chrism Posted July 24, 2008 Share Posted July 24, 2008 Not to go away from the topic but isn't that Mark Ralston's car on the EBAY add. Is a two row the same as a double pass? Quote Link to comment Share on other sites More sharing options...
johnc Posted July 24, 2008 Share Posted July 24, 2008 Is a two row the same as a double pass? No. Quote Link to comment Share on other sites More sharing options...
240zchevyv8 Posted July 24, 2008 Share Posted July 24, 2008 Just a bit curious are you running the stock viscous fan set up. I have a 327 v8 in my 240z and it was a real problem keeping it cool. Then i removed the chevy fan and fitted twin 12" lecky fans. I put one of the fans on a thermostat, and the other fan on a switch for manual overide. This way there isnt as much drag on the engine running two fans when one will do. I made a bracket that fits behind the stock chevy rad and now i have no problems with car getting hot at all. and the car actually pulls better now that ive converted it. Quote Link to comment Share on other sites More sharing options...
Zmanco Posted July 24, 2008 Author Share Posted July 24, 2008 Just a bit curious are you running the stock viscous fan set up. I have a 327 v8 in my 240z and it was a real problem keeping it cool. Then i removed the chevy fan and fitted twin 12" lecky fans. I put one of the fans on a thermostat, and the other fan on a switch for manual overide. This way there isnt as much drag on the engine running two fans when one will do. I made a bracket that fits behind the stock chevy rad and now i have no problems with car getting hot at all. and the car actually pulls better now that ive converted it. No, I'm running 2 12" efans. But my only issue is at speed on the track. The rest of the time I have no issues so fans aren't going to solve my issue. I'm working on sourcing an oil cooler per JohnC's suggestion. That makes the most sense to me. Quote Link to comment Share on other sites More sharing options...
Zmanco Posted July 28, 2008 Author Share Posted July 28, 2008 Last Friday I put on an oil cooler as JohnC suggested and had a track day on Saturday in Pueblo. It was probably only a few degrees cooler than the previous weekend (low 90s) but a longer track with a lot more WOT time. The oil cooler did the trick. The highest water temp I saw from megasquirt logs was 206. Also, I noticed that the heat soak was greatly reduced. I found that when I would back off a little (such as when I was making mistakes and decided to focus on my line instead of speed) that the water temp would come down very quickly, often it would be a few degrees down within 2-3 corners. Unfortunately I don't have an oil temp gauge so don't know how much that was reduced, but I'm guessing it was significant. By the time I exited the track after a cool down lap, the water temp was nearly normal. The fan shut off within a minute of parking the car and opening the hood. Before it could take 5 or more minutes. Thanks John for the good advice! Quote Link to comment Share on other sites More sharing options...
johnc Posted July 28, 2008 Share Posted July 28, 2008 Glad to hear it worked. Quote Link to comment Share on other sites More sharing options...
2eighTZ4me Posted July 28, 2008 Share Posted July 28, 2008 Which cooler did you end up going with? That Sertrab is mighty pricey. BUT - I guess if you have a ton of money tied up in your motor, it's cheap in comparison. Quote Link to comment Share on other sites More sharing options...
Zmanco Posted July 28, 2008 Author Share Posted July 28, 2008 In the end I went with an Earl's (EAR-41010ERL) mainly due to cost and my confidence that I would get it the next day from Summit. It's a flat style like the Setrab and Mocal. Quote Link to comment Share on other sites More sharing options...
2eighTZ4me Posted July 28, 2008 Share Posted July 28, 2008 That looks like a nice unit. Earl's makes good stuff. Where did you mount it? I am going through the same dilemma - I got a B&M unit 70273, and I'm hoping it will be adequate enough to keep the temps down. I plan on mounting it in front of the radiator standing up, so as to get the best airflow, but am worried a bit that that mounting location might take away from the cooling of the radiator. Any thoughts? Quote Link to comment Share on other sites More sharing options...
johnc Posted July 28, 2008 Share Posted July 28, 2008 but am worried a bit that that mounting location might take away from the cooling of the radiator. Any thoughts? The big gain in oil cooling outweighs the small cooling loss from reduced airflow through the radiator. Quote Link to comment Share on other sites More sharing options...
