Engine shroud / fan housing on ‘83 SC

[REVerend]

After seeing pics of a number of other 911SCs I have come to suspect the engine shroud and fan housing on my car aren’t quite right. As far as I can tell it doesn’t have a significant negative impact on cooling, but it doesn’t seem quite right with the gap.



As far as I can tell the fan housing is correctly in place as is the engine shroud… but I’m not quite sure why they don’t fit together better.

There is a relatively minor crack in one vane of my fan housing which got me digging around old threads here and reading about the different depths of fan housings used on the later cars to accommodate the larger alternator. The casting number for my fan housing seems correct an ‘83 911 SC but I’m wondering if perhaps the engine shroud could have been replaced with a later version and was intended to accommodate a deeper fan housing?

Alternately maybe someone installed a larger alternator and (somehow?) shifted the fan housing rearward to accommodate it?



I’m really kinda grasping at straws here, but it’s the only thing I can think of. Of course for all I know there is some simple adjustment that I’m ignorant of.

Due to the vane crack I’m planning to replace the fan housing at some point in the future and would like it all to fit back together a bit more correctly.

If anyone has advice, experience, opinions or even just rumors about why I should pick a particular fan housing to replace it i’m interested to hear it. As far as I can tell the options are upgraded aluminum casting (either Porsche or some other brand) or billet aluminum from Rennline. Currently leaning toward the Rennline option as it’s already anodized which would save me from having to powder coat.

[Funracer]

I too have an 83SC with the same orange shroud you have. My shroud does not fit perfectly either, although it does look better than yours. I had my engine out a few years back and when I reassembled it all I tried to get the fan housing and shroud to fit better but was not really successful. I decided to pick my battles and just be ok with it.

Maybe its just a “late SC” thing.

[83_Silberpfeil]

Happen to come across JWolfe's '83 SC build thread just after I read your post. Take a look at his fotos from his build thread:

https://forums.pelicanparts.com/12458980-post67.html

There doesn't appear to be a gap, not visible in the fotos, at least.

Now, I'm curious and will also check my '83 SC. Report back later.

[MBAtarga]

This is my 83 from a handy picture already on this computer - I see no gap like that one above. I think your fan housing is not sitting flush/fully upright and instead is leaning forward (toward the rear of the car.)

[REVerend]

Originally Posted by MBAtarga

This is my 83 from a handy picture already on this computer - I see no gap like that one above. I think your fan housing is not sitting flush/fully upright and instead is leaning forward (toward the rear of the car.)

That’s an interesting idea… I’m not sure how it could be leaning with the way the fan housing sits on its “cradle”. But having said that I suppose it’s a possibility. The fan belt seems to be well aligned.

Not my pic, just one I found.

[Dpmulvan]

Originally Posted by REVerend

After seeing pics of a number of other 911SCs I have come to suspect the engine shroud and fan housing on my car aren’t quite right. As far as I can tell it doesn’t have a significant negative impact on cooling, but it doesn’t seem quite right with the gap.



As far as I can tell the fan housing is correctly in place as is the engine shroud… but I’m not quite sure why they don’t fit together better.

There is a relatively minor crack in one vane of my fan housing which got me digging around old threads here and reading about the different depths of fan housings used on the later cars to accommodate the larger alternator. The casting number for my fan housing seems correct an ‘83 911 SC but I’m wondering if perhaps the engine shroud could have been replaced with a later version and was intended to accommodate a deeper fan housing?

Alternately maybe someone installed a larger alternator and (somehow?) shifted the fan housing rearward to accommodate it?



I’m really kinda grasping at straws here, but it’s the only thing I can think of. Of course for all I know there is some simple adjustment that I’m ignorant of.

Due to the vane crack I’m planning to replace the fan housing at some point in the future and would like it all to fit back together a bit more correctly.

If anyone has advice, experience, opinions or even just rumors about why I should pick a particular fan housing to replace it i’m interested to hear it. As far as I can tell the options are upgraded aluminum casting (either Porsche or some other brand) or billet aluminum from Rennline. Currently leaning toward the Rennline option as it’s already anodized which would save me from having to powder coat.

That chart isn’t right. I have 2 sc’s here an 80 and an 81 both fan shrouds numbers.

[REVerend]

Originally Posted by Dpmulvan

That chart isn’t right. I have 2 sc’s here an 80 and an 81 both fan shrouds numbers.

Well that’s interesting… thanks

[83_Silberpfeil]

Another data point for you...

This is from my '83 SC Coupe. Same "shroud casting #" as yours: 930.106.102.0R
Shroud/FanHousing seem to be fitted pretty close, no gap.

[Funracer]

Here is mine. Kind of on the edge and doing the washer trick to grab the lip. Funny how there is no hole drilled through the shroud for that middle bolt hole.

[MBAtarga]

Originally Posted by Dpmulvan

That chart isn’t right. I have 2 sc’s here an 80 and an 81 both fan shrouds numbers.

Some of the castings are interchangeable. Fan diameter, shroud depth and alternator length are identical for several different casting numbers.

[Flat6pac]

The fan extension in not properly installed and the fin is against the shroud holding the fan housing from seating properly. Probably off 1 on the rotation of the extension.
Bruce

[REVerend]

Originally Posted by Flat6pac

The fan extension in not properly installed and the fin is against the shroud holding the fan housing from seating properly. Probably off 1 on the rotation of the extension.
Bruce

Thanks… I really appreciate it

[Funracer]

Which part is the fan extension?

[Dpmulvan]

Originally Posted by MBAtarga

Some of the castings are interchangeable. Fan diameter, shroud depth and alternator length are identical for several different casting numbers.

I understand I was just saying that chart was incorrect.

[Dpmulvan]

Originally Posted by Funracer

Which part is the fan extension?

The grey cone that goes on the back of the alternator.

[Dpmulvan]

Originally Posted by Flat6pac

The fan extension in not properly installed and the fin is against the shroud holding the fan housing from seating properly. Probably off 1 on the rotation of the extension.
Bruce

You get the prize!

[Flat6pac]

Taking the bow….

[REVerend]

Problem seems solved… the fan housing always seemed to be very firmly fixed in place but it turns out the bolt on the strap was quite loose. Barely took any effort to turn and out it comes.

A little wiggling it around and the whole fan housing slides right in and fits the way I think it should. It did give me a chance to look it all over and search for cracks. As mentioned previously there is what seems to be a minor crack on one of the vanes but that’s it. I will still replace it at some point but I’m now slightly less concerned that the whole thing is going to fall apart in the next few months.

Although I have had the car for two years now it just wasn’t anything I had gotten around to messing with… now I feel a bit silly for not trying this sooner.

Fan housing and shroud now nicely together:

[porschedude996]

Good thing you didn’t bend the housing. I did bent mine when I didn’t have it aligned.

[REVerend]

Originally Posted by porschedude996

Good thing you didn’t bend the housing. I did bent mine when I didn’t have it aligned.

I was concerned with that after reading in another thread how people seem to want to really crank down on the strap bolt. The fan still spins freely and seems to have the same gap between blade tips and housing as before. I guess I could have used feeler gauges to measure it but visually it looks just fine.

What happened with your bent housing? Did the fan start rubbing?