[batman09]

This is something new since I did my top end rebuild?It gets up to 215-220* at hwy speed?Any idea why?Stays at 190 all day around town?engine specs...sbc 350 ,afr 180/64 heads,voodoo 268 cam,eddy intake and carb.turbo 350 with 3.42 gears.Thanks for the help.bm

 

[The Big Al]

Timing?

Lean carb?

Are you running underdrive pulleys?

Are you running a thermostat ? If not, you may need one.

Al

 

[Smittys62]

This is something new since I did my top end rebuild?It gets up to 215-220* at hwy speed?Any idea why?Stays at 190 all day around town?engine specs...sbc 350 ,afr 180/64 heads,voodoo 268 cam,eddy intake and carb.turbo 350 with 3.42 gears.Thanks for the help.bm

I get the same thing, just not that hot. Im at about 200 - 210 on the freeway. Im running at about 3500rpm at 60mph. Around town the 383 runs at 180 - 190 all day long. Could just be the rpm in my case but not sure. I really need to get my carb dialed in.

 

[JRouche]

Sounds like the higher sustained rpms are creating heat you are not getting rid of. With it staying cool around town I say yer stat is working as is your fan. Almost like the additional air pressure from the higher speeds isnt able to move freely through the engine bay. Is there an additional tranny cooler in front of the radiator? Tranny getting hot? Dunno, just grasping for answers. JR

 

[pxtx]

What kind of fan do you have and do you have a decent fan shroud? Pics of your bay might help.

I checked your link and the car looks great! I think you could do much better on the fan shroud though. The one you have looks nice, but you could do a better job of making the fan draw all of its air accross the entire rad. I could not see what you've got for a fan.

 

[batman09]

Timing?

Lean carb?

Are you running underdrive pulleys?

Are you running a thermostat ? If not, you may need one.

Al

Timing is at 14 initial/36 at 3000rpms.I have a 180 thermostat,no under drive.....i'm thinking its the carb...I still need to get the holly set up.

Sounds like the higher sustained rpms are creating heat you are not getting rid of. With it staying cool around town I say yer stat is working as is your fan. Almost like the additional air pressure from the higher speeds isnt able to move freely through the engine bay. Is there an additional tranny cooler in front of the radiator? Tranny getting hot? Dunno, just grasping for answers. JR

no tranny cooler...except the radiator...I have one I need to install.I do not think my tranny is getting hot?

What kind of fan do you have and do you have a decent fan shroud? Pics of your bay might help.

I checked your link and the car looks great! I think you could do much better on the fan shroud though. The one you have looks nice, but you could do a better job of making the fan draw all of its air accross the entire rad. I could not see what you've got for a fan.

I have a full radiator shroud(repo 66/67)bm

 

[71SS454]

You could try and seal the radiator to the support to force all the air thru the radiator so none can go around it. Maybe consider fabricating a lower air deflector to get more air thru the radiator at speed. What kind of radiator are you running? Maybe time for a bigger one. Are you running an electric fan? If so make sure it's off at highway speed. With it under power and running, it may be creating a restriction to the free air flow the cars movement creates.

 

[Nova 404]

I had a Griffin replacement radiator with repop shroud and a 16 inch haden flex fan and it worked great.Oops I also had a Flowcooler water pump.
Now I have a miezere water pump and twin 11 inch Spal fans and it is ok in town but gets hot 200-210 on the freeway.The mechanical fan seemed to cool much better than my electric fans.

 

[batman09]

You could try and seal the radiator to the support to force all the air thru the radiator so none can go around it. Maybe consider fabricating a lower air deflector to get more air thru the radiator at speed. What kind of radiator are you running? Maybe time for a bigger one. Are you running an electric fan? If so make sure it's off at highway speed. With it under power and running, it may be creating a restriction to the free air flow the cars movement creates.

I have a u.s. radiator desert cooler 4 core radiator...I have a hayden 17" clutch fan.I had this radiator before and never had a cooling problem til my new rebuild?bm

 

[chevyIIheavy]

thats right mechanical fans work better than electric fans looks like you may need to see if something is restricting airflow through the radiator. i run a jegs aluminum universal radiator , a stock 63 fan shroud , edelbrock aluminum water pump, flex fan, and a 180 thermostat mine stays around 190 on the street and maybe 190 on the freeway and thats running a 11 to 1 pumpgas sbc with edelbrock aluminum heads, 3000 converter and 3.73 gears im also running my trans cooler in front of the radiator behind the grill. maybe pull the cap off the radiator and see if your getting flow if not id say your pump aint working. ive been told that aluminum headed motors are ok at temps of 200 to 220 in fact most ls1 motors run a tad hotter than this. due to the fact they can disapate heat better than cast heads. but i dont like to run my motor that hot its just my prefrence.

 

[The Big Al]

I have a hayden 17" clutch fan.

Thermal Fan Clutch or Non-thermal?

A non-thermal can cause the problem your having.

Al

 

[batman09]

Thermal Fan Clutch or Non-thermal?

A non-thermal can cause the problem your having.

Al

thermal clutch

 

[1quik69]

How old is the clutch unit? Have you noticed any fluid leaking from it?

 

[batman09]

How old is the clutch unit? Have you noticed any fluid leaking from it?

Its about a year old..no fluid.

 

[1963wagonman]

Sounds like the higher sustained rpms are creating heat you are not getting rid of. With it staying cool around town I say yer stat is working as is your fan. Almost like the additional air pressure from the higher speeds isnt able to move freely through the engine bay. Is there an additional tranny cooler in front of the radiator? Tranny getting hot? Dunno, just grasping for answers. JR

No but i noticed that he had a high efficiency radiator that has very close together fins......and it's a 4 core!

 

[1963wagonman]

I wonder if your carb is running lean under freeway conditions.......

 

[batman09]

I wonder if your carb is running lean under freeway conditions.......

could be????

 

[onecarnut]

Heating up at highway speeds (only) is usually an air flow problem.

Most cars can function without a fan after they get up to speed.

I think you must make all available air pass through the radiator.

Secondly, reducing your RPM will also help.

The latest "Hot Rod" magazine has a nice article in the "Pit Stop" section about solving cooling problems.

Cross flow and dual-pass radiator designs are mentioned.

Lou
Older than dirt

 

[64PRONOVA]

All the problems I've had with heating-up at highway speeds when the car stayed cool putting around and idling were water pump-related. Not enough flow.

What is your water pump pulley ratio? I know you say it's not underdriven but is it 1:1 or what? Your new engine may be generating more heat than your old one and may require more flow to keep cool. What water pump are you using?

 

[JRouche]

Heating up at highway speeds (only) is usually an air flow problem.

Exactly. Thats why I was looking for a tranny cooler blocking off the high pressure air at freeway speeds. He doesnt have one. The air needs to flow in and out. Being a good setup I think he has flow out. Some cars Ive seen are restricted out the back side of the engine bay, the air flow just cant happen.

Hmm.. Lean engine could cause "some" over heating, but you would see it around town too.

Kinda funny, yer heating issue is kinda backwards of most peoples. They are over heating on the city streets not the freeways. At least you are running cool on the city streets.

A severely under driven coolant pump would cause this, but you would see it even more on the city streets. Under driven pump along with a low air flow on the city streets would be a major heat issue.

Hmm, higher road speeds, more air flow, more heat?? Hmmm...

Since the top end rebuild. Same parts? Just a freshing up? Or new parts? How bout them gaskets? Head water ports or not? Water ports but a block off gasket?

Hell, I dont know. What did you do during the top end rebuild? Thats the key. What you did changed the operating temps. JR