454 Tends to Overheat???

[kmpro]

Several M/H owners have said they have had problems with the 454 overheating. Has this been true of the AS 310? Mine has extra Air vents in front and a vent on the right and left side just above the front wheels. Anybody had experience with this problem?

[Mike Leary]

The old story is to put the steak, potatoes and corn on the manifold; drive fifteen minutes, dinner ready; the 454s run that hot.

[guy99]

Many people here have reported battles with engine temp. Based on experience I can say the first thing to do is validate and/or correct your engine temp readings.

I run 180-195 unless climbing or idling in hot weather. A product called "water wetter" seems to help as do headers, unplugged radiator, oil cooler, and properly functioning fan clutch.

[ROBERTSUNRUS]

Hi, an engine doesn't overheat until the coolant is puking onto the street no matter what the gauge reads.

Water boils at 212 degrees.

Add 3 degrees for every pound of pressure. [cap]

Usually a 15 pound cap and that gives you 45 more degrees.

Now you are at 257 degrees.

Add another 30 degrees to it if you have the pressure cap and a proper 50/50 mixture of coolant.

Now we are up to 287 degrees max before actual overheating ocurres.

[Boom Sounds]

Fan clutch is usually the problem. Heavy duty replacement is 60 bucks from Autozone

[Mike Leary]

I like my steak rare, so a dinner on a 454 exhaust manifold should only take 7.5 minutes.

[easyride]

Originally Posted by ROBERTSUNRUS

Hi, an engine doesn't overheat until the coolant is puking onto the street no matter what the gauge reads.

Water boils at 212 degrees.

Add 3 degrees for every pound of pressure. [cap]

Usually a 15 pound cap and that gives you 45 more degrees.

Now you are at 257 degrees.

Add another 30 degrees to it if you have the pressure cap and a proper 50/50 mixture of coolant.

Now we are up to 287 degrees max before actual overheating ocurres.

Now how did you come about the extra 30 degrees to get up to 287,I think a 50/50
solution is good to a min of -20 F,most people don`t need that high of a solution ,the antifreeze people like to make you think you need it for cooling which is a falsehood,the best heat conductor is pure water.
I run water and a corrosion inhibitor,which works fine for me. Dave

[345bill]

I've got to second what Guy99 said. First thing I'd do is verify your temp. readings. The factory dash guages that we all have are not that accurate, I think that's why alot of those reports get started. I live in the desert so engine temp. is something I watch carefully and though I'd like it to run cooler than it does mine has never gotten to the point of overheating or even hot enough to be really concerned.

I wasn't hungry when I started reading these posts but now I'm suddenly looking for dinner, think I'll start er-up, get some tin foil ......

[Mike Leary]

Originally Posted by 345bill

I wasn't hungry when I started reading these posts but now I'm suddenly looking for dinner, think I'll start er-up, get some tin foil ......

Yup, it's not the water, it's those stupid manifolds. Bon appetit.

[osolow]

water has draw backs it freezes at to high a temp boils at to low a temp and causes metal corrosion

coolant helps water buy lowering its freezing point raise the boiling point it also reduces foaming and cavitation and prevents rust and corrosion.
yes some places don't need a 50/50 mixture but its easy to remember and mix up that way.
Basically coolant makes water better in the long run.
and yes i had to pull a book of the self to paraphrase this but i wanted to get it right, and i had the book how cool is that?

[ROBERTSUNRUS]

Originally Posted by ROBERTSUNRUS

Hi, an engine doesn't overheat until the coolant is puking onto the street no matter what the gauge reads.

Water boils at 212 degrees.

Add 3 degrees for every pound of pressure. [cap]

Usually a 15 pound cap and that gives you 45 more degrees.

Now you are at 257 degrees.

Add another 30 degrees to it if you have the pressure cap and a proper 50/50 mixture of coolant.

Now we are up to 287 degrees max before actual overheating ocurres.

Originally Posted by easyride

Now how did you come about the extra 30 degrees to get up to 287,I think a 50/50
solution is good to a min of -20 F,most people don`t need that high of a solution ,the antifreeze people like to make you think you need it for cooling which is a falsehood,the best heat conductor is pure water.
I run water and a corrosion inhibitor,which works fine for me. Dave

Hi, Dave. I got this information from General Motors mechanic's training school. It was from their engineers, to explain on GM vehicles the fact that their vehicle's overheat warning light would come on at 262 degrees. So if these vehicles had water only and a 15 lb radiator cap, they would puke their guts at 257 degrees and the warning light would never come on. Therefore it was necessary to have a 50 / 50 mixture of coolant to bring the max temp to 287 degrees.

And yes you are correct that pure water is a better conductor of heat, but that's all. Water does cause corrosion, it freezes sooner, and the ultimate boiling point is lower. [good idea to use the corrosion inhibitor]

[osolow]

Originally Posted by ROBERTSUNRUS

Hi, Dave. I got this information from General Motors mechanic's training school. It was from their engineers, to explain on GM vehicles the fact that their vehicle's overheat warning light would come on at 262 degrees. So if these vehicles had water only and a 15 lb radiator cap, they would puke their guts at 257 degrees and the warning light would never come on. Therefore it was necessary to have a 50 / 50 mixture of coolant to bring the max temp to 287 degrees.

