Installing Front Cooler w/911 Gearbox- A Little Trouble
 

I'm installing factory SC oil lines and thermostat that will lead to a trombone cooler mounted in the front of my '70E. I had purchased a '74 style crossover pipe, and was displeased to find that it conflicted with the cluch cable anchor boss as outlined by others here:

http://forums.pelicanparts.com/showthread.php?t=246782&highlight=911+crossover+oi l+line

I have the original, rubber, crossover line, and the combination hard/soft line that is supposed to go from a hard crossover line ('74 type) to the thermostat. The soft crossover line and the new hard/soft line both have female connectors, and the new line has a fitting larger than the old. How to connect? Is it possible that I could have new rubber hose swagged into the old crossover line with an appropriate fitting at the outside end? I have an assortment of old lines that could perhaps be pirated for their fittings. Anyone done this conversion?

Thanks in advance,
-Scott

Scott,

Every ’70-’71 911 trans with push-type clutch has to use the flex oil hose that goes over the transmission.

Best,
Grady

Grady-
That is what I thought. How do I connect the flex hose to the thermostat?

Scott,

It is going to take a custom hose assembly.

First, I would use 25 mm hose common from ’72 and not the 20 mm ’71 and earlier. You will need to use the later case fitting also.

While there are many ways to do this, I’ll explain the two I would choose.

I would start with a used SC pipe that goes into the thermostat from the engine and modify it to accept an over-the-transmission custom hose. It is possible to do this using the stock ’70-’71 smaller hose.

I would prefer a new custom 25 mm hose from the case fitting, over the transmission, past the engine oil cooler, between the oil tank and chassis, over the wheel well and down to the thermostat. The difficulty is both ends of the hose assembly have 90° fittings. This necessitates a straight fitting in the middle.

I plan this latter arrangement on my ’68 using my type 911 trans and pull-type 225 mm clutch as it gives maximum tire clearance.

Best,
Grady

Grady-
Thanks so much! It sounds like I have some work to do, but being steered in the right direction will save huge amounts of time and money.

Scott,

I’ll be glad to help with the details.

Best,
Grady

Grady, heard about your spill, are you feeling better?

-Wayne

Parker Hydraulics Stores/shops(If you have one local) can mate/connect the fittings and oil line for you........FYI.
bruce

Just to provide an illustration here's one vendor's catalog page

http://forums.pelicanparts.com/uploa...1194389413.jpg

John,

Thanks for the reference. Unfortunately, it is full of errors.

I have some errands (and a ride) today but I’ll try and straighten things out this afternoon.


Wayne, thanks for the thought. Bags packed and loading the car and then out like a light. After a 9-hour ER visit, the general consensus is: low blood pressure, low blood sugar, off the oxygen, stood up too suddenly, bent over too long and/or unknown. At least I didn’t have an episode like Bruce A. did.

I had been looking forward to RRIII all year. The good news is Delta, Dollar, Hilton and the golf cart co returned all but 1¢ – honest, Delta kept exactly 1¢.

Best,
Grady

I've done a little research, and have found that the typical fittings for the SC era hoses seem to be M30X1.5. The early crossover hose has M26X1.5 (I think). A call to my local Parker dealer reveals that everyone else in the world uses M30X2.0. The M26X1.5 they can do. So, does anyone make any kind of adapter to get from a male M30X1.5 to anything else? It occurred to me that adapters both at the sump and thermostat open up the possibility of using AN hoses and fittings.:(

JB racing have AN adapters for you. No affiliation - just saw it on their website.

Grady, glad to hear you are back on your feet. Literally.

The biggest error I see is that example 1 was used through and including 71.

A similar hose can be made with 30mm hose ends.

Gradys suggestion of adapting the 74-89 thermostat-to-crossover oil line is smart since it keeps tire interference down. Swage a new, longer hose onto that pipe, then a 30mm 90 degree elbow to the other end.

The explanations are confusing because they are focused on AN conversion. For the sake of our discussion, examples 2/3 are the same.

Sorry for the thread hijack, but this is somewhat relevant. I bought an entire oil cooler setup from a '78 SC for my '73S. Will I need to order a cross over pipe or will the SC one fit with my early stock heat exchangers? I haven't taken anything apart, so I can't tell.

