Bergmann

I just installed a Bergmann 911 fan shroud on a car we just built for one of our customers. I painted it gloss black. Had an issue with the alternator voltage regulator not working on initial startup, however Bergmann called me first thing in the morning the following day after I left him a message. Already had it fixed however at a local alternator repair shop.

I'll post some pics:

These shrouds function best in road race type competition or long, high speed autobahn runs, where the engine is running continually at higher rpm's and needs a ton of air to keep cool. The first problem with the Bergmann piece is that it doesn't have the internal baffling (unless you took the time to engineer it) to cool both sides of the engine properly. One side will run hotter than the other and there's also no way to block off the air (like the stock thermostat and flaps do) when first started for faster warm-ups; these will both cause accelerated wear internally. You haven't done your client any favors. Sure looks pretty though!

 

As usual, just my 2 1/2 cents (I'm Canadian, eh). Never thought I'd say that here, but it just seems so appropriate at the moment....

 

And my apologies as I'm sure this isn't response you're looking for. I didn't mean to insult, but think it needs to be said.

When fitted to a 911 based engine I agree with the comments. Direct experience has proven to me that in Road Racing heat soak is the biggest enemy. Road Racing and Land Speed Racing are the only two Motorsports activities that we work with. Lots of 911 arrangements have been replaced with other systems over time.

Opinions vary. Very, very few people have actually carried out direct evaluations of different systems back to back. Because of that most of these opinions are based on speculation and vaporware.

I have a 911 fan that's going on my old beater rail buggy with a "sweep the floor" engine (built out of whatever parts we found laying around). It'll look it's best covered in 1/2" of Georgia red clay. I'll have to post some pics:-)

I never said they were the best; I said," These shrouds function best in..."

Not trying to be a mark at all, but I disagree with this statement as well. The only application where the 911 style fan really shines is in off road racing and activities. This is due to the axial fan handling dirty environments bette than a radial fan more than anything else.

 

BTW- The issue with the 911 shrouds is not like those that are seen with radial fan systems that have a tendency to distribute air in the tangential flow of the fan, always directing more air to the 1-2 bank that the 3-4 bank. The 911 fan just wants to blow all its air to the furthest aft cylinders, being #1 and #3. This is a much more concerning situation, because the heads are siamese castings that need to expand and contract at the same rate across themselves. Since 1/2 of each casting is running cooler than the other half of the same head thats where issues begin. I'd much rather have an entire side of the engine hotter/ cooler than 1/2 of a cylinder head running hotter/ colder than the rest of that head. With the discharge of the axial fan being directly toward the 1&3 cylinders, and no internal vanes/ deflectors to route it anywhere else, this leaves cylinders 2&4 to run hotter. Why? Because on a 4 cylinder engine those two cylinders are directly under the fan! Every try to twist air 90 degrees within a 2" confine? It doesn't work, and I have tried it.

 

The -6 Porsche engine is designed properly for the axial discharge and the first par if cylinders are NOT under the fan, they are 6" away from the discharge point of the axial fan, making it much easier to route air to these cylinders. It was designed that way, it wasn't just made to fit and endure compromise like it is on any -4 engine utilizing a 911 style fan.

 

I studied this stuff for years. It kept me awake at night and it drove me crazy.

I would think the highspeed runs would be the worst for the bergerman unit.it can be made to work,just needs work,like makeup on a old blond,i think it can work as good or better than the oe type 1. vanesinside  arnt the answer,unless your bleeding all over it. it's not all that hard to fix, but takes time& a tad bit of skill.with the addtion of a little bit of brains and some goggles&mask. a dummy engine of the proper size is also helpfull to get everything where it needs to be.

"...like makeup on a old blond"

 

I'll have to remember that one for future use.