I was in the shop today talking to the owner just bsing and dynoing my truck when I brought up coolant pressure. They had been having many problems with an 04 blowing freeze plugs etc.(it has twins and is around 700hp) While talking to him he told me you were much better off going to an electric pump to control pressure than using a bypass. It was explained to me that that pump simulates the motor being at 1800 rpms as that was optimal coolant circulation. This also never lets pressure build to a dangerous level since rpms are the main culprit in blowing freeze plugs. They specialize in diesel repair/performance and claim this appartently solved the problem. What say you guys? Is it even cost effective? This would mean even an opie bypass(which he had previoulsy put on the truck) is not ideal.

 

Not the best fix for a daily use truck but could be an option for a pull or drag truck.

 

Can you explain why? The truck in question is only street driven.

 

It might work IF the freeze plug problem is due to RPM. I'm not sure anybody really knows the reason for the plugs popping out. RPM is just one of the theories floating around.

 

The optimal water flow in the system will exceed the heat rejection rate of the engine and maintain then thermostat somewhere between full open and full close. The belt driven water pump is reactive to this changing flow demand by increasing water flow as the heat rejection load goes up with increased engine speed.

A water pump that runs at the equivalent rate of 1800 rpm would most likely not sustain the needed flow for a truck running at 2200 rpm down the highway.

All designers primarily work on steady state design models, not on spike or transient conditions models. As such the reaction time of the thermostat is perfectly fine with the normal operation of our trucks and with the "normal" transient conditions. This also goes for the head gasket stability/durability.

Once you start doubling HP and spiking the rpm higher and longer then normal street driving dictates you are outside the design envelope for the system and bad things can happen.

 

i dont think rpm is the only reason for the plugs popping. the heat cause lots of pressure in the head and i dont believe that the electric water pump will fix it. i think the bypass is a lot better setup to keep from blow the plugs out because it lets the pressure bypass

 

Everyone familiar with Texas Diesel Power's "first and only diesel funny car"? Well that is a common rail block, p-pumped, with 24v injectors. I just spoke with him, John Robinson at Texas Diesel Nationals before I weighed in for the pull and he lined up with Scheid. I've also seen the car in his shop with the valve covers and body off. He's never had a freeze plug issue with that engine. He's running an electric water pump at god only know's how many rpm's.

I just bought my 04.5 6 weeks ago and within the first 6 day's I goofed up and TNT'd it. Well, needless to say I have a new long block. 3,700 rpm isn't a theory, it's just flat out too much volume/pressure. Since then I've taken it up to 3,500 a couple times but, it has been WARM to HOT. IE, thermostat should most likely be wide open. Without any blowouts.

Where am I going? For a daily driver (DD), I'd just run a bypass kit. And b/c most of the truck pulling classes, that I can afford, only allow you to run electric fans, not electric water pumps, that's the route I'm going to go with. And I've spoken to a few people about this now and have decided it's the route for me. But, if you don't care about pulling and drag racing rules, and don't tow 99% of the time and just want to play in short spurts, the electric pump may be the way you want to go.

http://www.enterpriseengine.com/elec...ater_pumps.htm

 

It is a theory because it hasn't been proven to cause the plugs to pop out.

The only problem with that theory is that numerous people have popped the freeze plugs turning stock RPM's.

 

That was my first thought as well, but talking to a few diesel techs I've been changing my mind. They say that is optimal flow. With the correct pressure. Belive me there is no expense spared on this truck and they wanted it done right.

 

You want the increased flow!

Bypass trumps Electric Pump any day!

 

I was way under 3k when mine blew out. I think it has more to do with cold water from the radiator hitting the hot freeze plug when the thermostat opens, combined with other factors mentioned.

 

i AGREE WITH CHRITIAN. Between cylinders 5 and 6 the coolant turns to seem and in theory turns into pressure which pressureizes the coolant and boom blows coolant and freeze plugs. The by pass eliminates that. With an electric water pumps the coolant will still turn to steam in the head.