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140 hp 4 carb engine temperature
Posted by: joewryan ()
Date: March 29, 2020 02:58PM

Went for a long drive on this beautiful Socal day. I'm sorta new to the car, so bear with me. The PO had removed the heater shrouds, so I replaced them. The mornings here are a bit cold. I did notice an increase of temp since the reinstall. Today the ambient was 65 F. When I first got on the freeway the temp was about 250 F, but once i got to freeway speeds of 65-70 the temp went up to 375 F. I can imagine that at higher ambient temps of 95-100 here the temps could be quite high.

What temp is acceptable here?

Joe Ryan

Valencia, CA

1965 Corvair Corsa Vert

1954 Corvette Vert

1999 Land Cruiser Behemoth

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Re: 140 hp 4 carb engine temperature
Date: March 29, 2020 04:07PM

Stay below 425-450 and you will be fine. I used to remove shrouds in summer and replace in winter but got old and lazy here in Alabama. Plenty hot here and no problem unless you climb a mountain.

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Re: 140 hp 4 carb engine temperature
Posted by: steve c goodman ()
Date: March 29, 2020 04:09PM

Joe you will get many comments and thoughts on your question. Here is only a couple and others will follow: In hot areas it is common to remove the bottom shrouds. I remove mine in summertime here too. The head temps are lowered 50 and even more degrees. Obviously wintertime has the shrouds back in place.

Now this is where you MIGHT run into some issues: cold temps with shrouds off make for lengthy warmup times so chokes are a least partially closed for way too long and fuel can wash the cylinder walls/pass through into oil also. SO the cure is don't do that. When temps high in summer remove and when cooler times arrive re-install. There are some that suggest even in summer heat the chokes are a bit slow and that can happen. Some will even unhook the choke rods and let choke plates stay open all summer. Your engine will start just fine with no chokes as long as accel pump squirt is good.

Now to change subject a bit: Is your your head cooling fins clean? Have they had the casting flash removed? If NO then you have answered a bit of the question of higher head temps. Also is every hole in fan shroud closed? Oil cooler cover/side shrouds on oil cooler/spark plug boots/dipstick boot/fresh air hose either good or opening blocked off/shrouds under your cylinders?

Last remember the temp gauge is not perfect accurate. 375 degrees is a tad high but many indicate that but actually less. Time with the car and listening for 'hot'sounds of detonation/run-on are helpful.

Sorry all, this has gotten too long, time for others to comment ggg

best wishes, Steve
Rear Engine Spec. Inc. Golden, Colo.

1962 spyder 3.0L turbo---1965 Crown V8
1967 monza 110/4---1968 monza 110/4
1971 amante gt 110/4
CORSA/RMC/PPCC/V8 Registry

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Re: 140 hp 4 carb engine temperature
Posted by: 63turbo ()
Date: March 29, 2020 04:18PM

joewryan Wrote:
-------------------------------------------------------
> Went for a long drive on this beautiful Socal day. I'm sorta new to the car, so bear with me. The PO had removed the heater shrouds, so I replaced them. The mornings here are a bit cold. I did notice an increase of temp since the reinstall. Today the ambient was 65 F. When I first got on the freeway the temp was about 250 F, but once i got to freeway speeds of 65-70 the temp went up to 375 F. I can imagine that at higher ambient temps of 95-100 here the temps could be quite high.
>
> What temp is acceptable here?
>
> Joe Ryan

You never want the heads to go past 350F. The maximum temperature that the heads can go to without losing any hardness at all is 320, and 350 is generally considered to be the maximum temperature without losing enough hardness to matter, but it is all down hill at higher temps. If you need to have the shrouds off to keep it to 350 or less, do it.

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car



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Re: 140 hp 4 carb engine temperature
Posted by: joewryan ()
Date: March 29, 2020 04:22PM

Thanks Ralph.

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Re: 140 hp 4 carb engine temperature
Posted by: joewryan ()
Date: March 29, 2020 04:30PM

Thanks to all. I have closed off all known holes and seals, but I have not deflashed/cleaned the head fins. I'll set that as a Covid project this week! Also, I am running Shell Rotella 15w-40 oil. Is that too thick? Can that thick oil contribute to the increased temp? Most recommend Rotella 10w-30, even in my warm desert climate.hot smiley

Joe

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Re: 140 hp 4 carb engine temperature
Posted by: 63turbo ()
Date: March 29, 2020 04:34PM

Here's a link to a article by Bob Helt (deceased) that shows how the temperature, time at temperature are related to hardness. It shows why it is so bad to be running the engine past 350.

[www.corvairs.org]

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car



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Re: 140 hp 4 carb engine temperature
Posted by: 66vairman ()
Date: March 29, 2020 04:38PM

Joe - PM sent.

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Re: 140 hp 4 carb engine temperature
Posted by: Timothy Shortle ()
Date: March 29, 2020 05:18PM

Kind of a scary article but thanks for posting it Kevin (and thanks Bob [RIP] for posting it).
Wasn't Bob a member at one time of the Tuscon Corvair Club?

I seem to remember back in the 80s my 66 Corsa with A/C running at about 400 constantly on a hot
So Cal day and I felt since it stayed consistent it was a normal temperature. This car was in a
stock configuration w/ lower shrouds.

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Re: 140 hp 4 carb engine temperature
Posted by: vairmech ()
Date: March 29, 2020 08:06PM

In addition to what Steve said about the fresh air hose put a block off plate there anyway, even with the hose on.

With everyday use and abuse, I know what the numbers say, but anything steady between 325 and 375 is good. I have even had an engine run as hot a 425, yes it was that hot, and the engine never failed me. Many have indicated 375 while cruising on the freeway for hours, again never had an issue.

Ken Hand
Handy Car Care
248 613 8586

Vairmech@aol.com

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