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All TURBO Oil Line rebuild

 
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Zuffen  



Joined: 31 Jul 2001
Posts: 1421
Location: Owasso, Oklahoma 74055

PostPosted: Sat May 11, 2002 12:26 am    Post subject: Reply with quote

I have located a local Tulsa Company that has a special hydrualic line crimping setup and bender. The place specializes in Porsches, Ferrari and other fine autos.

I have showed him the oil return line and he feels he can replace the hose with near as factory hose as possible. The estimate is 50 to 75. He won't know until he does one as to how much labor is involved.

What I was thinking is that if anyone has any loose ones or an interst in having theirs rebuilt, please send them to me and I'll put in a group order and try to get a price break.

I have several myself mostly 80 units without the vent update. I could have these rebuilt if there is an interest. Otherwise what I need is the 81/82 units with the vent tube.

Same goes for the feed and return lines to the oil cooler. I plan to bring him a set so he can qoute me a price for them. But I only have a couple sets myself.



_________________
Bob Dodd - 924turbo@cox.net
931 1982, 944 1982 euro, 924S 1988SE, 93 968 tip 06 Silver Cayenne S, 06 Black Cayenne S

I have Way too many cars, parts for the 931,944 and 951
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John Brown  
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PostPosted: Sat May 11, 2002 12:48 am    Post subject: Reply with quote

Bob:

This is primarily in regard to the oil supply, not the vent. Just this past month I have been looking at that part of the engine myself. Before you commit to the direction of redoing the old system; what do you think of scrapping the factory installtion and going with a new design largely getting rid of the metric stuff and going the standard AN? That way you would be free from the future need to have a special maunfacture done for repairs.

System Description:
1) Standard adapter on block
2) Standard AN hardware and hoses
3) Remote mounted filter
4) MoCal cooler

The advantages are elimination of the expensive and hard to match metric hardware. Reduced heat transfer into the oil system. Better oil cooler. Standard replacement repair possible in the future. I figure about $400 for us do it ourselfers. Maybe less. If you pay $75/line that's $150. A third of the total system replacement cost and you still have the old cooler which may be marginal for any power increases. The new system includes a cooler with plenty of headroom plus improved design. Heck, it's going to be hard to find room for the heat shielding wrap on the factory system!

I dunno, what are your thoughts?
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numbers  
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PostPosted: Sat May 11, 2002 4:19 am    Post subject: Reply with quote

Bobby, I have posted on here before that you can rebuild the return line for about $2.00 US. You just need standard 3/4 inch heater hose. The return line is not under pressure. I used a hacksaw to cut the crimps and removed the old hose. The pipes have about an inch long barb on them, and you just use standard stainless hose clamps to install the new hose. I got ten years out of my first replacement, and am about seven years into the second one. You should be able to do the same with the cooler lines, but would probably want a higher pressure hose.
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Peter  
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PostPosted: Sat May 11, 2002 6:15 am    Post subject: Reply with quote

I have to agree with Numbers, as I have done the same thing.
I am now thinking of eliminating the vent line altogether by using 1" steel braided hose w/ metric fitings, thinking that the increase from 3/4" to 1" will allow enough oil to pass out of the turbo without the need of the vent line as protection.
-Peter A. Holiat
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Zuffen  



Joined: 31 Jul 2001
Posts: 1421
Location: Owasso, Oklahoma 74055

PostPosted: Sat May 11, 2002 1:37 pm    Post subject: Reply with quote

I agree on the fact that it can be done cheaper.

There is some pressure but not enough to warrent special high pressure line.

The biggest problem is keeping the stuff from leaking. I know that the fix has always been to pop in a new hose and some stainless clamps. At least for the return line.

For the purests out there, that isn't a factory look.

Are you guys running the vent update?

If the interest is updating to ansi fittings, I'll take a look at the system and see what can be done. This same fellow can redo all the bends as that is the other side of his hose replacement machine.

Personally I would love to have a factory looking remote filter mount, maybe on the frame rail up front so I don't have to get burnt each time I change the hot oil filter.

