|
|

|
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. |
|
|
![]() ![]() |
| TRP |
Mar 28 2026, 05:21 PM
Post
#1
|
|
Member ![]() ![]() Group: Members Posts: 274 Joined: 2-September 23 From: Morgan Hill, CA Member No.: 27,559 Region Association: None
|
What is this metal tube? I assume its part of the EGR / emissions system for a 1.8 and it allows gasses / vapors to flow back into the intake system. On my 1975 1.8 I do not have this metal tube, my car has this replicated via a series of rubber hoses and plastic connectors. Im wondering if a previous owner lost ir and recreated this part with the hoses/plastic connectors?
My car is a 1975, but it is not a smog system car. Should my car have this tube? Thank you, Ted |
| JeffBowlsby |
Mar 28 2026, 06:28 PM
Post
#2
|
|
914 Wiring Harnesses & Beekeeper ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 9,220 Joined: 7-January 03 From: San Ramon CA Member No.: 104 Region Association: None
|
The tube is part of the 1.8L EGR system. The 74 and 75 tubes are different.
49 state 75 1.8L cars did not have an EGR system, only the CA market cars. https://bowlsby.net/914/Classic/Emissions.htm https://bowlsby.net/914/Classic/zMan_1975_S...iningManual.pdf |
| wonkipop |
Mar 28 2026, 07:30 PM
Post
#3
|
|
914 Guru ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 5,475 Joined: 6-May 20 From: north antarctica Member No.: 24,231 Region Association: NineFourteenerVille
|
as per Jeff.
@TRP i have your L jet data filed away in my L Jet files. as i recall your car no longer had the emissions sticker on the fan casting to identify the engine and compliance. but it did have the 918 paint stamp on the engine tin. from my files. which means its a 49 state USEPA only certified. also that it originally was base model engine (not appearance group) as 918 stamped engines lacked the temp sensor in the sump plate and associated wiring running up behind the fan casting. the hose diagram is here. http://www.914world.com/bbs2/index.php?sho...7407&st=280 refer engine family 15 hose diagram. cars with an EGR were california only as jeff bowlsby notes. also had a CAT and the throttle body was a twin port TB. the EGR was activated by the vacuum port above the throttle plate in the TB and the EGR connected to the PCV hose via the metal plumbing piece you are asking about. you should not have any of that. also indicates your car was originally sold outside of california when delivered new. (IMG:style_emoticons/default/beerchug.gif) |
| wonkipop |
Mar 28 2026, 07:36 PM
Post
#4
|
|
914 Guru ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 5,475 Joined: 6-May 20 From: north antarctica Member No.: 24,231 Region Association: NineFourteenerVille
|
as per Jeff. @TRP i have your L jet data filed away in my L Jet files. as i recall your car no longer had the emissions sticker on the fan casting to identify the engine and compliance. but it did have the 918 paint stamp on the engine tin. from my files. which means its a 49 state USEPA only certified. also that it originally was base model engine (not appearance group) as 918 stamped engines lacked the temp sensor in the sump plate and associated wiring running up behind the fan casting. the hose diagram is here. http://www.914world.com/bbs2/index.php?sho...7407&st=280 refer engine family 15 hose diagram. cars with an EGR were california only as jeff bowlsby notes. also had a CAT and the throttle body was a twin port TB. the EGR was activated by the vacuum port above the throttle plate in the TB and the EGR connected to the PCV hose via the metal plumbing piece you are asking about. you should not have any of that. also indicates your car was originally sold outside of california when delivered new. (IMG:style_emoticons/default/beerchug.gif) EDIT ps - it does have a smog system. (IMG:style_emoticons/default/biggrin.gif) (IMG:style_emoticons/default/biggrin.gif) its called the distributor and retarded timing. all the L jets 74 and 75 had variations on the theme of retarded timing depending on the jurisdiction - USEPA or CARB. (IMG:style_emoticons/default/biggrin.gif) its just that the 75 californian models had to conform to the highest levels of a progressive 2 tiered regulation structure. basically your car in stock form is pretty much identical to the set up on the 74 californian L jets. |
| TRP |
Mar 28 2026, 08:02 PM
Post
#5
|
|
Member ![]() ![]() Group: Members Posts: 274 Joined: 2-September 23 From: Morgan Hill, CA Member No.: 27,559 Region Association: None
|
Thank you both, I figured the two of you would know. (IMG:style_emoticons/default/biggrin.gif)
|
| bkrantz |
Mar 28 2026, 08:10 PM
Post
#6
|
|
914 Guru ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 8,643 Joined: 3-August 19 From: SW Colorado Member No.: 23,343 Region Association: Rocky Mountains
|
Reminds me how complicated (and desperate) auto emissions designs got in the 1970s, and how terrible engine performance got. And also how creative car owners got.
I had a 1976 X1/9 that had a restrictive exhaust, with (I think) a cast iron thermal reaction exhaust manifold with EGR injection, tiny pipe, and early tech catalytic converter. In my attempt to get more than 61 hp from 1300 cc (don't laugh--6 hp would be a 10% improvement) I got some headers and a custom "performance" exhaust. But with annual emissions testing that included a visual inspection, I had to remove my headers and reinstall the factory exhaust every year. |
| wonkipop |
Mar 29 2026, 02:38 AM
Post
#7
|
|
914 Guru ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 5,475 Joined: 6-May 20 From: north antarctica Member No.: 24,231 Region Association: NineFourteenerVille
|
Reminds me how complicated (and desperate) auto emissions designs got in the 1970s, and how terrible engine performance got. And also how creative car owners got. I had a 1976 X1/9 that had a restrictive exhaust, with (I think) a cast iron thermal reaction exhaust manifold with EGR injection, tiny pipe, and early tech catalytic converter. In my attempt to get more than 61 hp from 1300 cc (don't laugh--6 hp would be a 10% improvement) I got some headers and a custom "performance" exhaust. But with annual emissions testing that included a visual inspection, I had to remove my headers and reinstall the factory exhaust every year. only for yank tanks on carbs. the germans with their EFI just went forwards. the only drop off for the VWs (and 914s) was the drop in compression for unleaded fuels. you got to love the germans. futurists. krautrock and fuel injection and beer and the berlin wall. |
![]() ![]() |
|
Lo-Fi Version | Time is now: 29th March 2026 - 03:36 AM |
| All rights reserved 914World.com © since 2002 |
|
914World.com is the fastest growing online 914 community! We have it all, classifieds, events, forums, vendors, parts, autocross, racing, technical articles, events calendar, newsletter, restoration, gallery, archives, history and more for your Porsche 914 ... |