Zmanco Posted July 28, 2008 Author Share Posted July 28, 2008 Look at the pictures in my post #25. It's mounted towards the upper left (passenger side) corner. My water temps were about 10 degrees cooler on a track with much longer straights (0.5 miles of WOT). I was at 6100 rpm at 110 mph before braking. I remember reading somewhere that although everyone focuses on the water temps, in fact nearly 40% of the engine's heat is dissipated by the oil system. Like John said, the extra cooling of the oil more than offset whatever impact the warmer air had on the water radiator. Quote Link to comment Share on other sites More sharing options...
Daeron Posted July 29, 2008 Share Posted July 29, 2008 Also, buy a real racing oil cooler like a Setrab or a Mocal. John, I highly value your opinion as a top-notch racer who cuts no corners; therefore, I am very curious as to what you would consider so much better about a "real racing oil cooler" and what difference might exist between, say, the Earl's unit he installed and the 2nd gen RX7 oil cooler of junkyard fame? Is this an airflow thing? I was unaware of any oil cooler disparity, please enlighten me:coollook: Or was that just said that way because he had mentioned the idea of using the trans cooler coil in the aluminum radiator as an "oil cooler?" Regarding the aero ducting and air flow through the radiator.. the key fact to cover is that all the air flowing INTO the front opening flows both... ..through the radiator, and ..out from under the hood. Reducing frontal face area is one method of reducing total air flow into the engine bay, which helps with the stalling, but another key point is that much of the air hits the front opening, and then rolls down below the radiator cross member and thence under the car. The MOST IMPORTANT PART of the radiator air ductwork is the effective transmission of all air entering the "mouth" through the radiator coil. Air can be eliminated from the engine bay by ventilating it behind the wheels, underneath the fenders without even adding actual grills in the sheetmetal fender.. just discharge the air to the space underneath the fender, and it will flow out. Trust me, I know, I seen it on the internet somewhere (No, seriously, I DID see someone here successfully venting this excess air through hidden holes underneath his fenders.. they were essentially under the hydraulics and battery tray. I just can't for the life of me remember who, or even in what thread.) Quote Link to comment Share on other sites More sharing options...
johnc Posted July 29, 2008 Share Posted July 29, 2008 One of the important things is to reduce the pressure drop across the cooler. Plate type coolers (like the Mocal, Setrab, and B&M) give the oil multiple flow paths, just like a car radiator. Tube type transmission coolers, like some of the Permacool, units have one long tube that snakes back on itself. Some even have internal spirals or fins which cause large drops in pressure with the higher viscosity engine oils. I tend to recommend products that I or my customers have used and had good experiences with. Quote Link to comment Share on other sites More sharing options...
Zmanco Posted July 29, 2008 Author Share Posted July 29, 2008 Daeron, on the airflow issue you bring up, I think you are going back to the discussion elsewhere regarding managing airflow at the front of the car. I realize there is overlap in this and cooling, but in my situation, I have an MSA spook with the brake ducts covered. I've also put Al tape over the remaining holes into the engine compartment and have the factory rubber seal between the hood and the top of the radiator support. All gaps between the radiator and the support have been closed. In other words, all the air that enters the mouth goes either through the radiator, or through the 2 openings shown in this picture between the turn signal lenses and the bumper gaurd: http://forums.hybridz.org/attachment.php?attachmentid=8266&d=1217219012 which then flows around the front suspension under the fenders. The splash guard was on for this last session, but not the one about which I started this thread. I realize that there are benefits to be had with regard to overall aerodynamic efficiency, but as for cooling, which was the focus of this discussion, the airflow into the engine compartment has already been controlled and by itself did not solve the engine temp issue. The lesson learned here for me is that when running the engine at its peak outputs (WOT on a track for extended periods), the water cooling system should not be the sole method for dissipating heat. Quote Link to comment Share on other sites More sharing options...
