uninformed Posted January 27, 2021 Author Share Posted January 27, 2021 12 minutes ago, Jon W said: Out of interest why is the bleed hole a reduced diameter? What does this help with? When I did my V8 conversion in my series I ran without this for a while until the radiator was modified, think it ran cooler once fitted. Thanks on the HD core. And yes most all vehicles motor and commercial stack coolers. It’s a packaging thing but works , LR went to it 🤷🏻♂️ the bleed hole allows water to bypass not going through the cooling process of the radiator. If you reduce it down so the flow is more restrictive than going through the radiator, that’s the path coolant will take. Quote Link to comment Share on other sites More sharing options...
Sigi_H Posted January 27, 2021 Share Posted January 27, 2021 Back in, because the general information is really interesting. Just an idea to test whether a bigger rad could be a solution: Why not spray the rad with water (water/methanol), when the system is hot? Easy to realize with the windshield pump, bottle and a separate switch. Since more energy will be transported from the rad it will be a sign, that a bigger rad will do the work. Otherwise there will be another reason for getting to hot. Just an idea. Quote Link to comment Share on other sites More sharing options...
mmgemini Posted January 27, 2021 Share Posted January 27, 2021 Two things to ask. Why is it that the 300Tdi isn't fitted with either a proper radiator like the series or a proper crossflow like the 200Tdi The viscous fan can and does at certain fan speeds stop the airflow through the radiator Quote Link to comment Share on other sites More sharing options...
Snagger Posted January 27, 2021 Share Posted January 27, 2021 Given the age of the vehicle and that it sounds as if the rad and intercooler have been out a few times, have the foam seals between them and the mounting frame and between each other been replaced, and is the fan shroud installed? If the seals or any baffles are missing, the airflow through the cores will be reduced as it’ll pass through the gaps, and if the shroud is missing, the fan will be almost completely ineffective, recirculating air in a torus behind the rad rather than drawing air through it. I still think that cheap TGV oil cooler system is a part of the problem, though. 1 Quote Link to comment Share on other sites More sharing options...
mmgemini Posted January 27, 2021 Share Posted January 27, 2021 27 minutes ago, Snagger said: Given the age of the vehicle and that it sounds as if the rad and intercooler have been out a few times, have the foam seals between them and the mounting frame and between each other been replaced, and is the fan shroud installed? If the seals or any baffles are missing, the airflow through the cores will be reduced as it’ll pass through the gaps, and if the shroud is missing, the fan will be almost completely ineffective, recirculating air in a torus behind the rad rather than drawing air through it. I still think that cheap TGV oil cooler system is a part of the problem, though. Youve completle missed my point. The 300Tdi radiator is NOT a crossflw even when new. 1 Quote Link to comment Share on other sites More sharing options...
rusty_wingnut Posted January 27, 2021 Share Posted January 27, 2021 8 minutes ago, mmgemini said: Youve completle missed my point. The 300Tdi radiator is NOT a crossflw even when new. This is a good idea, crossflowing the rad and utilising the whole length in flow is a much better design. 1 Quote Link to comment Share on other sites More sharing options...
reb78 Posted January 27, 2021 Share Posted January 27, 2021 So can you fit a 200tdi rad to a 300tdi and achieve that ^^^ I think you would have to adapt the top hose? Quote Link to comment Share on other sites More sharing options...
mmgemini Posted January 27, 2021 Share Posted January 27, 2021 56 minutes ago, reb78 said: So can you fit a 200tdi rad to a 300tdi and achieve that ^^^ I think you would have to adapt the top hose? Well at one time I did get a 200Tdi rad for my 300Tdi but gave up. I thought about using the bottom hose and changeing that. The easiest answer is an African mod to the radiator Quote Link to comment Share on other sites More sharing options...
uninformed Posted January 27, 2021 Author Share Posted January 27, 2021 8 hours ago, mmgemini said: Two things to ask. Why is it that the 300Tdi isn't fitted with either a proper radiator like the series or a proper crossflow like the 200Tdi The viscous fan can and does at certain fan speeds stop the airflow through the radiator Can you explain the difference between the two, and do you know the speeds and why that happens re the fan? Quote Link to comment Share on other sites More sharing options...