And yes you are correct that pure water is a better conductor of heat, but that's all. Water does cause corrosion, it freezes sooner, and the ultimate boiling point is lower. [good idea to use the corrosion inhibitor]

Wow you got a way better memory then me i had to pull a book off the self to remember that

[GlenCoombe]

Originally Posted by guy99

Many people here have reported battles with engine temp. Based on experience I can say the first thing to do is validate and/or correct your engine temp readings.

I run 180-195 unless climbing or idling in hot weather. A product called "water wetter" seems to help as do headers, unplugged radiator, oil cooler, and properly functioning fan clutch.

Yup, get a point and shoot temp gauge. I put the old "belt and suspenders" to work and added a big electric puller fan on the outside of the new radiator.

The gauges could be lacking ground. Once had a Mooney 231 with bad trend of rising temp and dropping oil pressure that had me land just outside of Minneapolis as a precaution. Mechanic comes out and shoots temp gun, all is o.k. Then he says to me watch. He proceeds to push gently below the two gauges on the panel and low and behold the darn things drop back into normal range. It was a very special moment.

While you're in there do change out the thermostat. I run a 160 degree and short of climbing hills never see a temp above 180 on Airstream One.

Headers will help dissipate the heat much better but won't help cook dinner quite as well as the old cast iron manifolds.

[kmpro]

My 454 runs at about 205 on the dash gauge so maybe it's not overheating after all. FO said they had the system flushed and new coolant in 50/50 mixture put back in the system. We'll see how it works on the road. Fan clutch seems to be OK, but Radiator hoses and heater hoses and the bypass hose look like they need replacement. Someone has added the fans in front of the A/C condenser so maybe I can keep the Silver Hornet cool.

[GlenCoombe]

Check the thermostat as well and then point and shoot to verify the gauge is correct.

Stay cool.

[kmpro]

Thanks Glenn. I am always suspect of dash gauges anyway. I will know more when we head South with the toad for a 300 mile round trip to Abilene as a test run. Later we plan to go North to Denver which will include pulling Raton Pass with car in tow. If the Silver Hornet will overheat, it will be up the long pull up Raton Pass. Our diesel pusher would have a temp rise of 20 degrees up the pass. I am hoping we can have less on this unit. Our other gasoline m/hs have not been a problem on Raton, but the Silver Hornet may be different.
Mike

[kmpro]

Glenn, after much freeway driving and stop and go in traffic I am happy to report temp got up to 215 degrees without using auxilary fans. Of course it was'nt 100 degrees out today either. Temp stayed at 215 and varied some when the fan clutch would kick in, but that seemed to be where thermostat and fan kept it.
Mike

[VIKING]

Originally Posted by kmpro

Thanks Glenn. I am always suspect of dash gauges anyway. I will know more when we head South with the toad for a 300 mile round trip to Abilene as a test run. Later we plan to go North to Denver which will include pulling Raton Pass with car in tow. If the Silver Hornet will overheat, it will be up the long pull up Raton Pass. Our diesel pusher would have a temp rise of 20 degrees up the pass. I am hoping we can have less on this unit. Our other gasoline m/hs have not been a problem on Raton, but the Silver Hornet may be different.
Mike

My first drive ever in a moho was from San Jose to Black Rock City, Nevada, which took me up highway 80 into the Sierras, past Lake Tahoe and Reno. I was in a 30' Fleetwood with a 454, and I learned a lot about driving it uphill. If I didn't keep my speed up on grades it would drop a gear and never recover it until it got fairly level. It would run cool and smooth at 60 to 65mph uphill as long as I didn't let up on the pedal, though. In Gerlach, Nevada it was 107 degrees, and as I slowed from 65 to 25 to go through town(lined with police and rangers) it vapor-locked on me and I had to wait until night for it to cool enough to run again. An old codger on a porch across from where I stalled told me he sees it all the time, because of the heat and the slow limit as you go through town. In fact he told me that I had a 454 with vapor lock before I knew what it was or what was wrong with it, and this from across the street!

Rich the Viking

[GlenCoombe]

Originally Posted by kmpro

Glenn, after much freeway driving and stop and go in traffic I am happy to report temp got up to 215 degrees without using auxilary fans. Of course it was'nt 100 degrees out today either. Temp stayed at 215 and varied some when the fan clutch would kick in, but that seemed to be where thermostat and fan kept it.
Mike

Mike, in about half an hour and for about $10 you could be running cooler.

Just swap out the thermostat for a cooler one. I'm running below 180 on the highway at 68 mph / 2600 rpm / electric fan on, though it's flat here except for the bridges mostly.

[kmpro]

Sounds like a plan, Glen.