passenger side of the motor running 20 degrees hotter than driver side

[tubman]

I think we are all assuminging (probably correctly) that he has iron heads, but he has never said explicitly.

[RandyMettler]

Tubman,
"I think we are all assuminging (probably correctly) that he has iron heads, but he has never said explicitly."

I have finned aluminum offys. I torqued to 40 pounds as per VANPELT specs at "35-40". I am going to re-torque twice more. Torque after each heat cycle and keep the torque wrench at 40 pounds, no more.

[Kurt in NJ]

I put a 49 Merc in the truck we used for flea markets, I converted to duals, one side kept the original truck muffler, the other side I had a near brand new mustang 302 muffler, on hard pulls that side would overheat, the muffler that was good for a 302 was too restricted for 1/2 the flathead, got another truck muffler and no more problems

[RandyMettler]

Kurt in NJ

I have true dual exhaust, original exhaust manifold with dual glasspacks. Both sides with the identical setup. Wish my solution was that simple.

Regards

[aussie merc]

wouldnt worry to much sounds to me just a case of miss matched thermostats easy enough to check remove them and place in a pan of cold water and bring to boil they should open together as matched pairs are near impossible to buy these days so you just have to keep trying and get a pair thats reasonably close took me 5 thermostats to get a pair that was close

[tubman]

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Have you tried swapping the thermostats side to side? That's the first thing I'd do,

[RandyMettler]

Yes, I I've tried that. Good advice though. I had original ford thermostats that I took out and water tested, they passed. I purchased two Speedway Stats for a possible cheap fix. It was a waist of money, although I knew it would be. I water tested them before installing. They passed at 180 degrees. Same results as original thermostats, as it should be. Both sets open at roughly 180.

I have run without thermostats to test flow restriction. I don't get any noticeable change in the passenger side running hot.

I have had both water pumps off and they are smooth and tight.

The temperature drop on the driver side of the radiator is about 10-15 degrees cooler at the bottom of the radiator outlet tube. The temperature actually increases as the fluid drops down the passenger side of the radiator. The bottom outlet of the radiator gets as high as 20 degrees warmer at the bottom. I don't see and leaks in the new radiator.

Its almost like the passenger water pump has the impeller mounted on backwards. I know this is not possible.

The radiator is a new aluminum, an electric puller fan with a full flush mounted shroud. I have the fan currently set up to run continuously. When the sheet metal is installed, the fan will hold a piece of paper on the outside of the grill, so I don't believe airflow is an issue.


I am repeating myself a little but no water jacket restrictions, no head leaks, blue test fluid stayed blue, oil is staying the color of oil, valve tappet lash recently set. Motor sound smooth with no ticks or taps. The tick I had after head installations went away after retorque procedures. (Thank God)

The one unverified thing is the ignition timing. I do not however see how that would only affect one side of the block.

Thanks to barners reply's, I am now testing with the pressurized cap off.

Regards

[ReggieK]

I had a Dodge Chassis Motor Home that was running so hot on the right side that the exhaust manifold would be a cherry red after about two hours of hwy running. I checked everything I could think of. One day it came to me while I was putting new plugs and points and going through the carburetor, I found that the right side jet was .010 smaller than the left, drilled it out and exhaust ran normal. Like I said this was a Dodge, my first and last, and it came from the factory this way. Considered installing Ford running gear, but decided to just sell it. I have always been told you can't make a silk purse out of a Sows Ear!!

[JWL]

If there is higher compression on one bank than the other the low side will run hotter.
Also, the Flathead block is designed with longer intake ports and shorter exhaust ports on one bank. That is the primary technical reason one bank runs cooler than the other.

[revkev6]

Originally Posted by JWL

If there is higher compression on one bank than the other the low side will run hotter.
Also, the Flathead block is designed with longer intake ports and shorter exhaust ports on one bank. That is the primary technical reason one bank runs cooler than the other.

this. JWL knows better than I, but I've often heard that 10 degrees was common just due to the port differences. if you have offy heads... i would be wondering if you have higher compression on one side. when I assembled my 8ba there was a .010 differences in deck height left to right bank. I had the heads cut to fit...

[RandyMettler]

JWL and revkev6 response to your comments:
"If there is higher compression on one bank than the other the low side will run hotter."


I checked the compression and all cylinders are close to 110. I do have offy finned heads and an offy intake with dual 94's.

All jets in the bowls are 47's.

I have new dual exhausts with original exhaust manifolds and they have good compression at the tail pipe based on feeling the pressure with my hand.

[46kustom]

When you replaced the coolant, did you refill through the radiator or did you fill the block first? I say this because I had a similar issue and found it to be a airlock in the block. so I now fill the coolant to the thermostat level in the block, refit the top hoses then top off the radiator. now runs petty even on both banks.

[RandyMettler]

46kustom
In response to your question,
"When you replaced the coolant, did you refill through the radiator or did you fill the block first?"


No, I just filled the system at the top of the radiator cap. I rigged a test using a vacuum cleaner tube to check circulation for each side. I disconnected the chrome radiator "riser" tube going into the top inlet of the radiator and hooked the hose up to that and taped the joint. Then refilled the radiator and started the car while maintaining the coolant level. I had flow out of the vacuum cleaner tube, but in spirts, and seemed a little weaker than what I expected. The "spirts" is what bothered me. I don't know if a air bubble would cause the inconsistent fluid transfer?

Don't try this test unless you add lubricant to the water and have lots of water at hand to keep the level as full as possible. Really a two person job. I captured my water in a clean container to reuse. If the pumps run dry you will have to rebuild them.

The picture is of the driver side test. I tested both sides, similar results.

Thanks for your comment.

[46kustom]

When trying to sort my issue, I tried a similar test, I had good flow on the right hand bank and poor flow/zero on the left, I assumed I had a duff water pump. Like a goon,I replaced both pumps and found I had the same result, that's when I decided to try filling the block with coolant before finally topping off the radiator I think it may be worth you giving my idea a try...you have nothing to lose.
Good luck

[RandyMettler]

46kustom
In response to your suggestion,
"I think it may be worth you giving my idea a try...you have nothing to lose.
Good luck"

Yes I absolutely am going to drain the radiator fluid and refill the block first then the radiator. Your suggestion makes since. I will post my results when tested.

Regards