308 Coolant

I use the Shell Rotella ELC NF RED. Not the regular stuff. I would not mix them.

Nitrite-Free Coolants on the Rise Due to More Aluminum in Engines


This story appears in the March 13 print edition of Equipment & Maintenance Update, a supplement to Transport Topics.

 

I bought a case of it Monday.

 

Get the Airlift, drain all the coolant, pull a vacuum, and refill with coolant.

 

My mechanic swears by Evans since it will not boil. Since switching my temp gauge hasn’t moved right of center. Image Unavailable, Please Login


Sent from my iPhone using FerrariChat

 

I looked into Evans a few years ago. I didn't like the fact that once you switch to it, it is the only thing you can (should) add to the coolant. IOW, if you develop a leak. a hose breaks/cracks/splits, you can't just quickly repair and add readily available coolant. You need to keep some Evans on hand - maybe with you in the car.

Also, I have read that it will elevate the cylinder head temp over conventional coolant - by as much as 100F. IOW, the the temp gauge might read the same/lower than with conventional coolant but the actual engine temp is higher because the Evans is less efficient than 50/50 water-based coolant. Reports are not unusual that some engines running Evans may need timing changes and/or higher octane fuel to avoid engine knock due to higher cyl head temps.

Evans says that it can tolerate no more than 3% water in the mix, otherwise the properties of Evans are compromised. The 3x8 seems to have a LOT of potential for retaining coolant. Whenever I change coolant, the fill is noticeably less then the "capacity" of the cooling system. I would be interested to hear how the mechanic that swears by Evans ensures that all the conventional coolant is removed before the conversion.

OTOH, IMO there are two big advantages. You can run much lower system pressure since the entire point of a pressurized system is to raise the boiling point of water. Since Evans boiling point is much higher than water (or water/antifreeze mix), you could use a very low pressure radiator cap, reducing any strain/potential leakage in the system.

You never have to flush/change it - it's "permanent coolant." If you perform maintenance that requires opening the cooling system, you can catch/reuse the coolant. So despite the fact that it is expensive compared to antifreeze, over the life of a vehicle it would end up less expensive with no requirement to flush/change coolant periodically.

 

I always get curious when I read posts about antifreeze. As some of you may recall, I've owned my car since new, over 38 years now. I have used nothing but Xerex original green antifreeze. The car has never had an over heating problem. Every mechanical part of the cooling: system, radiator, thermostat, water pump,.... is original. A few hoses have been replace. It's low silicates, no nitrates, borates, no amines.

 

Can't argue with the fact that standard antifreeze/water has been performing its function well for a long, looong time!

 

I always felt it was more trouble than it was worth. If "regular" coolant is doing its job, what is the point of making life complicated in case of an emergency ?

 

So this past weekend I put the Spal fans in with the bases that look like Lucas motor housings and flushed and refilled with the proper Shell Rotella red coolant.

As you can see in the picture I do not have an a/c condenser so I inched up the fans closer to the radiator. It was 92 degrees and a 30 min drive in deliberate stop and go traffic, the needle never moved further than this. I may reinstall the original copper radiator now.
Image Unavailable, Please Login Image Unavailable, Please Login

 

Are we talking about this?
Image Unavailable, Please Login

 

That's it.

 

Probably get roasted for this, but I put Prestone Platinum in both my 308 and NSX recently.

 

Any modern coolant, changed every 3-5 years should be fine.

 

Or 15 years/350K miles, if you use Prestone Platinum...

 

NO! First off, the wet liner 308 engine design is prone to cavitation around the cylinder liners, similar to some diesel engines - pictures have been posted here of the exterior of liners with pits that nearly penetrate the cylinder walls. There are a couple of coolants specifically designed to prevent cavitation, such as Shell Rotella ELC Red (a long life coolant, perhaps 5 years max?) or Zerex G05 - similar chemistry, but only good for 2 years, so should be changed at that interval. (Those recommendations both from Rifledriver)

NO NO NO!!!! See above.

Photo of outside wet cylinder liner cavitation pitting:

 

Thanks for the clarification.

 

I'm not too concerned about cavitation in these cars. If it was a significant issue, after going on 50 years for the 308, you would have heard about it long ago.

 

That was you I quoted in post #16, your post and the picture from 2019!

Gordon

 

Yes, it was a explanation on how cavitation occurs and what the effects can be. So let me make my position clear. Personally, I'm not concerned with cavitation.

Also from that thread,

 

Thanks for the clarification!

Gordon

 

Anybody have any experience with Evens coolant?

 

I ran it for a while in my 1,800 hp diesel drag truck. That is until I blew a freeze plug one pass and sprayed it all over the track! It is worse to clean up than transmission fluid and the track let me know it! I ran straight water from then on out.

Anyway, It kept the temps pretty low (too low actually for my application). It runs on ZERO pressure. In fact, I only had a catch can with a hole drilled in the cap as opposed to an expansion tank. You must COMPLETLEY clear your coolant system of any water or coolant for it to work as intended. And it is not cheap!

If you are willing to do what's needed to clear the system, it does work.

 

Here is a picture of an intake from a carb model. All the pitting you see is where the coolant channels from the head are running.
Image Unavailable, Please Login

 

What to do about it?