Whats the Best fix for this?? Small Freeze Plugs??

Glad to here it wasn't the pistons again. These CRs are something else.
Billy
 
XLR8R said:
3 years & folks are still learning this the hard way... :bang

The 2-stage BOE kit we use adjusts coolant bypass PSI low enough to reduce water pump drive HP by over 35% and flows enough volume when cycled to prevent the pressure spikes which blow "loose" freeze plugs.

Threading the soft plug holes is a good idea, but the coolant pressure will still find the next easiest point of exit - there's over 200 lbs. of force behind every one of the block plugs at rated RPM. :Cheer:
Click to expand...

so, are you saying installing a by pass will prevent any plugs blowing ? So, there would be no need for threading and plugging ?

It's funny the extremes my truck has seen and the extreme high water/egt's it's seen and I've not had an with blowing plugs. Where does the extra water psi come from in laymens terms ?
 
You can also buy a tap and plugs from places like MSC and McMaster-Carr.
 
I don't believe the water pump can develop 200psi. I don't know of any single stage centrifical pump to do much more than 60psi. With the thermostat closed the whole block including the heater core would be recieveing the same pressure. With the thermostat open I don't believe much pressure could be developed unless the radiator is clogged. Then you'd be blowing out the cap. All someone would have to do to find out how much pressure you have with the thermostat closed/open is to install a pressure gauge in one of the heater hoses and rev the motor to 4K. It seems like most of the plugs are blowing while the motor is under load mostly at wot. It seems like the head may be partially lifting causing a pressure spike affecting the closest thing.
Billy
 
Nothing wrong with threading the soft plug holes, but not required IMO if the engine has a proper coolant pressure bypass system fitted.

Supposedly, some of the earlier CR blocks had insufficient interference fit between the plugs & block - surely it was corrected by '07.

Please note I stated 200 lbs. of force acting upon the large block plugs - not 200psi.

We tested the ISBe coolant system a few years ago - that's how I know what the pump performance is... single-stage C-pumps developing more than 60psi might be unusual, but most of us can find one by opening the hood!

I found very little difference in the pump curve from thermostat cycling or coolant temperature extremes.

A freeze plug is usually ejected at WOT under load because RPMs tend to be high... and the pump curve is still climbing pretty well at redline (any brave souls wish to test their parts at >4K rpm?).

I've no doubt that high combustion temps can cause localized phase changes adjacent to the cylinders' water jackets - the associated pressure spikes may well serve to help hammer the plugs out, but that data would be hard to capture without sufficient instrumentation resolution. Perhaps the cylinders' wet side could be 'scoped to check for signs of cavitation.

Lifting the head during max power production could certainly pressurize the coolant system beyond what the pump is already generating - from anecdotal evidence, I'm sure that's why some of the block plugs have ejected. :Cheer:

p.s. I believe the 6.7L water pumps have superceded with a larger pulley to reduce coolant pressure.
 
i have a bypass system and still blew out the front freeze plug before stacking and tapping the new set up...
 
... as well as others with small volume systems.

Pressure rise can take too long to stop ramping up without adequate relief flow.






Front block plug?
If so, likely an insufficient interference fit - normally the block plugs start ejecting from #6 forward.
 
XLR8R said:
Nothing wrong with threading the soft plug holes, but not required IMO if the engine has a proper coolant pressure bypass system fitted.

Supposedly, some of the earlier CR blocks had insufficient interference fit between the plugs & block - surely it was corrected by '07.

Please note I stated 200 lbs. of force acting upon the large block plugs - not 200psi.

We tested the ISBe coolant system a few years ago - that's how I know what the pump performance is... single-stage C-pumps developing more than 60psi might be unusual, but most of us can find one by opening the hood!

I found very little difference in the pump curve from thermostat cycling or coolant temperature extremes.

A freeze plug is usually ejected at WOT under load because RPMs tend to be high... and the pump curve is still climbing pretty well at redline (any brave souls wish to test their parts at >4K rpm?).

I've no doubt that high combustion temps can cause localized phase changes adjacent to the cylinders' water jackets - the associated pressure spikes may well serve to help hammer the plugs out, but that data would be hard to capture without sufficient instrumentation resolution. Perhaps the cylinders' wet side could be 'scoped to check for signs of cavitation.

Lifting the head during max power production could certainly pressurize the coolant system beyond what the pump is already generating - from anecdotal evidence, I'm sure that's why some of the block plugs have ejected. :Cheer:

p.s. I believe the 6.7L water pumps have superceded with a larger pulley to reduce coolant pressure.
Click to expand...


Don't the 6.7's have more fins also?
 
Hey Guys....

Where are these freeze plugs located??? Top or bottom of the head? I just remember seing them.... of course I wasn't looking either.

Thanks!

:Cheer:
 
HRDROKN said:
Hey Guys....

Where are these freeze plugs located??? Top or bottom of the head? I just remember seing them.... of course I wasn't looking either.

Thanks!

:Cheer:
Click to expand...


Hey now that I'm looking closer... looks like this doesn't apply to 12 Valve heads? Just 24V and CR's.
 
HRDROKN said:
Hey Guys....

Where are these freeze plugs located??? Top or bottom of the head? I just remember seing them.... of course I wasn't looking either.

Thanks!

:Cheer:
Click to expand...

Well, on my CR head they are under the valve cover on the Exhst. Side, lined all the way down the head..
 
Why don't you use the correct stock freeze plugs with some permanent thread locker or similar adhesive? Although a threaded plug sounds very secure and permanent, threading 11 holes at a shop has to cost more than new plugs and some thread locker.
 
at a shop? what does a tap cost $13 or so? I have a hard time understanding why you would take a head to a shop for something as simple as tapping some holes? it's pretty straightforward.

on a side note, the green locktite should do the trick if you are dedicated to that option.
 
just wanted to add $.02 to this. In talking to guys at Scheid and Enterprise, both who build trucks with a lot of power and run very high rpm's say that tapping and plugging those holes isn't the fix. It's obvious that by doing that, the psi is going to want to blow out some where else...e,i... head gasket, block freeze plugs, water pump seal.

Their way around the problem isn't to thread those plugs, they use electric water pumps with a by pass. Neither has seen a problem with any freeze plugs by doing this.

Probably not a great idea if the truck is used for DD but, for a dedicated racer/puller.... a electric fan/pump w/by pass is the trick.

Take this for what it's worth.... I for one don't want to do things twice and will be opting out of threading.
 
Electric pump is great until the damn thing starts blowing fuses every 5 miles, then you're back to melting things.

I'd say a mechanical pump, with a good bypass, and maybe clip some fins.

But I run a 12v and don't have these problems:D
Chris
 
Signature600 said:
Electric pump is great until the damn thing starts blowing fuses every 5 miles, then you're back to melting things.

I'd say a mechanical pump, with a good bypass, and maybe clip some fins.

But I run a 12v and don't have these problems:D
Chris
Click to expand...

the key word though to a electric pump is " race only "
 
How many CR's that blow freeze plugs are care only? I thought you guys were looking for a solution for them?

Chris
 
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