As for removing the vent, hmmm, by going with larger lines that would help the flow but maybe the vent is there to let off exhaust and boost that is getting past the seals and into the oil system. Is it possible?

You would have to worry that the bearings have enough back pressure to stay submerged in oil with no chance of air or gas cavitation.

What about the bypass valve in the filter housing?

Please let me know your ideas. It wouldn't take long to build and probably run cheaper than what John was thinking.

I would change out the oil cooler if this went all the way. Keep thing simple.

_________________
Bob Dodd
13 Porsches and counting.
5 931 ,including a 80S
3 924 77,77,80 all for parts
4 944 82,84,85,86 all for parts
1 sad 912 for parts
KIA list
82 931

[ This Message was edited by: Zuffen on 2002-05-11 12:46 ]
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Peter  
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PostPosted: Mon May 13, 2002 10:56 am    Post subject: Reply with quote

Hummm. The issue of exhaust gas getting into the crankcase and pushing up into the turbo sounds interesting. However, I was under the impression that oil is always flowing through the turbo and thus the pressure of the oil ( along with the force of gravity pulling the oil down) would be stronger than any exhaust gas pushing up, especially since there is already a crankcase breather which is clear and offers no resistance for the exhaust gas to escape the crankcase. What do you think?
From several DIY turbo boards, especially the air-cooled VW sites where people fabricate there own turbo setups, the consensus was to always use a large oil exit hose and to angel it downward to let oil flow from high (turbo) to low (oil pan). Similarly, what I understand is that the exiting oil is hot, under low pressure, and can be foamy. Thus you want a larger line to accommodate the increased volume.
I took apart a vent line and it was basically a perforated metal tube.
-Peter A. Holiat
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John H  
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PostPosted: Mon May 13, 2002 11:19 am    Post subject: Reply with quote

When I added an additional oil cooler to my GT replica I cut the ends off the rubber hoses and for the standard cooler welded AN type fittings to the metric fittings (allows use of standard cooler but aftermarket type fittings).
In addition we have recently started using "pushloc" type hoses - these are a push fit onto the fitting (requires abit of brute force if you haven't the equipment) but you don't need hose clips and the hose will take over 200lbs before it even looks like blowing off the fitting.
We tested one and it went to 300lbs before the hose burst (still stayed on the fitting).
I also cut the rubber hoses off the metal lines from the block to the oil cooler and added AN type fittings - certainly makes it easier (Cheaper) if and when I replace lines.
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John Brown  
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PostPosted: Mon May 13, 2002 12:22 pm    Post subject: Reply with quote

John H:

When you add the AN fittings to the lines between block and cooler; what size and style fit? Are you using compression or welded type?

Speaking of presson hose. Has anyone found a replacement for the fuel lines?
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John H  
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PostPosted: Mon May 13, 2002 1:28 pm    Post subject: Reply with quote

John,

I haven't got a proper web site so it's hard top post the photo's. But in answer to your question I used I think compression fittings.

I just gave the hydraulic guy the instructions: I wanted a readily available fitting, and it was not to leak and the rubber line had to be and a start up pressure of around 140 lbs. (10 bar).

If you go to the following http://communities.msn.co.nz/924CarreraGTInfoSite/olicooler.msnw?action=ShowPhoto&PhotoID=13 you will see some photos of the lines I had made up - Sorry about the quality. Also shown is the secondary oil cooler. I run a 937 replica and have added a secondary cooler for racing. This was the driver for the change in fittings


Picture 708 and 711 shows the oil line from the block going to the aux cooler then from the aux cooler to the main cooler top and then out the bottom. I think I've put the lines on back to front for the photo but will correct this later.

Hope it helps


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John Brown  
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PostPosted: Mon May 13, 2002 11:11 pm    Post subject: Reply with quote

Yes, thanks. I see the compression fittings. Expect if I need additional cooling my first action will be to change the lines as you did to AN and replace the factory oil cooler with a larger Mocal. The Mocal is not that expensive. About $130 in the size I think appropriate. Making my own lines up will add about another 75 but out of that I should have line left over for other future use.
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