LT4 Do LT4's run hotter than LT1's?

[Ruby Fan]

I have an LT4 and seems that normal running on the highway the temp goes to about 204 degrees. I have an LT1 and it seems to run around 189-193. I also have an L98 that runs the coolest at about 175 or less(seems that it just never gets that hot). I know that this is a minor thing and some may say that the gauges could be off, but I was wondering in general does the LT4 run hotter? Thanks

 

[gmjunkie]

They probly all 3 have different temp thermostats!! The cooling fans don't kick on till about 226-228 deg without the air running!! Normal running temp would be around 195- 232 deg depending on thermostats and conditions!!
PS there could be some variance in gages too!!

 

[simbadb]

I have an LT4 and seems that normal running on the highway the temp goes to about 204 degrees. I have an LT1 and it seems to run around 189-193. I also have an L98 that runs the coolest at about 175 or less(seems that it just never gets that hot). I know that this is a minor thing and some may say that the gauges could be off, but I was wondering in general does the LT4 run hotter? Thanks

No oil cooler in an LT4 (LT1...dunno?) (which is why one needs to run synthetic). Mine was running too hot for my mechanics liking so we replaced the: Radiator Cap(Must be able to hold pressure). Thermostat with a 180"o" and Hypertech Tuner to kick the fans in at a lower temp.

Runs like a dream now

 

[Tuna]

Generally, I think the LT1 and LT4 should run about the same coolant temperatures if they have the same thermostat settings and cooling fan settings.

I've gotten used to the higher temps the LT1/4's run, so it doesn't bother me anymore. Even the LS1, LS2, LS3, and LS6 seem to run hot but not really.

Check the radiator for trash. With the C4, trash (leaves, bugs and plastic bags) can get between the airconditioner coils and the coolant radiator, so look close between them, not just on the airconditioner's fins.

If you don't know what value thermostats are in the cars, you might want to check them.

Ditto, the fan on settings in the computer.

 

[Boeingdriver]

I have an LT4 and seems that normal running on the highway the temp goes to about 204 degrees. I have an LT1 and it seems to run around 189-193. I also have an L98 that runs the coolest at about 175 or less(seems that it just never gets that hot). I know that this is a minor thing and some may say that the gauges could be off, but I was wondering in general does the LT4 run hotter? Thanks

Mine does the same thing (200 to 210 F summer on the interstate w/ AC on). After much review from other posters on this and another forum, I've accepted the explanation from some very well-informed Chev. experts that this engine is designed to run in this range. There are lots of reasons why and you can find them if you want to really spend time on this, but I'm satisfied that the low 200s is where this engine is designed to run.

With that said, yes, do make sure that the radiator is free from debris. C4s are like a giant vacuum....at least mine is. A plastic bag in the nose will run the temps. right up.

One suggestion. When I stop after running long enough for everything in the engine compartment to get fully heat soaked, I pop the clamshell and prop it open about 18 inches with a sawed-off golf club. This prevents the engine compartment including hoses, belts, switches...and most importantly the computer.....from simply baking for an hour as the engine cools down. I had a tell-tale remote sending thermometer in the engnine compartment for awhile and I recorded 180 F at the housing of the computer a few minutes after the engine was shut off. That can't be good for the electronics. Call me crazy but venting the engine compartment makes good sense to me. When I do this at gatherings like FunFest, other owners are all over me to find out what's going on.

Stay tuned. I'll bet these posts will prompt other opinions.

 

[LT4man]

No oil cooler in an LT4 (LT1...dunno?) (which is why one needs to run synthetic).

The LT1 does not have an oil cooler. With the reverse flow cooling system the engineers designed for the LT1 (coolant is routed to heads first and then block) they were able to eliminate 'hot spots' in the heads. This enabled them to boost the compression ratio up and still not have the engine ping. With more compression comes more horsepower.

Being able to eliminate the oil cooler freed up some space and took some weight off the car. GM then specified synthetic oil for the LT1. The LT4 is a derivative of the LT1 and also received a factory fill of synthetic oil.

SAVE THE

 

[wickedlt4ce]

Have the ecu tuned to turn the fans on sooner. Or install a manual "overrride" switch to turn the fans on when you want and leave them on as long as you want to. This switch is nice to have when at the track or strip and you want to cool the radiator down faster than just leaving the hood open.

 

[Kevin Doyle]

Hyper tech tuner

The only reason I used the hyper tech tuner was to set the fan parameters,Thanks Kevin.

 

[KANE]

LT1s in different cars...

... GM then specified synthetic oil for the LT1...

I saw this thread yesterday and went back and looked over my Trans Am's owner's manual to see if GM called for synthetic for its LT1.



Not a mention of synthetic as a recommended oil. Did call for 5w-30 though.

I wonder why GM would call for synthetic in one and not the other. :confused



Racing came to my mind as a need for synthetic- but everyone knows that Fbodies are beaten on harder (or punished!) than most Vettes by younger, more inexperienced drivers. :L

 

[bucket]

I have an LT4 and seems that normal running on the highway the temp goes to about 204 degrees. I have an LT1 and it seems to run around 189-193. I also have an L98 that runs the coolest at about 175 or less(seems that it just never gets that hot). I know that this is a minor thing and some may say that the gauges could be off, but I was wondering in general does the LT4 run hotter? Thanks

.

my LT1 runs 204 all day long..the oil runs 217...all day long..
but i do have an adjustable fan relay..so it ciomes on a bit sooner than stock...thermostat is stock
and...i use "water wetter" by red line..this is good for 6 to 10 degrees easy

 

[CAJUN C4]

No oil cooler in an LT4 (LT1...dunno?) (which is why one needs to run synthetic). Mine was running too hot for my mechanics liking so we replaced the: Radiator Cap(Must be able to hold pressure). Thermostat with a 180"o" and Hypertech Tuner to kick the fans in at a lower temp.

Runs like a dream now

I did the same to my 95' & 96'.At say 60F ambient temp. both run about 176-177F at 70 mph.Pretty much identical both with Hypertech 180 T.S.s
Hope this helps