I was wondering if anyone knows what type / spec of hose should be used to rebuild the oil cooler lines that lead from the engine to the radiator. I just had mine done at a local hydraulics shop, and since I really know nothing about these hoses, I put my faith in the guys at the shop.

When I got home I looked up the specs on the hoses they used which are as follows:

Parker SAE 100R2 BXX10
- Size 16mm or 5/8"
- Pressure: 2750 PSI
- Application:

Are these specs in line with the factory hoses / operating requirements? Temp seems like it could be an issue.

Here's a couple of photos of the hoses and their work. Thanks for your help!

Dave

http://www.flickr.com/photos/51967142@N00/5839589772/
http://www.flickr.com/photos/51967142@N00/5839590638/
http://www.flickr.com/photos/51967142@N00/5839041201/
http://www.flickr.com/photos/51967142@N00/5839040739/
http://www.flickr.com/photos/51967142@N00/5839591266/

 

I don't know the optimal specs for the hoses -- put my faith in a reputable lcoal hydraulic shop (based on a recommendation from another 928 owner -- Glen L -- that had his hoses done there).

The specs for what I got are (pic attached)...
300 PSI WP, -40 deg F to 212 deg F for oils, MSHA IC-40/26, 16 mm ID.

Contruction -
Inner Tube: Synthetic rubber.
Reinforcement: One textile braid.
Cover: Synthetic rubber, MSHA accepted

Application -
Shop & general industrial air lines. Automotive,
hydraulic & lubrication low pressure lines.

I've had them in since March of this year with no issues at all, including a couple of track days (DT/DE) in mild temps (70 deg F).

Hope that helps. Curious to hear what others have to say.

 

Funny, I've just been researching oil hose, as I'm going to crimp up a few sets.

From previous posts on Rennlist by Kibort (RIP) and Mrc of Devek, I've decided that sustained oil temps of 240 degrees F and the odd spike to 270F is about the upper end of the likely range for a 928 engine. (Marc said he had a customer with a GT who'd drive long distances at 3.5k rpm and see oil temps about 240°F (115°C). Mark K said with his in-radiator oil cooler he saw 270°F on hot days at the track).

What I'm getting at is I've already ruled out all hoses with 100°C rating.

I've got a list at home (will be back there later) - from memory the brands I've got listed so far are Gates, Parker, Ryco and Sunflex. I'll post the hose types later.

 

Uh What can I say.... I own and operate a hydraulics business, I would probably have made the same set of hoses as the original poster, because that is what I keep in stock. It is the basic standard for hydraulic hose, will never be bothered by to much pressure but the ultimate lifespan wil be shortened by heat cycles.

Quite honestly the job is not worth them even contemplating using anything other than what they had in stock, by the time they spend time researching which would be the most suitable hose, trying to procure a few feet of it, and the correct ferrules, the job cost has blown out to hundreds of dollars. when instead they can use a not quite suitable hose and send the customer on thier way none the wiser, safe in the knowledge that when or if it fails 15 years down the track noone will be coming back to bother them.

Cheers Roy

 

I'm not in a hurry, and will happily wait an extra week or two for hose that meets the working conditions to come in stock.

Here's some of the hose I've got on my list:

Gates - G1H
5/8 ID, 0.94" OD, 135 degrees C, one wire braid, 103 bar working

Sunflex - R1AT
15.9mm ID, 23.7mm OD, 120 degrees C, one wire braid, 130 bar working

Pirtek - R5HT-12
16.4mm ID, 27.4mm OD, 150degrees C, one textile & one steel braids, 103bar working

Ryco - Survivor RQP110
5/8", 23.7mm OD, 150 degrees C, one wire braid, 130 bar working pressure, blue

 

Roy -
Based on your experience, how long would the above hoses (rated to 212 deg F) last in a normally driven 928? I worry about the temp rating on the hoses I have, so just wondering. If they'll heat cycle out over 10+ years, then I won't be as urgently worried about a failure, but if it's sooner than I would probably want to be more proactive in getting the correct hoses so I'm not stranded somewhere. Thanks!
-Phil

 

Phil, Roy, Hilton, thanks for posting...it sounds like the 100C hoses should last for a while...I had visions of the line failing quickly and leaving a mess in the bay once "at temp" engine oil started moving through it - obviously not the case. The higher numbers Hilton posted still leave me uncomfortable with the 100C hose though, so I did a little searching, and came up with a few posts / sites with info - some works for, and other against the 100C hose.

