99SilverC5Coupe

A friend of mine recently bought a 77 shark with the L48 engine - with the AC running, in 93 degree heat, he had temperatures around 220 - 240 degrees, is this an issue? What is the normal temp under these conditions? If high, any suggestions? :cheers:

Gameshow Bob

That's a bit on the high side in my opinion. <200 is ideal. The radiator support foam seal seems to make a big difference. Fan clutch replacement perhaps? I personally run electric fans but I'm not concerned with stock appearance.

standup

Too hot.....was this at idle or highway?????

Although our weather never gets anywhere near 93 degrees, mine runs cool at 180 on the highway (or so my 32 year old temp gauge shows).........but it recently blew it's top at 230 at idle for 15 minutes in 70 deg weather........my answer was to replace the entire cooling system.....your mate's answer may not have to be so drastic, but he should at least check out the system....hoses, connections, thermostat and fan clutch......then rad and water pump.........

tippi58

Mine runs 180. Thats with cleaned out radiator, new hoses, new water pump.

Also took the A/C cooler off so radiator gets better flow.

My front undertray and spolier cracked so they are off at the moment.

I dont have top rad seals so I spose mines not typical as it set up for max cooling. :auto:


:cool: :cool: :cool:

gmcclurg

My 77 is similar to your friends. It runs just below the 200 deg mark, so I would guess about 195. Sitting in traffic the other day in in 90+ air temp the temp rose to the 200 mark, but I did shut off the air and put it in neutral. I have a standard water pump and 50/50 mix. Check the items mentioned above.

jerryp58

That is a little on the warm side (195 to 205 is probably typical).

Has he done a "flush & fill" of the system? That will probably help. When the coolant is a couple of year's old, my '77s temp starts to climb.

Is the fan shroud in place? What about the foam on the top & sides of the radiator? Both help air flow through the radiator rather than around it.

If he hit those temps at speed, does he have the "chin" spoiler under the front? It's very important for pushing air up into the radiator.

A lean running engine can also run hotter. If everything with the cooling system is as it should be, check timing & carb adjustment.

Hope this helps.

Ganey

Probably needs to rod rad. out.

jetech

My 77 runs around 195 to 200 at idle, sometimes when it hot it will climb to around 210. On the highway it hangs close to 200 but if I get on it it sometimes climbs to 230 to 240. I did a rebuild on the engine last winter including having the radiator cleaned and I sealed around the radiator. :cheers:

Dalannex

My 81' runs 220-230, but never over that. How many daily drivers run 230 and nobody worries about it? I say it never hurts to look into the things listed above, but I wouldn't worry too much about it until it get to 240.

-Justin

FeedVaal

Solid @ 180 with a 180 degree thermo. new water pump, new radiator, fan shroud in place, front spoiler in a box while waiting for paint. I'd flush the rust out, replace the thermo and use a heat gun to find out the real temps at the heads and intake.

OHSIXX

Mine stays at 209 which is slightly high in my opinion. For that reason, I am changing to a Supercool Waterpump to see if it helps.

77Dream

Mine runs between 185 and 195 under all conditions. But I have a DeWitts aluminum rad with dual spals. And since I live in southern CA I run 80% water and 20% anti-freeze with a bottle of water wetter. I also have a 165 degree t-stat. Back when my car was stock it it ran up too 230. When I got my rad acid washed it never went above 210.

:cheers:

bigvette1

You bet 220 -230 is too hot. For iron heads this temp is close to detoniation, fuel percolation etc. Besides think what the oil temps and trans temps are at this coolant temp.

A base 350 with A/C should be able to maintain 200-210. I would sure go over the cooling system as the other posts said.

hunt4cleanair

I just returned from two major road trips in my stock L-48 78 car and the temp ranged between 160 and 180 the entire trip...includes afternoon runs with a/c on and also sitting in interstates traffic a couple of times. Car has no mods and 35,000 miles.