fabbed up cooling shroud

[CLKWRK]

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]

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]

Bry,

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

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]

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]

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]

Originally Posted by CLKWRK

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]

Originally Posted by Bad bug

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]

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]

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]

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.

[Sandeep]

Originally Posted by Bad bug

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 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

Sandeep

[zen]

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. 176hp with belt on and dual BAS mufflers.

[zen]

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]

Originally Posted by Sandeep

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 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

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]

Originally Posted by zen

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.

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

Sandeep