Frustrated overheating, timing issue?

[69swb]

Originally Posted by rockyrivermark

Those temps are normal for a modern engine
You are not overheating

That’s already been answered twice and not the topic of this thread

[my kids toy]

69swb
I got the 14" fans and shroud and the fans are quieter then the 12", I am very happy about that because those 12" fans are loud, the 12" fans are 1400cfm each and the 14" are 2200 cfm each.

[Richard]

A remark on dual fans. IMO just running only one fan at any time is a mistake. Air follows the path of least resistance. If only one fan is running more air will just be recycled in the engine compartment through the other fan opening instead of being pulled through the radiator.

[SCOTI]

Originally Posted by Richard

A remark on dual fans. IMO just running only one fan at any time is a mistake. Air follows the path of least resistance. If only one fan is running more air will just be recycled in the engine compartment through the other fan opening instead of being pulled through the radiator.

What exactly is this statement trying to tell him/us? Can you elaborate?

[HO455]

I believe he is trying to point out that with the vehicle not moving and idling, running one fan may create a high pressure area under the hood and a lower pressure area in front of the working fan. The warmer air in the higher pressure area will bleed back through the area of the unused fan part of the radiator (Certain fan shroud designs will contribute to this) causing a net loss of radiator cooling ability.

As everyone knows the cooling ability of the radiator (at any given time) is determined by the difference in the averaged air temperature passing over the fins and tubes of the radiator and the averaged temperature of coolant passing through the radiator. If warm air is passing through the radiator from the engine compartment it is raising the average air temperature passing over the cooling fins and tubes thus the difference in temperatures is decreased.

[72c20customcamper]

Originally Posted by SCOTI

What exactly is this statement trying to tell him/us? Can you elaborate?

The air will move from the non operational fan through the working fan and not pulling through the radiator air is like water it will flow the path of least resistance . So in essence hot air being circulated . This would happen with a fan shroud not so much with fans mounted directly to the rad .

I’ve used duel fans on cars with a/c and one would turn on with the compressor . But the fans were isolated in the shroud with foam or like above mounted to the radiator like a trans oil cooler

[SCOTI]

Originally Posted by 72c20customcamper

The air will move from the non operational fan through the working fan and not pulling through the radiator air is like water it will flow the path of least resistance . So in essence hot air being circulated . This would happen with a fan shroud not so much with fans mounted directly to the rad .

I’ve used duel fans on cars with a/c and one would turn on with the compressor . But the fans were isolated in the shroud with foam or like above mounted to the radiator like a trans oil cooler

Gotcha. Thanks!

[RichardJ]

I don't agree. The open spaces around the sides and bottom of the engine would, in my opinion would offer far less air resistance than past the fan blade and cooling fins on the non-running fan. If enough air were to flow back through the non-running fan, you could expect that fan to start spinning.
I'm reminded of old fluid coupling drawings.
As in this image, shroud or not.

[72c20customcamper]

In a shroud like this there is no chance for air to come from the engine area without going threw the non running fan a proper shroud is sealed all the way around the perimeter of the radiator. This is my setup

[mr48chev]

Originally Posted by Lethal Tendencies

What temp were you running at to consider hot?

Again, an honest answer to his question rather than evasive wiggling around it would help.

230/240 might be hot on that engine. There are a lot of 350 Chevy Small blocks that come with a 205 thermostat and happily and efficiently run in their original installation but let some clown put one in an old car or old truck and he craps his pants because OMG it gets more than three degrees over the rating of the thermostat he put in the engine.

Water boils at 212 degrees, Each pound of pressure on the cap raises the boiling point 2 degrees, the percentage of antifreeze raises the boiling point even more. If that truck isn't puking coolant out of the overflow and out of the beer bottle onto the ground it isn't running hot. it is just running a bit hotter than you think it should because you have an older truck rather than a new truck.

Spal fans may not be an automatic improvement over any other fan, if you study their catalog you can have several units of the same size fan with greatly different CFM ratings. They are good reliable fans but just because it is a ___ inch Spal fan doesn't mean that it pulls the same air as another same diameter Spal fan. That is especially true with the 16 inch.

I've found in Chevy trucks that off brand temp sending units won't read correctly at times. I had to take what ever was in my 454 and replace it with the correct Delco sending unit.

Pertronix distributors and ignition aren't happy unless you run exactly the setup Pertronix tells you to verbatim. There is no mixing and matching other parts to a Pertronix distributor, you have to have their designated coil and every other piece they say to run.

Hard to crank when the engine is warm/hot. Those little skinny l12 V battery cables that you buy at the parts house just flat don't carry enough amps. Switching from 4 gauge to 1 gauge battery cables makes a serious difference in that department.

A heat shield on the starter also helps quite a bit.