Well, I see that this outfit called Elephant Racing has 30mm hose ends, both with a straight and 90 degree fitting. Anyone ever hear of these guys?;)

Chuck-
What do you think of Grady's idea about an "up and over" line? I could use the 90 degree fittings at both ends, and one segment of rubber hose between. If I purchase the fittings, will my local hose shop be able to correctly swage a rubber hose in place? Alternatively, I do have a used Carrera engine oil to thermostat line, which does not have the 90 degree bend, and I have a new '74style hard line to thermostat unit. I'd hate to sacrifice the latter, as it is unused and therefore salable. Also, the fittings available seem to be female, and the '74 type has a female fitting already. Also, note that Grady recommended the use of a thermostat to engine oil line, and not the thermostat to tank line Chuck mentioned.

Thanks for all the info from everyone!

Brain fart on my part. The line to use is the tstat-to-crossover. I will edit my post above to correct.

The up and over approach is fine and give the most tire clearance.

Any hydraulic hose repair shop can do this. However some don't want to for various reasons.

The Period-Correct Police will impound Scott's car if he uses AN fittings...

Well, here is how it turned out.http://forums.pelicanparts.com/uploa...1199116403.jpg
http://forums.pelicanparts.com/uploa...1199116416.jpg
Note that, as an idiot, I mounted the clamp for the other (hard) line right in the middle of the depression that is provided for tire clearance. Be smarter then me, and put it somewhere else! The fittings came from Chuck's joint, as did the hose and sleeves. I had a great deal of trouble working with my local hose shops. For anyone attempting this, I recommend having Chuck do the whole thing. I ended up making a lot of trips to various hose places, and making multiple orders from Chuck, which added both to the cost of the project and the time it took and aggravation it generated. Thanks to Chuck for helping me through this, and supplying first rate products. The fittings are 25mm, and utilize 7/8" hose. 7/8" is an odd size, hence my difficulty with the local shops. Here is the hose itself. The flexible portion is 9' long:http://forums.pelicanparts.com/uploa...1199116696.jpg

And Chuck's slick fittings:
http://forums.pelicanparts.com/uploa...1199116722.jpg

So, it seems that I'm ready for these 7R wheels, just as soon as my lotto ticket hits! I'd be happy to share any of the more arcane details with anyone interested. Grady- is this what you had in mind?

Scott, looks good. Any pictures of the case connection and clutch? Also, those are 30mm fittings.

Chuck-
I'll post some of the case in the near future. The line just fits between the heat exchanger and the gearbox. As for the fitting size, the 25mm referred to the line dimension (per Grady's description of 20mm and 25mm lines). The threaded part of the fittings, of course, is 30mm.

Scott, I have a similar quandary, I can't decide what crossover line to use, a factory hardline or a piece of flexible line. How much clearance was there between the scavenge fitting and the exhaust tubes on the side of the case? What fitting did you use there, a 30mm 90degree?

Any additional info would be much appreciated.

John-
The fitting at the sump is the 90 degree, 30mm one seen in the photo a couple of posts up. I have stock heat exchangers. The hose just clears between the heat exchanger (near the heater outlet) and the gearbox. I had to re-tighten the fitting a number of times before the hose ended up traveling at just the right angle. Other than that, I did not encounter any clearance problems. By exhaust tubes, do you mean those coming from the exhaust ports?

Scott, thank you for the reply.

I am wondering whether the port heat exchanger will have to come off to change the case fitting and whether a 90 degree fitting will work. But if your M30 one worked OK, that gives me confidence that there is enough room to get the hose in there.

The factory crossover line is so convoluted I was wondering whether a 90 degree could be made to fit.

Did you remove the heat exchanger to fit everything?

http://forums.pelicanparts.com/uploa...1201531066.jpg

Thanks in advance, I am probably going to go through the kick panel beneath the seat with a bulkhead fitting to get the lines into the cockpit. That makes more sense than going over with the crossover pipe and then up through the fender well and into the engine compartment and then forward.

John-
I did have the heat exchanger off. You can't get a wrench on the fitting with the heat exchanger in place. Just to be clear, my line does not go back into the engine compartment. It goes into the wheel well to the late type thermostat.

By the way, in a similar thread on the S Registry board (not started by me) two people claimed to have used the hard crossover line with the 911 gearbox. This still confuses me, as there is no way the one I have (shaped like a ?) would fit.

Scott, that is very helpful, thanks. I have the "early" hardline from '71 installed, nice to know that the later (74+) one with the 30mm fitting won't fit BEFORE I bought one to go that route.

