I have a custom Subaru powered 356 "replicar" - have installed twin radiators in left & right side of engine bay (with electric radiator fans). Radiators take air flow from the wheel wells.
Struggling to get enough cooling though.
Was thinking that some form of ducting may work, but any suggestions on alternative ways to cool my Porsch-aru!?
Thanks
Tony
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Hot rodders use Redline Water Wetter - try Summit Racing. Know EdNova was having problems getting air bubbles out of his MG-TD replica's system - but it had a front radiator.
Hard to say. I have a single radiator behind the passenger side splash shield with an air dam to increase the available air. The fan, controlled by the computer, turns on when the temperature reaches 204 degrees F. It works like a champ. The radiator is a high performance version from a source that I can't recall. And yes, any time air gets into the system, usually due to other issues (like a leaking hose), the burping process does take some patience.
I ended up installing a bunch of bleeders in my high spots, and the problem was solved. Should've done that first thing, as David Stroud advised. But I was too smart for that.
Stroud's car with the rad in front worked pretty good--again, once he put the bleeders in. I see a lot of people have grief with rear-mounted rads on Bugs & Vanagons. No so much with the front-mounted people.
-Tony are your fans pushers or pullers (pullers being the best)?
-Do you know what the CFM your present fans have? If you think a fan upgrade would be beneficial I'd recommend going with Spal fans http://www.the-fan-man.com/sho...cc3ba75e27223c7d3583
I had a set of these of my V8 Miata and they worked great.
-How much room do you have behind your radiators?
-Are you sure your thermostat is working properly?
-As mentioned above getting the air bubbles out of your system is very important.
Radiator up front. Nothing beats direct air. My thread is on here somewhere and we're in the process of making even more stealth. Runs at a constant 95 degrees, never has any cooling issues and I stay in South Africa.
Check out DrClock's #23 Speedster. It had Boxster like gills in rear just in front of wheels. His was air cooled but you could use to pull outside air throught vent and out the rear engine grill.
Adding bleeders to radiators, hoping that it is just a bubble problem. Direct air may have been a better call, but where would the fun have been then..... Boxter style vents would work, but trying for an all stock look.
"but where would the fun have been then"
Congratulations, you really have the madness!
By the way, I'm having frontal air ducted to my engine compartment for better air intake/cooling. The ducting goes by the rear wheel wells. I'll post photos when (if) I get the car back. This might be something for you to consider.
Tony, you can link any photos you have stored on an internet site, such as Photobucket. Just copy the IMG code and paste it in your thread reply.
......or click on 'Add Attachments'. If you're not a paying member I think you have some limitations.
Tony, are you able to post a diagram of your cooling system?
(sent from my iPad in downtown Vegas today )
Tony, are you able to post a diagram of your cooling system?
Have you verified full coolant flow by touching each hose with your hand ?
(sent from my iPad in downtown Vegas today )
Thanks David, my fantastic mechanic (no joke) is installing bleeders to the radiators today. We have 2 radiators in series and we are fairly sure that we had air in the system. With bleeders at the high points we are hoping to burp out the air and then we'll be "cool".
YouTube video history below, her first breath, first test run and final dyno run. As nice a sounding Sub-356 as I have heard in SoCal (but I am biased!).
Holy crapoly, did you forget the muffler? 
Sounds awesome! 
Even with a bleeder, you may still not get all of the air out. I have one at the high point and it was used to good effect when I had to replace a hose. Still, about a mile or two from the shop, the water temp gauge spiked, so following the builders instructions, I shifted into neutral, revved to about 3 grand and quite quickly the temp came back down to normal. A hundred of so miles up the road the guy on my six and I stopped in a rest area. I checked the expansion tank and it was down probably a pint. I topped off and was good to go for the rest of the trip to Pennsylvania and back home again.
Question: Do other cars have this air bubble problem and need to be burped? I had never heard of this before.
Hoss: Stock Subies actually have this problem. It's just worse when you start messing with the hoses and pipes. Worse yet when you make them long and hilly.
Tony: that exhaust note sounds badass. What's you're setup? Is it symmetrical? Which muffler?
As for the bleeders: if you put them on all the high spots, they will get all the air out. Stroud's got, I think, 38 of them on his car. I have 71.
OK, I don't have 71. I have five. But you really do need as many of them as you have "hills" in the system, not just one at the summit.
I've got no experience with any of this, but I do work on hydronic heating systems (boilers), and getting air out is a big deal. We will often use these:
I'm not 100% sure that they'd work... but they are reasonably cheap, and automatic. I'm not sure why they wouldn't. They vent air, but not water.
Anyhow, I like Anthony's vacuum idea better.
I have a bleeder up front by the radiator, the radiator cap as well as a bleeder out back and then my expansion tank.
I have used none of the bleeding points or the radiator cap and just top up (yes I had a leak or 2) by the expansion tank. The key is to actually avoid pipework that goes up and down. Do you have any pictures of your water pipes?
Tony,
Subi has set their electric fans to come on between 204 and 206 degrees F, so you're in the game. Heat soak the engine and see how long the fan takes to bring temp back down to 195 or so. Not sure where you live or what ambient air temps are, but, to be bulletproof, put a load on the engine when the air temp is summer time high. If you pass that test, you're pretty golden.
Good luck, Tony...your headed in the right direction. However, you didn't reply to my earlier suggestion to touch/feel each hose to ensure full HOT flow to the stat.
Without that confirmation, any further suggestion is speculation.