Daeron Posted July 29, 2008 Share Posted July 29, 2008 John, thanks for clearing me up on that; I had heard words bandied around but never managed to catch the complete definition between the lines. Daniel: Understood, I realize that most of the front end sealing work is an aerodynamic concern over a cooling one, but I was primarily concerned with establishing that YOU had, on your car, ensured that the radiator was the only path of escape for that air. If you have sealed your front end up, then the comment was moot; I just wanted to make sure you weren't losing any potential cooling airflow anywhere. (The comments regarding dumping the air were made because you expressed a desire to AVOID blocking the front off, and the racecar package is not one that can be looked at one subsystem at a time; when considering cooling, you have to think about airflow, which means you have to make aerodynamic design a part of the cooling system development process.) Quote Link to comment Share on other sites More sharing options...
yellowoctupus Posted August 28, 2008 Share Posted August 28, 2008 I just drove my 280 down to Charleston SC from Buffalo NY with a basically plugged radiator (didn't realize it since last time I drove it was last summer, from CA to NY, with no problems at all). Just two notes I'd like to add and a question afterwards. 1. Be careful with ducting, as you still need a bit of airflow over injectors (fuel lines in particular, i'd suppose this would be the same for carboureted guys too) as you'll get some real nice vapor lock if you're running hot and blocking airflow over those components as well. (Almost got stuck in VA when I shut off my car for 20 mins because of that.) 2. Removing the AC condensor does VERY little. I was running hot (aka...240/250 deg) and removed the condensor, which over its 30 yrs had a good collection of bugs, and mud wasp nests etc behind it and saw NO CHANGE at all in temp. ( I already had the tsat out) Then, I proceeded to remove hood vents and drove the rest of the way down with the hood popped open to try to help airflow to no avail. (needless to say I was pretty desperate). I've searched and seen other members discussing aluminum radiators, I was wondering if anybody's found at a junkyard a radiator that worked well with front mounted electric fans. I'm trying to A:cool my engine properly while B: making more room between the engine and radiator for my serpentine belt drive (Eaton M62 supercharger). Quote Link to comment Share on other sites More sharing options...
Zmanco Posted August 28, 2008 Author Share Posted August 28, 2008 FWIW, everything I've read suggests that puller fans are more efficient (move more air for a given fan/motor combination) than pushers. But that only matters when the car is stopped/moving slowly. Once the car is at speed the fans are no longer affecting the system's cooling capacity and the radiator and air flow determine how much heat can be dissipated. On your comment about removing the AC condenser, do you think the main issue was that the radiator was plugged? I wouldn't expect that removing the condenser would make a difference if the radiator already had issues. Quote Link to comment Share on other sites More sharing options...
yellowoctupus Posted August 28, 2008 Share Posted August 28, 2008 I do agree that the main problem was definetly the plugged radiator, and that probably anything I did besides fix the radiator would not significantly lower the temp. I should have thought that through before posting, sorry. On the other hand, the AC condensor's fins are relatively short and spread far apart; I think that unless the AC was on and creating heat (in which case you couldn't remove it either way of course) it won't do much as far as impeding flow goes. Quote Link to comment Share on other sites More sharing options...
timbo1jz Posted August 29, 2008 Share Posted August 29, 2008 I am running the aluminum radiator in from the first post on this thread with a 16" spal high cfm electric fan. Quality is nice and fitment is perfect. We will see how it works when the car is done! Quote Link to comment Share on other sites More sharing options...
yellowoctupus Posted August 29, 2008 Share Posted August 29, 2008 Holy wow that is a huge intercooler. I'm quite sure I've never seen one this large on a car so small! Great cooling I guess, but won't that cause huge lag time getting that volume to pressurize? I can see you have an equally large turbo back there too, but still! Quote Link to comment Share on other sites More sharing options...
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