Bernie Bergman air cooled with shroud.

No. Don't do it. That shroud is crap, the alternator/fan unit is crap, and the cooling is crap.

Get a doghouse shroud with flaps and thermostat. Period.

^^^That^^^  Right on.

The Bergman shroud usually comes with two external oil coolers in place of the stock VW cooling tower which doesn't fit inside of the Bergman shroud.  

Get a new, stock VW oil cooling tower for the new Doghouse shroud (either the original 36 hp style or the slightly larger, 1971 or newer, shroud and fan) and install that, along with one of the Bergman external, fan-assisted coolers in the driver's rear wheel well (keep the other one as a spare).  That should cool just about anything.

Or, if it hasn't yet been delivered, tell the builder what Danny and I say and don't let him talk you into a Bergman shroud - they aren't very good.

X3- The Bergman shroud looks great but has problems and takes a lot of work to make it cool (somewhat) evenly across all cylinders. Your engine will take forever to come up to operating temps and the longer an engine runs cold the more internal wear that happens. In cooler weather the engine may never warm up fully.

Bergman fans and shrouds blow a lot of air just like the inventor ! Many serious mechanics have tried to correct the issues but to no avail yet.  They really look cool but that's about it. Bergman told me one day that he invented hydraulic lifters for A/C VW's. Ed Iskaderian rolled over in his grave on that one............Bruce

i had a Bergmann engine, ran ok,looks good but dont know if its any better than stock..its fiberglass, mine developed a crack at 10 oclock, by the time i noticed it it was heading to front of car,Bernie(piece of work) couldnt care less,, I put a large Castrol decal on it to cover it..

Been gathering parts to try building a horizontal fan system similar to a Corvair. Properly made, they work well. A Berg or a Porsche fan/alt are just to expensive to use.

Currently I'm playing with the type Three fan, welded and balanced placed horizontal over the top of the engine. It's designed to turn the right way, large in diameter and yet thin. Shroud is simple and currently made of wood. Positioning the directing vanes is still in the works. Trial and error with an air speed indicator under the heads.

Small Toyota forklift alternator (also used in type 3's for alt.conversion) will work nicely on the left side and an idler fully on the right. Later a A/C compressor in place of the idler pulley or a very small ASN AMR 500 supercharger..............Bruce

Bruce, you're amazing. 

aircooled posted:

Been gathering parts to try building a horizontal fan system similar to a Corvair. Properly made, they work well. A Berg or a Porsche fan/alt are just to expensive to use.

Currently I'm playing with the type Three fan, welded and balanced placed horizontal over the top of the engine. It's designed to turn the right way, large in diameter and yet thin. Shroud is simple and currently made of wood. Positioning the directing vanes is still in the works. Trial and error with an air speed indicator under the heads.

Small Toyota forklift alternator (also used in type 3's for alt.conversion) will work nicely on the left side and an idler fully on the right. Later a A/C compressor in place of the idler pulley or a very small ASN AMR 500 supercharger..............Bruce

For the Spyder?

No Al, not for the Spyder. Just experimenting and inventing stuff that interests me. Right now this is “bench work” where I can sit a lot while my knee heals.........Bruce

Sorry to say all the above words of wisdom are true. The Bergman fan shroud looks good but is a serial killer in disguise. This shroud has possibly killed more engines than we know. Get away from this setup soon as possible if you care about your engine and wallet. You are hearing from others that have been there and done that for you.

 I think the best fan shroud is the stock shroud with all the air directing vanes in tact and working thermostats hooked to working flaps. The Raby DTM shroud is supposed to be better than this but still might be unobtanium. I had an engine built for my Speedster with the DTM setup but sold it to go Suby power before I tried it. The guy I sold it to in Canada to use in his Beck Spyder seems to be happy with it.

One guy's attempts at making a Bergman shroud work-

https://www.thesamba.com/vw/fo...p;highlight=bergmann

@Jimmy V.- Correct me if I'm wrong, but it's my understanding that there's no flaps/thermostat assembly (or any other device) for quick warm up? I've seen what happens to engines without the flaps and thermostat run in cooler weather- they may never achieve proper operating temps for extended periods. In the case of daily driven cars in Vancouver it can be for months at a time and shortens life by 40-50%. Gene Berg estimated that running without the thermostat and flaps in southern California cut short engine life by 12-15%. 

If you're able to get out and drive your aircooled Speedster in cooler weather and noticing the engine taking forever to get up to proper operating parameters- remove the engine tin over the exhaust so the engine is ingesting warmer air. The 1 friend in Vancouver that still daily drives a Beetle year-round removes that piece, throws it, the screws and a screwdriver behind the rear seat (so when it's time to re-install he can do it at a moment's notice) somewhere around the end of October or beginning of November and it goes back on in Spring when the weather has warmed up sufficiently. Bruce says it increase heat output slightly as well. 

You can make a 911 shroud cool more evenly, but yes, they have no thermostat for warmup. I will say I have no personal experience with the Bergmann setup. All I know is from a well-known engine builder and the Samba. I know they use a domestic alternator and Bernie had the fans and rings made. They are not the same as an actual 911 fan/shroud.

