Driver Side head runing hotter than the passenger side

496BBC

Well-known member
Joined
May 13, 2008
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210
Location
Deep in the marsh, South Louisiana
Still working on the temp issues with my car. I've got control of the temps but am not ready to say I have no issues.

I'm seeing the temp at the water outlet of the heads at the front between the heads and the T-stat showing a pretty good difference form the driver side to the passenger side. With a 180* stat in I have 205* on the driver side and 155* on the passenger side. These tmeps were obtained with an IR gun shooting the intake right at the outlet of the head. I also have a sending unit on the intake between the head and the T-stat on the drivers side and one on the intake between the passenger side head and the T-stat both are pretty close to the IR gun readings.

I have seen this before and was thinking it may be due to the exhaust vlv is in the front on the driver side head and the intake vlv is on the front of the passenger side head so this may cause a temp difference but this is a rather large difference.

What is yawls thoughts on this?

Maybe someone with a temp gun can take some readings of theirs and see if there is a temp difference.

Thanks Neal
 
How long did you measure? Do you know how the cooling system in a SBC actually flows, where the 2 sides battle it out for dominance and alternate over who flows out the thermostat? I think I posted it here sometime earlier. It's the reason you see those Y manifolds on sprint cars and 4 corner bypass hoses and sometimes even mid head bypasses to even out the temps

What I'm saying is...it may be normal, you want a mean temp reading. Rear it from both sides over a period of time.
 
I've been working on it for a few days now, I've allowed it to idle in the driveway for 20 minutes or so and its been the same thing. I've also driven it around town and noticed it to do the same thing.

I've driven the car for around 30 minutes to see if the temps would swap around or stay as indicated. The temp off of the passenger side head stays cool and the temp off of the drivers side head stays hot. The one thing that is odd on the drivers side head is that the temp swings a good bit, say form
190* to 230* while driving. The temps off of the passenger side head will swing a small amount, say 170* to 180*. I'm able to take temp readings off of three positions on the intake, one between the drivers side head and T-stat, one between the passenger side head and T-stat and one right below the T-stat on the front of the intake. The one right below the T-stat and the one between the passenger side head and the T-stat read close to the same. The one between the drivers side head and the T-stat is higher and swings more.

One other thing I noticed today is the cooling system with a little air in it does not build as much pressure as with a totally full system.

I took my car to the radiator shop today to have it checked for exhaust gases in the radiator. They found none but during the process of checking I lost some coolant.

I have a pressure gauge mounted in the intake to see what kind of pressure the cooling system runs at. With the system full of water it would run at 12 psi with the engine hot, even after turning the engine off the system pressure will hold at 12 psi until cool. I checked it once I got to the radiator shop, the shop is across town around a 15 minute drive across town. Once I took the cap off and we did the test the pressure was back at 0. When I arrived at home I checked the pressure and it was at 7 psi. This is the first time I've noticed this so I'll have to run this test again.

Neal
 
Neal,

I'm assuming (from 496BBC) you're talking about a big block? If so, do you have the by-pass hose from the intake to the water pump installed?

I'm running a BBC and have a 180 thermostat in it, with a 195 for the fans. The guage is connected to the drivers side head, the fan switch to the passenger side head and the ecm is connected to the intake between the thermostat and the driver side head. The fans come on after the gauge hits 180 so that seems correct, and the ecm won't allow the coverter to lock up until the gauge gets near 180 so that sensor seems to be reading similar to the others.
 
I do have the bypass hose connected, but to increase cooling capacity I ran the bypass hose through two heater cores mounted in the fornt bumper behind the grills.

I may try and bypass the heater cores and put the bypass hose as it was from the factory.

Neal
 
I do have the bypass hose connected, but to increase cooling capacity I ran the bypass hose through two heater cores mounted in the fornt bumper behind the grills.

I may try and bypass the heater cores and put the bypass hose as it was from the factory.

Neal

I would suggest that. What you have now is two separate cooling systems. I wonder if those heater cores interupt air flow to your radiator?
Bee Jay
 
I agree with Bee Jay. I have an aluminium radiator (three core) and two fans pulling about 3000cfm. And have zero heating issues. Actually I had to go with a hotter thermostat to keep the eninge at operating temp. Why do you need the extra capacity?
 
I've struggled with controlling the temps since I installed the BB in my car. I'm just now able to hold the temps at 180* after all the upgrades to the cooling system. Through suggestions here I've got a list of possible causes so I've been working on them one at a time to see if maybe I've missed something that may be causing my engine to be running a little hotter than it should.

I've looked over a lot of cooling issue threads here and at the other site and there are basically two types; issues that start randomly and issues that start after a new engine install or part of the cooling system is changed and that cooling issues start.

There are many BB that run without any cooling issues but there are many that are having cooling issues to that are installed in vettes.

I had no cooling issue prior to the BB install.

I'm just working any possible causes before I through my hands up and say its just the heat generated by the engine.

Neal
 
Well I removed the two heater cores up front and put the bypass hose back to the way it was form the factory. Backed the car out of the shop and let it warm up, temps were solid as a rock, no fluctuating.

For now both the temp gauges are reading very close to each other and stable.

That's the second time I've tried to remove or re-rout the bypass hose and both times its caused the temps to fluctuate wildly.


I guess the Stewart Stage IV pump needs it to stabilize flow through the heads.


Neal
 
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Well I removed the two heater cores up front and put the bypass hose back to the way it was form the factory. Backed the car out of the shop and let it warm up, temps were solid as a rock, no fluctuating.

For now both the temp gauges are reading very close to each other and stable.

That's the second time I've tried to remove or re-rout the bypass hose and both times its caused the temps to fluctuate wildly.


I guess the Stewart Stage IV pump needs it to stabilize flow through the heads.


Neal

Just curious, did you add the heater cores after you dropped the BB in?
 
You added cores to the bypass hose? It's not a bypass hose in that it bypasses the thermostat, it's an anti cavitation line. With a restriction in it, the pump will cavitate and this severely affects pumping volume, even completely stalling flow. No wonder you had those funky readings.
 
Yes I added heater cores to the bypass line to add some cooling.

It was recommended to remove the bypass line all together when I tried to remove it the temps would swing. The thinking here was a lot of hot water was bypassing the radiator and could be adding to the heating issues I was having so removing the bypass line would force all the water form the engine to pass through the radiator. Well along the same lines I added two heater cores to the bypass line to allow some water flow but to also add some cooling along with it. This seems to have caused enough disruption in flow to cause the pump to cavitate.

After I put the bypass line back like it should be the temps form each head are within a couple degrees of each other.

Neal
 
Sounds like it's all sorted out now! The next trick is to see how it works in August with the A/C on and in traffic. That's what I'm waiting for, if it stays cool then, all is right with the world!! :)
 
Sounds like it's all sorted out now! The next trick is to see how it works in August with the A/C on and in traffic. That's what I'm waiting for, if it stays cool then, all is right with the world!! :)

I dunno Dave, the way this hemisphere is cooling now, it maybe AUGUST before you can pull that test....:bomb::sos:
 
No kidding, the fountains here at the house have been frozen the past two mornings!!! Next thing you know we'll be shoveling driveways. That damn George Bush and his global warming!!!!:lol:
 
No kidding, the fountains here at the house have been frozen the past two mornings!!! Next thing you know we'll be shoveling driveways. That damn George Bush and his global warming!!!!:lol:

HUmm...so there is, on the front pot, pump running but a skin of ice....

shit....

:bomb::ghost:
 
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