I went the full nine yards on both my 71 and 77 and have the Ford Solenoid conversion on both. It took all three things to cure the 454's hot crank issues. That truck wouldn't crank over when it was hot but if you parked it where there was enough slope in the lot that it would roll at all you could clutch start it with if it was moving.

Still, Exactly how hot is that engine running exactly? 210/215 is just operating temp and not hot.

[72c20customcamper]

Originally Posted by mr48chev

Again, an honest answer to his question rather than evasive wiggling around it would help.

230/240 might be hot on that engine. There are a lot of 350 Chevy Small blocks that come with a 205 thermostat and happily and efficiently run in their original installation but let some clown put one in an old car or old truck and he craps his pants because OMG it gets more than three degrees over the rating of the thermostat he put in the engine.

Water boils at 212 degrees, Each pound of pressure on the cap raises the boiling point 2 degrees, the percentage of antifreeze raises the boiling point even more. If that truck isn't puking coolant out of the overflow and out of the beer bottle onto the ground it isn't running hot. it is just running a bit hotter than you think it should because you have an older truck rather than a new truck.

Spal fans may not be an automatic improvement over any other fan, if you study their catalog you can have several units of the same size fan with greatly different CFM ratings. They are good reliable fans but just because it is a ___ inch Spal fan doesn't mean that it pulls the same air as another same diameter Spal fan. That is especially true with the 16 inch.

I've found in Chevy trucks that off brand temp sending units won't read correctly at times. I had to take what ever was in my 454 and replace it with the correct Delco sending unit.

Pertronix distributors and ignition aren't happy unless you run exactly the setup Pertronix tells you to verbatim. There is no mixing and matching other parts to a Pertronix distributor, you have to have their designated coil and every other piece they say to run.

Hard to crank when the engine is warm/hot. Those little skinny l12 V battery cables that you buy at the parts house just flat don't carry enough amps. Switching from 4 gauge to 1 gauge battery cables makes a serious difference in that department.

A heat shield on the starter also helps quite a bit.

I went the full nine yards on both my 71 and 77 and have the Ford Solenoid conversion on both. It took all three things to cure the 454's hot crank issues. That truck wouldn't crank over when it was hot but if you parked it where there was enough slope in the lot that it would roll at all you could clutch start it with if it was moving.

Still, Exactly how hot is that engine running exactly? 210/215 is just operating temp and not hot.

210 to 215 in the head is normal as far as I'm concerned . If you compare the actual water temp at the radiator there can be a 10 to 15 differential. My big block runs at 195 to 205 in the head all day long ambient air temps above 80 without the fans coming on assuming im moving the fans come on aroung 210 in traffic , the water temp will be 195 kick off is 185

I had asked if the truck was puking antifreeze early in the thread never got a response .

[geezer#99]

Originally Posted by 72c20customcamper

I had asked if the truck was puking antifreeze early in the thread never got a response .

I asked that question in post #25 and his response was it goes thru the vent hose into a bottle and the end of the hose is always covered in coolant.

I suspect a problem with his overflow but he thinks there isn’t.

[mr48chev]

Originally Posted by 72c20customcamper

210 to 215 in the head is normal as far as I'm concerned . If you compare the actual water temp at the radiator there can be a 10 to 15 differential. My big block runs at 195 to 205 in the head all day long ambient air temps above 80 without the fans coming on assuming im moving the fans come on aroung 210 in traffic , the water temp will be 195 kick off is 185

I had asked if the truck was puking antifreeze early in the thread never got a response .

I have seen far too many guys who think that because the truck/car is older that they have to go into a panic if the temp gage gets more tad over 180.

A 15 lb cap with 50/50 antifreeze mix will have a boiling point of 268 degrees. 2220/230 shouldn't hurt a modern engine a bit. It might be hot for a babbit beater six or a flathead Vd8 but not a 350.

[jumpsoffrock]

Originally Posted by mr48chev

Still, Exactly how hot is that engine running exactly? 210/215 is just operating temp and not hot.

Originally Posted by 72c20customcamper

210 to 215 in the head is normal as far as I'm concerned . If you compare the actual water temp at the radiator there can be a 10 to 15 differential. My big block runs at 195 to 205 in the head all day long ambient air temps above 80 without the fans coming on assuming im moving the fans come on aroung 210 in traffic , the water temp will be 195 kick off is 185

I had asked if the truck was puking antifreeze early in the thread never got a response .

Originally Posted by mr48chev

I have seen far too many guys who think that because the truck/car is older that they have to go into a panic if the temp gage gets more tad over 180.

A 15 lb cap with 50/50 antifreeze mix will have a boiling point of 268 degrees. 2220/230 shouldn't hurt a modern engine a bit. It might be hot for a babbit beater six or a flathead Vd8 but not a 350.