Hmm, I think I better start soaking the heat exchanger hardware in PB blaster now . . .:)

Well, I ordered a 74- hardline, I am going to see if I can make it fit. I have the 71 style hardline on there now, so I wonder where the interference is? Grady said the early cars with a 911 gearbox can ONLY use the soft line, so I'm wondering whether my box has been modified or the line bent to fit? I guess I'll find out when I'm under the car covered in oil.

John-
The conflict is with the boss that retains the end of the clutch cable. I'll be interested to hear if you have an issue when the new crossover line shows up. Note that the '70 line for cars without front coolers went up over the gearbox, just as my custom line does.

Hmm, I'm looking for a photo of that exact area, this is the only one I can find.

http://forums.pelicanparts.com/uploa...1202411547.jpg

Here's my current 71-style hardline.

http://forums.pelicanparts.com/uploa...1202411915.jpg

http://forums.pelicanparts.com/uploa...1202412234.jpg

http://forums.pelicanparts.com/uploa...1202412663.jpg

A photo from the FWM (thanks Grady, (c) Porsche)

Yep, the thing you labeled as "Boss?", hidden by the heat exchanger.

Hmm, I wonder why my current hardline doesn't hit that? I can't wait to get under and find out. Maybe it's the diameter? But the difference in radius of the line is only like 1mm.

The world according to PET- everything you wanted to know about scavenge crossover lines until 1974 (the world, for all practical purposes, ends then)

64-71: soft rubber line 901 107 331 12 EXCEPT sportomatic, which used a hardline to flex hose combo 901 107 720 01 (same hose in 1973 sporto)

72: hardline to long flex hose 911 107 720 11 to oil filter console (Sportomatic had this same hose)

73: hardline to flex hose 911 720 724 10 to thermostat on oil tank with upward pointing fitting EXCEPT 911t, which used a conventional hardline to flex hose to the tank 911 107 722 00

74- Hardline to flex hose to 30mm fitting near oil cooler 911 107 739 10

So the hose I have is either the sporto or the 911t.

Guys,

I think the issue here is the clearance between the end of the clutch cable and the oil pipe if under the bell housing. Porsche chose to solve the problem with the oil hose going above the transmission.

Below are images of the ’70-’71 transmission with the end-of-cable support. I think there are two issues; first is the clearance between the end of the clutch cable and the oil pipe. Any contact can possibly puncture the pipe. Second is the ability to service the clutch cable. With the oil pipe in such close proximity, you can’t change the cable (and the clip to the transmission 'ear').

I think the solution that Scott did is the best. I’m afraid that the under bell housing pipe will eventually have problems with contact with the end of the clutch cable. John, you need to look and see if the pipe is contacting the cable end.

Here are some images. First is one posted above with arrows showing the oil pipe and hidden ear.

The next two are a type 911 transmission with a '73.5 case and oil pipe. Note the lack of clearance between the pipe and transmission 'ear'. Remember, the end of the clutch cable extends several mm forward toward the pipe. That 'ear' is peculiar to only '70-'71 911 transmission castings. If broken, it can be replaced with a custom steel part.

Best,
Grady

http://forums.pelicanparts.com/uploa...1202499281.jpg

I have the other images on my laptop. I'll have to post them sepertly.
G.

OK, look what came in the mail today. . .

http://forums.pelicanparts.com/uploa...1202564131.jpg

This is all aeroquip startlite, -16AN, the silver sheath is an insulator. Seven hoses of about 90" each should do the trick.

Most NASCAR teams aren't using long hoses anymore, they are using hardlines with short flex hoses (hello Porsche, circa 1967). Also, all the pro teams with the exception of one use ICORE hose-- it's lighter, has a tighter bend radius, and is $45.00 per FOOT. The one remaining team uses Goodridge, but only because Goodridge supplies it gratis.

Note the crimped-on fittings. All the pro teams use crimped fittings, more positive and lighter weight. Rather than reusing the hose ends after a season the whole hose is surplused (which is why these are in my living room).

Interesting that those are almost the perfect length for an "up and over" line. Do they have 90 degree fittings on both ends?

Scott, they are mostly straight fittings. I sent one to Chuck to have him put a 30mm fitting on one end. I decided that under the car, jamming to get this completed along with a dozen other projects before race season begins, was not the time for experimentation with the factory lines.

Scott, did you clamp the line to the transmission at the top like the old factory flex hose? Or did you just lay it on top?

John-
I used a rubber coated clamp, just like the factory except larger in diameter. I used the stock L bracket to attach the clamp to the gearbox per original configuration.

Grady,

Chuck now has the crossover pipe for this application. I am wondering if the trans needs to come down ti fit this, or just the heat exchanger?