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Question: 427 big block water pump pulleys

Tom66

Member
Joined
Mar 15, 2018
Messages
14
Location
CA
Corvette
1966 Nassau Blue Corvette roadster
Another question

A big shout out to all that have responded, THANK YOU!

I have decided to give a more robust fan a try. I will be testing that out tomorrow. I will not be using the smaller pulley; too many concerns. However the other two options are to get a stand alone new aluminum radiator or a radiator with built in fans. Does anyone have experience with DeWitts radiators: 1966-68 Big Block – DeWitts Direct Fit(R) Aluminum Radiators stand alone and combinations/with fans (the posted reviews are good)

Also it was suggested to me to run pure distilled water. Apparently that is done in racing. Thoughts?

Thanks

Tom
 

Hib Halverson

Technical Writer for Internet & Print Media
Joined
Jan 10, 2001
Messages
13,453
Location
CenCoast CA
Corvette
71 04 12 19
DeWitts makes great radiators.

You can use straight water for a coolant and it will cool better than a mix of antifreeze and water BUT there are a number of drawbacks to doing that. Provided you are understanding of them, you could consider that.

First, you absolutely cannot run just straight water. You also must also use a coolant additive intended for use in systems running only water. Two of these additives which work well are: Driven Racing Oil "CST" and Red Line "Water Wetter." These additives contain the corrosion inhibiters, antifoaming agents and water pump lubricants necessary for cooling system durability. Also, both contain a wetting agent which reduces the possibility of localized boiling inside the cooling jackets around combustion chambers. If the engine has a problem with localized boiling, which some BBCs have, that further reduces temperature.

Next, you cannot use straight water if the car is ever parked more than 8-hrs or stored where the ambient temperature goes below 32°F.

You cannot use straight water if the car is operated at high load above 5000 ft. altitude.

If you use straight water, you need to run at least a 12-psi system and preferably a 15-psi system.

You must change coolant every two years regardless of mileage.

Finally, know that straight water reduces the boil over temperature about 5°F below what you get with a 50/50° water/antifreeze mix. For example at sea level in a 15-psi system with a 50/50 mix you're going to boil at about 255°F. With straight water in a 15-psi system and you're going to boil over at about 250°F.

In all my Vettes, I use straight water and either CST or RLWW or I use an 85/15 mix of water and Dexcool antifreeze along with CST or RLWW.
 

Tom66

Member
Joined
Mar 15, 2018
Messages
14
Location
CA
Corvette
1966 Nassau Blue Corvette roadster
Water as a coolant

DeWitts makes great radiators.

You can use straight water for a coolant and it will cool better than a mix of antifreeze and water BUT there are a number of drawbacks to doing that. Provided you are understanding of them, you could consider that.

First, you absolutely cannot run just straight water. You also must also use a coolant additive intended for use in systems running only water. Two of these additives which work well are: Driven Racing Oil "CST" and Red Line "Water Wetter." These additives contain the corrosion inhibiters, antifoaming agents and water pump lubricants necessary for cooling system durability. Also, both contain a wetting agent which reduces the possibility of localized boiling inside the cooling jackets around combustion chambers. If the engine has a problem with localized boiling, which some BBCs have, that further reduces temperature.

Next, you cannot use straight water if the car is ever parked more than 8-hrs or stored where the ambient temperature goes below 32°F.

You cannot use straight water if the car is operated at high load above 5000 ft. altitude.

If you use straight water, you need to run at least a 12-psi system and preferably a 15-psi system.

You must change coolant every two years regardless of mileage.

Finally, know that straight water reduces the boil over temperature about 5°F below what you get with a 50/50° water/antifreeze mix. For example at sea level in a 15-psi system with a 50/50 mix you're going to boil at about 255°F. With straight water in a 15-psi system and you're going to boil over at about 250°F.

In all my Vettes, I use straight water and either CST or RLWW or I use an 85/15 mix of water and Dexcool antifreeze along with CST or RLWW.

Thanks Hib for the comprehensive reply. No wonder I have not heard of water as a coolant option. Seems very complicated for a questionable reward. I will take this off my options list. Thanks again.
 

LLC5

Well-known member
Joined
Sep 28, 2004
Messages
2,299
Location
Wa.
Corvette
98 black 6spd convert.
A big shout out to all that have responded, THANK YOU!

I have decided to give a more robust fan a try. I will be testing that out tomorrow. I will not be using the smaller pulley; too many concerns. However the other two options are to get a stand alone new aluminum radiator or a radiator with built in fans. Does anyone have experience with DeWitts radiators: 1966-68 Big Block – DeWitts Direct Fit(R) Aluminum Radiators stand alone and combinations/with fans (the posted reviews are good)

Also it was suggested to me to run pure distilled water. Apparently that is done in racing. Thoughts?

Thanks

Tom


I would get a name brand aluminum radiator with dedicated electric fans and be done with it, you need a lot of airflow across the radiator and condenser and that is a sure way to do it.

Racing requires a lot of work and constant maintenance, I would stick with coolant 50/50 mix with distilled water, or premix.
 

Tom66

Member
Joined
Mar 15, 2018
Messages
14
Location
CA
Corvette
1966 Nassau Blue Corvette roadster
Aluminum Radiator

I would get a name brand aluminum radiator with dedicated electric fans and be done with it, you need a lot of airflow across the radiator and condenser and that is a sure way to do it.

Racing requires a lot of work and constant maintenance, I would stick with coolant 50/50 mix with distilled water, or premix.

Thanks, I am coming to the same conclusion. While I want to keep the orginal look of the car, driving and good mechcanical solutions must take precedence.

Thanks again.
 

LLC5

Well-known member
Joined
Sep 28, 2004
Messages
2,299
Location
Wa.
Corvette
98 black 6spd convert.
Thanks, I am coming to the same conclusion. While I want to keep the orginal look of the car, driving and good mechcanical solutions must take precedence.

Thanks again.



Yep, I hear you.

Just keep all your OEM parts stored in a safe place.
 

Tom66

Member
Joined
Mar 15, 2018
Messages
14
Location
CA
Corvette
1966 Nassau Blue Corvette roadster
OEM Parts

Yep, I hear you.

Just keep all your OEM parts stored in a safe place.

Thanks, SOP. My garage is starting to look like a parts warehouse. :)
 

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