fabbed up cooling shroud [Archive]

CLKWRK

March 30th 2005, 20:54

Hi all,

last year i fabbed up a shroud for my 911 fan, here are some pics for everyone to review any suggestions or constructive criticizm are welcome.

basically i made it bolt in as a replacement for a type 1 shoud, I am not running an oil cooler in the stock location, it is at the front of the car since i am running a dry sump system. The engine is apart now, but i intend to run the stock warm up flaps and thermostat.

Bry

zen

March 30th 2005, 21:42

will you be running dual CHT or something to judge the performance of the shroud? i am far from an expert, but looking at how Porsche handled the air coming off the front of the fan, i suspect you will see some issues. you have a vertical divider which i would think will starve the right side since the air wants to work around in a clockwise motion. Porsche used a cone on the front side of the fan, to keep the air swirling i assume. i would think you need to move that divider further away from the fan.

just my amateur 2 cents. i'm sure there will be some more accurate assessments coming. considering the amount of air flow study Jake has done over the past year with the T1 DTM and the 911 shroud testing, he could probably add some valuable input as well.

Sandeep

March 31st 2005, 09:58

Bry,

I always wondered how you made that 911 fan fit the T1 cylinder tin :D

I have a datalogger that I built that could be used to monitor the temps, but you'll have to supply the TC's, could discuss at the April meet.

I have taken a closer look at the inside of an original 911 shroud from the -6, a 2.4L if I remember correctly. There is a cone-shaped diverter bolted to the back of the fan with 2 vanes, but the vanes on that diverter direct the air into a heat exchanger from what I could tell. The vanes point directly at a tube that connects to the shroud.

How did your engine run with it last year ?

I'll be fiddling with my 911 shroud this summer as well .. no cooling issues to report yet ! It will be fun to play around with diverters and such as all testing I have read about the 911 shrouds for VW engines has been using the shroud in its raw, unmodified form.

I bought one of those cheap fog machines at Walmart for Hallow'een ... would be cool to make a clear mold of that shroud and fill it with fog while the engine is running to see how the air flows.

Good Job.

Sandeep

CLKWRK

March 31st 2005, 10:55

Hi,

Yes i did run it last year, but with only one TC on #3, i will be adding another one on #2 this year. head temps were kinda hot, but i suspect thats cause im running superflo 1's on the street... they only have 5 fins!
I was gertting an average head temp of 225cel on #3 spark plug, I am thinking of adding 911 style oil squirters under the pistons to keep the temp down.
Also, hot air from under the car has been "leaking" into my engine bay from an oil cooler that i had above the tranny, that problem will be fixed this year.
All oil cooling will be done at the front of the car from now on (just like petes car )

Bry

Bad bug

April 1st 2005, 08:13

Hi Guy's,
I would really like someone to really produce a working shroud for this fan. I also have a 911 setup for my t4, its a Fat Performance shroud. I bought the engine just last december and haven't done anything to it as yet. Sandeep interesting point their my fan has a cone shaped divider on the back but i have noticed where it directs air down to number four piston and sleeve.

NO_H2O

April 1st 2005, 08:58

Hi,

Yes i did run it last year, but with only one TC on #3, i will be adding another one on #2 this year. head temps were kinda hot, but i suspect thats cause im running superflo 1's on the street... they only have 5 fins!
I was gertting an average head temp of 225cel on #3 spark plug, I am thinking of adding 911 style oil squirters under the pistons to keep the temp down.
Bry
I'm running Street Eliminator heads on my 2275(same # of fins) 9.8 to 1 C/R and read CHT on 1 & 3. Using a Type-1 DTM my heads are within 15- 20 deg. F while running down the interstate and range 310 to 340 deg. F. depending on the grade (up or down hill). That style head can be cooled. I know lots of people would like to see a 911 fan shroud developed to run as well on a flat 4. Stay with it,,,, you just might come up with a shroud that works. Then sell the hell out of it.

