Installing Front Cooler w/911 Gearbox- A Little Trouble

[Scott Clarke]

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:

Which crossover line with 911 gearbox?

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

[Grady Clay]

Scott,

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

Best,
Grady

[Scott Clarke]

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

[Grady Clay]

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

[Scott Clarke]

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.

[Grady Clay]

Scott,

I’ll be glad to help with the details.

Best,
Grady

[Wayne 962]

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

-Wayne

[hbkramer]

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

[304065]

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

[Grady Clay]

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

[Scott Clarke]

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.

[V12man]

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

[Chuck Moreland]

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.

[Neilk]

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.

[Scott Clarke]

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!

[Chuck Moreland]

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.

[RWebb]

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

[Scott Clarke]

Well, here is how it turned out.

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:

And Chuck's slick fittings:


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?

[Chuck Moreland]

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

[Scott Clarke]

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.