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Cooling system changes for high rpm use.

I'd check with an automotive machine shop that does a lot of "foriegn cars" engines. Or google & see what comes up. Seems like someone on here found some, IIRCC.
 
there is absolutly now way pressure is pushing out freeze plugs.

the radiator cap will open and let the pressure out before the resivoir bottle explodes because it is the 2nd weakest link then there is no way the radiator hoses will hold any thing past 40 psi not to mention the heater core would be leaking onto your feet already.

you guys having problems are just not putting them in right... maybe you should have never pulled the originals to begin with.

taking out a thermostat is just dumb because your car will over heat as no water will flow through the radiator.

evans waterless coolant is dumb too of course it dont boil. neither will water if you can contain it.

water pumps dont make pressure because it can only get its water from the radiator and the radiator from the motor so its a loop all it can do is make water flow faster or slower in the loop.

if you have everything right and they are coming out is must be because your shaking ths piss outa the block until it turns to jello and the block lets tension off the plugs. and yes 4 banger shake no matter how much you paid some guy to "balance" or "blueprint" it.

or your pinging the engine to death anyway but you cometic HG wont let go nor will you forged pistons and H-beam rods so what is left to break? how about the block.

dont believe me? look at this. almost 1050 horse power from a 2.0 vw it started pinging and this happend.

BROKE.jpg


you can clearly see he had some nice pistons/rods dry sump oil light weight flywheel fully built better than most cars here.

Dont let em ping not even a little. this thread sucks.
 
there is absolutly now way pressure is pushing out freeze plugs.

the radiator cap will open and let the pressure out before the resivoir bottle explodes because it is the 2nd weakest link then there is no way the radiator hoses will hold any thing past 40 psi not to mention the heater core would be leaking onto your feet already.

you guys having problems are just not putting them in right... maybe you should have never pulled the originals to begin with.

Interesting. So I ejected 3 when the headgasket let go and the cap did nothing... because they just felt like leaving? Localized pressure buildups can and do happen for a variety of reasons, faulty installation notwithstanding. A gradual increase in pressure will usually work it's way back to the reservoir and out the cap, sure; but a rapid increase will find the nearest easiest mode of exit.

and just what are you basing your lovely observations and "facts" on, or are you simply trolling?

this thread sucks.

you suck.
 
and just what are you basing your lovely observations and "facts" on, or are you simply trolling?

the cap should open at 11PSI if yours don't then get a new one. Ive seen people rebuild entire engines replace radiators and still have a problem because the cap was bad.

this is why you check the simple stuff first.

if the cap opens at 11 then your freeze plugs will never see more than 11PSI if they cant hold 11PSI then you put them in wrong.


moral of the story get a new coolant reservoir cap if you just built an engine. if the plugs fall out again then the block is flexing like John was talking about and if that's the case your probably pounding the hell out of your engine with detonation.
 
Gospel of Coolant Systems to TB

While you're off stating that this is the one and only true path to the solution of this problem, many of us infidels disagree with some of the basic principles that you are basing your arguments on. Perhaps this would work in an ideal world, but the world is not flat.
 
taking out a thermostat is just dumb because your car will over heat as no water will flow through the radiator.

evans waterless coolant is dumb too of course it dont boil. neither will water if you can contain it.

if the cap opens at 11 then your freeze plugs will never see more than 11PSI if they cant hold 11PSI then you put them in wrong.
1. In many (most, at one time) engines, no thermostat means more flow. Too much, in most cases.
In a bypass system, it can overheat at idle, but do OK at high RPM. As stated above, you can block off the bypass.

2. Any liquid will boil, there is no magic liquid. The boiling point of any liquid will increase as pressure increases. Antifreeze has a higher boiling point than water, but does not transfer heat as well.

3. a spring-loaded cap letting pressure out via a wee hose can do little if there is instantaneous boiling due to a pressure drop. Pressure increases the boiling point, and a temp spike makes a pressure spike, which can cause a sudden leak, at which point all hell breaks loose. You should see what built Clevelands do in 65 mustangs. Yes, they fit, no, they don't like it. That's where I got my hands-on training in stupid cooling mishaps. Kenny got his in the same way.

Lastly: He who posts the prettiest photo does not win by default. But it sure is a beaut.
 
Ok a collection of thoughts. Apologies in advance this is a bit long....


Do you guys use water wetter? I put some in my whiteblock as I figured I didn't have much to lose, but I've never really noticed any differences in coolant temps or anything.

It has been theorized that water wetter should help reduce the formation of steam pockets that can be one of the cause of localized hotspots that can result in freeze plug eruptions. There's no silver bullet and it's not like that will cure it, but it seems to claim to help with such things...


Next thought....
There's probably a combination of mitigating factors - some being either too much coolant flow or cavitation or both, and some being block flex. Not that there are tons of them around, but I've never heard of high revving NA motors doing this...

Regardless, just for the record anyone who expect the radiator cap to compensate for any of these conditions doesn't have their head wrapped around what is happening to what. ;-)


Next thought....
I don't think the tstat causes it necessarily, but it would be interesting to datalog coolant pressure on a dyno pull with and without the tstat installed. Reason being if the waterpump does generate too much flow then the pressure is a result of cooling system "backpressure" - if removing the tstat resulted in a noticeable reduction in high rpm coolant pressure then it might suggest that underdriving/modifying the pump might be worthwhile.

If not it might suggest the problem is more mechanical (block flex, undersized freezeplugs, whatever).


I know the waterpump is not positive displacement, but we don't really know what the "curve" looks like. So it's still not impossible that speeds over the intended 6000-6500rpm revlimit don't result in more flow and more system pressure...
 
I tend to think freze plug problems(if they are correctly installed) are most likely due block flex/vibes.Are not most of you guys having these problems running turbo boost pressures(& HP) way above what Volvo probably intended for these engines/blocks to stand? Especially when they get to be 18+ years old?

DO not most hi-perf V8 engine builders go to brass threaded freeze plugs for engines intended to run way above OEM intended HP engine blocks, figuring they will add a bit of rigidity in the freeze plug area, above the OEM press ins?
 
I do know that Smokey Yunick slowed the flow on water in the block on his NASCAR BBC engines. Said it was pumping too fast. But now they same the opposite.
 
so quick info about cooling systems. 1) NEVER RUN YOUR CAR WITHOUT A THERMOSTAT! a trick is to cut out the spring part, for serious engines. 2) Changing the Radiator cap will change the pressure in the cooling system thus changing the boiling point. 3) Freeze plugs are a part of an engine build up, which should be done by people who know what the heck they are doing! 4) It is very important to remove the air from the coolant if it is starting to boil. 5) If you have blown a properly installed freeze plug you have done more damage to then engine then just that. 6) NEVER RUN YOUR CAR WITHOUT A THERMOSTAT! over cooling can do just as much damage as over heating.
 
I do remember reading about freeze plug loss in road racing vintage Volvos with B18s and B20s, which have the same style freeze plugs as the B21/23. And that seemed to be high rpm problems. It does seem to be way more common in boosted Volvo motors though. Its not like people are making this up.

I do have a pressure gauge that I can install. I think I'll try to have it ready for the next dyno trip. Its time to get a little more scientific about this.
 
qwkswede....what kind of motor and tranny mounts are you running?
 
Only problem I've ever seen, runing V8s without a T stat, was that it never got to a good Operating temperature. Would stay about 160F-170F. Lots of Florida guys run with no T Stat in V8s.

So engine oil keeps moisture in it, because OT is always lower than WT, at least in an N/A engine. +t I do not know, suspect oil would get much hotter than n/a .
 
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