uninformed Posted January 27, 2021 Author Share Posted January 27, 2021 4 hours ago, Snagger said: Given the age of the vehicle and that it sounds as if the rad and intercooler have been out a few times, have the foam seals between them and the mounting frame and between each other been replaced, and is the fan shroud installed? If the seals or any baffles are missing, the airflow through the cores will be reduced as it’ll pass through the gaps, and if the shroud is missing, the fan will be almost completely ineffective, recirculating air in a torus behind the rad rather than drawing air through it. I still think that cheap TGV oil cooler system is a part of the problem, though. Always use the shroud. You keep referring to the Tgv oil cooler as cheap, implying less efficient, poor design etc. Can you explain how it’s cheaper to manufacture and how it is less efficient that the 300Tdi set up? Quote Link to comment Share on other sites More sharing options...
uninformed Posted January 27, 2021 Author Share Posted January 27, 2021 1 hour ago, mmgemini said: Well at one time I did get a 200Tdi rad for my 300Tdi but gave up. I thought about using the bottom hose and changeing that. The easiest answer is an African mod to the radiator African Mod? What is that? Quote Link to comment Share on other sites More sharing options...
reb78 Posted January 27, 2021 Share Posted January 27, 2021 (edited) 41 minutes ago, uninformed said: African Mod? What is that? Think its this - https://www.aulro.com/afvb/90-110-130-defender-county/188913-defender-300tdi-radiator-tropical-mod.html Edited January 27, 2021 by reb78 1 1 Quote Link to comment Share on other sites More sharing options...
uninformed Posted January 28, 2021 Author Share Posted January 28, 2021 3 hours ago, reb78 said: Think its this - https://www.aulro.com/afvb/90-110-130-defender-county/188913-defender-300tdi-radiator-tropical-mod.html If that’s it, as I have stated a few times, it’s been done and common practice amongst Tdi owners I know in Oz. Quote Link to comment Share on other sites More sharing options...
Snagger Posted January 28, 2021 Share Posted January 28, 2021 17 hours ago, mmgemini said: Youve completle missed my point. The 300Tdi radiator is NOT a crossflw even when new. I wasn’t replying to you, Mike. Quote Link to comment Share on other sites More sharing options...
Snagger Posted January 28, 2021 Share Posted January 28, 2021 13 hours ago, uninformed said: Always use the shroud. You keep referring to the Tgv oil cooler as cheap, implying less efficient, poor design etc. Can you explain how it’s cheaper to manufacture and how it is less efficient that the 300Tdi set up? It is a unit that doesn’t require as much plumbing and doesn’t need such an expensive radiator with internal oil cooler, so the likelihood is that the new unit was made that way to either reduce total installation costs or to ensure that the unit wasn’t installed in a vehicle that was previously normally aspirated and no oil additional cooler was installed. I very much doubt the new oil cooler has the capacity of the Tdi type, or better still, the transmission oil cooler I suggested. Unfortunately, in all forms of engineering, a lot of changes in approach are for cost engineering, not to improve system performance. 1 Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted January 28, 2021 Share Posted January 28, 2021 I'm genuinely curious about this radiator modification, I'm not familiar with the 300TDi rad and I'm not getting where this baffle is and how the mod works? Quote Link to comment Share on other sites More sharing options...
uninformed Posted January 28, 2021 Author Share Posted January 28, 2021 21 minutes ago, FridgeFreezer said: I'm genuinely curious about this radiator modification, I'm not familiar with the 300TDi rad and I'm not getting where this baffle is and how the mod works? In the left hand end tank, there is a divider plate half way up. Water enters left end tank, fills, hits divider plate, travels sideways to right end tank, drops down to lower half, moves sideways back to left end. There is a hole in the plate about 15mm dia, water will pass through it easier than going through the core, bypassing the cooling process. Terrible for hot climates, thats why we plate them but still leave 3mm for bleeding. Known as a dual pass radiator. 1 Quote Link to comment Share on other sites More sharing options...
mmgemini Posted January 28, 2021 Share Posted January 28, 2021 49 minutes ago, FridgeFreezer said: I'm genuinely curious about this radiator modification, I'm not familiar with the 300TDi rad and I'm not getting where this baffle is and how the mod works? The left tank, about one third up fit a plate to block the tank but with a 3mm bleed hole. This mod stops the water going from the bottom hose to the top hose making the water go through the matrix Quote Link to comment Share on other sites More sharing options...
uninformed Posted January 28, 2021 Author Share Posted January 28, 2021 (edited) 1 hour ago, Snagger said: It is a unit that doesn’t require as much plumbing and doesn’t need such an expensive radiator with internal oil cooler, so the likelihood is that the new unit was made that way to either reduce total installation costs or to ensure that the unit wasn’t installed in a vehicle that was previously normally aspirated and no oil additional cooler was installed. I very much doubt the new oil cooler has the capacity of the Tdi type, or better still, the transmission oil cooler I suggested. Unfortunately, in all forms of engineering, a lot of changes in approach are for cost engineering, not to improve system performance. I would say that’s an optimistic view point lol. That complex radiator is one pipe down the right end tank. Small radiator, hottest water enters, travels across only half height, half cooled, hits oil pipe, gets heated again and then travels half height across again... block cooler, hottest water enters radiator, gets full cooling, enters block, coolest part of engine and goes through oil cooler. I guess we will just disagree on that one. cost cutting by accountants, yep, and plenty of it over the LR years. Edited January 28, 2021 by uninformed Quote Link to comment Share on other sites More sharing options...