Sandeep

April 1st 2005, 10:34

I also have a 911 setup for my t4, its a Fat Performance shroud. I bought the engine just last december and haven't done anything to it as yet. Sandeep interesting point their my fan has a cone shaped divider on the back but i have noticed where it directs air down to number four piston and sleeve.

Can you tell me if that diverter will fit inside that shroud, as its the same shroud I have. My idea was to make some sort of cone to bolt to the back of the alternator, and then play around with fin locations on the cone, like what the stock cone fins look like.

The airflow off the back of the fan spins clockwise, and Porsche was able to almost redirect the air 90 degrees so it would enter that duct on the original 911-6 shroud.

So it can be done ..... My datalogger tells me I don't have any cooling problems right now, but I also am running a fairly stock engine.

Time to play ! Bryan .. I am with you on this, should be a cool project.

Sandeep

CLKWRK

April 1st 2005, 10:56

heya,

Im not trying to sell anything, actually it would be cheaper to go buy a DTM, I might just do that. I've been quietly watching Jakes work from the sidelines, maybe I should man up and take advantage of his diligent research.
I could sell my old 911 set up for what it would cost me to buy one. Hey, as long as it cools my engine, I just wanna boost the hell out of it at this point ;)

Bry

zen

April 1st 2005, 13:25

kind of the same logic i when through. i sold my FAT shroud and fan assembly and bought the DTM for the same price as selling those used (had even more into them). my head temps dropped 75-100 degrees each side and went from up to a 50 degree difference per side with the FAT shroud to at most a 25 degree difference per side with the DTM and most often dead on. running normal i am 225 each side. under heavy load i have yet to get them over 250. that's with a 2316 at 9.7:1 with 2.0l heads running 93 octane (best we have here).

that said, i love the looks of the 911 shroud more. i just decided i like my engine staying cool and living longer more. Jake is the only one i know that has put the time into testing that many shrouds, is willing to share all of his findings publically and i know for a fact that i can trust him and his information. that lead me to the decision i made. i know he has spent some time looking at impoving 911 shrouds, but was not able to complete the study with any meaningful results.

i'm sure there are ways to improve it. i personally would love to see that happen. just love the look and the sound. it all comes down to what is your acceptable level of cooling. they all cool.

keep at it Bry (and Sandeep)...even if you go with a DTM or other 911 shroud.

Bad bug

April 1st 2005, 13:38

Sandeep

April 1st 2005, 17:33

Sandeep,
The diverter fit's inside the shroud perfectly. I will try and get a Digital Camera to take some pictures. Their is a fin fitted to the cone. This cone then diverts air ( assuming 90*) onto #4 cylinder. I should note that the cone is offset to the side in the direction of number four cylinder.

Awesome .. thats good to know. I don't need the pics as I have seen the actual cone and can get one fairly cheaply locally.

I'm sticking with the FAT system because I love the way it looks and there is a documented (http://www.volksport.net/zensrat2316dynorun.htm) 6 hp loss from the fan with stock 2.0 heads, 94mm T4 cylinders and T1 under cylinder tin filling the shroud. With Nickies or other heads, the restriction could be more (Nickies have more fins/cylinder leading to a greater restriction under the shroud, less room for air to escape)

If my $#%^& AN fittings ever get here, I'll have the bug on the road ... its +15 C here and my car is still on jackstands :bawling:

Sandeep

zen

April 1st 2005, 18:33

Sandeep, i only saw a 6 hp loss during our runs at Jake's with that setup as well. it was 191hp with the belt off (open header) and 185hp with it on (open header). the latter is what you see on the chart posted in my image gallery on the VKG site (http://www.volksport.net). 176hp with belt on and dual BAS mufflers.

zen

April 1st 2005, 18:36

lol. guess is should have checked your link first, huh? that would be the chart. note though that those are 96mm jugs. heads are 44x38, as info.

Bad bug

April 2nd 2005, 15:22

Awesome .. thats good to know. I don't need the pics as I have seen the actual cone and can get one fairly cheaply locally.

