Hot Rods 55 Chevy heating up-advice pls.

55 Bel Air--had it forever
History-drove as our main car for many years. Engine is a 30 over 327 with 9.5 comp and a Sig Erson split duration cam. All the years we drove it, it never got hot-had an iron powerglide, 4 blade stock fan, no shroud and radiator in V8 location. Mech gauges installed about 1988?
Some yrs ago freshened the engine(no over bore), added a 700R4 and vintage air-also a vintage air shroud and 6 blade fan and elec pusher that comes on at 180 or with A.C and a Griffin radiator.
It will run up to 180-185 idling with the ac on and the fans on--checked with temp probes in radiator.
It also goes to 180-185 when driving with no ac on (thermostat is 160-new with small hole drilled)
Some times in traffic it will push 200+.have both mechanical and stock heat gauge (56 elec)
What I found-160 or 180 thermostat makes no difference (as it shouldnt)
-has never puked-has 50/50 antifreeze-always has
-goes up about 10 degrees with ac on
- water flowing well thru radiator with cap off
-top hose and bottom hose have a max of 15-20 degrees drop across radiator (strange)
-it did the same with a stock 55 radiator that was rodded and cleaned in this same configuration except I didn't check temp drop across radiator
-without the ac condenser it would never get hot with either radiator
Put a large portable fan in front of the car-no change.
I'm baffled especially by min temp drop across radiator
I know this isn't extremely hot but it is borderline and could get worse when it's 100
How much heat does the 700R4 add (it is in the rad tank)
Thank you in advance for any advice.

 

Don't know if it would help your case, but I always preferred a separate isolated trans cooler and not run it through the radiator

 

THX I'm thinking that too--always do it on the 40's I build

 

i have used puller fans with better results , agree with upspirate on cooler ......

 

Vacuum advance on distributor hooked up?
Manifold or ported Vacuum, it can make a lot of difference.
Manifold Vacuum hooked up to Vacuum advance on a properly set up distributor can cure a lot of over heating, or border line hot issues at idle.
With all the Beautiful 40's you have built I know this is not your first Rodeo, you will sort it out.
Oh, Pics of the 55 would surely be a great idea too!

 

sounds silly, but maybe try removing the pusher fan completely, and see how it does?

but having pictures would sure help.

And no, 200 is not too hot.

 

Wouldn't he need some kind of fan that comes on with the AC? What did they do before electric fans with a/c cars?

 

they had a bigass mechanical fan and a shroud, and it works fine.

 

I don't like your choice of radiators. Gasoline nowadays is going to make some difference in temps. As above the timing and carb setting. But you already know all this. Not unusual to run 190-5 these days. How close is the condenser to the radiator? I'm sure your aware of the depth of the fan into the shroud. Lower hose collapse? Be sure to ground the radiator with a good strap.

 

More info-65 327 L79 intake, afb,461X heads 69 DZ "480" distributor-full vacuum-timed on the money and vacuum gauge used too-engine was a circle track item built by Chris Zoodis (sp) in Healdsburg-won Championship at Lakeport Speedway in 81-82-Runs strong and is the same as it has been since 82-just refreshed and ac.700R and other stuff done that caused the change..
Squirrel-took off the pusher-no change except went up 5 degrees when ac came on without elec fan. The strange thing is the minor temp drop across the radiator. Usually it's 35-45 degrees on the 40's with ac ,etc-this one max is 20-mostly 15-doesn't sound right.
Condenser is 1/2" from radiator-has again 6 blade fan and a shroud--will get some pics Sunday

Thx all for your input--I'm not done yet

 

take out the gauge with numbers on it, use only the original gauge that says "C" and "H", and drive and enjoy.

that's how I've dealt with the marginal cooling on my 55. Decades of fun! no worries! since it never puked.

 

Squirrel-maybe you are right--the dash gauge is at half way straight up--the mech gauge is driving me nuts-185-200-it has not puked yet--it never got hot in 85,000 miles of driving every where including Yuma in the summer before these upgrades. Also drove it to Laughlin before the upgrades--it didn't have the gauges yet--it was 126 degrees and temp needle was straight up-didn't puke-maybe ditch the mech gauges and forget it
She used to run it regularly at the drags before the mech gauges and it never puked but did'nt have these upgrades--pics of car in my album--owned since 77-engine won Lakeport Speedway Championship in 81-82 in street stock in the #88 car--took out big cam and drove it many years after. It has never puked water--even in the staging lanes at the drags but we had to have a can in case.
I am suspect of the radiator as there is minimal temp drop across it-too big of tubes??

