Help! How to keep it cool.

[z1 zonly]

I'm finishing up a VH45 swap into a Z32--have it running and everything--but I'm frustratingly stymied on how to set up the cooling system. Here's the situation:

I have no room for cooling fans. 3" between the back of the radiator and the crank pulley (with a very skinny stock NA or TT Z radiator). That's doable for some fans, but they seem to have sub-2000 CFM and that's not really an option (I live in the South, there's always a full week of 100+ deg F days, plus, I want to run this car hard). The biggest pusher fan I could fit would be 13", and obviously that wouldn't do, even two.

I thought I'd be able to angle the radiator with the bottom at the front fascia, but after a lot of consideration there are a few reasons I can't get away with that. The only idea I have left is to mount it in the trunk, which I think would be super cool, but be a LOT of work to plumb.

Any thoughts or suggestions on what you guys are doing to cool your VH-swapped cars?

[holeset]

we stuck a toyota hiace radiator in the boot of our skyline with a big thermofan and it worked mint,definitely worth the plumbing and mounting labour,saw a massive drop in running temps.

[DRFTBLD]

Trunk mount is a nice set up. I would recommend it if you don't think staying in the front will keep it cool enough. The issues you will have with trying to make everything fit and work well in the front will not exist if you rear mount. Plus you can do some really do designs in for the air ducting in the rear! Make it bad A55!!

[z1 zonly]

I think I'm going to give it a shot, but again, I'm dreading doing it. The hardest part is going to be getting the coolant tubes out of the engine bay--there is hardly ANY room to work with.

I think the only way I can do it is run the tubes along the outside of the frame rails, in the fender wells, then cut a hole into the firewall, run the tube along the rocker inside the cabin, and through the inside of the cabin up to the radiator. May also try to run it along the frame rail under the car and up into the trunk.

[BlazingCopperZ]

I ran into the same problem, even after using a custom radiator. Of course the major issue is not having enough depth to put in a sufficient sized fan since the fan motor is so close to the crank pulley. I had both 10" and a 12" fan mounted as pullers, which barely had enough room to clear the crank pulley. It worked okay so long as the the temperature was below 80 degrees, anything above and it would start running hot in about 30 minutes (unless driving faster than 80 mph, haha).

Finally decided to bite the bullet last spring, and due to having too many other projects going on it wasn't drivable until a couple months ago. New setup is close to what you were not wanting to do, but I think is the most viable route. The radiator is now mounted so that the bottom is canted forward and the top is close to flush with the hood crossmember. I had to remove the center hood support, along with removing the gusset sections on the sides of the framerails. This now adds plenty of room for a shroud and big fan. I made the shroud out of 1/16" AL that stands off the back of the radiator about 1/2", and am using a Zirgo ZFU16S 16" 3630cfm fan, which was the most powerful fan that I found. The fan is actually rather quiet, and so far I have only gotten the temps to about 200 degrees, which rapidly cools back down to 185 or so when sitting at a stoplight. A great advantage to this setup is now there is enough room in front of the radiator to put the AC condenser back in, so maybe next Atlanta summer won't keep me from driving it much. Still need to add some gusseting to the hood latch and paint my new hood setup, but might take a while to get to it. I will take a couple pictures of it an post them next time I get a chance, hope this helps.

[z1 zonly]

What radiator did you use?

Honestly, I would do that in a heartbeat, but only if the inlets and outlets were both located on top of the radiator (i.e. custom). The radiators I have (Q45, Z32 NA, Z32TT) all have the bottom outlet pointed straight toward the ground when mounted at an angle, and I'm paranoid it will slice a hose.

I'm not really on a budget to where I couldn't get a custom radiator, it's just that I have several options on-hand that will work, and that makes it hard for me to justify dropping $300+ on a radiator and then buy fans too. My ideal is to just make the Z32 NA radiator with Maxima fans work, and I think that would cool it just fine.

Although, after calling some places today, I'm seeing that it's going to be a problem to get 1.25" tubing locally.

Still stuck. I can't believe after all the hell I've gone through to get this engine in that the cooling system is stumping me!!!

[BlazingCopperZ]

Mine is custom made by PRC, a local dirt track racing parts manufacturer, http://prcinc.com/store/. They can pretty much make any size or configuration that you need and are a good bit cheaper than most aftermarket radiators for Z's. I had to modify the outlet after slanting the radiator back, it is now at about a 45 degree angle to the radiator so that the outlet is horizontal. PRC sold me a piece of tubing with the ends flared that can be used to replace the stock VH steel piece so that you only need to get two 90 short sections of hose to finish the plumbing. My build thread shows the radiator in a bit more detail before the slanted setup. There is still some ducting that needs to be done, just haven't gotten to it yet. Here is how it looks currently:





Honestly I don't think that the stock NA radiator will do the job, especially in the South. VH45 motors take a ridicules amount of work to make them stay cool, other than the hood clearance problems I think that the cooling is the biggest hurdle to overcome in the whole swap.

[fluffybunny]

Howe racing crossflow 3" aluminum radiator 342AAF is what I plan on getting. It will provide much better cooling than the stock NA and by pushing it forward it sticks out the same amount as the stock one does. You have to cut the flange on the hood crossmember and remove the support and hood latch, which is fine for me because I already have hood pins. The front of the radiator rest up against the gussets on the bottom and the top touches the headlight buckets. I haven't sorted out the fan situation yet though. Anyway, I thought I'd just throw that out there for anyone that might be interested. The radiator is only $209 from Howe.

[New Jersey]

i would love details on all your guys vh swaps, please!
im having a shop do mine, but was also just gonna figure out a rad once i saw what kinda room i had.
not too sure what im gonna have em do as far as pan vs. crossmember moidding etc.
i would love any tips/details.
thanks!
i already have the car/motor/harness/ecu/tt light fly and clutch, and maintenance parfts for the vh.
im going to buy a mazworx adapter.

[New Jersey]

anybody?

haha

[DRFTBLD]

Whats it going into? What year Engine? more details and we can help. Also prolly wanna open your own thread and we can answer all your questions you have

[New Jersey]

motor is a 95 and its going into a 1990 n/a z32

[ghettoslide]

Im interested in the trunk mount idea. How you going to get air to it. You gonna cut the spare tire well out and use it to mount the radiator. Seems you will have to cut the floor somewhere either way the fan moves the air your in trouble. In the summer your blowing your AC cooled air out or blowing heat in from the 130 degree street. On a dedicated race car this will be no problem. Is there anyway to flat mount it and the fan under the car. Like under the rear bumper and make beakers from the spare tire well to hold it in place. If you see what I mean. Its just a idea.

[holeset]

on the skyline i just spaced boot lid up on hinges using some washers which forced air into the boot,kinda like what guys do tho their bonnets for clearance, who knows what this does to aerodynamics of the car but it seemed to work pretty good,also inside the skyline boot is some rubber flappy vent things in the side well which i just hacked out creating an escape for the hot air, pretty much made it possible to not run the thermo fan on the boot mounted radiator.

[speedeast]

Don't forget that rad fans can be in front of the radiator and reversed wired to "push" through.