I sure wish you could post a schematic of what you have and I could then offer real advice. I went thru several variations and fought my way thru to a winning solution. It's real easy to offer advice in this forum but some times logic and common sense does not apply in the real world.
Not to take anything away from Jim Kelly's words....he's a cool guy in a hot place and has a good grip on things. Trying to make a homebuilt cooling system can be tricky. I am living proof of that having spilt coolant from Canada to Florida and back several times. Water Wetter will not solve nor assist a faulty system either.
As I understand the 2.2L Subaru engine (mine) that came from a 1998 Impreza, there are two circuits controlled by the computer, one of which will turn on a fan in low speed mode at 204 degrees and the other that will turn switch to high speed when the temperature reaches 214 degrees. Mine is wired so that the non-standard fan turns on at high speed at 204 degrees. It works splendidly. Steve and I watched it operating on a diagnostic tool and it shut off properly at 194 degrees.
Among previous attempts to correct the overheating problems I had (before the "H tube"), we had tried grounding the fan circuit so that it ran full blast all the time. This worked well enough going across the Mohave desert in 2005 but I had to watch the temperature gauge carefully and adjust my speed accordingly. I also tried removing the thermostat and ran the car that way for years. This caused an over cooling problem especially noticeable in the winter since it took forever to get hot enough to produce any real heat. I now have the thermostat back in and am looking forward to a cold day test.
In short, all seems to be well. Subaru cooling, as already stated, is a tricky thing but certainly something that can be resolved.
my 2 kroner
Hoss
Sounds like you are getting close to the mark, Tony.
For reference, the EJ thermostat opens at 172 degrees, but that temperature maintained in the engine is supposed to be roughly between 190 and 210 F.
This weirdness is due to the Suby cooling system, with the therm on the bottom of the engine, guarding the block against incursion of too-cool water, instead of on top of the engine, set to allow too-hot water to escape.
Since the temperature-taking side of the thermostat is all-but-bathed in the cool, still water that's lined up on the low side of the radiator, the manufacturer employed what I regard as the Sube Goldberg design: It runs hot water out to the heater core and then back to the thermostat to signal it to open. And it uses a fairly low-temp thermostat (172F, stock, with cooler ones available in the aftermarket) to make up for the fact that the "hot" signal is coming through a 5/8-inch hose, and not the 1.5-inch hose the main circuit rides in.
Follow?
So 172F at the thermostat translates roughly to 200F at the temperature sender in the top of the engine.
This should work fine all the time so long as the flow through the heater core is unimpeded (or bypassed with a valve system).
The rads ought to lower the temp of the fluid going through them 8-12 degrees F. The fans are there to make sure there is enough air flow to do this when the car is idling. It should never need the fan to run above, say 10 mph and very seldom then. If it does, you'll want to improve your fan shroud, ducting or (possibly) the design of the system.
Pace Hoss, Sube's dual circuit fan system was and is designed to go heavy duty when the air conditioner is in use. The first circuit should activate at about 203F if the car is doing less than 7 mph. The second circuit triggers automatically with the A/C switch and will cycle with the main circuit if the A/C is running. It should be necessary only in really harsh conditions (or with the A/C running).
I have mine assembled without the high speed circuit and she's now maintaining at 190F (on my gauge, which is bulbed into the heater hose just ahead of the heater core to approximate what the stock sender is measuring).
I see no reason why you should not be able to get there as well.
Ed's got it right. You must have flow through the heater circuit and then all should be well, given no air pockets, big enough radiators and good airflow. The thermostat MUST see coolant through the heater circuit or it will never cool properly.
Subaru is different but as long as you understand how and why it works it'll be OK.
Nicely explained, Ed. And just to clarify, when Hoss referred to the " H tube " , that is the automatic heater bypass device which still allows the stat to see direct hot coolant from the engine if the heater's flow is turned off in some applications.
Justin, thanks. That is definitely what I want for my car.
Makes sure that you check this bloke out in AUS.
http://forums.aussieveedubbers...wtopic.php?tid=77027
He covered pretty much every problem that you could encounter. Great pictures too.
Hard to say. I have a single radiator behind the passenger side splash shield with an air dam to increase the available air. The fan, controlled by the computer, turns on when the temperature reaches 204 degrees F. It works like a champ. The radiator is a high performance version from a source that I can't recall. And yes, any time air gets into the system, usually due to other issues (like a leaking hose), the burping process does take some patience.
Hi Hoss, I'm a new member on the forum. My brother recently purchased a SAS cab which was for sale in Mi. Green in color. I believe you mentioned in another thread that you were familiar with the car. is there an email address or cell # he could contact you at? He has tons of questions about this car related to Brakes, cooling etc. you seam to have a SAS that was built around the same time.
Thank you
Kelly - kelly@phiconst.com
Speedster Fans
I thought i's send a post to close out my thread. On Tuesday this week I collected my "finished" car from Dave & Chris @ Buggy Works in Santee. They did an awesome job of installing a custom radiator at the from of my car (where the cool air is), we have a scoop that is virtually invisible under the front bumper and my new ride is purring along. The rad fans kicks in when in traffic (which is good!) and so far the car has been great.
Its so nice to actually be driving my car after it being worked on for so long (how many of us have felt that way!!!).
Regards
Tony
I went to the You Tube video post from early and I have to say that motor sounds pretty awesome and dang fast. Very cool. If you look at the dyno graph line it sort of resembles a 911.
Hi Tony,
Thx for letting the forum know you fixed your problem. For those of us who are still having overheating problems with Subi engines in our replicas, any photos you could post would really be appreciated. I tried to Google your shop, Buggy Works in Santee, but their website won't load?
