Porsche Style Fan Shroud

I love the look of the Porsche style fan shroud. Does anyone know much about it?

Does it cool as effectively as the standard shroud (I have an external fan cooler).

I have a 1915, do they fit without modification?

Who sells them?

Are there other considerations?

Thanks for any input!

Cole, there seems to be many discussions to the validity of the 911 shroud's cooling capacity. A recent thread, "For Those of You Using a 911 Shroud" was just up for the past few weeks along with others if you do a search. I'm about to be up and running (any day now...) with one.
Mine came from Sharpbuilt in Australia (http://www.sharpbuilt.com.au/sharpbuilt1/home.htm). While it does have a nice look, it will definitely need a hole cut into your rear deck inner liner in order for it to fit. Though the general consensus is that the Raby DTM shroud is the most efficient based on his testing.

above link would not work for me...

http://www.sharpbuilt.com.au/

Cole, way back in 2003 I went this route (Bernie Bergman 911 styled shroud) and the second time around, after the big fire, I went with a stock shroud on my 2276.
Go with a stock or a Jake Raby shroud.

Looking at other posts on other sites, it seems like a stock shroud is the way to go. I don't know much about the Raby shroud.

My motivation to go with the Porsche shroud was purely looks. If it is a pain, or less effective then I'm not interested.

The Raby shroud improves cooling, right? As far as I know, I'm not running too hot.

Yes, the DTM improves cooling; but does any one know if there is any sort of thermostat/flaps arrangement?

not that i am aware of. i have the V2 and it has internal veins, but no thermostat

When I had my new engine built the only reason I didn't go with a Raby shroud was it can't be used with heater boxes.

Looking at other posts on other sites, it seems like a stock shroud is the way to go. I don't know much about the Raby shroud.

My motivation to go with the Porsche shroud was purely looks. If it is a pain, or less effective then I'm not interested.

The Raby shroud improves cooling, right? As far as I know, I'm not running too hot.

If you have heater boxes you can't use a Raby shroud (unless you ditch the boxes).

Easy fix for the Raby Type IV is an Espar gas heater. Great combo.

"My motivation to go with the Porsche shroud was purely looks"

Classic.

Jack, send a picture of yonder heater, please. I sent my BN-4 unit to somebody else; too beaucoup for the car, GI.

Jake, you gotta admit they're neat-looking. It's a shame they're not good-to-go out of the box -- but they are fun to look at. ;)

I develop nothing for appearance.. We take pride in developing technology and not aesthetics and always have. All that matters to me is what works, lasts and performs.
If I want to see a 911 fan I look under the decklid of my 88 Carrera, thats the only place it was developed to be applied IMHO.

Looks kill on a routine basis, two cases of that was reported to us last week.
Aesthetics might matter to some, but I am super glad that those who come our direction aren't persuaded by them.

BTW I have an Espar heater in my double cab with a 2.8 liter 220HP TIV engine and I drove it all winter comfortably. Flip a switch and it just works, no warm up time, no chances of exhaust gas recirculation and you can fire it up 20 minutes before you leave in the morning for an instantly warm vehicle. I drive my aircooled cars daily in all weather conditions and the Espar pays for its self very quickly in many different ways.

I have your DTM on my 2.4, Jake. It hasn't let me down yet. :)

for looks...unbelievable someone would say/admit that. At first glance they do look cool. To the untrained. Once you realize how ridiculous they are on a Type 1 the shrouds lose all appeal

The DTM FTW. Engineered. Keeps ALL the holes cool. That's all you have to know. Worth every penny if you want your ACVW to run to it's full potential and last. Just my honest opinion

Are you guys serious! People build cars and engines to look cool all the time, anyone ever seen a concept car or a V8 with multiple Webers or some outrageous setup (4 v8's in one car) that was only built to see if it could be!.

I understand Jake's and the other guys point and its very valid but the Porsche fan shroud does look cool and it works, maybe not as well as others but these guys aren't running in Le Mans!

Beauty is in the eye of the beholder, some mechanical,some visual, some both.

Lighten up Frances!

Lots of cars are built for looks only. Lots of cars live on trailers, run on 3 cylinders and are good at nothing thats practical.

Exactly Jake, can you imagine if everything built was for performance alone, they'd look like the Nissan/Toyota/Mitsubishi/Ford Capri/Chevy Malibu multi-mobiles we have now.

Nothing wrong with them, they run great and look OK but don't have the style of the older cars or fun factor of custom cars.

The Chrysler Turbine, Porsche 356,Ferrari GT 250,Rat rods,Volvo P1800,Hemi Belvedere or Valiants,Big Block Mustangs,MGA,
Triumph,Fiat,Alfa,Sunbeam Alpine or Tiger,Chevy Impala Tri-Powers,
BMW 2002.