He already responded to similar comments in post 51

Originally Posted by 69swb

That’s already been answered twice and not the topic of this thread

[Richard]

Originally Posted by 72c20customcamper

The air will move from the non operational fan through the working fan and not pulling through the radiator air is like water it will flow the path of least resistance . So in essence hot air being circulated . This would happen with a fan shroud not so much with fans mounted directly to the rad .

I’ve used duel fans on cars with a/c and one would turn on with the compressor . But the fans were isolated in the shroud with foam or like above mounted to the radiator like a trans oil cooler

I come from a HVAC background. Dealing with airflow issues. Installing and designing ducting systems for homes and clean rooms. Was going to comment on my post but there is no need. Others have addressed what I what I was trying to convey.

[72c20customcamper]

Nevermind

[69swb]

Just to follow up with everybody on my troubleshooting, since this thread has understandably stuck to the topic of overheating due to the thread’s title.

I never had an overheating issue. I had about 4 severely worn valve guides, a dished and chipped lifter and that corresponding lobe was completely wiped.

[geezer#99]

Your wiped cam will give you all your symptoms including overheating.
It’ll also be a wallet drainer.
Not cheap these days for a complete tear down, clean out rebuild.

[my kids toy]

Originally Posted by 69swb

Just to follow up with everybody on my troubleshooting, since this thread has understandably stuck to the topic of overheating due to the thread’s title.

I never had an overheating issue. I had about 4 severely worn valve guides, a dished and chipped lifter and that corresponding lobe was completely wiped.

part of your original post, this is why I posted about the rad.here is your words.
It seems to overheat, stalls at idle, poor throttle response, gets harder to time the longer the truck sits with the fans running, seems to get really hot when running the timing procedure.

[jumpsoffrock]

Originally Posted by my kids toy

part of your original post, this is why I posted about the rad.here is your words.
It seems to overheat, stalls at idle, poor throttle response, gets harder to time the longer the truck sits with the fans running, seems to get really hot when running the timing procedure.

atta boy, toys.

This thread became a bit of a rabbit hole. Either way, glad OP found the issue.

[69swb]

Originally Posted by my kids toy

part of your original post, this is why I posted about the rad.here is your words.
It seems to overheat, stalls at idle, poor throttle response, gets harder to time the longer the truck sits with the fans running, seems to get really hot when running the timing procedure.

Don’t bother reading the rest of the posts where I explain it’s not overheating.

[69swb]

Originally Posted by geezer#99

Your wiped cam will give you all your symptoms including overheating.
It’ll also be a wallet drainer.
Not cheap these days for a complete tear down, clean out rebuild.

Already doing it. Will be done this weekend.

[69swb]

Originally Posted by geezer#99

I asked that question in post #25 and his response was it goes thru the vent hose into a bottle and the end of the hose is always covered in coolant.

I suspect a problem with his overflow but he thinks there isn’t.

It’s a closed system. Coolant returns from the bottle but never gets so low the the hose sucks air. I thought I answered that question directly when I responded “the hose is always in coolant.” I didn’t have a coolant leak anywhere in the system. Thanks to you geezer for pointing me in some good directions. While janky, i feel the yeungling bottle setup with the submerged drain hose was better than the open system which came equipped with the truck when I bought it. If I’m misunderstanding some theory on this please educate me. I read through the post from the dude with the office space profile picture and seems like I’m on the right track. (That guy’s front swaybar writeup is awesome, too - used it a few months ago)

I don’t think i ever had an overheating problem. I think I had a worn valve-train which behaved even worse once warmed up problem. Once i had the engine pulled apart and compared my bad valves to their corresponding plugs (i still had two old sets marked per cylinder), everything made a bit more sense. Head and intake gaskets/surfaces looked good.

But hey, during my 4hrs driving to Summit and back this weekend in my wife’s 2017 Silverado, it stayed at 210 the whole time. Could somebody please help me sort out that overheating problem?

[geezer#99]

Just one more!
When you pull the rad cap off (cold engine), how far down is the coolant?

210 on a ‘17 would be perfect.
But staying there on the gauge all the time tells you not to believe the gauge. Factory gauges are only rough indicators of actual readings.

[69swb]

Originally Posted by geezer#99

Just one more!
When you pull the rad cap off (cold engine), how far down is the coolant?

210 on a ‘17 would be perfect.
But staying there on the gauge all the time tells you not to believe the gauge. Factory gauges are only rough indicators of actual readings.

After the system loses it’s overfilled amount (i fill to the lip of the cap when installing), i check every morning for a few days and the coolant was always at the same spot, maybe a 1/4” below the lip of the cap spout (2 or three rows showing) a few weeks later coolant at the same level, no leaking out of the overflow or anywhere else except after install when it dumped its overfilled amount.

I was just being cheeky about the 210 thing because people really glommed on to LS operating temp in this sbc thread.