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So i blew out my rear freeze plug the other night and have decided to build my own coolant bypass. So far I have purchased a series 55 valve pre set to 30 psi from aquatrol and a billet freeze plug from EED. My ? is the freeze plug is drilled and tapped for a fitting should I bypass from the rear plug or plug it and bypass from the plug between 5 and 6 on the head? Also is it best to tap into the T-stat housing or the upper radiator hose? Thanks for any input.
 

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as far as i know it doesn`t matter if you tap into the t-stat housing or the upper hose...the upper hose is probably easier, but you can also get a t-stat housing from Chris @ E.D> that will go between the housing & the block. I`m not sure about the plate... i would think ou still go between 5 & 6 but i could be wrong. Maybe Dodge74 will chime in here he will have the correct info for you.
 

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if your new plug is tapped for a fitting, why NOT use it and bypass to the thermostat/upper radiator hose??? that's why it is tapped for a fitting...just sayin' :)
 

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if your new plug is tapped for a fitting, why NOT use it and bypass to the thermostat/upper radiator hose??? that's why it is tapped for a fitting...just sayin' :)
Thats what I was thinking too. I figure there was enough pressure at the plug to blow it out why not relieve the pressure from the same spot?
 

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Thats what I was thinking too. I figure there was enough pressure at the plug to blow it out why not relieve the pressure from the same spot?
:thumbsup:
 

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i took a piece of pipe cut a hole in it and welded a 3/4" nipple to it. cut the radiator hose inserted the pipe in the hose clamped it and put the valve betweent number 5 and 6 works great
 
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Definatley relieve the pressure from the rear. Have you heard of anyone blowing a plug after a relief kit that takes pressure from the rear freeze plug? I've heard none. But several from guys with kits that relieve pressure from elsewhere. I got the whole kit from eep for 150-160 i think delivered.
 
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just relieve the pressure from the rear
 

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The water flow in a Cummins is from the front of the block to the rear, with passages in the head gasket for water to flow from the block into the head. The water then exits at the thermostat which is in the head.

Putting the pressure relief in the block will certainly reduce the chance of blowing freeze plugs, probably more then from putting it in the head. The downside is that it greatly reduces the amount of water flow through the head. The water flow in a CR's head is already lower then any of the previous models.

Paul
 

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i took a piece of pipe cut a hole in it and welded a 3/4" nipple to it. cut the radiator hose inserted the pipe in the hose clamped it and put the valve betweent number 5 and 6 works great
Thats kinda what I did, I bought a billet alum. radiator hose drain and a alumimum -10 an adapter, welded the adapter on the drain, made a bracket with aluminum plate and angle to mount the reliet and plumbed it to the last coolant plug in the head between #5 and 6. I have to say it works great.
Here are a couple of pics of my set up





 

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Hey guys..I took a totally different approach to the problem........

To reduce the pressure in my coolant system....I run 100% Sierra coolant...Its made of the same stuff thats in Evans coolant at faction of the cost....The boiling point is 350F+....With NO WATER in the cooling system it elimanates hot spots..aka HIGH PRESSURE!!..The truck runs at normal temp...I could not be happier...I also changed the radiator cap to a 7psi cap....Its been a year now....With NO PROBLEMS!!:thumbsup:

With 46psi boost and Propane...Thats gotta equal a lot of cylinder pressure ..:shock:
 

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cylinder pressure is one thing- water expansion/steam pressure is another

thanks for the sierra info.... where do you find it?
 

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Discussion Starter #14
Thats kinda what I did, I bought a billet alum. radiator hose drain and a alumimum -10 an adapter, welded the adapter on the drain, made a bracket with aluminum plate and angle to mount the reliet and plumbed it to the last coolant plug in the head between #5 and 6. I have to say it works great.
Here are a couple of pics of my set up





DODGE74 thats is a pimp setup! Looks everybit as good as wickeds or opie's in my opinion! I was talking to our shop mechanic today and he suggested getting a larger pulley for the water pump and under driving it a little. I wonder if that would do the trick?
 

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I really cant say on the pulley trick, I know when I used to run underdrive pulleys on my race car I would have trouble with overheating issues, so I just kept the stock water pump pulley on it and under drove the crank and alt.
IIRC I think that I have right around 200.00 in it. So its not to bad.
I tried what Stovetop did and ran down the road running the rpms at 28-2,900 for maybe a mile after the engine was up to temp and the coolant temp dropped from 200* to half way between 140 and 200* in the matter of seconds. I was amazed at how fast it dropped the temps.
If you have any questions just ask.
 

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cylinder pressure is one thing- water expansion/steam pressure is another

thanks for the sierra info.... where do you find it?
SIERRA Antifreeze Home Page

The Sierra msds states it has 3% water = 4 oz of water in a gal of Sierra...Evans product says It has no water....That said... I cant argue with results.....:thumbsup:..Both are (Propylene Glycol) coolants....Sierra used at 100% with NO water added... works very well in my truck.........:party018:
 

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Has anybody put a pressure gauge on the rear plug (between 5 & 6) to see just what kind of pressures are present there at high RPM? And does anybody have an idea as to what is considered unsafe pressures that need to be worried about?

Obviously the "unsafe" pressure could vary from truck to truck, and be dependent on the operation temp of the engine. But I'm just very curious as to how much pressure needs to be avoided to prevent freeze plugs from popping out.

I used to run an electric water pump in my rig to avoid coolant overpressure, but the pump has given up the ghost, and I've had to resort to the trusty ol' mechanical water pump. I need to start looking into a coolant bypass, as well as tapping the passages in the head for NPT pipe plugs.
 

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There was 1 guy on here that ran a the coolant bypass and still blew the rear freeze plug out. He did a post on it last summer IIRC.
 

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it has been posted that there is 90+ psi seen on a gauge between #5/6
 

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it has been posted that there is 90+ psi seen on a gauge between #5/6
Wow! So, any idea at what PSI these bypass kits are relieving at? It's obvious that keeping some amount of pressure in the system is desirable (to increase the boiling point of the water). But at what point do we say enough is enough?
 
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