Many of which were overheating,underpowered or problematic but look really cool and fun to drive.

All those cars you listed came from the factory with glitches. I owned 3 that you mentioned. Of note the BMW 2002..and it came with a wimpy radiator. It would run HOT. To fix it I didn't put a smaller radiator on it though..NOPE I upgraded to a 320i radiator with more rows.

Personally i don't think the faux 911 shrouds look all that cool. It's like fake boobs. Look great from afar..then up close it's a big let down...and they don't jigglelllll.(Dont get me wrong Ill take a fake boob over a fake shroud any day but...)

Bottom line both the shroud and boobs are weak copies..imho


AND why in heavens name would someone want to sacrifice engine cooling in an air cooled motor for cool looks.

Everyone knows the majority of those 911 style shrouds don't cool evenly. It's crazy that someone would pay that kind of $$ for sh*tty cooling.

I'm with Jake on this one for sure. Function first. Many will probably laugh at my rad scoop if they see it at Carlisle. It's ugly as is but is really a prototype at this point as it's never been tested in hot weather as we've have none in Canada over the winter season. On the other hand I think it will work with the front mounted Saab rad mounted up front horizontally. We'll have to see this coming Wednesday on my way to Key West from Ottawa en route to Carlisle.

"Everyone knows the majority of those 911 style shrouds don't cool evenly. It's crazy that someone would pay that kind of $$ for sh*tty cooling"

Because:
-They don't know
-They don't care
-The car won't be driven 5,000 miles in 25 years time
-They are only concerned with the wow factor and what other people think about their car.

This is why I no longer attend events or share detailed technical information online.

Lol! Barne I see you have learned the secret of editing a post, very good grasshopper.

I do understand your point, and its a good one, serious performance is serious business.

But, there are 1000's? of those shrouds out there being enjoyed in looks and performance by their owners too.
Any one interested should check it out and make their own decision based on performance or looks.
By the way I dont know of any 1835,1904,1915,2054,2110,2180 or 2275 FACTORY engines coming in FACTORY 356 Replicas.

All in good natured fun Barne!


I do really appreciate your and Jake's posts. :-)

BTW- I get a ton of questions from guys wanting to debate their 911 shroud with the DTM. I don't even engage in those bits of dialogue with words that try to convince them to change their shroud or what they believe in.

This evening has sparked two of those emails and since both people mention a Speedster replica as their vehicle I can only guess that they are reading this thread. None of it matters to me, so do what you want to do and believe what you want to believe because its your car. Do your own homework and come to your own substantiated conclusions. I won't recommend anything.

From what I understand Jake I understand you've exhaausted yourself on this subject in the lab and online, rest assured those who care enough to do the research will find the right shroud for them whatever anyone says or thinks.

Reading your posts and website and other many,many posts the proof in in the pudding. Not many are as driven to find out what works. Hats off.

Thank you.
I will warn that next year marks a decade since I finished my cooling system studies and unfortunately most of the data is no longer accurate enough for current consumption.

Lots has changed in this decade to include fuels, lubricants cylinder head castings and crankcases. The market has changed so much that I am not driven to revalidate the offerings, especially since I no longer build T1 engines and don't have a single T1 engine on the property.

I am working to pull down most of my writings in the subject because the only thing worse than no information is inaccurate information. I'd hate to misinform anyone and will do my best to delete any information that's not up to date in its entirety.

"Lots has changed in this decade to include fuels, lubricants cylinder head castings and crankcases."
I agree, and it sounds like you've taken the T1 as far as you want to take it. I look forward to seeing upcoming endeavors. I'm sure your not done yet.
I didnt think T1's would go on for very long 20 years ago and I was wrong. One can't forget about the nostalgia factor and the fact it's a good little powerplant for what it is. Look at the guys who are into flatheads.

The ever changing quality of components is less than desirable for us.. On to more modern engines while continuing to offer our Type 4 engine offerings in standard forms. Even that has become a challenge in regard to quality component supply.

I was never really a leader in the Type 1 world; they were too generic to ever captivate my attention.

Well the Suby engines are exciting and offer more in a lot of different departments. Talk about a sexy and unique looking motor! Tho some will always like the aircooled engines.
It looks like the Speedster replica guys are definitely on board with them and the inline engines, more factory hp and sturdier platforms to build on.
As long as the transmissions/transaxles are able to keep up and the gearing works well as the whole package has to be in sync.

I know it's blasphemy to some..but real soon I'm moving on to Subie power (in a Speedster of course). An SAS is def' in my somewhat near future. I love this IM I just got. I'm gonna have tons of fun driving it for the next year or so.

