New doghouse fanshroud-no "themostat flaps"

[73SpeedBuggy]

I ordered a new doghouse fan shroud as part of my engine rebuild. I ordered the model without heat ducts, which I assumed meant the heater hose connections that are on the rear of my original set (that are, of course, not used). However, it arrived today and it also doesn't have the flaps inside that are opened and closed by the thermostat. Is this because it doesn't have the heater hose connections? Is not having these flaps a big deal if I don't run the buggy in the winter? Do I need to put the original flaps into the new tin? This would require some cutting and drilling.

[mel hubbard]

I read an article years ago in an old Gene Berg catalog/technical manual that stated the Taiwan copies do not provide the proper cooling or thermostat control locations which are critical to engine life. They also stated that they had made thousands of temperature tests on VW motors and verified that the stock VW parts created the best cooling. They went on to say, the VW was so well engineered that practically every change they made to the cooling system from stock ran much hotter. Ever since I read that I tend to stick with the standard cooling & just block the outlets on the fan housing. There is a lot more interesting info on VW cooling in the Berg tech manual,, well worth reading IMO.

[CairoManx]

[QUOTE="73SpeedBuggy"]I ordered a new doghouse fan shroud as part of my engine rebuild. I ordered the model without heat ducts, which I assumed meant the heater hose connections that are on the rear of my original set (that are, of course, not used). However, it arrived today and it also doesn't have the flaps inside that are opened and closed by the thermostat. Is this because it doesn't have the heater hose connections? Is not having these flaps a big deal if I don't run the buggy in the winter? Do I need to put the original flaps into the new tin? This would require some cutting and drilling.[/QUOTE] The thermostat and flaps really only help to make the engine hotter not cooler. They are designed to cut off the cooling air to the engine just after its started and hasn't warmed up. Once the engine reaches operating temperature, they open. If you live in a cold climate, they would help warm up the engine in the winter. If you're not planning any mid-winter buggying, forget about them. If you live in the Southwest and drive the buggy hard, you should probably use stock cooling tin like Mel said. Under moderate conditions, the aftermarket stuff should be fine. The one exception is probably the DTM fan shroud, which reportedly outperforms the stock system.

[73SpeedBuggy]

Honestly, other than the lack of heater hose outlets and the flaps the tin is completely identical to the stock one I removed. Can you even get new stock ones? I guess I'll run without the flaps and watch for any negative side effects.

[Manx-Australia]

[QUOTE="73SpeedBuggy"]Honestly, other than the lack of heater hose outlets and the flaps the tin is completely identical to the stock one I removed. Can you even get new stock ones? I guess I'll run without the flaps and watch for any negative side effects.[/QUOTE] mmm don't get me started of fan shrouds. They are usually not identical and are a POS. I have cut a few up and the ducts are not that special when you compare them to the factory VW one. The thing is that not being as good many not necessarily mean they will not work. In most VW engines and their cooling there is enough redundancy that most users will never notice the effect of a less than factory quality cooling effect. If you have a look inside your ?New? shroud you will usually see that the veins are sharp and often not curbed that well, there are also often less of them. With the various manufactures of crap VW parts I can?t say for sure that yours is one of the bodgy ones but chances are? Here is a pic of a fan shroud I cut up years ago to show someone what I was talking about : The other point of note that if it is a dog house unit then the "New" ones often don't have a very good design for kicking out the air to go over the cooler and as a result the cooler gets less flow than it should. Add to that the thinner fans many people run on them to help with alignment issues they sometime have and you have all the quality ingredients for needing a head job sooner than planned. For more pics and stuff - http://offroadvw.net/tech/brad/fanshroudtech.htm

[subimanx]

[QUOTE="Iguana"]................................................................................. you have all the quality ingredients for needing a head job sooner than planned. For more pics and stuff - http://offroadvw.net/tech/brad/fanshroudtech.htm[/QUOTE] I'll hafta get me one of those then!!!! LOL.....

[Lee]

post deleted by author

[73SpeedBuggy]

I need a CHT guage I think. What temp sender is everyone using for their CHTs?

[Lee]

post deleted by author

[Manx-Australia]

[QUOTE="Lee"]Do I really want to answer this, or should I keep it to myself? Oh what the heck, I'll have at it! You need the flaps. [/QUOTE] mm I must say I disagree with this. I always remove the internal flags from the buggy shrouds as I have seen more of them fail and cause the engine to cook, than do good. I have tested shrouds with the flaps and without meauring both cylinder temp on all 4 cylinders, oil temp and presure and an "Hand Held Touch Temp Guage" and I have never found any difference to speak of. Although in theory I would agree with the comment that throwing the air to the outside is a good thing I do not beleive the flaps when fully open assist in this enough to make a difference. Adding Type 3 Cyl Head tinware makes a lot more difference. Anyway just my findings.

