• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

Cooling system changes for high rpm use.

Toyota's current NASCAR engine does not even have a housing for a thermostat. Big pulley for most tracks, huge pulley for superspeedways, heat the hell out of the oil prior to qualifying but leave the coolant alone, only shut it off if it gets really hot, but about 20 deg. F cooler than the best teams.

Uhh, that's because all of the cooling passages and waterjackets were CFD designed and and 100% purpose built for the specific application for the specific rpm and flow rates the motor is operated with. They also don't need to idle in traffic or warm up quicky on cold mornings etc...

How does that have any relevance whatsoever to making a tractor-engine derived cooling system work on an 80's passenger car motor under conditions it was not designed for?
:???:
 
I've been putting pumps with that impeller design on for years and they always seemed to work well. I picked up a new GMB a couple weeks ago for the 940T just to have on hand and now their new pumps have been internally redesigned/reshaped and are running this impeller:


I purchased a GMB waterpump aswell not long ago and it had the same cast impeller like this factory Volvo pump.
P1000054.JPG

That is a 16mm shaft.

P1000053.JPG
 
The Hepu that Im running, looks like it has S shaped impeller blades on a cast brass wheel.
 
Uhh, that's because all of the cooling passages and waterjackets were CFD designed and and 100% purpose built for the specific application for the specific rpm and flow rates the motor is operated with. They also don't need to idle in traffic or warm up quicky on cold mornings etc...

How does that have any relevance whatsoever to making a tractor-engine derived cooling system work on an 80's passenger car motor under conditions it was not designed for?
:???:
1. They only designed those passages to flow water. No restrictions. I asked.
2. Because there is so much talk of racing engines, Smokey Yunick, etc. in this thread. It's about Kenny blowing **** up and all sorts of things. So why shouldn't I respond to a statement made about an earlier post of mine?
You could say the same about this post:

NEVER RUN YOUR CAR WITHOUT A THERMOSTAT! a trick is to cut out the spring part, for serious engines.
 
1. They only designed those passages to flow water. No restrictions. I asked.

Yes and you can do that when the whole system, in terms of operating speeds and flow rates was designed as a whole for a specific set of operating conditions.

The "restrictiveness", or lack thereof, may or may not be appropriate when the flow rate changes, or alternatively, if the operating speed of the pump etc is changed, then changes to the pump drive/flow rate may need to be altered to compensate in order to keep the system functioning optimally.

I thought that was what the thread was about. Keeping the system optimal when the operating demands are changed from the OEM demands.

I am honestly just trying to help re-focus a bit here...
 
Napa wwater pumps have worked great for me never had any of the problems others are describing. Of course I never put down more than 220whp, but I was in boost before the engine warmed up everyday, and barely ever came out of boost at all, everyday.
 
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.
I never said pressure was pushing them out. John pegged it correctly with the "block squirm" or maybe better phrased ,"block vibration/flexing/deflection.

It works the plugs loose & they come out.
 
This is a pretty interesting thread. I've read enough about the blowing of freeze plugs I'm concerned. I regularly turn my B230FT to 6800-7000 rpm.

I am running a stock radiator, Hepu water pump (new), newish 3 core Nissen radiator, electric fan conversion, stock Volvo thermostat. Can't remember exactly which WP pulley is on the WP, but I'm fairly certain it's stock B230FT. Crank pulley is an MVP underdrive pulley (anyone remember those guys?).

I've had zero issues cooling at speed - even without OD, and highway cruising at 70mph or so.

I have had some fairly significant issues keeping things cool in traffic when it's warm outside (above 75*F). It will heat up quickly, and I've had it burp some coolant about 3 times after driving around town, once was after coming in from several hours highway journey. But it is something that needs to get addressed and resolved.

I find it almost bizarre that I"m having the opposite issue of most folks here - fine cooling at high RPM, and insufficient a low RPM.

I plan on doing something when I pull the engine next month to be certain those freeze plugs are secure.

Keep ideas coming as to how to address this issue.
 
What are you using for cooling? It just sounds like your radiator fan can't keep up with the cooling demands is all... You probably want to go one range cooler on the thermostat as well, but at a bare minimum try to keep it at that temperature(87*C) and definitely no more.

Also, what's your idle speed? I don't know if low flow at idle speeds is a problem, but it won't hurt anything to bump the idle up to 1000rpm or so.
 