I'm sticking with the FAT system because I love the way it looks and there is a documented (http://www.volksport.net/zensrat2316dynorun.htm) 6 hp loss from the fan with stock 2.0 heads, 94mm T4 cylinders and T1 under cylinder tin filling the shroud. With Nickies or other heads, the restriction could be more (Nickies have more fins/cylinder leading to a greater restriction under the shroud, less room for air to escape)

If my $#%^& AN fittings ever get here, I'll have the bug on the road ... its +15 C here and my car is still on jackstands :bawling:

Sandeep
Thank god their are some data on the performance of the shroud ( only 6 hp loss ). Now on with the rest of the research. I am sure this shroud can be made to work. Sandeep what's the size of the alternater pully and flywheel pully. Can you post a photo of the porsche cone and diverter.

Sandeep

April 2nd 2005, 15:40

lol. guess is should have checked your link first, huh? that would be the chart. note though that those are 96mm jugs. heads are 44x38, as info.

:D I mean that the physical exterior of the cylinders and physical exterior of the heads ... those are the only surfaces restricting the airflow.

Sandeep

effvee

April 17th 2005, 00:24

Hi, looks good. Since you don't have the engine in, can you mount it to a bare block and use a electric motor to turn the fan? With a electric motor driving the fan ,tape one on each side of very large trash bags and start the motor. See wich side fills first, most likely it will be the right side. Then you can talor your vanes. With the stopwatch and the same size air collector (trash bags) you can continue your R&D, you are on the right track and it can be done on a engine stand. Good ideal :agree:

Wally

April 17th 2005, 15:19

Can you post a photo of the porsche cone and diverter.
I made a pic of the cone recently and will post it in one week from now when the flm is developed. I modified the cone somewhat and hope to post some results on that as well.
Cool developments we all got going :)

Massive Type IV

April 21st 2005, 17:50

I would really like someone to really produce a working shroud for this fan

Look for that one to come from right here in late 2006 or early 2007....

But I won't be working on one for a Type I engine, only Type IV.

My preliminary design includes the use of the OEM 911 diverter as well as added airfoils and directional vanes to get the air where it belongs.

Sandeep, While there is a documented 6HP loss from the Porsche set up, there is also a documented 23HP loss on the same dyno, with the same heads and cylinders and same drive ratio as the 6HP loss. Six HP is the absolute least i have ever seen with any 911 system- ever. Most are 15-18 or more.

At dyno day I made 187 HP with the belt on with my 3 liter DTM cooled engine, when the belt was popped that went to 195HP- do the math and atleast 4 members of this forum witnessed the numbers. My DTM is driven just like any other, the stock TI drive ratio @ 1.58:1

Making a 911 system that cools all 4 cylinders equally and doesn't rob HP is possibly going to be the biggest challenge I have ever taken on yet. I really doubt I can beat the DTM, but from what I have seen if I even get it to cool evenly they will sell like a maniac just because of that damn look.

Any system I work with will be set up to ustilize genuine Porsche alternator ring, fan and etc.

Scotts73SB

April 21st 2005, 22:42

Make a DTM with a fake 911 front :D

BOBTAIL

April 22nd 2005, 08:12

The simple solution is make more power.

I really have a problem with accepting that a T1 fan is the best solution.
If it were that good then Porsche would be using it too.

A 911 fan has the cooling capacity to cool an engine with over 400bhp at the crank.Russ has been using his car for over 10 years with a 911 cooling system and obviously he's not the only one.

Also worthy of note Russ uses a 5 blade fan for racing and the 11 blade for road use as the 5 wont cool the motor properly.Also the T4 heads seem to poorly manage the heat once you get in the 200bhp range the underside of the head seems to hold the heat in and distort the sealing surface.
The 911 heads definately manage heat much better.

My 2 cent fwiw

Paul

Sandeep

April 22nd 2005, 09:29

Sandeep, While there is a documented 6HP loss from the Porsche set up, there is also a documented 23HP loss on the same dyno, with the same heads and cylinders and same drive ratio as the 6HP loss. Six HP is the absolute least i have ever seen with any 911 system- ever. Most are 15-18 or more..

