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Cooling system changes for high rpm use.

Hey, ever hear of block squirm?
Youse running some crazy sheeet, mang, the Volvo block ain't as stiff as we'd like to imagine and it ain't as rigid as the two Fords I'm used to...
But even those fawkin Fords squirm at higher outputs and here's a common cure I've seen to 25 years:
2009051711362049982DSC00779.JPG


See the washers overhanging the freeze plugs?

Probably easier to drill and tap some little holes than all the other genius stuff folks here are suggesting.
The a little allen screw and the right size washer and I'll betcha a nickle the freeze plugs won't walk out...
 
i would agree john.......i ended up putting plates over the hole shibang for easness. i like the ideaa of one plate or the small washer bit but trying to do that in the car blows......so i chose the full plate method. i should post pics of it when i get home....there in my build thread.
 
I agree John thats pretty cleaver its alot like our aluminum freeze plug covers we have lasercut...but that just seems even easier.

great suggestion
 
I kinda like using Evans coolant. No water, so, no possibility to create small bubbles and create hot spots in the head. Plus, NO pressure in the cooling system, so, no real way to push out the freeze plugs. Just my 2cents. Been running Evans NPG-R for 5 years now. No issues ever that would be related to the coolant, only failures in other parts.

PJ
 
Re attaching the freeze plugs:

I have cleaned the block really well around the freeze plug area. Then i've used new freeze plugs and removed the zinc plating around the perimeter. After driving them in i've brazed them with silver to the block. This works worlds better than welding cast iron.

The result is neat and tidy, and the plugs will not come out on their own.
 
This is quite an interesting thread. Glad I stumbled upon it.

well it's OK except for the truly bizarre beliefs that the little non-positive displacement water pumps make any appreciable pressure...

Cavitation can certainly be a problem on all car water pumps run at consistent high rpm but judicious reduction in blade height can mitigate a good deal of that before the expense of a larger---slow pulley is resorted to.
 
Here is another cooling system thread that has some good info/thoughts about higher rpm use.

http://www.forums.turbobricks.com/showthread.php?t=121189

Thanks for that, I remember that post from a few years ago. That has some good analysis in it.

And to add another data point. The freeze plug that has been pushed out on my car is the passenger side one at the front of the engine. Its close to the water pump, and probably sees higher pressure than the others. And these are factory Volvo freeze plugs. But the older B21/23 style that are inverted saucers that you install by inserting them into the block and then putting a big dent in the middle to expand the disc into the hole. I've replaced it once before, and added some jb weld for sealing at that time. It lasted for about a year in that state. Though not much hard running until this last dyno/track day. I just don't see 7000 rpm for very long on the street like I do at the drag strip. Its always a much higher stress at the track. The car cools fine, the datalogs show very little temperature rise over the 1/4 mile.

The motor is coming out in the next week or two for some basic maintenance items. And the freezeplug thing will be fixed somehow.
 
When I blew mine out the first time, passenger side front was flush with block, and popped the rear 2 out. Drivers popped the front one and the next 2 were flushed with block.

They all were installed so the plug edge was just inside the chamfer.
 
A couple people have suggested running propylene glycol for cooling. You can run it straight with no water and its very high boiling. You run it without a pressure cap even. I ran it years ago and it works fine, but decided against it after running some track days at the road coarse. All of the glycol coolants are very slippery and technically not allowed at a race track for safety reasons. It is really tough to clean up the mess if you spill ethylene or propylene glycol on a race track. And the stuff is super expensive.
 
Alot of it has to do with pump speed and type. While I have limited experience with the volvo engines, I roadraced a 1st gen RX-7 for 2 years. With a gutted thermostat I was running pretty hot by the end of a run at SIR, but at Portland with the higher sustained speeds I ran stone cold ~130.
I had better success with the stamped and bent type water pump over the cast impellor type. The casting is very rough with large vanes that would cause more cavitation IMO.
My spare marine pump for my B230 is a cast impellor type and I figure the one in the boat is as well, but at 5300rpm tops I don't see it being an issue.
 
I've noticed in the last year that the new OEM/Volvo pumps now have stamped impellers too. I haven't compared it to any of the aftermarket ones though.
 
someone answer the thermostat question.

i dont run a thermostat in my 7mgte, i was about to recommend some of you try running without it. my guess is your thermostat is too much of a restriction. i never blew freeze plugs, but running the stock radiator the car would heat up very fast with the thermostat in place on hard runs. removed it and the cooling system was then able to keep temps down and not boil out of the cap, though im also running a 16psi car.

i have an aluminum radiator ready to go in so i may try adding the thermostat back, but her in fla, it isnt needed. havent run one for almost 10 years now.
 
i dont run a thermostat in my 7mgte, i was about to recommend some of you try running without it. my guess is your thermostat is too much of a restriction. i never blew freeze plugs, but running the stock radiator the car would heat up very fast with the thermostat in place on hard runs. removed it and the cooling system was then able to keep temps down and not boil out of the cap, though im also running a 16psi car.

i have an aluminum radiator ready to go in so i may try adding the thermostat back, but her in fla, it isnt needed. havent run one for almost 10 years now.

The Volvo t-stat also blocks off a re-circulation port between the head and water pump when it opens, so removing the t-stat would probably not be a good idea on these engines unless the re-circ port is restricted or blocked off.
 
Adapt to screw in brass freeze plugs. If they are made for Volvo B engines
 
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