500, Avalanche, etc?

 

[Dumpolina]

@Dumpolina check out this vid. Has my old and new fan. Old one is a pair of 12" spals.

New video by Kevin Chon

I have the old ones still if ur interested in a super thin setup.

Now that I redid the radiator setup a big issue I found with the old setup was the rad was sucking in hot air because there was big gaps between the radiator and the rad support. Wish I had tried addressing that first with foam to fill in those gaps before swapping fans but I was in there so I replaced fans since a bigger shroud doesn't hurt and and redid the foam.

I haven't had a chance to stress test the new setup as it's cold in LA now and truck is in body shop for a month for new paint.

That new set up is sweet! Do you have the Derale part number? I don't know if I have that much clearance, i'd like to look at the specs though

 

[rhah]

The steam port dumping into a heater hose is a problem. The idea is to remove air from the cooling system. By dumping it into a heater hose it is putting that air right back into the system. The steam port needs to dump into the upper tank, top of a side tank, surge tank or upper heater hose to be efficient.

I use a bypass valve in all my swaps and will continue to do so. My personal preference is a mechanical fan. Unfortunately not all LS series motors are set up to take a mechanical fan. A proper shroud is a must! I use Ron Davis radiators in my swaps and at anything over 35-40 MPH in the middle of the summer, 95-100 degrees, electric fans do not even turn on and the trucks run around 195-200 degrees.

Keep in mind, these motors do not have common over heating issue in the vehicles from GM.

thats where my steam port dumps into, have not had an issue with it yet at over 100k miles since i have done the LS swap

dual electric fans mishi moto 10 inch fans on a stock fj60 rad

i run a 167 thermostat and temps in the summer stay around 185-190, got up to 200 in moab this august in 115 degree temps outside

HUGE fan on the stock radiators they stay cooler longer and work great for the LS swaps, on my fourth fj60 swap and have swapped out x2 aluminum rads for the stock ones

yes yes yes a fan shroud is a must no matter what electric or mechanical

 

[rhah]

Do you have a recommended fan size, I believe there are a few options blade designs and diameters?

misho moto 10inch high output

 

[NCFJ]

Dumping the steam port into the system dumps air back into the system. Exactly why the steam ports are there, to remove air in the form of steam from the system. The design is for the steam to be dumped into the air space in the radiator or surge tank, the water condenses and mixes back in with the rest of the liquid in the system and the air remains in the tank. You are fortunate that it works dumping it into the heater hose and thus back into the system. Steam ports are easy to have put on a new radiator or added to an old one.

 

[lonelydriver]

That new set up is sweet! Do you have the Derale part number? I don't know if I have that much clearance, i'd like to look at the specs though

Derale Performance 16831 Gray/Black High Output Dual Radiator Fan

 

[cruisermatt]

Dumping the steam port into the system dumps air back into the system. Exactly why the steam ports are there, to remove air in the form of steam from the system.

Just curious, have you ever run one of these with the steam port left open just to see what happens?

 

[tmxmotorsports]

Just curious, have you ever run one of these with the steam port left open just to see what happens?

I had one with it ported into the water pump the water pump failed within two weeks so that is no longer an option for me.