 

The 327 in my pickup runs at about 195 and creeps up to over 200 idling on hot days. (180 thermostat). Checked everything, had the radiator rebuilt with a modern core and nothing changed. I've just run it and like yours it has never puked or gotten over about 210 so I guess that's where it likes to be.

 

I agree with you on the radiator... Should be at least 30 degree temp drop.

 

I like this idea!!!

 

I wouldn't be too concerned with temps at 200 withA/C on with high outside air temps. May be over time your old radiator may need a good cleaning out.

Gary

 

Curious why you need a pusher fan if you already have a shroud and a mechanical fan?

2) How old is the Griffin rad?

 

Is there any place the incoming air can go around or bypass the radiator core? I know on early 50's GM cars with the hump in the hood, putting a baffle above the radiator to fill the hump so the air has to go through the core makes a big difference.

 

I always consider 100 degrees over the actual outside temperature to be normal. Trying to achieve Anything less is pretty futile.

 

Did a pulley change in diameter when you put the A/C on?

 

Griffin rad is 10 yrs old but only 1000 miles-car has been in storage for 8 yrs til recently. Car had same symptoms before storage. Pulleys stock chevy.
I am still suspect of the minimal temp drop across radiator--lots of flow and clean
Don't know if 700R4 is adding alot of heat-may install an inline trans cooler with fan
Have done alot of 40's with ac,etc etc--never heat up-These have Walker radiators with CCI elec fans and shrouds but external trans coolers. Drop across radiators is about 30-35 degrees when up to temp and running. 55-The 6 blade fan with shroud pulls alot of air--elec pusher only comes on with ac or above 180.

 

Has engine rpm changed with the overdrive trans?

 

Basically only at Highway speeds when in OD--otherwise very close in all other situations. It will not heat up at road speed but stays 180-185 with AC. Same with 160 or 180 thermostat

 

Sounds silly but if it's only a problem in traffic and you can do it with Chevrolet, put a smaller pulley on the water pump to speed it up a little. You can check it out by removing the rad cap when cold, starting the engine, wait until the temp is high enough to open the thermostat, and look in the rad to see if there is any movement of the coolant. If not slightly raise the idle maybe 100 rpm and if you see coolant move change the pully by about 1/2". Before you start make sure the coolant is at least 1" low so you can watch the coolant and its expansion won't let it overflow. My problems went away when I did this. Good luck.

 

THX--did this a few times already--opens at about 160 (had two temp gauges in rad tank with cap off--lots of flow when stat opens-went to 185-190 idling with AC on. Still baffled by minimal drop across radiator.
Also as a side note-the replacement senders for these can be way off on ohms. Some will read about 450-some in the mid 500's and some low 600's all at about 75 degrees temp. These will throw the stock type gauge way off. I have a bunch of orig ones-gotta ck but recall they are the mid 500's-common problem when replacing stock sender-55 has a 56 elec temp gauge in the cluster

 

A quick story as told by Phil Herrera of Herrera Racing in the pit's one afternoon. "I finally took out all the gauge's from the car so the driver couldn't see them. It was only then we began winning races. Before then, the driver insisted there was something wrong because the gauges said so."

 

Still playin--still suspect of radiator-ckd a bunch of stock type senders all at 82 degrees ambient. One in car is 602 ohm others range from 430-480-530-555-580. One in it is straight up center at 185. WP pulley is 6.5 inches-have several more all same size.Does anyone know how much temp is added by auto trans thru radiator-May add in line cooler with fan as mentioned-had to do this on a 502/OD auto combo powered 56 Nomad but it's been 15 yrs--can't recall how much it helped-we also put the AC condenser under the rear of the car with dual fans at the same time--what a nightmare to install but worked excellent.

 

I think I'd wait for it to have an overheating problem, before doing all that work...?????

 

Do you have a all steel bladed fan? the lager the better.HRP

 

If your converter is higher stall than your other it will make more temp and if your low speed driving is not in lockup the temp will be more if the stall is higher.