• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

crossover debate

Okay, well I went over to the shop to take a picture... and forgot I bolted the backing plate back on the water pump :mad2: So I'll explain it.

Behind the water pump impeller there is basically a donut of open space that the coolant is drawn in through. Different diameters of that opening dictate the surface area of fins on the impeller exposed to the inlet. They range from 75mm to 92mm IIRC. What has to be done it the impeller removed from the pump, and the donut opening (inlet) widened to 114mm IIRC. You can go a bit bigger with this size, and they also radius the edges of the donut so that cavitation is less of a problem. There is also a notch cut in the side of the impeller, but I forget how of if they modified it. I believe the HO pumps had the notch, while the lower flow ones you have to cut the notch out.

To help equalize the flow from bank to bank out of the water pump, there are "points" that are part of the outer casting of the water pump. Altering the shape of these points "scrapes" more or less coolant off the fins from one side to the other. I don't know how to shape the points without some trail and error work. It's pretty easy to measure the flow as it is just measured in gallons/hour or gallons/minute.

I was concerned originally about putting work into a part that wears out, but they do last pretty long, and with no fan the load on it is less.
 
What does the restriction do? Where does it go? I'm interested in learning, and I will do a writeup with pictures, but I would like to know how and what I'm doing. How come so little info on the subject? Especially if it has been an ongoing problem.
 
chevydiesel said:
I've got a Kennedy fan clutch that works great and can engage when the engine is steadily running 2400RPM. The factory and many aftermarkets can't (require you to slow down engine to fully engage), or on time that is. So, I'd like to keep my KD clutch with HO pump and Dual stats.

I figure if we can modify the existing stuff, not for more flow, but for even flow, and increased flow where we need it (even # cylinder banks) that it'd be good.

My biggest obstacle is making some kind of test bench to verify this issue. What would you measure the flow with? Not exactly an autometer or isspro offering...

J
Click to expand...

I gave away my KD clutch I did not like the power it robbed once it engaged and would never disengage once locked in

I have the dual stat balance flow & retuned 4 bolt clutch from Heath (both old Heath rig no longer sold) on my truck with plastic fan towing up to 18K with my truck on 100F days no overheat issues thus far, plus trans stuff in my sig, and a Heath clutch/pump/fan on my burb with dual stat, that pump has a restrictor built into the bypass port that helps even the flow IIRC is how Bill described it when I bought the burb it would overheat idling in traffic, swapped to Heath setup and speeds to 109 mph max it will do with 95F ambient & no overheats on it since.

Best place for pump info is Bill himself
 
Last edited:
The restrictor is only for dual stat then? I guess my problem is, I don't have the coin to drop on a full upgrade. I am wondering how I can keep my truck cool taking my family on summer vacation , and not ruin a head, or block. Salvage yards won't sell just the crossover, unless the engine is scattered. Around here I just don't see many of them.
 
Been done. Was a brilliant fix, but I think my clutch is shot. I am working on a Heath replacement, but there again, it is alot of money. The other thing is that I need to replace my radiator, one is sitting in the garage, but time is also at a minimum. I think that will make a difference because the old one is still original as far as I know. I am just trying to do with what I have. I picked up some Royal Purple Purple Ice today, and plan on doing a full flush, radiator replacement, and clutch and fan replacement. I still wonder about the flow to both sides though. The hot side is the one recieiving the least flow.
 
You must log in or register to reply here.
Back
Top