Lets see your CHEAP coolant bypass systems...

L

LittleRed

Always Watchin'
Joined
Apr 28, 2008
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Im looking to build or put together a coolant bypass system and not spend a small fortune doing so. Im looking for suggestions on what to use for a pressure valve or switch and size of hoses, where to return the coolant during a bypass (radiator overflow or somewhere else?) and where to tap into the coolant system.

Does the freeze plug in the back of the head have to be the one that is tapped into? if so why?

How much pressure is to much before have to bypass?

any info or pictures and specs of your systems would be great....
 
Search for member Unbroken's thread... he has covered several pages with this same subject. I think is was bypass ver. 1 or 2... something like that
 
A few have blown plugs even with a bypass in use, so Im not convinced that the bypass is the solution.
 
we had a boy that poped 4 headgaskets 3 stock and one fire ringed. after that we put a bypass from Keating Machine and it has had no problems.
 
I'll go take a pic of mine...

Here you go, I pretty much read Unbroken's thread and then did this... Using shop air the relief valve opens around 30 or 40 psi when it's adjusted all the way down (can't remember).

Installed in the coolant port on the top of the head between #5 & #6 and routed to the thermostat housing.

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keep in mind if it lowwers the pressure in the cooling system the boiling point will go down and that's no good, so just be care full on what psi it opens at , just my 2 cents good luck with it
 
I understand what you are saying about not wanting to lower the pressure in the system so you don't loose your higher boiling point! (If I remember correctly: Each PSI you increase the pressure you will also raise the boiling point 4F).
But if the system is still closed from the atmosphere (And it is if you aren't loosing coolant!). then it will still hold pressure based on the radiator cap used. The pressure in the system goes up because it is held in by the radiator cap and it is caused by the temp going up after starting the engine. Only thing this bypass could do is to relieve internal restriction inside the block cooling passages from the water pump pushing the coolant through the block.
Only thing I would question about all of this is how high could the water pump really be pushing the water pressure and how bad could the restriction be in or near the back of the block to raise the pressure any measurable amount over any where else in there? The general design of a water pump on most engines doesn't look to be able to build over about 20 psi and it would take a very small orifice to restrict the coolant flow down very far any way. Is there any way there could be that much of a pressure difference in the cooling system from one end to the other?
Has anyone ever put a pressure gauge any where in the system on one of these? I think I will try and rig up something on mine . . . . At least long enough to see what is going on in there!

So many questions! I don't mean to be so rough on this; it just strikes me as kind of strange. Maybe something else is going on here. We had a soft plug come out of a 24V locally the other day. It is completely stock and doesn't see very high rpm at all...... Hmmm...... I just thought this was a kind of common problem with the Cummins 5.9L
 
I am running an electric pump on mine right...it has seem to fix the problem, but i just cant trust those junk pumps. We have had to many of them fail. This is why i am looking into the bypass system. Can you tap into the cooling system in any pace (the freeze plug on the side of the block below the turbo)? or does it have to be in back because this area is where the most restriction and pressure is created?
Should I be looking for a pressure switch between 30-50 psi range?
Keep the info coming.
 
I just trimmed my pump, modded my thermostat, make sure the block is up to temp, and haven't popped a plug in over a year.
 
I tried the electric pump first and it failed with not much use on it. Put a stock pump back in with the fins trimmed and modded the thermostat. Out on the road testing my wastegate, I popped my rear freezeplug at about 2400 rpm. Plugged the rear with a billet piece and installed the bypass system. No issues yet...
 
im not sure why pressure gets that high, the radiator cap opens at 16 psi or so? is it because of the thermostat that the pressure gets high in the block?

sorry for the stupid question, just trying to learn.
 
Rollin Coal said:
im not sure why pressure gets that high, the radiator cap opens at 16 psi or so? is it because of the thermostat that the pressure gets high in the block?

sorry for the stupid question, just trying to learn.
Click to expand...
These have all the info and pics i got four holes drilled in my thermostat and 2 530c set at 50psi one in head and one in block
My bypass kit.....version 1.0 - Competition Diesel.Com - Bringing The BEST Together
DIY coolant by-pass? - Competition Diesel.Com - Bringing The BEST Together
 
I think 2 things blow the plugs
Excess pressure from turning high rpm
Rapid change of temps(water gets hot in the block/head, plug and block heat up with water, then when the stat opens the cooler water hits the plug and it shrinks. Pop out goes the plug.

The bypass systems help address both. They allow the water in the radiator to get heated, and allow pressure to be relieved.
 
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what is this "stat mod". Are you just drilling small hole in the thermostat, letting coolant bypass it? does clipping the water pump throw it out of balance therfore shortening the life of a pump (not that it matters that much)?

Im looking to get rid of a constant popping headgaskets problem that is believed to come from water pressure.
 
LittleRed said:
what is this "stat mod". Are you just drilling small hole in the thermostat, letting coolant bypass it? does clipping the water pump throw it out of balance therfore shortening the life of a pump (not that it matters that much)?
Click to expand...

I believe what they are referring to on the thermostat is enlarging the holes already present.

I am sure it will throw the balance off but for competition it probably won't matter much.
 
bigorange said:
keep in mind if it lowwers the pressure in the cooling system the boiling point will go down and that's no good, so just be care full on what psi it opens at , just my 2 cents good luck with it
Click to expand...

A bypass kit changes the flowing pressure, it is different than the expansion pressure.
 
LittleRed said:
what is this "stat mod". Are you just drilling small hole in the thermostat, letting coolant bypass it? does clipping the water pump throw it out of balance therfore shortening the life of a pump (not that it matters that much)?

Im looking to get rid of a constant popping headgaskets problem that is believed to come from water pressure.
Click to expand...

I drilled 4 3/16th holes 2 on each side and tried to balance them
 
I have to wonder if most of this isn't just poor quality plugs? Maybe there isn't that much pressure build up in there. . . . Who knows?

Keep the ideas and findings coming!! I may see if I can't rig up that pressure gauge to see what is happening in there. . . .
 
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