I have an actual early 911 fan/alternator. I had the alt rebuilt and I converted it to an external regulator on the backside, so it ends up being a one-wire(are any REALLY one wire?) setup: power out and idiot light wire. I also modified the shroud's cooling with internal vanes on the back of the alternator. I used a 911SC factory vane/tailcone and bent and cut the vanes to fit the 4 cylinder shroud. It keeps my head temps within 10 degrees of each other. I also made my own sled tins to direct the hot air rearward like factory VW. This keeps the air circulating properly, instead of forming a heat loop under the clamshell. I never had a problem underway, say above 25, but always in the summer in stop-and-go traffic was the problem.

I have a plan to make my 911 shroud have flaps and a thermostat. Next time the motor is out I'll tackle it.

I did notice a 10 degree drop in CHT and oil temp after installing the sled tins, especially helpful in traffic on a hot day, where I used to watch the temps creep up. I also believe the sled tins give me a little back pressure which also helped even the temps across the cylinders. The sled tins, vanes, and careful attention to sealing the shroud all help a little.

Jimmy V. posted:

Sorry to say all the above words of wisdom are true. The Bergman fan shroud looks good but is a serial killer in disguise. This shroud has possibly killed more engines than we know. Get away from this setup soon as possible if you care about your engine and wallet. You are hearing from others that have been there and done that for you.

 I think the best fan shroud is the stock shroud with all the air directing vanes in tact and working thermostats hooked to working flaps. The Raby DTM shroud is supposed to be better than this but still might be unobtanium. I had an engine built for my Speedster with the DTM setup but sold it to go Suby power before I tried it. The guy I sold it to in Canada to use in his Beck Spyder seems to be happy with it.

I've run a DTM since Jake made them available. I've got 2, and will likely buy another. I've also got the standard 36 hp shroud everybody uses, modified with the flaps (and thermostat) and a Type 4 oil cooler. I hope to build some sled tin for one of the DTMs, as I think there's some value there. Jake doesn't sell these any more (indeed, he doesn't sell much of anything retail anymore), but LN Enterprises picked up distribution of the DTMs, along with the Type 4 Store. Almost nobody wants to pay $600 for a flimsy chunk of fiberglass, so nobody talks about them, but they work very well-- better than the stock VW stuff in the testing Raby did back in the day.

Everybody always brags on the stock stuff, and it's fine-- but dressing an engine with ALL of the tin and whatnots is like putting together an erector set, and it's pretty silly unless you are driving your car in the winter. I know Gene Berg said my engine would only last half as long without the thermostat, but Gene expected these to be daily drivers, and most of us just don't use them that way.

I got the DTM recently and am waiting until I pull my engine to install it. However, I have tried fitting it on a couple of long blocks we recently completed. The DTM doesn't just slide right on. It is going to require some modifications just to get it to sit down in the cylinder tin on both sides. I guess that s normal. I've got more than $700 in this thing after shipping. I expected it to slip right on. I still have high hopes though I don't have high engine temps now so I don't know what I'm trying to improve. I hope I haven't shot myself in the foot.

^ It's called madness, Paul.^

The DTM and 911 shrouds all require fettling. They can fit a small stocker with a 66mm stroke all the way up to a 2.3 liter plus. That's 20mm in stroke difference.

I had to drill the holes to screw mine to the heads, cut the plug holes, trim around my welded intake manifolds, trim around the alternator mount base and trim around the case and cylinders. And don't forget to drill the holes for the fan ring, plus seal all air escape paths. I used foam tape and clear silicone sealer.

I don't think one part on my car bolted straight on.

"I don't think one part on my car bolted straight on."

Wait...  

I thought you have a Vintage!  

Are you sure that's not a CMC?????

  
    

Well, Greg sent me his new CNC aluminum windshield supports. You know the ones that go through the body on the windshield ends? They bolted right up.......and replaced my old steel/pitted chrome pieces.

I had the windshield off to put the Beck top catches on.....

The DTM that I had was a nightmare to fit up. But in the end it turned out very nice. My engine was a fairly wide setup being at 2387cc. The DTM setup I had wasn't setup with thermostat flaps.

 I am glad I don't have to worry about engine temps any longer, I am happy with my Suby power. I had an opportunity to get my Speedster out yesterday as it was 72 degree and sunny here in Southern Indiana, a near record for Feb. 3rd. I love how my Suby motor winds on out to 6k, tight as can be. The work Special Edition did to convert my car is in my opinion near perfect. The car is fast and pulls hard, and has good balance.  The A-1 built exhaust puts out an exotic car like note, it sounds nothing like a stock Subaru Impreza, and not a person is going to say "oh that car sounds like a Subaru" as I go by. Before the Suby conversion, I had many say" oh your car sounds like an old VW beetle, is it a karman Ghia,?"  I would have to say " no but it is a shortened VW Beetle". I  had my expectation's far exceeded with the work Cary and his crew did on my Fiberfab Speedster. It is a true driver that is ready and willing to go anytime I turn the key. One of the best car decisions I have ever made.

Those last two pictures show exactly how the DTM fit on neat stock width engines. These were just test fittings. I'm Iot ready to pull my engine but I was surprised to see how the DTM wouldn't sit down on both heads at the same time. I'm using B pistons and short rods on my engines to keep the overall width almost stock. I tried the DTM on a 2276 drag car engine and it fit, or didn't fit the same way.

Haven't read good things on that system. Stock or DTM from Jake Raby are the most efficient systems I know of.