banshee Posted June 6, 2011 Share Posted June 6, 2011 Running a stroked 4.7L with stock cooling system, problem Gets hot ’220+degF’ rodding in deep mud or hard trail wheeling, otherwise around 180-195degF Even with new motor mounts the mechanical fan rubs the shroud, SO I want to remove the entire old cooling system install new radiator without the flow-thru bottle, install A dodge inline fill spout adaptor ‘radiator cap’, and new overflow/recovery bottle like any other jeep, Two 10” 1,550cfm electric fans and custom shroud My question Go with the shroud utilizing only the fans cfm’s or without and get better blow-thru?? Note my MJ is offroad use only, no highway speeds… B… Link to comment Share on other sites More sharing options...
Eagle Posted June 6, 2011 Share Posted June 6, 2011 220 is not hot. 210 is the normal operating temperature. If the needle doesn't get into the red, I wouldn't worry about it. I doubt you can actually read the difference between 210 and 220 on the gauge. If the mechanical fan rubs the shroud, you have a problem that should be addressed that's unrelated to temperature and not related to the fact you have a stroker. I'd figure out what the problem is before making wholesale changes to the cooling system. Link to comment Share on other sites More sharing options...
kro10000 Posted June 6, 2011 Share Posted June 6, 2011 If the mechanical fan rubs the shroud, you have a problem that should be addressed that's unrelated to temperature and not related to the fact you have a stroker. I'd figure out what the problem is before making wholesale changes to the cooling system. Actually it could very well be related to the fact he has a stroker. I'd try some urethane motor/trans mounts. That would be the best solution to that problem IMO. On the other hand if you do the dual fans setup, use a shroud. It isn't going to limit your highway cfm much, and the issue you have is heating at low speeds. 220 degrees isn't much to worry about though. Link to comment Share on other sites More sharing options...
Eagle Posted June 6, 2011 Share Posted June 6, 2011 If the mechanical fan rubs the shroud, you have a problem that should be addressed that's unrelated to temperature and not related to the fact you have a stroker. I'd figure out what the problem is before making wholesale changes to the cooling system. Actually it could very well be related to the fact he has a stroker. I'd try some urethane motor/trans mounts. That would be the best solution to that problem IMO. How? The stroker uses the same block and the same peripherals as a stock 4.0L so HOW could changing the crankshaft and rods inside the engine make the fan hit the shroud? Link to comment Share on other sites More sharing options...
banshee Posted June 6, 2011 Author Share Posted June 6, 2011 as i rod it the motor twists more, thanks about the 220 not being bad, all my gauges are digita so it gives me something to look at and worry about, just overthinking it?? again thanks... B..l If the mechanical fan rubs the shroud, you have a problem that should be addressed that's unrelated to temperature and not related to the fact you have a stroker. I'd figure out what the problem is before making wholesale changes to the cooling system. Actually it could very well be related to the fact he has a stroker. I'd try some urethane motor/trans mounts. That would be the best solution to that problem IMO. How? The stroker uses the same block and the same peripherals as a stock 4.0L so HOW could changing the crankshaft and rods inside the engine make the fan hit the shroud? Link to comment Share on other sites More sharing options...
kro10000 Posted June 7, 2011 Share Posted June 7, 2011 If the mechanical fan rubs the shroud, you have a problem that should be addressed that's unrelated to temperature and not related to the fact you have a stroker. I'd figure out what the problem is before making wholesale changes to the cooling system. Actually it could very well be related to the fact he has a stroker. I'd try some urethane motor/trans mounts. That would be the best solution to that problem IMO. How? The stroker uses the same block and the same peripherals as a stock 4.0L so HOW could changing the crankshaft and rods inside the engine make the fan hit the shroud? The engine shifts under torque, it tries to move the opposite direction of the driveshaft. The factory mounts might be fine under max factory torque, but with the added torque of the stroker it will shift more under initial load. Link to comment Share on other sites More sharing options...
Eagle Posted June 7, 2011 Share Posted June 7, 2011 The engine shifts under torque, it tries to move the opposite direction of the driveshaft. The factory mounts might be fine under max factory torque, but with the added torque of the stroker it will shift more under initial load. Only if the motor mounts are bad. When my '88 Cherokee 4.0L hit around 100k one of the motor mounts broke. I drove it like that for several weeks and the fan never hit the shroud. As already suggested, try urethane motor mounts. Link to comment Share on other sites More sharing options...