Is this with the same shroud as well ? Interesting ... any idea why ? I would think that HP loss has to do with the fan trying to compress the air in the shroud as the shroud can't get rid of it quickly enough (too much restriction from cylinder and heads + tin).

Look for that one to come from right here in late 2006 or early 2007.....

Cool ... If you can get one to cool evenly, even if it does not beat the DTM, you will have alot of buyers .. me included. :agree:

I blew out a CV joint this week, have the parts to fix it, datalogger is installed ... looking forward to seeing some graphs. I'd be happy to share them.

I really have a problem with accepting that a T1 fan is the best solution. If it were that good then Porsche would be using it too..

I believe the reason the T1 fan works on a T4 is because there are only 4 cylinders to cool, and the output of the T1 fan can be routed between the 4 cylinders like on a stock T1.

I'm thinking in the early days of the T4 upright conversion, someone found out that the 911 fan was easy to adapt to a T4 for upright cooling, and designed a shroud just to get the engine in the bug and that was the main reason, not even cooling.

With all of the tuners offering the 911 shroud, each seems to be a variation of that original theme, but trying to take cooling into account.

Sandeep

Bad bug

April 23rd 2005, 15:10

This is what i am talking about, finally a 911 shroud that will work. Can someone post pictures of a diverter i want to check if i have the correct item.

Massive Type IV

April 26th 2005, 15:01

If it were that good then Porsche would be using it too.

Nope, the 911 engine was designed for an Axial fan- Thats why it works well on a 911 but not a TIV..

BTW- It IS that good, ask Zen or email nosubt2@aol.com and ask him what his race engine (F prod 1800 TIV) did after removing the 911 shroud and opting for a DTM..

The DTM works well enough to keep my 3 liter cooler than a stock 2 liter and thats with 10:1 CR....

The dyno says it works and the satisfied users back it up.

BOBTAIL

April 27th 2005, 07:17

I'm thinking evolution here, the 356 had a bug style fan and the cammer had a different style ...why?

The Gol had an axial fan, at the end of play its about air flow and pressure.

Ah I don't know why I'm posting this who am I trying to convince?

BTW I think you'll find the cooling was designed for the engine, not vice versa.

Wally

April 27th 2005, 09:03

I'm thinking evolution here, ...
True, the later a new engine type is designed, the more one would presume its a better design than its predecessor.

However, the engineers had a lot of constraints they had to stay within. One obvious one that comes to mind (especially regarding fans and besides build-cost) could be the available 'space' on top, in front or whatever side of the engine.

So, the best technical solution, is not always what has been produced... :rolleyes:

Greets,
Walter

Edit: The mail just brought a 993 head by today :) Nice design. I believe it has a 49mm intake valve and a 41mm intake port stock for a 100 mm bore :eek:

Massive Type IV

April 28th 2005, 01:19

The fan was designed for the engine and the engine designed to work with the fan as a unit...

Sit down and look closely at a 547/587, 616 engine and the 911... Then look at the TI and TIV and compare them all to each other. Compare the thickness of the fins on the cylinders and heads, their placement and even their length...

I think Russ's 911 shroud works fine for what he does because the engine is more closely related to the 911 than a TIV or any other radial fan equipped engine. I would like to get some data from all 4 cylinders of russ' engine to see how they compare to what I have seen with the TIV head based engines and even what I have seen with my billet heads and the DTM. It might help shed some light on why some things occur.

VW didn't spend the huge money on equipping the engines with Aluminum cylinders and etc so they had to create a coling fan that had a ton of potential. This was way cheaper than putting more into the money into the engine internals that would generate less heat.... Thats my hypothesis on why that fan works so well on the TIV, the added surface area gets the heat into the cooling ai stream faster and the high pressure air is forced in ever nook and cranny to get that cooling air stream more powerful and effective.

