Show full size 924Board.org
Discussion Forum of 924.org
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
 Technical FAQ924 FAQ (Technical)   Technical924 Technical Section   Jump to 924.org924.org   Jump to PCA 924 Registry924 Registry

Bolt-in off-the-shelf water-cooled turbo for 931
Goto page 1, 2  Next
 
Post new topic   Reply to topic    924Board.org Forum Index -> General Discussions
View previous topic :: View next topic  
Author Message
ideola  



Joined: 01 Oct 2004
Posts: 15462
Location: Woodstock IL

PostPosted: Tue May 20, 2008 1:56 am    Post subject: Bolt-in off-the-shelf water-cooled turbo for 931 Reply with quote

Well boys, I've just confirmed it. The 951 K26/6 water-cooled bearing housing is part number 5326-151-0089.

Why should you care?

Because it is a direct, bolt-on replacement for the 931 bearing housing. Take your SI or SII K26 turbo, get the 951 bearing housing, send the bits to your favorite rebuilder, and voila, you now have a water-cooled 931 turbo unit. The unique 931 top and bottom oil lines / bracket fixtures are a direct bolt-on to the 944 bearing housing (John at Majestic confirmed this for me).

Of course, you'll need to plumb in the water lines and a pump. For this you can either source the stock 951 components (pump and relay, which operates the pump for 30 seconds after shutdown), or you can go aftermarket (for example, a Davies-Craig electric booster pump). The easiest way to tap into the coolant circuit is to tap the cold and hot side respectively of your rad.
_________________
15 981 GTS | 88 924S SE | 82 931 Holbert | 82 931 Rallye | 81 937 | 81 Euro 931 | 81 Weissach | 80 US 928 | 80 US 931 '941' | 80 US 931 | 80 931 GTR | 79 Sebring | 78 D-Prod Replica | 78 w/D-Prod kit | 78 Poli-Form | 78 Limited Edition | 77 Martini
Back to top
View user's profile Send private message
tuurbo  



Joined: 09 Aug 2007
Posts: 1463
Location: East Windsor, New Jersey

PostPosted: Tue May 20, 2008 2:05 am    Post subject: Reply with quote

Excellent.

That is what I call an upgrade. Now I'll Google for the 951 bearing housing...no luck there. Lindsey doesn't list them.

So are these bearing housings available from the same people who sell rebuild kits?
_________________
1980 924 turbo, MSD, Meth. Inj, otherwise stock.
Back to top
View user's profile Send private message
ideola  



Joined: 01 Oct 2004
Posts: 15462
Location: Woodstock IL

PostPosted: Tue May 20, 2008 2:13 am    Post subject: Reply with quote

Your best option would be to find a used 951 K26 unit, possibly from a Pelican or Rennlist user, or eBayer. The 951 crowd like to upgrade their turbos, so you should be able to find these used without too much difficulty. In my case, John at Majestic happened to have one sitting on the shelf. He didn't even know what it came from, so I took the part numbers, did some sleuthing, and found out it was from the 951 K26 unit.

I suspect that because orientation and oil line connections are completely different on the 951 unit, it never occurred to anyone to check to see how similar the bearing housings were between the 931 and 951. As it turns out, the oil ports and stud patterns are identical to the 931, so our oil fittings and brackets bolt right up, as do the hot and cold side housings, no mods required. The only thing to sort out is how to plumb in the water lines, but as noted above, this can be achieved pretty simply.
_________________
15 981 GTS | 88 924S SE | 82 931 Holbert | 82 931 Rallye | 81 937 | 81 Euro 931 | 81 Weissach | 80 US 928 | 80 US 931 '941' | 80 US 931 | 80 931 GTR | 79 Sebring | 78 D-Prod Replica | 78 w/D-Prod kit | 78 Poli-Form | 78 Limited Edition | 77 Martini
Back to top
View user's profile Send private message
Mike924  



Joined: 12 Aug 2004
Posts: 2601
Location: IoW UK

PostPosted: Tue May 20, 2008 2:42 am    Post subject: Reply with quote

...or to save time, you could buy a 951!

Seriously, good detective work, Dan.
_________________
1985 Porsche 924 'Lux', Kalahari Beige (my ex)
1993 Porsche 968 Coupe, Midnight Blue, 6 spd

'There is no substitute for a little grease under your fingernails.' - Chrenan, 924board.org
Back to top
View user's profile Send private message
ideola  



