Davies Craig Cooling System

[Will L.]

Anyone currently running a Davies Craig cooling system on any vehicle, I would like to talk about it, and possible adaptation for the 6.5. I have contacted the company already and awaiting responses from their experts.
Thanks.

 

[THEFERMANATOR]

I've never heard of them myself, but after searching, it looks like stuff many other manufacturers sell. What parts in particuliar are you looking at?

 

[Will L.]

Im wanting to hear about any sucess or failures in their systems. The quality of their products seem unmatched in production. When they started building components for large manufacturers like GM- they are getting Zero rejections- just perfect production numbers. So no concearn in poor quality.

I would guess there gpm numbers are accurate as well, but if anyone had cases where they replaced a known pump with one of theirs in an aftermarket application and it under performed- that would be good to hear before hand.

But the entire system of design by removing the impeller and thermostat, then running all flow control by cycling on and off the electric waterpump- genius in concept. Eliminate the delay of opening and the water cavitation that always occurs from thermostats closing- Only problem I see in replacing the 6.5 system is it could take 4 of their biggest waterpumps to do the job. They are designed to run multiple pumps, but wanting to understand it more. The 150 is the biggest I see at 40 gpm.

No way could the mechanical fan be eliminated and replaced with electric like they do for gasoline engines, but engauging an electric controlled fanclutch can be done multiple ways. The system with electro viscous being tested by @ak diesel driver , the 100% lockup electric fanclutch being tested by @Burning oil , or the 100% lockup Hmmwv fan clutch like done before by @uniquediesel , and another who escapes me currently that iirc both used the 4 bolt no balanced flow waterpump- that is what the unit bolts onto currently- I am very slowly working on adapting it to the balanced flow/spin on waterpump.

Now, if the no thermostat and no impeller waterpump system with electric waterpump(s) can be acomplished affordably- the 4 stud waterpump becomes instant sucess for the hmmwv fanclutch because no modification is required for it- only controls for a/c comes into question.

Also the possibility of running just one of the auxiliary pumps. My plan of last resort if I cannot burn off enough BTUs through the stack after thermal coating has been a roof mounted radiator. Other hummer owners have done it, other hummer owners are considering (1 right now about to) add an auxiliary radiator in the bed of the hummer. Past attempts have shown just the engine waterpump is not capable of doing it well. So I am wanting to hear from users of their differnt pumps just to get input.

Running the auxiliary radiator in series or in parallel becomes an issue of debate as well. I have been focusing on a parallel system like the heatercore operates, but doing it with high volume I believe stealing coolant out of the primary radiator and creating cavitation can be an issue.

I really dont want to play with differing flow out the heater hose circuit-all the differences the rear head experiments caused eddycurrents in the block- has me uncomfortable pulling high volume from it- so really wanting all flow to both radiators going out the thermostat port. So that leads to needing one way valving, which adds complexity and cost.

Running them in series is the best way conceptually, but will need a second waterpump equal to or greater than the 127 gpm engine pump mounted in the bed for that location, or engine compartment for front of roof location. Best option there is to buy a second engine waterpump (from you know where) and build a backing plate with king nipples welded on the back for hose attachment, and a couple mounting tabs.

For front of roof application belt driving it as if it were a secondary alternator is the easy fix, then head pressure and extra flow drag of auxiliary radiator is not too bad. But bed mounted radiator will require an electric motor to drive it back in the bed. Trying to determine the needed motor for that is a mathematicians dream- cost is another hurdle.

Have I ever mentioned how much I miss the not so hard to solve overheating problems in the 6.5 pickups compared to hummers that drive high speed in freeways or tow on freeways? haha.

Still yet to be seen in hummer heating relief is the larger turbo advantage of eliminating gmx turbo. But the n/a hummers overheat on the freeway just as bad as turbo hummers- and the n/a pickups were not quite as bad as the turbo pickups were until the heavy loads are applied. Still the biggest turbo onto a hummer yet I have seen not living off of wmi for overheating purposes is the switzer s300/s400 hybrid like on ourfriends rv here that is fighting their custome header leaking issues. It is slightly larger than a hx35/40 hybrid- so slight that a ww2 hx35/40 probably overtakes it. So moving to ATT or similar big boy should let it breathe well. Especially because hummer overheating is all done at close to 3,000 rpm, and the weight and gearing in a hummer can spool an ATT easier at lower rpm than in a pickup. Stuffing it in there somehow...
Not trying to jump the tracks, but all part of the equation.