[mel hubbard]

Some Berg quotes,, theres a lot of it on the subject, so I will just pick the bones out >>> ''WE DISCOVERED THAT THE THERMOSTAT SHUTTERS ARE DIRECTIONAL DEVICES TO DIRECT AIR TO THE PROPER LOCATIONS THROUGH WARM UP AND ALSO WHEN THEY ARE OPENED ALL THE WAY TO DIRECT AIR TO THE MOST CRITICAL AREAS. SPEAKING OF THERMOSTATS,,,REMOVING THE SHUTTERS AND THE THERMOSTAT INCREASES ENGINE WEAR 15% to 17% AND OFTEN CAUSES CRAKED HEADS EVEN IN SOUTHERN CALIFORNIA. NATURALLY,, IT IS MUCH HIGHER IN COLDER AREAS THE INTERNAL ENGINE PARTS CANNOT HEAT UP AND EXPAND TOGETHER AT THE PROPER RATE WHEN THE THERMOSTAT IS REMOVED. THE INSIDE GROWS FROM HEAT AND THE OUTSIDE IS BEING COOLED FAR TOO MUCH AND IS KEPT SMALL. THIS MEANS VALVES,,GUIDES, PISTONS AND CYLINDERS, PINS AND ROD BEARINGS ARE ALL BEING SUBJECTED TO STRESS AND ABNORMAL WEAR WITHOUT THE THERMOSTAT AND SHUTTERS. AFTER ALL, YOU DON'T TAKE THE THERMOSTAT OUT OF YOUR NEW WATER COOLED CAR DO YOU ?? A few more interesting Berg quotes on the subject > EVEN IF YOU COOL THE OIL,, THE HEAD TEMPERATURE IS STILL RUNNING FAR BEYOND NORMAL AS YOU NEVER FIXED THE SOURCE OF THE OVERHEATING PROBLEM. I HAVE NEVER EXPEIRIENCED ANY OVERHEATING OF ANY ENGINE WITH THE CORRECT CR,, CARBURETION, TIMING, DISTRIBUTOR AND PROPER OCTANE FUEL REGARDLESS OF HP OUTPUT EVEN 200 HP DAILY DRIVEN. < using stock cooling tin BTW. '' I HAVE HAD MANY PEOPLE MAKE ADVERSE COMMENTS ABOUT MY COOLING AND CR TESTS AND RECOMMENDATIONS.. IT IS OBVIOUS THESE PROPLE DO NOT DRIVE DAILY AN AIR COOLED VW FOR OVER 100,000 MILES OF TESTING OR HAVE NOT CONSIDERED THAT I DO NOT MAKE ANY MONEY BY RECOMMENDING THAT YOU KEEP YOUR STOCK COOLING SYSTEM. IM COMMITTED TO YOUR ENGINE RUNNING CORRECTLY AND LIVING AS LONG AS POSSIBLE'' G BERG quotes from the mid 90's. Some those above quotes seem to support Lee's theory from how I remember it, so why delete it Lee??. Im in NO WAY confessing to know as much as some of you guys on the subject, but I do feel that years of VW factory R&D went into developing the cooling system of a type 1 VW motor which Berg and most of us will agree that the stock fan shrouds are far superior to the AM ones, so why doubt the stat flaps? after all it works together as a unit, which explained by Berg seems to make sence to me.

[newmanx59]

Berg's statements were all made with the expectations that the engine will be in a Beetle's enclosed engine compartment and that the engine is expected to run for 100,000 miles. The chance of a buggy running 100,000 miles before the owner decides he wants more HP or something else that requires the engine case be split are very slim. I had 60,000 miles on my Baja that had everything done against the laws of Berg.....It had slip in 88's, high volume oil pump, oil cooler over the fan inlet, no flaps and an aftermarket fan shroud. It never ran hot and the leakdown was always good and tight. Jake Raby did a lot of very scientific testing with factory VW and aftermarket shrouds in the development of his DTM shroud. Jake did mention that the SCAT fan shroud is the best performing aftermarket fanshroud. I have been using the SCAT shrouds with no flaps on my sandrail, Baja, and Manxes with no head temp issues.

[Manx-Australia]

now who openes thi scan of worms ?? hehe. As I said early on everyone has an opinion and most of them vary slightly. I am well aware of what GB wrote and I am also aware that I did my own testing and was happy with the results. Anyway I run mine without them and I would say most aircooled VW in my part of the world are the same. That being said everything I own and drive is water cooled now, all be in VW based with Subaru Power....... now that fixed a great deal of VW problems...

[mel hubbard]

[QUOTE="newmanx59"]Berg's statements were all made with the expectations that the engine will be in a Beetle's enclosed engine compartment and that the engine is expected to run for 100,000 miles. .[/QUOTE] Jerry, Would that not make the thermostat & flaps in a buggy even more crucial ? I just fail to see the purpose of cooling a cold VW motor at the same rate as a hot one.

[newmanx59]

What I was getting at is, I have driven a VW engine with thinwalled 88's, no flaps, etc. 60,000 miles to date and never had an engine issue. I don't think the flaps are that crucial. To me, the flaps are just another part that can fail and cause a problem.