 1.8 Liter Race Motor Questions, L Jet and Cam |
|
|
|
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. |
|
|
| motorvated |
 Sep 18 2022, 09:06 AM
Post
#1
|
|
Member  Group: Members Posts: 282 Joined: 13-February 13 From: Colorado Member No.: 15,519 Region Association: Rocky Mountains  |
I am thinking of building a reliable race motor from my stock L Jet 1.8. I am thinking of increasing the bore and going to flat top pistons and slightly higher compression ratio, keeping it below 2.0 liter displacement. Either single heavy duty or dual valve springs and stainless steel valves, etc. I am thinking of using the L Jet system that is on it now, going to 2.0 liter injectors. Are there any performance camshafts that will work well with the L Jet, or am I barking up the wrong tree. My other option is dual 40 IDF Weber carbs and a cam to go with them. I'd like to try to use the L Jet if a suitable cam is available. Anybody done something similar? All comments welcome.
|
   |
 
|
  |
Replies
| Geezer914 |
Oct 1 2022, 06:11 AM
Post
#2
|
|
Geezer914 Group: Members Posts: 2,260 Joined: 18-March 09 From: Salem, NJ Member No.: 10,179 Region Association: North East States 
|
Just rebuilt my 1.8L to 2056.
AAA 96mm Biral cylinders with flat top Pistons Hoffman RS heads Rabby 9550 cam Vanagon 50mm throttle body. Let injection. 9.1 compression ratio. 2.0L crank and rods I tried 2.0L injectors and melted the cold start injector and part of the wire harness! 1.8 injectors have the same flow rate. Mallory distributor with silver springs Adjusted the air flow meter large wheel 4 teeth counter clockwise 26mm CB Performance oil pump. |
|
|
|
| brant |
Oct 1 2022, 06:43 AM
Post
#3
|
|
914 Wizard Group: Members Posts: 12,167 Joined: 30-December 02 From: Colorado Member No.: 47 Region Association: Rocky Mountains 
|
QUOTE(Geezer914 @ Oct 1 2022, 06:11 AM)  Just rebuilt my 1.8L to 2056. AAA 96mm Biral cylinders with flat top Pistons Hoffman RS heads Rabby 9550 cam Vanagon 50mm throttle body. Let injection. 9.1 compression ratio. 2.0L crank and rods I tried 2.0L injectors and melted the cold start injector and part of the wire harness! 1.8 injectors have the same flow rate. Mallory distributor with silver springs Adjusted the air flow meter large wheel 4 teeth counter clockwise 26mm CB Performance oil pump. Would not be a legal vintage race motor due to displacement |
|
|
|
| motorvated |
Oct 1 2022, 01:31 PM
Post
#4
|
|
Member Group: Members Posts: 282 Joined: 13-February 13 From: Colorado Member No.: 15,519 Region Association: Rocky Mountains |
QUOTE(brant @ Oct 1 2022, 06:43 AM) QUOTE(Geezer914 @ Oct 1 2022, 06:11 AM) Just rebuilt my 1.8L to 2056. AAA 96mm Biral cylinders with flat top Pistons Hoffman RS heads Rabby 9550 cam Vanagon 50mm throttle body. Let injection. 9.1 compression ratio. 2.0L crank and rods I tried 2.0L injectors and melted the cold start injector and part of the wire harness! 1.8 injectors have the same flow rate. Mallory distributor with silver springs Adjusted the air flow meter large wheel 4 teeth counter clockwise 26mm CB Performance oil pump. Would not be a legal vintage race motor due to displacement So how about 96 mm cylinders flat top or domed pistons Stock 1.8 heads ported and polished dual valve springs Webcam 86b or 86b/c Vanagon 50 mm throttle body L Jet injection 9:0:1 - 10:1 Compression Ratio (?) Stock 1.8 Crank and Stock 1.8 Rods 1.8 liter Injectors Displacement stays below 2.0 liter, and no change in stroke, so engine is legal for Vintage, correct? |
|
|
|
Posts in this topic
motorvated 1.8 Liter Race Motor Questions Sep 18 2022, 09:06 AM
Charles Freeborn What flavor of racing? Sep 18 2022, 11:16 PM
motorvated
What flavor of racing?
Vintage road racing.. Sep 19 2022, 07:08 AM GregAmy Given there's no real historics rules...I... Sep 19 2022, 07:27 AM Charles Freeborn If you're building to SCCA VP rules they'r... Sep 19 2022, 08:34 AM GregAmy Concur with Charles' advice.
However, this ca... Sep 19 2022, 09:51 AM Charles Freeborn I found the supplemental regs for Vintage SCCA in ... Sep 19 2022, 03:01 PM brant It’s an RMVR vintage racer
So those rules :
N... Sep 19 2022, 03:39 PM Charles Freeborn Alen Johnsen is definitely the go-to for those cri... Sep 19 2022, 08:27 PM stownsen914 The stock injection will be a big limiter of hp. C... Sep 22 2022, 09:42 PM Brett W Agree with all of the above. Toss the Ljet in the... Sep 24 2022, 08:36 AM GregAmy Now all of that said, the six makes a lot more sen... Sep 26 2022, 06:24 AM brant Check the rules
Might work
Check the rules
40 ... Oct 1 2022, 03:55 PM brant Found it in the 1972 GCR
1.2 mm bore
So a 95mm cy... Oct 2 2022, 08:52 AM stownsen914 Another consideration if you want to keep the L Je... Oct 3 2022, 06:50 AM |
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:
|
Lo-Fi Version | Time is now: 2nd April 2026 - 11:19 AM |
Invision Power Board
v9.1.4 © 2026 IPS, Inc.