Joined: 01 Oct 2004
Posts: 15462
Location: Woodstock IL

PostPosted: Tue May 20, 2008 2:57 am    Post subject: Reply with quote

Incidentally, I should mention that the Borg-Warner catalog part number for the 944 Turbo bearing housing is 5326-150-0020. That may help you source the part from a rebuild shop. However, that number is not stamped anywhere I can see on any of the units I have seen (in photographs) or heard of. I don't understand why the different part numbers, but it might be a useful cross reference. I've posted this info over in -nick's all-u-want-to-know-about-KKK thread.
_________________
15 981 GTS | 88 924S SE | 82 931 Holbert | 82 931 Rallye | 81 937 | 81 Euro 931 | 81 Weissach | 80 US 928 | 80 US 931 '941' | 80 US 931 | 80 931 GTR | 79 Sebring | 78 D-Prod Replica | 78 w/D-Prod kit | 78 Poli-Form | 78 Limited Edition | 77 Martini
Back to top
View user's profile Send private message
Rasta Monsta  



Joined: 12 Jul 2006
Posts: 11332
Location: PacNW

PostPosted: Tue May 20, 2008 3:02 am    Post subject: Reply with quote

One thing that will be needed for this conversion (not a criticism. . .I am considering it, therefore thinking about engineering issues) is some sort of heat shielding for the water lines. Remember, the 951 unit dwells in relative luxury on the cold side of the 2.5. I think timed pump run-on will be mandatory for the same reaon.

For the source (because I can't bring myself to drill holes in my Davis rad), I would consider a short section of pipe with nipple spliced into the lower rad hose. For the return, I would consider epoxying a fitting to the overflow tank, 951-style.

Very interesting, Dan. Do Majestic have any more of these housings laying around?
_________________
Toofah King Bad
  • Shaggy (1980 931) - Got Boost?
  • Red (1987 924S) - Pro44/Spec944
  • Weiße Scheiße (1987 924S) - In Progress
Back to top
View user's profile Send private message Visit poster's website
ideola  



Joined: 01 Oct 2004
Posts: 15462
Location: Woodstock IL

PostPosted: Tue May 20, 2008 3:18 am    Post subject: Reply with quote

Rasta Monsta wrote:
One thing that will be needed for this conversion (not a criticism. . .I am considering it, therefore thinking about engineering issues) is some sort of heat shielding for the water lines. Remember, the 951 unit dwells in relative luxury on the cold side of the 2.5. I think timed pump run-on will be mandatory for the same reaon.

For the source (because I can't bring myself to drill holes in my Davis rad), I would consider a short section of pipe with nipple spliced into the lower rad hose. For the return, I would consider epoxying a fitting to the overflow tank, 951-style.

Very interesting, Dan. Do Majestic have any more of these housings laying around?

Here's a couple of pix that John sent to me of the bearing housing uninstalled:

I won't know precisely until I get the built unit in my hands, but you can see from the photo that the water fittings are at 90 degrees to the oil fittings. In the case of the cold inlet, I believe it will actually be sitting directly beneath the large bracket that bolts the turbo to the block. It should be relatively easy to add a small heat shield on that side. In any event, I plan to use braided stainless for the water lines. Heat gain may be a bit of concern, but I think it can be adequately addressed.

Timed pump run-on is a no-brainer. Since I'm going with the Davies-Craig electric water pumps (primary and aux), I may opt to try their new digital controller. We'll see.

Yeah, I think your approach for plumbing would be just as effective. In my case, I'll just modify the stock rad.

You'd have to ask John if he has anymore, but I believe he said it was the only one he had laying around. I would think that these housings would be easy to find though. There are at least 8 or 10 different places throughout the US that specialize in sourcing used KKK stuff that I've been in contact with (including Majestic) so now that we know what to look for, I'd think we'd be able to find it, especially given the popularity of the 951. Heck, even a trip to a few boneyards might yield something...you could grab the whole turbo and possibly get trade-in value on the other components if they were any good.
_________________
15 981 GTS | 88 924S SE | 82 931 Holbert | 82 931 Rallye | 81 937 | 81 Euro 931 | 81 Weissach | 80 US 928 | 80 US 931 '941' | 80 US 931 | 80 931 GTR | 79 Sebring | 78 D-Prod Replica | 78 w/D-Prod kit | 78 Poli-Form | 78 Limited Edition | 77 Martini


Last edited by ideola on Sat Jul 18, 2009 3:39 am; edited 1 time in total
Back to top
View user's profile Send private message
bass gt  



Joined: 02 Dec 2004
Posts: 971
Location: Johannesburg for now!!

PostPosted: Tue May 20, 2008 3:24 am    Post subject: Reply with quote

Dan,

If you are going with a decent ECU you can use a PWM output linked to the water temp value to drive the water pump. Saves money and you can fit a seperate switch/timer relay to override the ecu output to turn the pump on permanently. have serious concerns about the Davies Craig controllers and their robustness. If you went with my DTA for example, this is doable, as the PWM outputs list the water temp as a ref value
Steve
_________________
Front Wheel Drive is the Devil's work.
Back to top
View user's profile Send private message
peterld  



Joined: 10 Dec 2006
Posts: 658
Location: Noosa Heads QLD Australia

PostPosted: Tue May 20, 2008 12:05 pm    Post subject: Reply with quote

Brilliant work, Dan!
Back to top
View user's profile Send private message Send e-mail
ideola  



Joined: 01 Oct 2004
Posts: 15462
Location: Woodstock IL

PostPosted: Thu May 22, 2008 4:09 am    Post subject: Reply with quote

Rasta Monsta wrote:
Do Majestic have any more of these housings laying around?

