 1973 914 2.0 Pistons, Domed or inverted dome? |
|
|
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
|
  |
| szcesuil |
 Jan 28 2018, 06:49 PM
Post
#1
|
|
Newbie  Group: Members Posts: 6 Joined: 19-June 17 From: Bolton, MA Member No.: 21,197 Region Association: North East States  |
My father-in-law is rebuilding the engine on a 1973 2.0. The repair manual mentions that the pistons should be domed. However, the actual pistons have more of a dwell at the top. If the pistons and crank shaft were replaced at some point, we aren't sure what would be the best way to move forward. Should we use the same type of pistons that are in there or go back to what the factory originally used? If we revert back to the factory domed pistons, would we also need to replace the crank shaft?
Thanks, Paul |
   |
 
|
| 914Sixer |
Jan 28 2018, 07:12 PM
Post
#2
|
|
914 Guru Group: Members Posts: 8,897 Joined: 17-January 05 From: San Angelo Texas Member No.: 3,457 Region Association: Southwest Region 
|
Only 1.7 pistons are domed. 2.0 USA have slight dish NOT be confused with VW bus piston which has a deep depression. Flat top Euro 2.0 are more commonly used for replacement. 5 hp better according to spec book.
|
|
|
|
| mihai914 |
Jan 28 2018, 07:24 PM
Post
#3
|
|
Senior Member Group: Members Posts: 800 Joined: 2-March 05 From: Montreal, QC Member No.: 3,697 Region Association: None
|
This is how 2.0 US spec pistons should look. As mentioned, they are dished.
(IMG:style_emoticons/default/welcome.png) Attached image(s) 
|
|
|
|
| TheCabinetmaker |
Jan 29 2018, 07:56 AM
Post
#4
|
|
I drive my car everyday Group: Members Posts: 8,301 Joined: 8-May 03 From: Tulsa, Ok. Member No.: 666 |
I've dismantled engines of all sizes. Only once have I encountered domed pistons, and they were not stock. Between the 914S on your other thread, and domed pistons, you have a lot of misinformation. What repair manual said that?
|
|
|
|
| szcesuil |
Jan 29 2018, 08:05 AM
Post
#5
|
|
Newbie Group: Members Posts: 6 Joined: 19-June 17 From: Bolton, MA Member No.: 21,197 Region Association: North East States |
QUOTE(mihai914 @ Jan 28 2018, 08:24 PM)  This is how 2.0 US spec pistons should look. As mentioned, they are dished. (IMG:style_emoticons/default/welcome.png) Thank you! |
|
|
|
| szcesuil |
Jan 29 2018, 11:41 AM
Post
#6
|
|
Newbie Group: Members Posts: 6 Joined: 19-June 17 From: Bolton, MA Member No.: 21,197 Region Association: North East States |
QUOTE(The Cabinetmaker @ Jan 29 2018, 08:56 AM) I've dismantled engines of all sizes. Only once have I encountered domed pistons, and they were not stock. Between the 914S on your other thread, and domed pistons, you have a lot of misinformation. What repair manual said that? He was using the Haynes Owner's Workshop Manual, Porsche 914, 4 cylinder 1969-1976. Page 11 says light alloy with steel inserts, domed crowns for fuel injection, flat crowns for carburetors. Mine is a 2.0 with fuel injection. |
|
|
|
| McMark |
Jan 29 2018, 11:54 AM
Post
#7
|
|
914 Freak! Group: Retired Admin Posts: 20,179 Joined: 13-March 03 From: Grand Rapids, MI Member No.: 419 Region Association: None |
If you haven't bought pistons yet, and if you're not building this engine to a racing-rule-book, then get AAPistons 96mm pistons and cylinders. Drop in ready and will work the factory fuel injection.
|
|
|
|
| MikeM |
Jan 29 2018, 07:53 PM
Post
#8
|
|
Senior Member Group: Members Posts: 564 Joined: 16-May 10 From: Calgary, Canada Member No.: 11,733 Region Association: Canada |
QUOTE(McMark @ Jan 29 2018, 10:54 AM) If you haven't bought pistons yet, and if you're not building this engine to a racing-rule-book, then get AAPistons 96mm pistons and cylinders. Drop in ready and will work the factory fuel injection. Mark...does your recomendation include the 96mm flat top set for 309.00 ? Or are you suggesting a specific set from AA? Thanks. |
|
|
|
| MikeM |
Jan 31 2018, 10:56 AM
Post
#9
|
|
Senior Member Group: Members Posts: 564 Joined: 16-May 10 From: Calgary, Canada Member No.: 11,733 Region Association: Canada |
Bump please...
|
|
|
|
| Mueller |
Jan 31 2018, 11:28 AM
Post
#10
|
|
914 Freak! Group: Members Posts: 17,146 Joined: 4-January 03 From: Antioch, CA Member No.: 87 Region Association: None
|
QUOTE(McMark @ Jan 29 2018, 09:54 AM) If you haven't bought pistons yet, and if you're not building this engine to a racing-rule-book, then get AAPistons 96mm pistons and cylinders. Drop in ready and will work the factory fuel injection. Make sure to properly gap the piston rings (IMG:style_emoticons/default/smile.gif) |
|
|
|
| McMark |
Jan 31 2018, 12:27 PM
Post
#11
|
|
914 Freak! Group: Retired Admin Posts: 20,179 Joined: 13-March 03 From: Grand Rapids, MI Member No.: 419 Region Association: None |
|
|
|
|
|
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:
|
Lo-Fi Version | Time is now: 1st June 2024 - 05:55 AM |
Invision Power Board
v9.1.4 © 2024 IPS, Inc.