HOrnbrod Posted June 7, 2011 Share Posted June 7, 2011 The factory mounts might be fine under max factory torque, but with the added torque of the stroker it will shift more under initial load. This is BS. Have run the stroker at max torque at the strip many times - no problems with the factory mounts (new) and zero fan interference. Have broke a couple of axles though. And I run dual electric fans with much less wiggle room up front than the stock mechanical fan. Strokers don't cause any more "shift" than a stock engine if the mounts are in good shape and the mounting points are intact. Suggest you peruse the various stroker forum and check out the preferred motor/tranny mounts. Link to comment Share on other sites More sharing options...
kro10000 Posted June 7, 2011 Share Posted June 7, 2011 The factory mounts might be fine under max factory torque, but with the added torque of the stroker it will shift more under initial load. This is BS. Have run the stroker at max torque at the strip many times - no problems with the factory mounts (new) and zero fan interference. Have broke a couple of axles though. And I run dual electric fans with much less wiggle room up front than the stock mechanical fan. Strokers don't cause any more "shift" than a stock engine if the mounts are in good shape and the mounting points are intact. Suggest you peruse the various stroker forum and check out the preferred motor/tranny mounts. I'll rephrase that, it is possible that a stroker may overcome factory motor mounts, the stroker WILL be more likely to shift under load than a stock 4.0. So if the fact that it is a stroker isn't the problem itself, it is not helping the situation. It is common for hotrods with built motors to do this, and the same goes for our Jeeps. On the other hand the 4.7L stroker my brother and I built for his TJ has never had an issue with rubber mounts. So it is possible that the new mounts are of poor quality, or there is another reason as to why this is happening. Link to comment Share on other sites More sharing options...
banshee Posted June 8, 2011 Author Share Posted June 8, 2011 Kelly /Eagle First thanks for the feedback, just thought 220 was too warm while wheeling, i'd just like to see it under 200-210 all the time... Second have ALL new mounts, just the torque is enough to cause the top of the fan to hit the shroud, didn’t want to start an argument, just a question The question is simple when I go to total electric would you recommend running a shroud or not??? My MJ’s live as on road is over, I hall it to where I wheel… :bowdown: B… Link to comment Share on other sites More sharing options...
HOrnbrod Posted June 8, 2011 Share Posted June 8, 2011 The question is simple when I go to total electric would you recommend running a shroud or not??? My MJ’s live as on road is over, I hall it to where I wheel… :bowdown: B… As you know, the MJ fans are pullers. The fan shroud's main purpose is to direct the pulling air flow from the outside through the radiator to cool the coolant, especially at low speeds. i.e. off road. With no shroud the fan will just recirculate more hot air within the engine compartment than it pulls through the radiator. So yes, you need the shroud to stay cooler longer. Why the fan blade hitting the shroud you're going to have to figure out - it ain't natural. Is the frame/unibody area where the motor mounts are located all rotted out? Link to comment Share on other sites More sharing options...
jimoshel Posted June 8, 2011 Share Posted June 8, 2011 Could it be possible the shroud has just moved? Maybe shifted closer to the fan blades? Link to comment Share on other sites More sharing options...
zagscrawler Posted June 8, 2011 Share Posted June 8, 2011 In my opinion if you mount the electric fans flat against your radiator then you can do away with your shroud, if your electric ones have built in shrouds, most do. The shroud is ment to direct air flow in a specific direction or in a sence help create a vacuume through the cooling rows of your radiator. The mechanical fan needs the factory shroud because it can only get so close to the fins in the first place..via flex in motor mounts and transmounts and such. In my experience If you can make the mechanical function like it is suposed to then keep it, it flows much better then most electric ones, and put your secondary electric fan on a manual switch and run it when you know you are going to run your rig hard. Link to comment Share on other sites More sharing options...
duster1971 Posted June 8, 2011 Share Posted June 8, 2011 I had this issue with my old xj the shrowd ended up going. Didn't help turns out that the new trans mount I got was bad (took a radiator for me to figure this out) just remember to check that again word of advice new isn't always new if ya get what I mean. Link to comment Share on other sites More sharing options...
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