KLR, It's a Spal Fan, don't recall what the CFM is off the top of my head, but its pretty powerful, and covers about 90% of the radiator. Thermostat is an 87*C model. Even traveling at low speeds (25mph or so) if it's hot, and the car is hot, it'll want to overheat, and then engine is turning at 1500-2000rpm or so then. Sometimes more, if I have it locked in 1st, but typically if it's warm, I'll keep it in second and lower speeds. Idle speed is around 800rpm or so. I agree, the fan isn't doing all the work it needs to, but I'm also wondering if my intercooler/tranny cooler radiator package is so thick it's not allowing proper airflow through.
 
I see I see. Yeah, I guess just check on improving the efficiency of airflow through the front of the car and make sure the air that does get in there, goes where you want it to. Assuming you haven't already, of course.

Is this only after getting heavy into boost or just even around town, traffic cruising without adding any extra thermal load into the system? Maybe the air needs a way to escape your engine compartment easier?

Throwing out thoughts, anyway.
 
Like the factory one?

No he means so it's clutched to the water pump shaft. Kind of a neat idea but the engineering involved would probably be pretty nasty. Most likely easier to just get an electric water pump+ controller or control it via your EMS.
 
IMG_20110116_155500.jpg


Cavitation damage on a stock Volvo pump housing. If using the stock water pump, find the largest water pump pulley and install a smaller crank pulley.
 
My 79 n/a 245's water pump looked like that RSI. Mine was due to large chunks of rusted water jacket off the block.

I pulled the drain petcock & adapter bushing & stuck a screwdriver in there, and even more came out.

I refilled & drained and rodded a few more times to get it all out.

Next WP change no scoring was on the inner WP hsg.
There was all kinds & sizes of chunks in the drain pan when I was done.
 
This is a very interesting topic, and one I feel should be taken very seriously on high speed turbo motors.

There must be a relationship between the optimum water flow rate to pick up heat from the upper areas of the water jacket/ liners and the head water passages, the flow rate and overall sizing best suited to dissipating it at the radiator, and also the water pumps ability to create that flow without causing cavitation and other issues at the engines normal operating speeds.

At least on most Volvos lack of frontal area for mounting radiators isn't going to be a problem!

I personally feel that all else being equal and for any given rpm, there could be advantages to slightly increased coolant flow rate through those areas of critical heat soaking at higher outputs to avoid localised boiling on high output motors.

The additional waste heat issue is one part of the problem with greatly elevated outputs, but running at higher rpm as well compounds the situation.

On N/A rally car engines I used to work on that could be operating at up to 3000rpm faster than stock, drastic water pump (and alternator) drive ratio reductions were normal. These cars usually ran very low final drive ratios and were cammed to 'scream'. It was 'believed' at the time on these that beyond a certain coolant flow rate that it was actually less effective at cooling, but the reasoning for this was only ever theory.

On very high speed engines though the additional power loss in driving the ancilliaries to those speeds IS significant..... I could believe 10 or more horsepower being lost in driving them, which is also why some rally cars used to be able to electrically disconnect the alternator on long straights to take the load off!


As for a thermostat, I'd never run without one.... but then I live in a relatively cold climate where warm up times, engiine wear and emmissions would be adversely effected.

Thermostats can and do fail, but usually stick in the closed position where you can't fail to notice the problem after only a few minutes....

I'd be extremely wary of copying the boring of additional holes for coolant in a head or modifying a gasket in a similar way without having a very good reason to, or thoroughly understanding why and for what purpose this was done on the other engine.
I've seen people haphazardly open up gasket 'holes' on engines not realising that the flow is 'balanced' along the block and doing this can cause a short-circuit and overheating in the rear cylinders.
 
has anyone tried one of the heat transfer agents like redline water wetter or amsoil coolant boost? i have used them for years in my EP autocross jetta motor that runs very hot with a 13.5:1 cr and turns 8k. but i do also have an electric motor driving my WP. it can be a big help with heat transfer from the coolant to the metal its touching.
 
i'm reading this post in Z and im asking question about over pressure possibility at high RPM....anyone have take a pressure gauge and do a inrun high rpm pressure test ??
i have tested my block at 100 psi air pressure (checking for crack) and never pop a frost plug ?? so the question is if the pressure raise up to 100 psi in block at 7200rpm or more !
 
Back
Top