Snagger Posted January 28, 2021 Share Posted January 28, 2021 It is a simple pipe in the rad tank, but it’s surface area and flow restrictions are likely to eat lot less than the one on the 2.8, and in the case of the 200Tdi rad, immersed in fully cooled water. The 300 rad is different, I don’t know why LR did that. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted January 28, 2021 Share Posted January 28, 2021 33 minutes ago, mmgemini said: The left tank, about one third up fit a plate to block the tank but with a 3mm bleed hole. This mod stops the water going from the bottom hose to the top hose making the water go through the matrix Ah, having googled 300TDi rads it's clear now - the thread someone linked about it had a standard crossflow rad pictured which obviously would be a weird thing to put a divider plate in. My 109 has a dual-pass radiator with very open core / low FPI and that cools the 4.6 without issue, although I've not driven it in the desert. Quote Link to comment Share on other sites More sharing options...
mmgemini Posted January 28, 2021 Share Posted January 28, 2021 26 minutes ago, FridgeFreezer said: Ah, having googled 300TDi rads it's clear now - the thread someone linked about it had a standard crossflow rad pictured which obviously would be a weird thing to put a divider plate in. My 109 has a dual-pass radiator with very open core / low FPI and that cools the 4.6 without issue, although I've not driven it in the desert. My 300Tdi is standard ? I run an electric fan. I had no problems in southern Africa even with a seed net fitted. Aparently not every 300Tdi needs the African mod though some rads require two baffle plates fitted to that left hand tank Quote Link to comment Share on other sites More sharing options...
mmgemini Posted January 28, 2021 Share Posted January 28, 2021 40 minutes ago, Snagger said: It is a simple pipe in the rad tank, but it’s surface area and flow restrictions are likely to eat lot less than the one on the 2.8, and in the case of the 200Tdi rad, immersed in fully cooled water. The 300 rad is different, I don’t know why LR did that. COST Quote Link to comment Share on other sites More sharing options...
Snagger Posted January 29, 2021 Share Posted January 29, 2021 On 1/28/2021 at 3:52 PM, mmgemini said: COST It’s the same size rad with the same core, same oil cooler and same header tanks, just with the cold outlet moved to the same header as the hot inlet and a baffle plate in that header. Seems slightly more expensive to me. A mechanic friend told me it was to have the oil cooler in semi-cooled coolant to help warm the oil quicker, but that doesn’t quite make sense to me. I assumed it was just an ease of engine bay plumbing issue. Quote Link to comment Share on other sites More sharing options...
mmgemini Posted January 29, 2021 Share Posted January 29, 2021 3 hours ago, Snagger said: It’s the same size rad with the same core, same oil cooler and same header tanks, just with the cold outlet moved to the same header as the hot inlet and a baffle plate in that header. Seems slightly more expensive to me. A mechanic friend told me it was to have the oil cooler in semi-cooled coolant to help warm the oil quicker, but that doesn’t quite make sense to me. I assumed it was just an ease of engine bay plumbing issue. The 300Tdi radiator is very different to a 200Tdi one. The 200Tdi radiator maybe the same sise. Have the oil? water hear exchanger tank fitted but both are very different. The 300Tdi radiator is not a crossflow radiator, the 200Tdi radiator is. The coolant in a 300Tdi radiator enters the radiator at the bottom of the left hand tank, then goes straight up that tank to the outlet. Nowhere is it in anyay pushed by coolant pressured into the matrix. The 200Tdi on the other hand is a crossflow radiatot, The coolant enters the bottom of the right hand tank and must pass through the matrix to the exit at the top of the left hand tank. A proper crossflow. Also the pipeing for the oil coolant in that right hand tank also helps the coolant through the matrix The other thing I was taught about cooling, Was to have as much coolant as possible above the enging/ radiator. No Tdi has that. The header tank is lower than the thermostat housing Quote Link to comment Share on other sites More sharing options...
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