Specs for oil relief/bypass valve springs in 912 motor

356 Porsche-related discussions and questions.
Post Reply
Message
Author
Tom Frisardi
356 Fan
Posts: 2
Joined: Fri May 02, 2008 3:24 pm

Specs for oil relief/bypass valve springs in 912 motor

#1 Post by Tom Frisardi »

Can someone, please, tell me the wire diameter and free length of the springs for the oil pressure relief and bypass valve springs in a 1968 912 motor? The parts manual says they are the same, but I don't have the data. Are the earlier motors superseded to the same, identical springs? Also, what is the correct overall length of the pistons for the two applications?

Thanks in advance.
Tom Frisardi, Massachusetts

Brad Ripley
356 Fan
Posts: 4205
Joined: Tue Mar 25, 2008 9:28 pm

#2 Post by Brad Ripley »

Info is right there in your Spec Book, bottom page 25, top page 26.

Both the spring in the crankcase and the timing cover should be the same free 66 mm length, 1,40 wire crossection and 4.7 kp +- 7% compressed at 46 mm length. Part number: 999 521 016 00, $1.95 each.

Note, springs were different lengths in the early days, but superceded to the same spring in later days.

Guest

Specs for oil relief/bypass valve springs in 912 motor

#3 Post by Guest »

Tom,
Wire diameter is 1.4 mm and free length is 66 mm and if you want to
go further it has a tension of 10.35 lbs. at 46 mm. BTW all this is in
the Porsche spec book.
This for the horizontal spring/piston. This regulates the oil
pressure from the pump.

Alan

Tom Frisardi wrote:
Can someone, please, tell me the wire diameter and free length of the
springs for the oil pressure relief and bypass valve springs in a 1968
912 motor? The parts manual says they are the same, but I don't have
the data. Are the earlier motors superseded to the same, identical
springs? Also, what is the correct overall length of the pistons for
the two applications?

Thanks in advance.


------------------------------------------------------------------------

Tom Frisardi, Massachusetts




-------------------- m2f --------------------

To contact an administrator admin@356registry.com
<mailto:admin@356registry.com>
To unsubscribe go to http://www.356registry.com/forum/m2f_usercp.php
Read this topic online here:
http://356registry.com/forum/viewtopic.php?p=4581#4581

-------------------- m2f --------------------
Post generated using Mail2Forum via email.

Tom Frisardi
356 Fan
Posts: 2
Joined: Fri May 02, 2008 3:24 pm

#4 Post by Tom Frisardi »

Alan and Brad,

Thank you, both, for getting this info to me. I have the 356 B/C service manual and the 356 "Information Please" spec book. I could only find the specifications pertaining to different springs for the bypass and pressure valves, and don't list specs for the supersession. The motor I'm assembling is a 912, so I wanted to be sure.

I felt that I had to say something, because I always read the manual.

Tom
Tom Frisardi, Massachusetts

Brad Ripley
356 Fan
Posts: 4205
Joined: Tue Mar 25, 2008 9:28 pm

#5 Post by Brad Ripley »

Note, the 356 Spec book indicates a supercession of the springs. The 912 Spec Book says clearly " Spring in oil pressure relief valve (crankcase) and spring in bypass valve (crankcase cover), free length 66,0
tension 4.7 kp +- 7%
wire dia 1,4 unquote.

Post Reply