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Inspired by the Head cooling on cylinder #5 thread (http://forums.hybridz.org/topic/59029-head-cooling-on-cylinder-5-solutions/), I decided to make my own diagrams of the cooling system for US Z/ZX L6 engines. I had to exaggerate and diminish a few proportions to maintain decent flow while using a flat layout. These charts are as accurate as far as my knowledge and research have shown so far. I will gladly accept any corrections and update accordingly. The year cutoffs are approximate and do not reflect all of the small month-to-month changes of course. On the ZX diagrams, some cars got the throttle body heaters while others didn't. I left them in both diagrams just to cover all the bases. I did spend a fair bit of time on these, so if they do happen to find their way elsewhere on the web, make sure at the very least to cite where they came from. Red = oil passages Blue = water passages and flow direction Yellow = direction of water flow in flexible hoses 1970-1974 240Z / 260Z 1975-1978 280Z 1979-1980 280ZX 1981-1983 280ZX

Hello Im Will and this is my 75 280Z the day I recived it as a birthday gift from my dad the the original owner. And this is my dad the day he bought the car in 1975. In 1990 my dad made the choice to do a sbc swap in to his z and this was the result A nice but low cost swap that has stood up to the test of time . Over the years the car has had many different carb setups but this was the state of the motor when I got the Z. And its a bit tired and needs some new life breathed in to it , and thats just what i am going to do . Please feel free to offer helpful tips and tricks and any advice thanks Will S.

Hi everyone, Thought I'd post my layout for an oil cooler with measurements and the like if anyone wants to replicate or take some design cues from it in the future. I'm planning on running it bosozoku style with the lines outside and will probably tuck the cooler just behind the bumper but visible. As for the pieces I'm going to be using I have the quantity, name and number listed: (1x) Earls Oil Cooler 4x13x2" 41308ERL (2x) Jegs -8AN Polished Banjo- 555-101022 (1x) 15' -8AN SS Braided hose 555-100923 (2x) Jegs -8AN Polished straight fitting 555-101002 (2x) Jegs -8AN to 3/8" NPT 45* fitting 555-110127 I was planning on using the 280zxt sandwich plate I have but realized that I don't have the center piece to it so I'm lanning on using the transdapt 1313 model sandwich adapter. Stay tuned for pictures.

Its been a while sense I've posted here so I thought I'd throw these pics up. I'll preface this by saying I'm running a 3.2 Rebillo motor on 110 with ITB's and an Adaptronic ECU. 5 speed 240sx trans with a 5.5" clutch and a flex plate. 4.11 final drive with some Hoosier R7's I was having an issue pushing water out of the radiator during race like conditions. Only happened after several laps at full tilt. Not sure if I'm getting exhaust gas pushing by the head gasket or what. I did a test on the coolant to see if gas was present and it was negative but I'm not sure how accurate those auto zone test kits are. The other strange thing is the system wouldn't suck the water back in from the catch can after it cooled down. So… we decided to look into a recirculating system. We took a trip to the junkyard and scored this tank. I made some brackets for it and mounted it. I have an inline filler on the upper radiator hose that has a overflow outlet, I connected the inlet on the tank to the outlet on the filler neck and installed a 0 PSI radiator cap there. I have a 15 PSI cap on the recirculating tank. The outlet on the tank goes where the heater return line would normally go. I ran this setup at VIR full a couple weekends ago. Everything seems to work great, it built pressure as it should and cleared air out of the system.

Hey guys, I'm trying decide which radiator to buy for my sr20det swap in my Z. I want to spend around 3-400 dollars. If anyone has had a good experience with a certain radiator I would appreciate the input.

**UPDATE** I have a 280ZX I'm not using, so I pulled its coolant inlet port off and installed it on the 240Z. I've learned that the later L-series engines have a threaded inlet port. I've plugged it with a 1/2" pipe plug and installed the Lower Radiator hose. Note: If you choose to do what I did, the lower radiator inlet port from my '81 280ZX is slightly pointed more engine-side than the original 240Z port. So watch out for the lower radiator hose touching your alternator. What I did to fix this problem was to twist the lower radiator hose at the bottom of the radiator to clear the alternator. Well, it doesn't completely clear the alternator, but as long as it's not touching the fan blades, I'm fine with that. ** I've completed plugging my cooling system. Thanks, HybridZ. Your input was very helpful. ** Hi Hybridz. First off, I'd like to mention that I removed my heater core. So no coolant flows through the interior. I'm trying to bypass that and apparently there are two popular alternatives to that: "looping" or plugging. I'm convinced that plugging the cylinder head outlet is the most logical way to go, since all that looping does is move cold water from around the left side of the block/cylinder head and back into the water pump inlet. Since I've deleted the heater core, the cylinder head coolant outlet is no longer necessary. Also, my engine is stock. I found a popular thread pertaining to cooling on L-series motors for racing purposes, but I feel that for stock motors that advice doesn't apply. With that said, I'm having a tough time searching on hybridz advice on how others deleted flow to the second inlet. Maybe it's so easy to do, that it goes without saying, but I'd like to know what people who have plugged their systems have done in order to delete their loop. This is what I'm going to do: Thermostat housing => intake manifold plug Intake manifold plugs (front and rear) Cylinder head coolant outlet plug by the #6 cylinder And here is where I'm stuck. The water pump inlet is branched into two, one for the lower radiator hose and one for the heater core hose. Should I tap the second one and then plug it with an npt plug?

I recently made some changes to my cooling system and am now having an issue or two. Before the change my temp ran right at ~180 degrees with little variation. Whether I was cruising, idling or driving "spiritedly" the temp stayed fairly constant. I was running a 16" electric fan, set up as a pusher (I know) slightly angled off the rad (3 core) because it was too big. Not a great setup, but it was working. I have since made two changes: I switched out to a more powerful 14" fan setup as a puller which has a good seal to the rad. When it runs, it's moving a ton of air, seemingly much more than the old setup. I also removed the water circuit for the manifold heat to my SU carbs. I assumed since this circuit ran parallel to the heater core that it shouldn't be an issue; worst case I just open the hot water valve and the coolant system is essentially unchanged. My issue: The car now runs hot (~210deg) at anything over ~1500revs. At idle, the temp settles right back down to ~180. While cruising, if I clutch it and let it idle, it drops down to 180. And, if I cruise slowly enough to keep the revs down, it rides around the 180 mark. As soon as the revs go higher, the temp runs up. What seems odd is that it drops down/up about as quickly as the guage is capable of moving, so I'm pretty sure it isn't actually changing temp by ~30 degrees that quickly. Even if I open the heater valve so that circuit is active, it behaves the same. I'm thinking that I have an air pocket stuck someplace, but I've done everything I can think of to bleed the system. Are there any tricks that I should know about? Does the manifold heat circuit really have an affect on running temp? Absolutely any help would be appreciated! Thanks! Rob