More air into the engine compartment

[mondshine]

Tooter-
The key is to draw cooling air from the right place. Removal of the rear rubber seal would cause the fan to draw in air heated by the exhaust system; no good. Removal of the front tin (like some bus drivers do) would cause the fan to draw hot air from the oil cooler outlet; also no good without some serious re-direction of that duct.
Cool clean air is available at the side of the car where the air intakes are mounted. The duct I fabricated delivers this cool clean air not to the rear of the engine compartment, but directly into the fan inlet.
Since this modification, I have spent 8-10 hours above 75 mph and have never exceeded 350 deg. CHT. I call that sucess. As I mentioned in a previous post, this modification is not for everybody, but I take a few long trips each Summer, and appreciate the ability to keep up with fast freeway traffic without the fear of overheating the heads. What I have done may not be the only solution, but it is certainly a viable solution.
Best regards, Mondshine

[74 Thing]

It seems that the conclusion that everyone comes too is that the fan does not get enough air in the engine compartment and this is especially noticable during the summer heat when driving on the highway for an extended period of time. By propping the decklid, modifing the decklid, modifing the front tin, or adding a tube to direct air into the fan these modifications have all been successful in helping to control engine temps.

Gary, I would like to see a pic of your tube modification from the side scoop to the fan-you thing you could get away by just using an aluminum dryer heater hose and zip ties from the hardware store?

[tooter]

Last summer I drove from TN to NC (KTE) to IL to IN to WI to KY back to TN. Over 3000 miles. It was 104 in Chicago. Very toasty! We went over 3,000 miles on our trip. It was HOT! The engine never seemed hot, smelled hot, or anything that whole time. Oil never got hotter than 220, but hung around 200 more often than usual.

We had only one problem on the trip. Thinking she was doing me a favor, Wifey ran up to the gas station while I packed the tent and gear back at the site. Unknownly she had filled up with an Ethanol blend. Although I had replaced the 30/31 PICT with the correct new 34PICT, I still used the original fuel pump with a rubber diaphram. It wasn't too long before the rubber swelled and stretched, the pump stopped pumping. Sputt...Sputterr...

Open the lid, no fuel in the fuel filter. Tank reads 1/3 left. Humm.... A little homework to discover the lines aren't clogged. "Honey...what gas did you fill up with?" "I don't know, the gas at the station..." I check the ticket...Ethanol Blend! Ahhhh! Fortunately a replacement fuel pump was one of the things I bought at the show...I can tell you the new pumps seem to be Ethanol friendly...

[alsehendo]

You could put some holes above the shroud--behind rear seat.

Jake Raby says he has a T1 shroud, (DTM), that cools much better than stock.

[LEJ]

Jake's shroud is just more efficient at managing the air flow within his shroud, it doesn't increase air flow it provides a more uniform distribution of air. It too is limited to the quality of air available. Since the quality of air in the Thing engine compartment is poor, then cooling in general will be poor

[Towel Rail]

Jake Raby says he has a T1 shroud, (DTM), that cools much better than stock.

... which works great for high-performance T1 engines. Jake (unless he's changed his mind) generally recommends the regular doghouse (with all tin and seals) for stock engines.

I've been away from STF for a while, but I see all you folks are still paranoid about cooling. In truth, how many of you have actually dropped a valve seat? Seized a piston? Cracked a head? Burned oil to the rocker side of the heads?

I'm of the mind that the stock cooling system will take care of itself, as long as it's maintained well. The PO of my Thing ran it HARD off-road in the summer without an engine compartment seal, blocked-off fresh air ports (keeping the heater boxes), and plates over the side intake vents (!) When Dad and I tore down the engine, it was just fine. The heads weren't cracked, and the valves were in good shape.

It's probably alarming to see a slight vacuum in the engine compartment, but that's what's going to happen. The fan is trying to push a LOT of air through the shroud, in addition to what the engine wants for combustion. A stock engine should be running out of horsepower at the point the cooling system loses effectivity. The VW engineers weren't dummies.