I found the following thread on RL (https://rennlist.com/forums/928-foru...mperature.html - see post #5) where IR temp readings were taken at the "oil cooler top" and "oil cooler bottom" - which I assume are the hoses - with the following values in C:

All of these readings appear to be in line with the spec of the 100C hoses. I also noticed that the oil thermostat opens at 87C (https://rennlist.com/forums/928-foru...-question.html) so perhaps the system is designed to work with the 100C hose???

Working against the 100C hose is something I found on the site of a company selling after market oil coolers. They say:

From this, I infer that the oil could be running in the range of 200F - 275F range for our cars. Maybe even a bit hotter if the cooling system had an issue. FWIW, I have to take info from a site like this with a grain of salt since its in their best interest to discuss the most extreme conditions, though these estimates are not far off from what Hilton came across in the RL post. Nice find BTW Hilton, I never found this in my RL search.

Hilton, thanks also for posting the hoses you've researched. Where would you source from? I Googled these hoses, but I only found what I think are the Pirtek hoses which I think may be sold as SAE 100R5 in the U.S. (seems to have similar specs):

Cat: Automotive & High Temp - SAE 100R5 (5/8 or 16mm Type is model: 100R5-12)

• Application: petrolium based hydraulic fluids, air, water, diesel, and lubricating oils
• Uses: Medium Pressure Hydraulic Line
• Temp: -40F - +302F (-40C - +150C)
• Air to Max: +158F
• Water to Max: +185F
• PSI of 5/8 or 16mm: 1500psi (~103 bar)

The U.S. Pirtek site also had another high temp hose, which might also work, that also looks like it could be a bit more flexible than the coiled hose I have now. Could make fitment a bit easier. The hose is:

Category: Chemicals & High Temp - 100STH (5/8 or 16mm Type is model: 100STH-10)

• Application: petrolium based hydraulic fluids, air, water, diesel, and lubricating oils
• Uses: Automotive, food processing, pharmaceuticals, petrochemicals
• Temp: -40F - +450F (-40C - +232C)
• Air to Max: N/A
• Water to Max: N/A
• PSI of 5/8 or 16mm: 1500psi (~103 bar)

One last point...from what I have read, the PSI / Bar ratings of all the hoses seem to be well within the operating requirements of the 928. I don't know nearly enough about the pressures in the system yet - something I want to read more about when I have a chance - but 150 psi seems to be on the high end of what I have seen listed in threads. Please correct me if I am wrong.

So in the end, I really don't know what the right answer is. From one side the 928 IR temp readings post show the lines are within range and possibly have an additional ~10% - ~50% leeway on temp. The other example has the lines at near peak hose temp to ~40% over. Since the lines are already out, I'll probably give my local Pirtek a call and see what they want for the materials / work. If they were back in, I would probably just keep an eye on them and deal with them when convenient since they are kind of awkward to deal with otherwise.

 

My nickels worth is to call Mary Brown and place a order for Gregs hoses, they will be the right hoses, he does not do anything but Porsche and race car/truck plumbing so he will have the hoses, not generic hydraulic stuff.

I do know that the hose he uses for the trans cooler lines is some special stuff and I would assume that the engine oil cooler line would be the same.

EDIT: I am pretty sure that the hoses GB uses is a Goodrich (SP?) kevlar hose.

