With all we know about how hot the D2s run, and the head gasket issues, and the discussions of inline thermostats and 180 degree soft spring thermostats, what about hood vents?

If the heat can get out wouldn't that make the fans more efficient and keep the engine cooler? I have seen some online for sale, and seen some home-made vents on hoods as well. I know it may not be a "rover" look, but if I can get my engine cooler and make it last longer, I can live with that, and would try to do it tastefully. My real question is what problems does rain and snow cause when the water goes down through the vents? Couldn't it cause issues with some electrical parts if the vents are put in some locations on the hood? What about vents that you could route to the upper side of the finders like you see some of the fake chrome vents?

I also like the idea of the "saudi type grill", although I am not going to pay for a real LR saudi grill, I have seen some home-made that look quite good. Again better air flow, coming in in this case.

 

https://landroverforums.com/forum/di...ight=hood+vent

 

Great idea. Wonder if you could make/buy one that could "close" so if it was going to rain/snow you could close it to ensure no water got through (less water)!

 

I have been thinking of trying these... But like you, the water issue concerns me.

RunCool Hood Louvers/Hood Vents For Your Vehicle - Cool Your Engine

Also, check this out: Vents on the hood - Pirate4x4.Com

 

IMHO you won't make much difference with the hood vent. Before slicing and dicing measure temps with a scanner on a particular day. Lets say at idle. Then pop the hood and see if your temps drop like a stone. Don't think you'll see much change, and for a real test remove the hood and drive around doing same test.

The heat from the engine is removed by the air passing thru the radiator. It does not recirculate. The air entering the radiator has not heated much by the space under the hood. Big staionary standby generators run at 1800 (diesel) or 3600 rpm (gas), and don't move (so only air flow of their fan), sit out in the sun, and don't have a lot of vents. Their fans are different, in that they normally are set to pull air across generator windings, then thru radiator, then out.

 

I am fabbing up a real working hood scoop with a flap that i can lock closed during wet conditions!
On the inside of the scoop there are two small hinges that apply pressure to the sturdy rubber flap so it will take moving to force open the flap When raining i will be able latch it closed with the long airbox clip from a donor. I fixed to the hood!
* i don't know what effect this will have but i haven't seen another D II with a hood scoop. And i dont want to start but there is my idea i working on.

 

Actually, I have popped my hood while driving to see what happens. I had a nearly instant drop according to scangauge of about 12 degrees (went from 200 to 188 or so). I did pull over quickly though because I didn't have much faith the hood latch would hold while moving. But I confirmed my suspicion. Looking at the design of the Runcool vents, their claims seem plausible. Anyone want to donate a hood so we can all find out? Lol.

 

Also if you remove the rubber on the bottom front side of hood and both sides you will notice a drop in temp on highway.

 

Yeah, I tried that but for some reason my hood rested on the sheet metal where the rubber was so I put it back. Didn't want to hear aluminum cans over every bump lol.

 

IMHO you are changing the air flow thru the radiator (change the cfms by changing the "static pressure" the fan pushes), not venting extra heat or removing radiant energy from the exhausts and block at such a rate that you are cooling things. Perhaps repeat your tests and add an IR thermometer measuring the temp of the block, manifolds, etc. You could also hole saw a series of opening in the firewall that would allow air to flow out through the cavity under the windscreen, and out the pollen filter array. If the holes don't work for you, they could be filled with knock out plugs or some fender washers and bolts.

Now I certainly think the Rover fan is smaller than it needs to be. You can increase cooling with a fan with deeper pitch blades. I saw 6 - 10F change with that. But my best result was going to a 180F stat. I now run 180 -183 at modest speeds and perhaps climb to 187 at 70 while I watch the gas gauge move. It is hot and humid where I live, frequently in high 90's or low triple digits. All my hood strips are in, as wells as radiator rubber strips. And for sound control I added the hood blanket from a D2, don't know if D1's came with or without them.

Another problem IMHO for D2's is that they only have a single AC condenser fan, and it does not run whenever AC is on, like the D1 does. If you modified the fan to be on when AC is on I bet temps we be lower at slow speeds.

However, if you have a radiator that is partialy full of sludge, the more sludge will make radiator performance change faster with changes in cfm. A sludged radiator would show greater changes in temp because of air flow, it is unbalanced and on the edge for the cooling system. So each truck may read differently, based on how clogged the rad is (inside and outside).

BTW, I'll try the removal of rubber strips and report back.