Machining '72 Filter Housing

[Roger 911]

Two part question:

1. Does anyone know what the approximate cost is to have the '72 filter housing machined to accept a thermostat (for use with an external oil cooler)?

2. Any suggestions on a good place to have this done? By chance, any suggestions for a shop in the Chicago area (NW)?

Thanks.
Roger

[1968SWTs]

$40
ANY machine shop
10 minutes


_some_ of the 72's were already machined for the thermostat

[1968SWTs]

make sure it is not already 45mm - else bore from rough 42 to smooth 45
http://forums.pelicanparts.com/6653682-post1.html

[KTL]

Originally Posted by 1968SWTs

could not find the right tool to get the pressure release cap off. I did bend a couple of stacked quarters however :-)

Traced the curve in the slot with a profile gauge- one of those things with a bazillion pins sticking out of it



Then I ground a fat chisel to the shape of the curve. Still had a hard time not boogering the slot edges. Worked best for reinstall. Bottom line, on a stubborn cap? Use a pipe wrench

BTW the Porsche part number for the M26 to M30 adapter is currently 90091500802 and is $14.50 thru Pelican

[daepp]

I believe the 72 S console is already set up for this.

And FWIW, I have been running my 72 for years with a large oil cooler up front and no additional thermostat.

[Roger 911]

Originally Posted by daepp

I believe the 72 S console is already set up for this.

And FWIW, I have been running my 72 for years with a large oil cooler up front and no additional thermostat.

Mine is a '72 T, so I doubt it is machined for the t-stat. I have also been running a front cooler for years using a Mocal t-stat in place of the filter housing mounted unit. I will be replacing my entire external oil cooling system as part of a 3.2 swap (don't ask me why, but for some reason when I installed the entire system 8 yrs ago, I used AN10 lines/fittings instead of AN12!). I thought I may as well go with the factory arrangement this time.

I'll find a local machine shop. I suppose it would be a good idea to bring a t-stat with me so they can see exactly what they need to do.

Thanks.
Roger

[Roger 911]

I finally took my filter housing out today. Does anyone know a good machine shop in the Chicago area (preferably Northwest)? I also can't get the pressure relief valve out, with the funky "curved slot" on the cover. I assume a machine shop could do this as well, and clean the whole thing.

If I can't find a local shop, I'll just send it out. I was thinking some place like Otto's. Any other suggestions?

Thanks.
Roger

[Roger 911]

I meant Ollie's, not Otto's. I assume they could do this with their eyes closed.

Roger

[techweenie]

I've been directed to TRE to get this done -- doing the same on a '72T

[KTL]

I bet Apex in Bensenville could do the machining. They do all of Midwest Eurosport's machine work.

The curved slot tooling in the t-stat is a joke. The same slot is on the typical 74-89 ext. t-stat. I just use a pipe wrench. Ugly it may sound, but it is what it is. Sometimes those caps are real SOBs to get off.

I made an install tool out of a chisel and ground the chisel to the width and curve of the slot. So installation is done "properly." But removal just doesn't cut it with the custom chisel tool

[Roger 911]

Originally Posted by KTL

I bet Apex in Bensenville could do the machining. They do all of Midwest Eurosport's machine work.

The curved slot tooling in the t-stat is a joke. The same slot is on the typical 74-89 ext. t-stat. I just use a pipe wrench. Ugly it may sound, but it is what it is. Sometimes those caps are real SOBs to get off.

I made an install tool out of a chisel and ground the chisel to the width and curve of the slot. So installation is done "properly." But removal just doesn't cut it with the custom chisel tool

Thanks. I'll check them out.

I also heard back from Ollies that they can't do this job, don't have the equipment.

Roger

[356racing]

Patrick Motorsports just did mine but it's pretty straight forward for any competent machine shop.

[RWebb]

pics before & after?

[Roger 911]

Originally Posted by RWebb

pics before & after?

Sure, I can do that.

Apex looks like the place for me, and they're 15 min from my office. I'll stop by there tomorrow and see what they say.

I'm still trying to figure out why the heck I installed my original external cooler with 10AN lines! Everything you look at, including all the info in BAT's catalog, shows 12AN for 911s.

Roger

[KTL]

There's some links in this thread that detail the machining needed to the filter housing, in case Apex needs some info on what to do

http://forums.pelicanparts.com/porsche-911-technical-forum/732392-machine-shop-resource.html

[Roger 911]

Here are a couple before pics. You can clearly see the ridge about 10 mm down from the top. This needs to be machined away so that the wider bore extends down approx 42 mm more.



This pic shows the t-stat inserted until it hits the ridge. I'll bring the t-stat with me to the shop so they can clearly see what we need to achieve. It probably makes sense to bore an extra millimeter or so to make sure the t-state is properly seated/sealed.



I'll also ask them to remove the pressure relief valve and clean everything.

Roger

[Roger 911]

"It probably makes sense to bore an extra millimeter or so to make sure the t-state is properly seated/sealed."

For clarification, I'm referring to the depth here, not the bore.

Roger

[Roger 911]

Got the housing back from Apex. Looks great and it was only $40.




Bill, the owner, made a tool to take the pressure relief valve cover off (nice welding!). He gave it to me so I could put it back on myself.



Roger

[Porboynz]

That's nice work, you can tell a craftsman at work when they casually produce something like that tool for removing the relief valve because that was what was needed. It looks like it will also fit the engine relief spring plugs, good value. I cheated when I did the same job and modified a large panel washer to fit the relief valve.