In EVERY dyno test I ran my dyno cell ran hotter with DTM cooled engines than with any of the 911 systems, while the engines ran cooler... Proof that the air was being shed into the room at a much higher volume. These temps were as much as 30 degrees on the same day without variable weather between a DTM and two different 911 style shrouds...

Just an ironic thing that we noticed while plotting every damn temp we could!

Bad bug

April 29th 2005, 08:53

Hi Guy's
Can someone tell me if this is the original 911 turbo fan. The markings on it are 901 106 101 5r. Wally what ever happen to the photo of the diverter.

Wally

April 30th 2005, 03:58

Ha, its still on my camera... :rolleyes:
Be patient. I did some very rudimentary mods to it and in the shroud and also did some tests with those on the street. It will take some weeks maybe untill the film is full and gets developed and put on CD-rom...

Greetings,
Walter

Bad bug

May 1st 2005, 20:05

Jake will your 911 shroud be a bolton.

Massive Type IV

May 6th 2005, 13:55

No, it will require machine work to fit under the decklid.

oicdn

May 19th 2005, 23:13

You would think with the production of that shroud, R&D would have been done and they would have realized unequal cylinder cooling and adapt the vanes accordingly. Especially when adapting it to Beetle engines....

Just my noobie 2 cents, but wouldn't a + shaped vane placed closer to the fan blades, of course, sized to where the sizes of the "sqaures" are proportional to where the airflow comes be the optimal wy to divert cooling? Vanes closer to the blades prevents any turbulent "void" for the air to be in....couldn't that atleast help the cooling characteristics?

I remember in high school physics class I had a project of explaning why a ceiling fan, doesn't output the same amount of air in all 360 degrees when it's drawing the same amount of air in all directions. It output more air in certain areas. I can't remember why, but couldn't you just produce the vanes according to that fans' optimal air output areas?

I have no idea if that sounds jumbled...I'm on a Starbucks caffiene buzz....work sucks.

Wally

May 20th 2005, 09:26

.Also the T4 heads seem to poorly manage the heat once you get in the 200bhp range the underside of the head seems to hold the heat in and distort the sealing surface.
My 2 cent fwiw

Paul
I just reread this and I think you have a point: Why else would Klaus make an eleborate 'under-side-cooling' ducting for his cooling shroud system and why would Remmele adapt the existing Lackstätter design (basicly the engine plus heads) by adding huge amounts of fins underneath the heads?

FWIW, I never understood the 5th-stud design where they only make an extra head stud at the top of the head stud pattern instead of underneath...
especially, as the bottom row of studs are not only longer, but also have an extra 4mm of stud spacing! Obviously, if there is a problem, it lies at the bottom of the heads...Because of the aformentioned 2 issues, the exhaust ports being at the bottom may not even matter that much (hence the Remmele design where the exhaust ports are at the sides and he still gave it extra fins at the bottom).

Paul , you get your 2 cents returned :D

SuperRSi

May 21st 2005, 00:49

I think even Porsche got headaches thinking about it. They just went water cooled and don't worry about cooling anymore. Uh, Oh. Sorry could not help it...

Randy

BOBTAIL

May 21st 2005, 03:43

The fan was designed for the engine and the engine designed to work with the fan as a unit...

I think Russ's 911 shroud works fine for what he does because the engine is more closely related to the 911 than a TIV or any other radial fan equipped engine. I would like to get some data from all 4 cylinders of russ' engine to see how they compare to what I have seen with the TIV head based engines and even what I have seen with my billet heads and the DTM. It might help shed some light on why some things occur.

Worth noting that Russ has used the same cooling setup from 100 hp all the way to 400+ and always using the stock undercyl shrouds
In 10 years of racing i think he still is using the same crank and rods (we keep telling him to push the boat out and treat himself to some new stuff!!)
Its true he's had less sealing issues now he's got 911 heads on but it could be for more than 1 reason i.e better sealing technique, better air managment of 911 heads etc