How high a steady temp is safe to run?

[DocDirk]

Yesterday the temp topped 105F as is often does in the summer here. I took the cobra out for a cruise midafternoon and it rose gently to stop at 210F fully hot and running on the freeway after 20-25 minutes. In town traffic caused it to rise a bit further to about 215F. Oil pressure dropped from usual 38-40# running down to about 32# while running, 20# idling.


I've optimized the cooling system by every possible move short of shrouding the front to the radiator which I will soon be doing and in ambient temps under 95F it runs very nicely from 185-195F.


Summers are really hot here; I know some of you Texans and Arizonans have high temp outdoors experience...how high can I run a stable temp. without harming the engine? Should I be measuring oil temp too? Cylinder head temps?

Thanks for any replies!

Dirk

[FWB]

Originally Posted by DocDirk

Yesterday the temp topped 105F as is often does in the summer here. I took the cobra out for a cruise midafternoon and it rose gently to stop at 210F fully hot and running on the freeway after 20-25 minutes. In town traffic caused it to rise a bit further to about 215F. Oil pressure dropped from usual 38-40# running down to about 32# while running, 20# idling.


I've optimized the cooling system by every possible move short of shrouding the front to the radiator which I will soon be doing and in ambient temps under 95F it runs very nicely from 185-195F.


Summers are really hot here; I know some of you Texans and Arizonans have high temp outdoors experience...how high can I run a stable temp. without harming the engine? Should I be measuring oil temp too? Cylinder head temps?

Thanks for any replies!

Dirk

dirk,
i don't think it will hurt it, i have hit those temps now and then. i have also pulled over sometimes,when i can, and let her cool off. the shrouding may help, but when its that hot out there isn't much you can do to prevent it. if you know your going to be driving in extreme temps, you could turn the timing back a couple degrees, that usually gets me around 10 degrees less temp.

Fred

[Rick Parker]

Dirk if you do not already have one consider an oil cooler. When the 385 series was packaged in a Truck for trailer towing with an Automatic it always had an oil cooler of some sort. You have obviously stepped up the HP significantly, it's another means to get rid of heat.

[DocDirk]

Thanks Fred and Rick,

I'm running an oil cooler and a tranny cooler.... they're finned cylindrical units and they're in front of the radiator top and bottom...I'm wondering if moving those out from in front of the radiator would make a significant difference in cooling capacity? It would be a PITA but I'd be willing if it would contribute.

Primarily I'm hoping that I can run at 210-215F summertimes without longterm adverse effect on engine quality or longevity. I presume Fred that you don't think that would be the effect. By moving the timing back a couple of degrees 10 degrees cooler, wow that's a real bonus...I'll give that a try! I'm running 15 degrees base with 32 total in by 3200 RPM.

Thanks again for your responses

Regards,

Dirk

[jdean]

Dirk, although 215 is higher than most would like to see, you can run all day and not damage anything.

[fastraxsg]

Add some Water Wetter to the radiator for a bit of help....

[Bobcat]

We are seeing upper 90`s to low 100`s here now . I see about 190 at a stoplight and it drops to 180 to just under 190 when moving . I`ve got a Ponds 482 engine . I`m surprised your timing is that low .... my engine wants and needs 38 degrees for a max and about 20 degrees when idling ( 800 to 900 rpm ) . When I retarded my timing , it ran slightly hotter .... but then everyone`s engine and location is different .
The location of those two coolers may be dirtying up the air through the radiator .... try a smoke test and see how the airflow is . I have nothing in front of my radiator .
On my race car some years ago , we ran a consistent 200 degrees and oil as high as 230 degrees . One of my friends who is involved with NASCAR said his team ran some tests and found best power and life with a water temp of 195 to 200 and oil temp about 200 to 210 degrees ... but that was for their specific engine combination . They also wouldn`t hesitate to run 210 degrees on water during a race .... and they ran water ... NOT antifreeze/water mixture .

[kitcarbp]

Dirk, I have not seen an updated pic with your new SPAL fan, but there are improvements that can be made your existing alum. shroud to help with highway cruising temps in terms of getting more CFMs through the core. Air flaps can be added to the shroud to get the extra airflow through that core. Now, your air is forced to travel through the back half with a diameter opening (16.5" or so).

SPAL can get you ( you probably need to call the tech line) their rubber flaps that are used on their twin fan shrouded assemblies that can be installed on your current shroud (need to remove shroud for this). You can also make your own with rubber material. see pics found on a site where this work was done to a 60's muscle car. The documented results in this article showed highway temps dropped 7 degrees F after the changes were implemented (flaps are just one item). They ultimately concluded the SPAL fan did not need the aluminum shroud and mounted fan directly to core. Shroud removal is a PITA of course. Shrouding air in front of rad is very important to help keep flow moving through the rad and will also help. Article link uses flexible material to seal off rad sides to accomplish this also. check this out.


http://www.highperformancepontiac.co..._radiator.html

[mdross1]

You probably do not remember that the 60's big block vets used to run near 230 degrees all the time.The oil back then was no where near as good as it is today.My 460 runs at 195 all the time,in traffic it may creep up over 200,by then the electric fan is running constantly.Running synthetic oil is the way to eliminate that fear.

[John S Peterson]

Dirk: Think about what all the Nascar boys do......They run as much pressure as the radiator will allow. You could always bump up to an 18lb cap, that will bring your boiling point up to 250-260 degrees F. Most newer vehicles the fans don't even come on until 220-230 anyway.