 

I cheat and use Google to search rennlist for the hard-to-find stsuff

My bad - the Gates hose is just called "G1H", the -10 is part of a local suppliers part number. Here's a link to the Gates page:

http://www.gates.com/brochure.cfm?br...cation_id=3842

The outer surface of the cooler fittings is already cooler than the oil - there's a temperature gradient between the hot oil and atmosphere, so the oil temps in the line will be a little higher. Whether they're high enough to exceed 100 degrees C I don't know - but for peace of mind I'm going to get some higher temp hose for the oil cooler lines. The 928 pressure bypass opens at 10bar (145psi) so hydraulic hose is generally way outside of spec. It may be overkill, but when has that ever stopped me spending money on a 928

edit: posts from Marc@devek and Kibort that I found are in these threads:

https://rennlist.com/forums/928-foru...-no-3-a-2.html
https://rennlist.com/forums/928-foru...coolers-2.html

 

Using hydraulic hose on engine installations is common in industry and they are not a source of unreliability. as I mentioned I would expect a service life of 10 to 15 years, interestingly hydraulic hose is lifed at 8 years from manufacture, so that would seem to be the expected life, from the manufacturers perspective.

Hose sizes are in 1/16th of an inch, thus 5/8 will always be -10 , 1/4 is -4, 1inch is -16 etc etc

I'm sure what Hilton is looking at will be a better option as the bend radius for single wire hose will be less than 2 wire hose making it easier to install etc.

My experience with temperatures in engines is, water temperature is higher than oil temperature, under normal conditions. As the engine overheats more heat is conducted to the oil, oil temperature rises to a point, then drags the water temperature up with it till the engine is well and truly overheated, oil pressure starts to drop as the oil breaks down and the engine enters the terminal zone. what fails first is probably determined by engine design.

thinking about it, the 928 engine has an inbuilt failsafe, the hydraulic tappets, become noisy and cut output as they lack oil pressure to function correctly thus reducing output from the engine and acting as an audible alarm to the operator !

Cheers Roy

 

I've seen some RL photos of Greg's hoses - really nice looking stuff - but I have the sense they might be a bit out of my price range. Regardless...a call can't hurt, and it would be nice to stay within the group that supports these cars.

Nice. Tried it out, and it does a nice job of cleaning up some of the results.

I noticed in the MK thread posted over the weekend, there was a bit on engine oil temp. Seems that under race conditions, 260-270F is likely, with spikes of 300F+. (https://rennlist.com/forums/928-foru...guna-seca.html - Post #1). Doesn't perfectly answer the question for the average driver, but at least it provides some clarity for what to plan for on the high end.

 

Any cliff notes on how / where to source ferrules and crimp tools; also, comments on DIY makeup of oil, trans or A/C hoses?

 

i have made oil cooler lines out of teflon lined stainless braid with standard AN fittings with no problems. both on my old off road cars and my old drag car.

 

I just ordered a heap of AC bits (hoses, ferrules, some fittings, compressor gasket and seal kits etc.) and will be taking pics when I do the rebuild. The parts are shipping to my freight company in California who will then pack them in with my 928intl Aluminum undertray - so the parts are at least 2 weeks away from my doorstep.

My plan is to posts pics and info on which bits are needed, once I've got the system filled and verified none of the hoses leak My aim is to re-use the factory fittings - but if any leak I'll replace those with new beadlock ends.

I'll be rebuilding all three hoses including the section that runs along the engine bay on the hardline that can't be easily removed with the engine in (will crimp it in place). FOr a crimp tool, Mastercool make a couple of small crimpers which should be able to do on-car crimping - the 71500 and 71550 are the model numbers for the hydraulic and screw-type crimpers (the hydraulic comes with about twice as many dies but costs about 3x the price).

For those wanting to try it, the AC hoses for an S4 with a 6E171 are: 30cm of #6 hose, 32cm of #8 hose, 30cm of #12 hose.

I bought the hose and ferrules from www.docsblocks.com - and the compressor kits and a few fittings from www.acsource.com.

I'm also investigating engine oil cooler lines.. but haven't yet worked out how ferrules for those work - whether I need the typical "single braid" hydraulic crimp fittings, or can make do with #10-size steel AC ferrules on the stock fittings given the low pressures. More experimentation and learning required

 

+1 Please