Fan Shroud Education

I have read several posts about different configurations. I also see ads at parts houses for shrouds with or without dog house. Now for the questions from ignorance:
1. What is the diffence between with or without dog house
2. Which one should I have
3. How do I tell which one I have
4. Any other inforamtion I should know but don't know to ask about.

Oh yea the engine is a 1776 with dual weber ict's.

Other than education I plan to add a 356 pulley and welded/balanced fan and want to make sure I do the right thing.
Thanks
Troy

My understanding is that you want the dog house style. The dog house refers to the extra projection off the back drivers side of the shroud that houses the oil cooler. I believe VW did this because in the early non-dog house shrouds the same air that went through the oil cooler also passed over cylinder #3. This resulted in cylinder 3 always running hotter than the others thus reducing it's life span. I think the dog-house style also uses a wider fan.

Some of the VW gurus here can correct me if I'm wrong.

Jerome

Troy; Jerome is right on; the "dog house" came out somewhere in 1971. Your car has definitely got it since all VS builds have them. Verify if your car already has the 356 pulley, mine came with it from VS since new. It's a smaller diameter than the regular VW. If you don't have it the new one bolts right in to the alternator and it's three pieces instead of the regular VW which is a two piece. My friend Jjr retrofitted one in his car. If I recall correctly he got the parts from either Tweeks/Mid America Motorworks or Klasse 356. The welded & balanced fan assemblies that are being offered just replace your existing one.

Troy, I would suggest staying away from aftermarket shrouds - they don't have the same directional vanes the original German shrouds had, and there are problems with the spot welds coming apart inside causing an annoying rattling sound.

I would also stay away from aftermarket welded balanced fans (Gene Berg may be an exception) the two that I ordered were total crap - out of round, and wobbly. Go with an original German fan - before buying, you can test it by putting on an alternator and spinning by hand.
Also, make sure the fan fits snugly on the alternator - there should be some resistance when you install and remove.

I went to a local auto wrecker, and found an oem doghouse shroud and all the original appurtenant tin.
To restore, media blast everything down to bare metal, then prime and paint with automotive grade paint or powder coat.
If you paint with rattle can paint, you'll have issues with carb cleaner/gasoline attacking the paint.

David is right about the fan shrouds; OEM are more efficient (but not as cool looking as the 36 HP style). There is an aftermarket 36 HP style shroud that according to Jake Raby's tests is even better than OEM; he just wouldn't reveal the name because the manufacturer would not pay for an endorsement. I strongly suspect it's the unit from Scat.

So in answer to the question of how do i know which one I have then If I find a box on the back of the fan on the drivers side then I have the newer version. My car is an 01 VS so hopefully I am OK but just want to be sure before I make the switch to the 356 pulley and a german fan from '71 or later.

Right??

To add one more thing, many owners install a T4 cooler in place of the T1, for the extra cooling. I haven't done the conversion, but I hear it is fairly simple.

Ron and Troy:

A T4 cooler conversion is "relatively" simple (I've done a couple) but the back of the shroud has to be modified slightly to accept the larger cooler. The question here is, WHY?

Troy wrote:
1. What is the diffence between with or without dog house
Yup, just feel behind the fan shroud half-way between the fan and the left end of the shroud and there should be a big "hump" on the back where the cooling tower is. Also, looking up from the bottom, there is a small duct (2"X4") on the front (as the car faces) of the engine on the driver's side where the cooling tower air exits, just ahead of the driver's side head.
2. Which one should I have
a fan shroud, cooling tower and fan (it's bigger) from a 1971 - 1973 GERMAN engine (NOT after-market)
3. How do I tell which one I have
See #1 above
4. Any other inforamtion I should know but don't know to ask about.
Probably, but I don't know, either.

Oh yea the engine is a 1776 with dual weber ict's.

Other than education I plan to add a 356 pulley and welded/balanced fan and want to make sure I do the right thing.
*************************
If you are racing, and/or consistently shifting over 5,000 rpm ALL THE TIME, then the welded, balanced fan might be considered.

If you're running a 1776 (not much more than stock displacement), don't hardly ever go over 5,000 rpm, are not seeing an overheating problem and already have a "doghouse" cooler/shroud, then a welded/balanced fan will be a waste of money. These fans are only needed if you have really big engines AND are hammering it all the time while going through the gears, thus, seeing very rapid increases in RPM over relatively short periods of time (like racers do). Welding the fan blades keeps them from flying off when rev'd really high really quickly, and balancing the fan keeps it from vibrating like hell if the engine is rev'd over 5 grand frequently.

If you don't do these things and are not having a cooling problem, then save your money.

Adding a 356 fan (slightly smaller diameter) adds 11% more air flow across the heads (a good thing) and brings the cooling effect down 11% in the RPM range (also a good thing, especially at turnpike speeds) and is MUCH cheaper than a welded, balanced fan that you may not need.

GN
One of the Crusty Old Coots from Rhode Island

Troy; yep you're right and Gord said it all......

Troy;
I couldnt agree more with Gord, I have a 1776 and never have the need to rev it higher than 4500rpm, no fan troubles here. Im using the small generator pulley without any issues. If your alternator has the stock size vw pulley and you want to take advantage of this better cooling improvement I recomend you get both halves, the hub and about (13-15) adjusting washers. Yes, it takes so many and they're not the same as stock vw ones, BTDT. BTW You can get the parts from klasse356.com. Good luck - cheers - jJ.