Once I heard about SAS and all their Subie powered shenanigans I knew my IM's days were numbered

Till' that happens I'll treat it like gold and that includes cooling it the best I can

Subaru boxer. I've always loved them. Low center of gravity.. and the sound...ahhh. Nothing like unequal length headers and that funky burble

Jake and Barne; so I'm some sort of superficial chump because I like the looks of the Porsche style shroud, and apparently all the more superficial for admitting it? You know that's why I purchased the 356 replica, for the looks! I'm not ashamed of that.

This the first time I've experience such a "holier than thou" attitude here. Fortunately I'm not intimidated by such attitudes, but, it will make me look for a friendlier place to learn.

Sayounara!

Hey Cole,

This is a big tent SOC has erected on this site. There's room for everyone, but, as you now know, the crowd can sometimes be a tough one. Don't give up. It's kind of like real life, eh? Some folks you like, some you ignore. Stick around, man! There's a lot of knowledge in between the jabs and left hooks.

Like I said, it's you car and do whatever you wish with it and own it for whatever reason you want. I agree that it's a replica and no speedster is very practical for daily use anyway.

Cole
You will notice that my tub also has a 911 shroud, and for the life of me I can't imagine why I did this other than it looks so focking cool....I could give a shit about what Jake and the rest think, I have been assured by my builder that I shouldn't have any problems and If I do, he gets it back to fix...
You do however need to have a thicker skin to hang with this crowd..

Cole,



Here is the problem with forums, it allows everyone with an opinion, good, bad, right or wrong, to voice it and put it out there for others to read. The bad part is that there are a ton of people that do not have a clue, or think they are the top dog, and sometimes even the big boys that are well respected to give an opinion on something and pass judgment saying a part is either good or bad.



So here is what I do, i read what people put out there, take an average, and make my own choice on what I have read.



This whole debate is like the type 4 verses type one motor debate. I've run both type of motors, and I can tell you I will never waist time and money building another type 4 motor. I could build two type one motors for the cost of building one type 4 motor. As for the fan shroud, I am currently running one ( a bernie bergman unit) I find it hard to believe that if none of these work worth the crap, why and how can they be selling so many of these. I'm using head temp sensors and pyrometers to see what (if anything) needs to be done to make it work properly. I have run many Porsches and fully understand how and why the original 911 fans work so well on a 6 cylinder engine. So after I complete testing and any mods (if needed) I will post my findings up here.


I've talked to guys first hand that have run the 911 shrouds in street and full blown off road cars, have been told they work great. So hang tough and let the head strong guys go on their way.

As you can see I like to make things look cool and function even better.....

Kevin "Coolrydes" Zagar

damn Kevin - you engine bay is lookin really, really good. i love the attention to detail.

Heres a link for help choosing you fan.
http://www.engineeringtoolbox.com/fan-types-d_142.html

The Porsche type fan is an axial fan.
The VW type and DTM fan is a centrifugal( radial ) fan.
I have seen the Bergman shroud. It's a big open cavity with no flow vanes to direct the air flow. So it working off positive air pressure to cool the cylinders.

Think of your home HVAC system. It uses a centrigul fan to push air through large ducts in long runs in your home. So its obvious which fan system is much more efficient.

Remember looks ain't everything ... it's the maximum cooling that counts.

Kevin - The engine compartment & engine looks great nice detail. One question - and I'm not picking on you . Are the speed holes around the compartments perimeter thru - holes( open to the opposite side) ? And are you going to seal off the area below the fan shroud in the engine compartment? If you don't you will draw hot air from the bottom of the car back into the engine / fan. So you will just recirculate hot air through the engine. Thats way the rear deck opening is so important to get the fresh air through the cooling fans.
The side ducts in my car force cooler air into my engine compartment which aids in the cooling. The the Webbers also like fresh air.

One of the biggest power hogs on an air cooled engine is the cooling fan. While it has been many years, and my memory has never been perfect, my recollection is the 911 style fan moves a lot more air than does a stock fan and shroud, or a DTM. The 911 style is nothing but a big open cavity and it is extremely inefficent in directing air. If it is doing an adaquate job of cooling it is doing so by moving a lot more air and in moving that air it is eating a lot of HP. Both a stock VW and a Raby DTM use a lot less HP, move a lot less air, but keep head temps in the right range by dividing air flow and carefully directing the flows to the 4 cylinders.

I have read that a stock fan may require as little as 5 hp to drive it at 6000 engine rpm. A 911 style fan will require several times that amount of HP, I have seen people claiming it will take 25 hp to push the 11 blade fan to 6000 rpm. (fan rpm will be more in the 10,000rpm range at 6 or 7000 crank rpm....)

I don't know how correct the HP numbers are, I liked the look of the 911 fan, I have had them on 2 cars, and have had 3 or 4 engines with stock style fans....that said, I am currently running a DTM. I would recommend the DTM, I will not buy another 911 fan setup, but that is just me.....others should do what they like and understand the implications of their choice, or maybe ignore it all and go for looks?