GT2Race

I know this one's got some of you fuming but I gotta ask ...
Im a first corvette owner but I restore mostly British sports cars and a bunch of Vw's for my living for over 30 years now

My 84 L83 cross fire vette has got me overheated to put politely

The darned thing wants to creep up temp while sitting at a lights or sitting idling .. Im talking between 220 to 240 ( with 2 electric fans running wide open )

My first question is so simple
What temp should my L83 run ... how many degrees
considering I live in So Cal with the average day of 75 to 105 degrees outside of the car ... where should she run water temp wise

I would love to use this brand new 1500 buck ac system

Before you bark at me .. let me list what I have done so far with
I Installed a 3 Row Hi capacity aluminum Radiator
installed 2 new 12 inch Hipo electric radiator fans
installed 2 different thermostats to see which one worked better
one was a 160 and the other is a 195 degree thermostat
not much difference between them
changed the Rad pressure cap to a 15 pound unit twice
replaced the water pump with a new one
I installed a set of analog ( old school gauges ) onto the window post
along with having the digital dash rebuilt and upgraded to a 1985 setup
installed 2 new temp sending units ...
the small air dam under the front of the car is in perfect shape
and last but not least .. I triple checked for any obstructions like a plastic bag or something stopping air flow to the radiator
Punched 12 holes through the top of the hood the relieve some heat and added the reversed hood scoops .. this did help it run bit cooler
pics attached

remember ... my average temp is over 200 and it's not even spring time yet .

am I going Coo-koo over coo-coo puffs here or am I just expecting the engine to run cooler than it should

the last time it overheated ... it cost me a top end rebuild
that was caused by a non working dig dash problem .. maybe Im being over cautious here ... yes no

Help is so good
cheers
Lawrence from So Cal

blackozvet

what sort of coolant are you running ?
some of the more expensive coolants that have high temp ratings can work well,
or some of the racing products, such as wetter water, can also help.

the c4 is like a shark, it needs to keep moving !

Rockcrushervette

My 88 ran those temps when I first bought it! Then I added a external trans cooler after tranny rebuild! When it was 110 out here in the IE never went over 130 and would cool down fast when start driving! Now yesterday 186 driving can sit at a long light goes 227 fan on drops down 200! Just a idea smell your tranny fluid maybe cooler is plugged inside radiator! But that's what happened to me just thought I'd share! Later bra!

mtwoolford

First things first.

(one) as a former English car owner, my sympathies

(two) As to your new water pump, make sure it has the correct rotation for your application, serpentine belt driven pumps rotate in a different direction from earlier ones driven by conventional V belts...and you can't tell by looking at the outside;

You have to understand the Chevy cooling system, a
"one size fits all" for everything from a North Dakota winter to an Arizona summer. You need to optimize your set up for the Arizona summer.

Unless you've fallen in love with your water pump, ditch it and bust the bucks for a high performance pump with an impeller with machined, curved vanes, NOT the usual parts house pump with a stamped sheet metal impeller with flat vanes. This will significantly increase the efficiency, and output of the pump

When you remove the water pump you will notice a third hole 3/8 ths of an inch or so; this circulates the water from the discharge side of the pump directly back into the block (and the suction side of the pump) with out being cooled; this aids the engine warm up during those North Dakota winter mornings. Block this hole, either with a pipe plug in the engine block, or a thin piece of stainless steel sandwiched between the pump and the block. A high performance pump will most likely have this passage already eliminated in the pump body. Now ALL the water that flows through this hole will be rerouted (assuming the thermostat opens) to the radiator to be cooled.

Very similar, the hot water from the base (engine side) of the thermostat is routed to the heater core, this allows the heater to continuously receive hot water. Trouble is that during the summer when the heater is off, the air flow doesn't go through the heater core, and again a substantial amount of hot water bypasses the radiator and is fed directly back into the engine. Not good. Install a valve in the heater hose going from the thermostat housing to the heater core.

(three) thermostats. While you're trouble shooting the cooling system, take the thermostat completely out of the equation; order a restrictor plate from any race oriented parts supplier or make your own. Take an old thermostat, clip and remove the center "pellet" from the thermostat and reinstall the remaining flat disc.

I prefer a 160 degree thermostat, at least during the summer . When you do install a thermostat, get one with a 1/8 inch (or so) hole drilled in the disc, possibly drill one or two more. This not only allows any air which might have become entrained in the coolant and which tends to gather underneath the thermostat to bleed off. Since now (theoretically) the heater hose is closed off and the passage from the block /pump is blocked off, during start up with a cold engine this also allows some fluid flow through the pump before the thermostat opens.

All these mods are pretty much recognized race / dirt track mods which can be verified with a little research; And I can personally attest to their effectiveness....Hey, it gets pretty hot up here in Northern California during the summer too..

(four) Air flow to the radiator, since you have a new radiator, I doubt this is an issue, but trash, sometimes an amazing amount, gets caught between the A/C condenser and the radiator; also an otherwise clean appearing condenser or radiator may have its fins clogged with a thousand little tiny seeds, bugs, grains of sand, who knows what; I spent hours with a dental pick cleaning mine.

(five) temps. You're not over heating until the coolant boils at the system pressure; with a 15 pound cap that would be what? 235 degrees or so (more with antifreeze). Still no one likes to push the envelope and I would expect to see temps, even on a hot day, in slow traffic within the 205 - 210 range.

(six) A final, and , at last something easy, add some product that decreases the surface tension of the water, allowing it to more closely contact the cooling surfaces; for example "Water Wetter" or something similar.

Oh, and enjoy your new A/C system.

Rockcrushervette

Something else came to mind after all that good advice from Mtwoolford! Had a over heating problem on my 56 chevy found out it was the lower radiator hose was collapsing because the wire rings in it had broke and it was collapsing from the pressure of the pump sucking ! Maybe grab that hose and squeeze it all around make sure it stays solid! Just saying! Later bra!