Bartman Posted September 12, 2011 Share Posted September 12, 2011 As most people are probably aware, cooling a Z is not an easy task. Stock 240’s ran hot without any modifications, and once you start increasing the horsepower, driving in the desert, and/or adding air conditioning it gets even harder to keep your Z cool. I’ve been working hard to keep my Z cool, and I think I finally have a solution that keeps my modified LT1 V8 240Z cool even on hot days with the A/C blowing nice cold air. The solution isn’t just one thing, it’s a combination of things that all work together to get cool air through a radiator that’s as large as possible and then force the hot air out of the engine compartment. My solution consists of the following: Radiator Ducting: I worked on several designs and created several iterations before I created what I feel is the best solution aesthetically and functionally. It still keeps the same grille opening but ensure that air is routed directly through the radiator starting with a smaller opening and opening up as it approaches the radiator. Everything is sealed as well to ensure air doesn’t escape. Radiator: I’ve gone through three different radiators starting with the JTR radiator, moving onto a 3-row all aluminum model, and then finally a Monster aluminum 4-row. I used the Champion radiator MC110 which are all aluminum, has 14-16 cooling fans per inch, and incorporates brackets for OEM mounting. Fan: Even with ducting most people are going to need to pull in air when running AC or sitting in traffic on a hot day. I used the dual speed Taurus fan which pulls about 2500 CFM on low speed and 4500 on high. These fans work great and are fairly cheap and easy to find. Hot Air Venting: I noticed that when my car would run hot it would cool off if I kept it running and I opened my hood. So I figured that I need to find a way to get that hot air out without opening the hood. Since I already installed gills (fender vents) I decided that I should cut out openings in my inner fenders and install fans to force air out. These work great for me and made a big difference with my setup. You may not need the same level of cooling but getting hot air out is important. You may be able to get away with just using a vented hood or inspection lids or the hideous looking (in my opinion) Datsun Competition Hood Scoop. Quote Link to comment Share on other sites More sharing options...
74Adam Posted September 12, 2011 Share Posted September 12, 2011 Did you do any structural reinforcement to the inner fender? I see alot of people say that is a sensitive area to put holes in? Quote Link to comment Share on other sites More sharing options...
Oddmanout84 Posted September 13, 2011 Share Posted September 13, 2011 Not to be a nasty critic, but I see three of those upper small holes are tapped into the hollow part of the chassis that feeds into the fresh air ducts. Perhaps you have your ducts blocked up at the end, but it's worth mentioning. Doing so will feed hot, smelly engine bay air into the cabin. 74Adam, When I did mine, I made several small holes about the same size as you see here, then used a dimple die to reinforce them (not an original idea of mine). I believe it was bjhines that inspired me to do it. Last question though, what type of fan is that blowing out the large hole? Quote Link to comment Share on other sites More sharing options...
Bartman Posted September 13, 2011 Author Share Posted September 13, 2011 I didn't add any reinforcing to my inner fenders and I plugged the other existing holes. The fans are Spal 4" fans that are generally used on Motorcycles and ATVs. Quote Link to comment Share on other sites More sharing options...
74Adam Posted September 13, 2011 Share Posted September 13, 2011 Do the Spal fans always run or just under certain parameters? Quote Link to comment Share on other sites More sharing options...
Bartman Posted September 13, 2011 Author Share Posted September 13, 2011 Do the Spal fans always run or just under certain parameters? They only run when my high speed fan is on, which is either from high water temperature or from having the A/C on. Quote Link to comment Share on other sites More sharing options...
260DET Posted September 13, 2011 Share Posted September 13, 2011 Non fan assisted fender vents tend to work better when the car is moving but bonnet/hood vents work in any situation. If you have a V engine which is shorter than the L6, one large bonnet vent immediately in front of the engine works very well. As hot air rises this action can promote air circulation through the radiator by itself, a fan will assist this process. Of course any bonnet vent has to be placed in a low pressure area which basically is anywhere except the front and back of the bonnet. All the above has been proven with my V6T engined 280ZX. Quote Link to comment Share on other sites More sharing options...
dandyZ Posted September 14, 2011 Share Posted September 14, 2011 Word to the Mother Ship. Quote Link to comment Share on other sites More sharing options...
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