Coolant for 68 plymouth 318

Messages
105
Location
RI
Hello all. Working on fixing the cooling system in the 68 plymouth with a 318 that was passed down recently. Seriously neglected. Wondering after cleaning it all and multiple flushes, once I install the new parts any coolant you would reccomend? I believe it said something about prestone yellow on the radiator cap but can't remember and the car isn't with me. I just ask because I can read what it says but also realize that was 40+ years ago. Thank you.
 
Messages
1,427
Location
NY
I use autozone or napa conventional green in my sbc. Back then all they had was iat coolant. Any conventional green changed every year or 2 is fine
 
Messages
1,800
Location
Rijeka, EU
Hi. Did you changed radiator and heater matrix on this car? New antifreeze tend to be aggressive on old radiators. I would use some highly diluted mixture for fill, then if it's all good it's easy to top it up with some undiluted antifreeze.
 

mac9128

Thread starter
Messages
105
Location
RI
Yeah changing almost the entire cooling system. Aluminum radiator, hoses, waterpump, thermostat, larger fan. Might try and convert it to a clutch fan as opposed to belt driven. Have to see how everything fits once the new radiator gets in.
 
Messages
1,800
Location
Rijeka, EU
I wouldn't bother with clutch fan to be honest. Can you squeeze an electric fan in there? If there is no room for it you can always fit one on outside of the radiator.They usually work both ways.
 
Messages
8,598
Location
Florida
Originally Posted By: mac9128
Yeah changing almost the entire cooling system. Aluminum radiator, hoses, waterpump, thermostat, larger fan. Might try and convert it to a clutch fan as opposed to belt driven. Have to see how everything fits once the new radiator gets in.
Sure, but you would still have a copper or brass heater core. Also, you should consider replacing the valves that guide coolant into and out of the heater core, so your repairs are complete. So I would still use the old style green stuff.
 
Messages
601
Location
sweden
Originally Posted By: chrisri
I wouldn't bother with clutch fan to be honest. Can you squeeze an electric fan in there? If there is no room for it you can always fit one on outside of the radiator.They usually work both ways.
i on the other hand would say that a clutch fan is the way to go. - old green or G05 will work in this car.
 
Messages
1,313
Location
Alaska
Originally Posted By: ac_tc
Originally Posted By: chrisri
I wouldn't bother with clutch fan to be honest. Can you squeeze an electric fan in there? If there is no room for it you can always fit one on outside of the radiator.They usually work both ways.
i on the other hand would say that a clutch fan is the way to go. - old green or G05 will work in this car.
No reason messing with an electric fan and having to deal with a fragile electrical system that old. That clutch fan would work just fine on even a warmed over 318.
 
Messages
19,686
Location
Sunny Florida
Originally Posted By: jayg
Originally Posted By: ac_tc
Originally Posted By: chrisri
I wouldn't bother with clutch fan to be honest. Can you squeeze an electric fan in there? If there is no room for it you can always fit one on outside of the radiator.They usually work both ways.
i on the other hand would say that a clutch fan is the way to go. - old green or G05 will work in this car.
No reason messing with an electric fan and having to deal with a fragile electrical system that old. That clutch fan would work just fine on even a warmed over 318.
Yep. Many of those 60's cars have alternators of about the same capacity. No reserve for a power hungry fan.
 
Messages
6,773
Location
Fort Lauderdale, FL
The clutch fan is a good idea for a few reasons, but mostly because any solid hub Mopar fan back then was generally a lame and tame design, since it had to operate over the entire powerband, rather than just at clutch limit. The clutch fan designs had more, larger and more aggressive blade designs to pull more air through the radiator, and will not drain nearly as much horsepower at higher rpms. I run G05 in my 68 Charger, and cannot complain.
 
Messages
257
Location
Oklahoma
Put the old copper and brass radiator back in the car. The new aluminum jobs don't cool as well and don't last either, most are Chinese made. Run the old school green antifreeze. As others said make sure it's not a newer formula that's green. Clutch fans are fine. They are on millions of vehicles with zero cooling issues. A shroud enhances it's performance dramatically, get one if you go this route. Use some Prestone Super Flush then later add some water pump lube/anti corrosion in the final coolant fill. This stuff enhances the corrosion properties of the coolant.
 
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