 

[ak diesel driver]

IIRC SCTrailrider said Uniques set up is not 100% lockup.

 

[WarWagon]

Stop the water pump vs. closed thermostat gets you what exactly? IMO local overheating as all water flow stops. Our engines are used to using a bypass to circulate the water in the engine block till the Tstat opens and puts the radiator in the loop. This has somewhat even warm up temps throughout the block. Stopping the water pump completely would have a cold block and hot heads. Running the water pump to cool hot heads and dumping into the radiator would have the block never get up to temp. (Load dependent of course.)

Additional radiators was a solution that some had luck with on the Duramax LLY overheating. Notice the monster 25" fans and hugs grilles used in the 2008+ years.

The cooling system is only one part of the system. Excessive exhaust backpressure and other things that keep heat in the engine including intercooling all add load to the cooling system. The ATT made a huge difference in the amount my fan ran under full towing load on grades here in AZ. Even the little "hills" where the fan was screaming with the GM3 could go without a fan sometimes.

 

[Twisted Steel Performance]

IIRC SCTrailrider said Uniques set up is not 100% lockup.

It is 100% lock up.....

 

[ak diesel driver]

Glad you chimed in to correct me. Went back and found the post I was thinking of and it said that it was not a total freewheel and was similar to a viscous clutch in that regard. So bad memory on my part.

 

[Will L.]

Yeah, the 100% lockup is crucial to hmmwvs. They can not operate with the fan clutch unless it is the ecv system.
John's system is with the 4 bolt nonbalaced flow waterpump. Several have tried running that in hummers with the hmmwv and it results in cracking the #8 cylinder and or head. The optimizers with that set up withstand it longer, but still loose the driver side head.
If he would have made the adapter to make the spinon work for a few hundred dollars, I would already bought it from him. My understanding is his r&d time was spent on the switch for the a/c control as the 12volt solenoid info has been out there a while, and the rest of the system is straight hmmwv iirc. The a/c control is a challenge to deal with, so accomplishing that was not a 1 day issue. But it is irrelevant to 90% of hummer guys and probably 40% of pickup guys. A simple high pressure switch from too hot of a condenser about 10* below desired wcould kick it in and bring temps back down. His system probably fire ice cubes from the word go?

As for stopping water flow, is is simply a choice. If you want slight flow, say 1 gpm, then just set it there. Their systems on everything that has shown research so far is major improvements over the system designed 100 years ago of operating a pump and plugging it off at the same time. The turbulence created by a high volume pump getting 3/4 of the flow shut down isnt helpful. It creates aeration in the coolant and that is the cavitation making the pitting.

They completely saved bmw with the auxiliary pump solution. Their electric waterpump system is unmatched by anyone out there, along with their electro viscous fans. They just haven't messed with any diesels yet that I have found.
Their cooling system does a better job with a 30gpm pump on small block ford and chevy then the 50 & 55gpm mechanical driven systems. So everything they have done so far has had home run results by all reports.
Really wanting to see any headaches or speed bumps people hit to see what is going unreported. Who knows, maybe hear of some monster system like is needed for a 6.5 about to go into production- haha- yeah right.

 

[schiker]

1. Interesting to think about. Pump sizing and space limits look daunting. I have kind of wondered about actual flow rate of water pump and where it flows. Did increased GPM pumps and 2 thermostats just help mixing and normalizing head temp with more agitation, balance, and re-circulation vs. how much flow actually increased through the radiator.

2. Would direct bank feeds and returns with big hoses and decreased flow restrictions, balance, and reduced re-circulation be enough to get actual BTU rejection improved to counter GPM of pump size? Would increased pressure or Evans coolant be better????

3. The 6.5's IDI heads are a very hot local head heat. I sometimes wonder and picture cooling hot metal in a bucket of water. Hot metal will steam and boil the water next to the metal weather the water is cold or warm . The biggest help seems to be to thrash the metal around in the bucket. Its hard to get around flowrate. I have seen hot metal put on ice and it doesn't seem??? to cool any faster than thrashing it around in a water bucket of warm water. So in the above paragraph the increase in flow from cleaning up bank feed and returns would have to be pretty big just imagining it.

4. I have always liked the idea of adding auxiliary pump to run a parallel heat exchanger loop from the heater core circuit or similar. Might be better to pull from heater core feed and return to rear head according to the thoughts in paragraph 3. But returning it to bottom radiator hose is similar to cooling radiator with locking up air fan so lower radiator hose temperature does matter.