Question for the Big Block guys and Small

[crebo]

I've finally gotten my vette back. I went from the 350 ---- 402BB. I'm running between 200-210 without my A/C. I was wondering what the normal operating temp is. I have a 165 therm. I do need to buy a new fan shroud and seals..I'm still using my old fan and I have a heavy duty fan clutch.
Do I need to have a big block fan clutch....maybe a differ fan? I also live in the high desert, but the temp has been nice lately. It was 75-95.

Any help will be most appreciated!!
Ashman

 

[JohnZ]

At a minimum, you need a correct fan shroud and all the seals between the shroud, radiator, and support, and the hood, and you MAY need a BB fan clutch if your existing one doesn't position the fan blade tips half-in and half-out of the rear of the shroud.

Thermostats have nothing to do with max operating temperature; they only determine minimum temperature, assuming your cooling system is capable of cooling the engine to below the thermostat's rating (which is unlikely). Make sure the plastic deflector under the front fascia is intact, as that provides the airflow for cooling at highway speed; without it, you'll definitely overheat.

 

[SwaveDave]

Make sure your cooling s ystem is very clean inside ; use a good cleaner like Prestone H.D. CLeaner, and flush the system with the block drain plugs removed . SInce u have a/c, run 80 percent distilled water with 20 percent antifreeze and 1 bottle of Redline Water Wetter solution. Power wash your condensor fins and radiation fins back and front, and seal everything to the max. For those real hot days, open your headlights to admit more air to the radiator . Make sure your lower radiator hose isnt collapsing otherwise youll starve the system of waterflow. Seal off the top of the radiator , which alot of guys fail to do. Put in a manual stop valve in the heater inlet hose in the summer - no sense in having any hot water going into your dash - you need all the water for your block and heads.

SwaveDave

 

[crebo]

I'm so glad that I've gotten a few responses. I'm having a heating issue. I'm running around 200 in the mornings. Usually when the outside temp is around 75-80 without the A/C.
My radiator cap was leaking. My A/C bracket broke so it was alittle loose.
Now that I've gotten those issues fixed it runs hotter than ever. I was up to about 240 today.
I've taken my fan shroud half way off. It looks as though I'll have to take my radiator out or move it to replace my shround. I plan to get a BB fan clutch and fan. I'll get some additives as well..

I had planned on buying a set off valve covers from the local speed shop. Still waiting on my hood to be completed. I'll have a modified L-88. I hope it looks nice. With the heating problem I'll have to fix my eyesores later.

Quick question? Sounds silly but should the car temp go up or down with the hood off?
Ashman

 

[69MyWay]

Crebo,

If you can swing the bucks, take a look at the complete radiator/fan/shroud packages from Dewitts.

http://www.dewitts.com/

I run with a/c now that the engine is breaking in, and running loose in 100 degree weather around 210 with my 454 punched .060 over.

I have the dual spal 11" with shroud. It was around $400. Very nice, neat, clean, and quite compared to the big clunky mechanical fan. Plus, no draw off the engine except the extra pull on the alternator.

 

[SwaveDave]

I have twin radiator fans with shroud from a 1990's LT 1 Vette ; It has never gone over 200 even when my parking brake was dragging ! In fact, my cooling system is so efficient , that, if im going at least 30 mph and the outside temp is no higher than 75 degrees...the electric fans dont even come on. When they do, it cools from 200 to 185 in no time. I did everything dreamable to make the cooling system work at peak performance , and it paid off.

DO the cleaning measures i mentioned, then use the distilled water/coolant ratio with water wetter ; youll see an improvement from that alone.

Twin electric fans will move more air than a mechanical fan , but you want to be sure the cooling system is operating at peak performance too.

Dave

 

[SwaveDave]

P.S.....

One other big reason i have no problem cooling, is because i went with a Stewart Water Pump. After this was put on, i noticed a big difference. It really moves the water over the stock pump.

Until you can get a handle on your high water temp of 240 degrees...id take the thermostat out of the engine which will allow greater flow ; you will be up to operating temperature in no time anyway in those high ambient temps anyway. Id also take out the manifold - water pump bypass hose restrictor to allow more flow also. Give it a try and see what happens. After you get a permanent handle on your present problem...put them back in . I did this once and it really helped alot.

Dave

 

[crebo]

Thanks Fellas,
Money is alittle funny now. I should be able to make some adjustments.
Man I want to thank you guys alot. I didn't think anyone wanted to help. I started searching threads and found alittle info.
I can't wait to get this car right.
Ashman