When you say 5 gallons of coolant and to use one bottle in our trucks, are you meaning that it treats 5 gallons of straight coolant and when we 50/50 dilute it one bottle is enough? IIRC our trucks hold 8 gallons and I read that its two 8oz bottles to start and then one every 15k/year like you said.

Still wanna understand why you can't mix SCA and RMI but the general consensus is to not to. I might give them a buzz to ask.

 

RMI told me via email that it was OK to use their product in coolant that already has its own SCA package. He said the RMI will work with other SCA's. Not sure what that means but it evidently does no harm when added to coolant already containing SCA's.

 

The way I understood him is 8 oz will treat up to 5 gallons of coolant, I took a random guess and said our trucks hold about 2.5 gals and he said use a full 8 oz , so with your spec of 8 gallons our trucks would get two 8 oz bottles. I assume that at 15,000 miles or 1 yr service the Ph will be out of spec and then add two more 8 oz bottles.


Heres Dan's contact info, give him a call get some more info for the site., Dan is eager to talk RMI. Contact Dan Watson at RMISource.com

 

Dan at RMI said not to add SCA but gave no reasoning, I did not ask cause my truck will get a complete flush before the RMI therefore zero SCA wil be present.

 

Jack,

According to the manufacturer, RMI-25 is SCA and provides similar erosion protection as the other SCA's. So, no need to add additional SCA.

 

What type and color coolant you guys running?

 

I used the fleet pre-charged concentrate. Did the block flush, added 4 gallon of concentratethen I topped of with distilled water till it was full. Should be a 50/50 mix.

 

Acidity (pH) has nothing to do with cavitation. Once again, cavitation is not corrosion. So I wonder why the vendor recommended testing with pH strips. From their web site, they do claim the product contains:
along with a slew of other additives (including a ph "stabilizer"). But checking for pH won't tell you how much of the "oxygen scavenger" is still left and active. Either they need to come forward with exactly what that is, so users can find and use the right _anti-cavitation_ test strip to monitor it, or they need to come out with their own test strip that includes a pad for THEIR anti-cav.

"Fleet" is ambiguous. There are two companies making anti-freeze with "Fleet" in the name. FleetGUARD is a brand of products, including some ELCs; IIRC some are pre-charged with SCA and some are not. FleetCHARGE is a Peak product that's pre-charged with SCA, but is conventional "green" (even though it's pink) chemistry otherwise.

 

Yes, I used the "FleetCharge", and it was pink but as you said it is a SCA pre-charged "green" coolant.

 

Here's a link (I think) to a pretty good Cummins Filtration article on Diesel engine cavitation.

http://cumminsfiltration.com/pdfs/pr...s/3300963A.pdf

 

I'm trying to wake some old brain cells up. I'm not sure oxygen has much to do with cavitation. It's the expanding and imploding of water (or other fluid) vapor pockets that cause cavitation damage, not oxygen. Most all of my cavitation experience has been with big non-Diesel related pumps though.

That's another question for the RMI-25 guys, how does their oxygen inhibitor prevent cavitation? Worst case we might get them to be more accurate on their website, assuming it needs more accuracy. Maybe it doesn't.

 

pumps don't cavitate, the cylinders making the huge explosion does it


Understanding & Preventing Cavitation in the 7.3L IDI Diesel

 

That ^^^^ is very informative, but.... it would be better if they didn't use the word "corrosion", because it's too easy for readers to associate that with either rust (oxidation) or some sort of pH-based (acidic) corrosion. Cavitation is really a "physical" process; the imploding bubbles act like tiny chisels. And even though SCA is a chemical (or set of chemicals, depending on which), it's the _physical_ deposition of the additive on the coolant jacket wall that prevents the cavitation. This is why it needs to be monitored and renewed; that deposition process is constantly consuming the supply.

Also, they reference the cylinder "liner" that separates the coolant jackets and combustion chambers. That might lead readers to think that cavitation only occurs in engines with lined cylinders. AFAIK, cavitation can happen on solid-cast blocks as well, where there's no liner, and the combustion chamber is just a cylindrical cavity in the block casting. The block wall between the chamber and the coolant jacket can vibrate in the same manner as they describe.

Also, it needs a proofread. They used "effect" in the column title where it should have been "affect". And "preventative"? My dad is turning over in his grave....

 

Yeah, I should have been more detailed. I was trying to explain that all of my cavitation experience is with large pumps found in electrical generating power plants but that's not what I wrote. Those pumps do cavitate under poor operating conditions.

The way I put it, I guess it sounded like I was talking about water pumps in IC engines. This is an interesting and educational topic. It doesn't take much information to double what I know about it.

 

That's something I don't understand about how RMI-25 works. When added to coolant that's already charged with SCA's it evidently cleans the cylinder water jackets down to bare metal, removing any protective coating deposited by the existing SCA while simultaneously making the coolant cavitation-proof through chemical hocus pocus? It doesn't protect against the effects of cavitation, it actually prevents cavitation in the first place? I don't believe that an oxygen scavenging chemical is going to prevent cavitation. Corrosion maybe, but cavitation, no. And I could be wrong. I'm just a little suspicious of one product that claims to do so many different things so well.

Cooling system cleaning ability is easily demonstrated and proven, but cavitation erosion protection is a long term phenomenon and not easily tested. I sure wouldn't want to use this stuff for 75,000 miles only to find out that I had very clean and pitted water jackets.

Cavitation makes high frequency sound waves that can be detected by special sensors. If this stuff prevents cavitation they should be able to conduct a test on an untreated Diesel engine showing the cavitation pulses on a scope or FFT analyzer. Pour in some RMI-25 and the cavitation spikes should disappear. If it works. And yes, I know I'm overthinking this.