Oil circulation systems 356A T2

[Tom Markussen]

Hi can anyone help. I am restoring a '58 normal engine. I have a few parts from other engines and I can see the oil circulation systems are different. But I can't find an overview/description of the differences anywhere. Does this exist on 356Reg somewhere? I wonder if the external tube is needed when there is an internal tube cast into the the third piece? Would love to see a drawing of this. I will enclose a picture to show the issue. Thanks, Tom

[Vic Skirmants]

External tube NOT used when internal tube is present. The far right photo is wrong.

[Martin Benade]

Vic, there were two versions of the thermostat cover? Functionally the same?

[Tom Markussen]

Yes please explain!

I have the same quiry. See photo. One is a cover, the other a valve.

[Al Zim]

The THERMOSTAT CASE was at best a really STUPID IDEA. Do not try to rebuild them unless you have all the parts on the table for the assembly! BECAUSE you are NEVER going to find the parts you need! Many of the hoarders are no longer on the planet. I was there when these engines were in use 1962 Fortunately most of them blew up or were thrown away (because Porsche did not supply parts for the case).

[Jacques Lefriant]

Hi Al
Both versions were supplied by Porsche at the time. Now a nuanced cover is supplied by some vendors to improve the initial oil pressure on startup to fill the void. i think the thermostat it was a good idea to improve the function of the oil cooler. i think the demise was a cost cutting decision and the low volume cover option could have been implemented by Porsche but they would have had to admit to a brain fade.
j

[Jon Bunin]

I have the same quiry. See photo. One is a cover, the other a valve.

The oil thermostat was discontinued in October '58, with engine numbers P71452 and P82748.
A simple cover plate closed the thermostat hole.
It seems the timing cover casting was changed sometime prior to this.

[Jacques Lefriant]

Hi Jon and Brad
When thermostat parts were getting low did Porsche allocate the cover to Speedsters or Normal engines to improve the bottom line?
j

[Brad Ripley]

Jacques, I have no idea about that . Brad

[Tom Markussen]

Hi Jon, great with this kind of documentation. Much appreciated. Do you also have a record of the the change of the third piece cast (integrating the oil tube in the cast/mould)? Must be between #67425 and #68410. Thanks, Tom

[Tom Markussen]

Hi experts.

Oil thermostat: What is the specified opening temperature? Also, what was the technical issue with these? Too wide tolerance for the opening temperature? Did they break down or stick (non robust function) and stopped opening for the oil flow? I would guess the latter would be catastrophic!

Tom

[Vic Skirmants]

I have some old notes from July 2012:
External line on Supers up to 81707, internal line 81708 up to 83424, then deleted.
External line on Normals up to 68897, internal line 68898 up to 73237, then deleted.
I don't remember where this info came from, but it doesn't agree with Jon's post, so we need more data.

[Jon Bunin]

Oil thermostat: What is the specified opening temperature?

Tom, the system was outlined in the 356A Workshop Manual Supplements, with operating temperatures and pressures.
The thermostat is illustrated separately, in the upper right of these pages.

[Jon Bunin]

I have some old notes from July 2012:
External line on Supers up to 81707, internal line 81708 up to 83424, then deleted.
External line on Normals up to 68897, internal line 68898 up to 73237, then deleted.
I don't remember where this info came from, but it doesn't agree with Jon's post, so we need more data.

Vic, here are your external-to-internal numbers, from the 356A Workshop Manual Supplements.
Your last numbers and "deleted" reference is when the new '59 timing cover was introduced (Feb '59), with the thermostat chamber deleted.

[Tom Markussen]

Hi Jon

Thank you very much for the prints. Beautiful documentation. Same high quality as everything else from the old Porsche engineers. I really need to buy my own original manual.

I have looked at ebay for available copies. I guess you need both the full manual, plus the supplements?

Kind regards, Tom