 -4 Fan Housing Modifications, Sharing pictures of what I did |
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| URY914 |
 Apr 7 2004, 07:50 PM
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#1
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I built the lightest 914 in the history of mankind.  Group: Members Posts: 120,614 Joined: 3-February 03 From: Jacksonville, FL Member No.: 222 Region Association: None  |
The thread earlier today about removing blades from the fan reminded me that I hadn't posted pics of my worked over fan housing. Instead of just blocking off the two outlets that run to the heater boxes, I went the next step.
I took some 1/8" aluminum sheet and cut out covers or plugs to cover the outlets on the INSIDE. (IMG:style_emoticons/default/wink.gif) I was able to shape (cut, file, grind, bend) the aluminum to fit tight in the opening. Than I used KB Weld (hey, it is still holding after 2 years) to bond the pieces in place. Than I used bondo (like I said, it's still in place) to fill and shape it up real pretty. I also sanded the whole thing and filled some holes to clean up the air flow. It has to be an improvement over the stock set-up. Simple and cheap too. Paul Attached thumbnail(s) 
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| lmcchesney |
Apr 7 2004, 07:59 PM
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#2
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Member Group: Members Posts: 488 Joined: 24-November 03 From: Ocala, Fl. Member No.: 1,381 Region Association: None |
Paul,
I do not see the changes you describe in your picture. Could you mark the image? If you obstruct the outlets, does that not prevent heat to the cabin? And if it does, can you not make it a seasonable alteration? I have heard previously about removing teeth from the fan blade to imporve function, would you describe which teeth, how many, resulting balance of the fan blade and imporved flow? Jake has worked extensively with the design of the DTM system. Even with his best drawing table design, when tested on the bench, the flow was not better. I don't guess there is data for your design or is there? Not being snooty, just interested. Thanks, L. McChesney |
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| URY914 |
Apr 7 2004, 08:39 PM
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#3
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I built the lightest 914 in the history of mankind. Group: Members Posts: 120,614 Joined: 3-February 03 From: Jacksonville, FL Member No.: 222 Region Association: None |
Here it is again with the arrows to the pieces I added. This indeed prevents heat to the cabin and no it not a seasonal change. This is for good.
See the post below by synthesisdy for the details on the fan blade removeal Attached thumbnail(s) 
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| Jake Raby |
Apr 7 2004, 08:49 PM
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#4
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
Ury,
do you use an alternator on you race car?? if not I could have saved you alot of work, and it bolts on! work looks good! |
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| Mueller |
Apr 7 2004, 08:55 PM
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#5
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914 Freak! Group: Members Posts: 17,146 Joined: 4-January 03 From: Antioch, CA Member No.: 87 Region Association: None 
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Hey Jake, are you going to tease us or what????? (IMG:style_emoticons/default/smile.gif)
what to do you have for those NOT running an alt.???? |
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| URY914 |
Apr 7 2004, 08:57 PM
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#6
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I built the lightest 914 in the history of mankind. Group: Members Posts: 120,614 Joined: 3-February 03 From: Jacksonville, FL Member No.: 222 Region Association: None |
Jake,
No alt on my car-too heavy (IMG:style_emoticons/default/laugh.gif) When I rebuild the engine I'm thinking of doing a housing in fiberglass. I don't think it will be that much work. Paul |
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| Jake Raby |
Apr 7 2004, 09:58 PM
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#7
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
Use a shroud from a 1980-83 Vanagon! No heater outlets and they bolt right on. The have a smaller plenum area on the left bank and I have seen drastic differences in 3-4 cylinder temps when using one. The smaller plenum gives a higher pressure on that bank and allows the air to follow its path better. I found that plenum size was the key to effectively creating pressure to move air where it needs to be. Until you get 9PSI of air pressure or 6" or so of water the air cannot be routed effectively, or at all... That was the key to my Type I shroud!
The 80-83 vanagon had no heater outlets as the special alternator had a weird fan on it that provided the extra air for the heater helper system..... Thats why you cannot run an alternator easily with this set up... I have rigged a chevy alternator to one on a weird occasion and it worked fine.... Now here is one for ya..... On my 914 I run with the fan shroud openings wide open.... not blocked off... It ran cooler that way by 15-25 degrees on #3, I'll explain why tomorrow- I'm beat tonite. |
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| URY914 |
Apr 8 2004, 07:16 AM
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#8
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I built the lightest 914 in the history of mankind. Group: Members Posts: 120,614 Joined: 3-February 03 From: Jacksonville, FL Member No.: 222 Region Association: None |
Jake,
I was thinking that when I make an f-glass housing, I'd make it smaller to increase the speed of the air over the heads. Less volume but more volescity (sp). Is my thinking correct? Paul |
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