Rasta, you have PM...
_________________
15 981 GTS | 88 924S SE | 82 931 Holbert | 82 931 Rallye | 81 937 | 81 Euro 931 | 81 Weissach | 80 US 928 | 80 US 931 '941' | 80 US 931 | 80 931 GTR | 79 Sebring | 78 D-Prod Replica | 78 w/D-Prod kit | 78 Poli-Form | 78 Limited Edition | 77 Martini
Back to top
View user's profile Send private message
ideola  



Joined: 01 Oct 2004
Posts: 15462
Location: Woodstock IL

PostPosted: Fri Jun 06, 2008 8:22 am    Post subject: Reply with quote

Just arrived (Click pix for larger photos)







_________________
15 981 GTS | 88 924S SE | 82 931 Holbert | 82 931 Rallye | 81 937 | 81 Euro 931 | 81 Weissach | 80 US 928 | 80 US 931 '941' | 80 US 931 | 80 931 GTR | 79 Sebring | 78 D-Prod Replica | 78 w/D-Prod kit | 78 Poli-Form | 78 Limited Edition | 77 Martini


Last edited by ideola on Sat Jul 18, 2009 3:40 am; edited 1 time in total
Back to top
View user's profile Send private message
ideola  



Joined: 01 Oct 2004
Posts: 15462
Location: Woodstock IL

PostPosted: Fri Jun 06, 2008 8:36 am    Post subject: Reply with quote

Here are the components:

Stock 931 Turbine housing, shaft & wheel
Stock 944 K26 water-cooled bearing housing
K27 compressor housing (5327-101-5079)
- machined to accommodate wheel
- 2" outlet / 2.75" inlet
K27 compressor wheel (part number unknown)

Total cost:
- Rebuild: $335
- New compressor wheel: $125
- Bearing housing trade: $65
- Compressor housing trade & machining: $140
Total cost from Majestic: $665
(not including ceramic coating and shipping)
_________________
15 981 GTS | 88 924S SE | 82 931 Holbert | 82 931 Rallye | 81 937 | 81 Euro 931 | 81 Weissach | 80 US 928 | 80 US 931 '941' | 80 US 931 | 80 931 GTR | 79 Sebring | 78 D-Prod Replica | 78 w/D-Prod kit | 78 Poli-Form | 78 Limited Edition | 77 Martini
Back to top
View user's profile Send private message
macBdog  



Joined: 16 Aug 2004
Posts: 1094
Location: Brisbane, Australia

PostPosted: Fri Jun 06, 2008 11:26 am    Post subject: Reply with quote

Good work, that looks incredible! Hardly off the shelf though...
_________________
1979 931 with a 350 chev
1973 911E with EFI
p-talk wrote:
I'm still convinced the word 'Porsche' makes people crazy in all kinds of ways
Back to top
View user's profile Send private message Visit poster's website
ideola  



Joined: 01 Oct 2004
Posts: 15462
Location: Woodstock IL

PostPosted: Fri Jun 06, 2008 11:28 am    Post subject: Reply with quote

For my hybrid turbo, the only thing not off the shelf is the machining of the compressor housing. Everything else are stock KKK parts that you can source from anywhere, including used turbos.

In terms of the original post, the point was: you can simply swap out the stock 931 bearing housing for the 944 bearing housing. Everything else is bolt-on.
_________________
15 981 GTS | 88 924S SE | 82 931 Holbert | 82 931 Rallye | 81 937 | 81 Euro 931 | 81 Weissach | 80 US 928 | 80 US 931 '941' | 80 US 931 | 80 931 GTR | 79 Sebring | 78 D-Prod Replica | 78 w/D-Prod kit | 78 Poli-Form | 78 Limited Edition | 77 Martini
Back to top
View user's profile Send private message
!tom  



Joined: 28 Aug 2006
Posts: 1869
Location: Victoria, BC Canada

PostPosted: Fri Jun 06, 2008 11:37 am    Post subject: Reply with quote

ideola wrote:
you can simply swap out the stock 931 bearing housing for the 944 bearing housing.


Shouldn't this be 951 rather than 944?
_________________
78 924 NA
5-lug
Back to top
View user's profile Send private message Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic    924Board.org Forum Index -> General Discussions All times are GMT + 11 Hours
Goto page 1, 2  Next
Page 1 of 2

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group