Home  |  Forums  |  914 Info  |  Blogs
 
914World.com - The fastest growing online 914 community!
 
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.
 

Welcome Guest ( Log In | Register )

3 Pages V  1 2 3 >  
 Reply to this topicStart new topic
> Type 4 rebuild questions
mepstein
post Nov 19 2018, 08:14 PM
Post #1


914-6 GT in waiting
***************

Group: Members
Posts: 19,213
Joined: 19-September 09
From: Landenberg, PA/Wilmington, DE
Member No.: 10,825
Region Association: MidAtlantic Region
What can I do to rebuild my 1.7 for more HP and torque but keep the original d-jet.

piston and cylinders
crank
camshaft
heads
?

I know I can't change the cam too much but is there one that will do better and still work with d-jet.

I know there is modern FI but I'm not interested. No carbs. I'm not looking for all out HP or dropping 10K on an engine kit. I just want a nice bump in power, if possible, while keeping a stock looking engine.
User is online!Profile CardPM
Go to the top of the page
+Quote Post
Mark Henry
post Nov 19 2018, 08:58 PM
Post #2


that's what I do!
***************

Group: Members
Posts: 20,065
Joined: 27-December 02
From: Port Hope, Ontario
Member No.: 26
Region Association: Canada
Webcam #73
96mm KB's for 66mm crank and move up to 1800S heads. I'd guess 90hp max.
Headers would be a consideration, only true bolt on HP, but at your HP it won't be a huge improvement. Maybe 5%.

No replacement for displacement, consider stepping up to 2,0, but no idea how well it would work with 1.7 djet. L-jet works for sure and 2,0 djet.
I love the 2056 2.0 head Ljet combo.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
mepstein
post Nov 19 2018, 09:39 PM
Post #3


914-6 GT in waiting
***************

Group: Members
Posts: 19,213
Joined: 19-September 09
From: Landenberg, PA/Wilmington, DE
Member No.: 10,825
Region Association: MidAtlantic Region
QUOTE(Mark Henry @ Nov 19 2018, 09:58 PM) *

Webcam #73
96mm KB's for 66mm crank and move up to 1800S heads. I'd guess 90hp max.
Headers would be a consideration, only true bolt on HP, but at your HP it won't be a huge improvement. Maybe 5%.

No replacement for displacement, consider stepping up to 2,0, but no idea how well it would work with 1.7 djet. L-jet works for sure and 2,0 djet.
I love the 2056 2.0 head Ljet combo.


I do have a set of nos mahle 94mm P&C's. Also have a 2.0 crank. I don't know if either of these will fit or work to improve power. I was hoping to see 100 but I realize the stock 1.7 d-jet has limitations.

Weight reduction (of the car) will also help to increase performance.
User is online!Profile CardPM
Go to the top of the page
+Quote Post
Chris914n6
post Nov 20 2018, 01:20 AM
Post #4


Jackstands are my life.
****

Group: Members
Posts: 3,300
Joined: 14-March 03
From: Las Vegas, NV
Member No.: 431
Region Association: Southwest Region
The big difference with Djets is ecu and injectors.

But for all that trouble might as well put it into that Suby....
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
BeatNavy
post Nov 20 2018, 06:05 AM
Post #5


Certified Professional Scapegoat
****

Group: Members
Posts: 2,924
Joined: 26-February 14
From: Easton, MD
Member No.: 17,042
Region Association: MidAtlantic Region
Mark (E) I'm doing a similar build right now. 2056, webcam, Hoffman heads, and stock-djet. Not to contradict Mr. Henry (who has a world more experience than I will ever have), but I thought something like this was good for north of 110 hp. Maybe anything less than 200 to Mark (H) just looks like 100-ish (IMG:style_emoticons/default/smile.gif)

I guess we shall see.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Racer
post Nov 20 2018, 07:05 AM
Post #6


Senior Member
***

Group: Members
Posts: 787
Joined: 25-August 03
From: Northern Virginia
Member No.: 1,073
Region Association: MidAtlantic Region
I know a bump to a 1911 was always popular for 1.7s wanting more.. but the djet question is one I cant answer. I know 2.0/2056 with 100-110hp with djets were possible.. Are the 1.7 and 2.0 djets different?
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
saigon71
post Nov 20 2018, 07:08 AM
Post #7


Senior Member
***

Group: Members
Posts: 1,993
Joined: 1-June 09
From: Dillsburg, PA
Member No.: 10,428
Region Association: MidAtlantic Region
FAT 440 MP camshaft is great with D-jet.

I think a good budget build would be 96mm pistons with 1.7 crank, lightened flywheel and FAT 440 MP cam. Send the MPS to Jeff Bowlsby for 1911 calibration. Have stock heads rebuilt.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Literati914
post Nov 20 2018, 09:35 AM
Post #8


Senior Member
***

Group: Members
Posts: 1,425
Joined: 16-November 06
From: Dallas, TX
Member No.: 7,222
Region Association: Southwest Region
Posted in the classifieds?, you amateur (IMG:style_emoticons/default/poke.gif)

I do kind of envy the built 1.7, they can be quick/high revving engines AND gas mileage! I like that.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
914Sixer
post Nov 20 2018, 09:42 AM
Post #9


914 Guru
*****

Group: Members
Posts: 8,859
Joined: 17-January 05
From: San Angelo Texas
Member No.: 3,457
Region Association: Southwest Region
Correct me if I am wrong, but the stock 1.7 made 88 hp in 70,71 according to brochure. They made it happen with domed pistons.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
GregAmy
post Nov 20 2018, 10:07 AM
Post #10


Advanced Member
****

Group: Members
Posts: 2,264
Joined: 22-February 13
From: Middletown CT
Member No.: 15,565
Region Association: North East States
"Subscribing". My 2L street car is running nice with the stock D-Jet, but I heard that the system does not respond well to engine mods.

I also question how much more power you're going to get through that small single-port throttle body.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
yellowporky
post Nov 20 2018, 10:26 AM
Post #11


Member
**

Group: Members
Posts: 422
Joined: 18-October 09
From: Martinez, Ca.
Member No.: 10,948
Region Association: Northern California
getting ready to build up my 73 1.7 next month.
This was perfect timing.
Thanks for the info
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Alapone
post Nov 20 2018, 11:09 AM
Post #12


Member
**

Group: Members
Posts: 105
Joined: 4-April 13
From: Nj
Member No.: 15,734
Region Association: None
Just curious, has anyone built a motor with a 66mm crank and 100 or 101mm or larger pistons, like a short stroke 2.1. Is it possible? what would the characteristics of that set up be>?
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Racer
post Nov 20 2018, 11:22 AM
Post #13


Senior Member
***

Group: Members
Posts: 787
Joined: 25-August 03
From: Northern Virginia
Member No.: 1,073
Region Association: MidAtlantic Region
QUOTE(914Sixer @ Nov 20 2018, 10:42 AM) *

Correct me if I am wrong, but the stock 1.7 made 88 hp in 70,71 according to brochure. They made it happen with domed pistons.



i think that is incorrect. I believe my Stock early 1.7 was rated at 80hp. By 72 or maybe 73 they were down to approx 75hp.

Really might depend if you are looking at DIN, SAE, Gross or Net too as all were popular Brochure horsepower tools (IMG:style_emoticons/default/wink.gif)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
mepstein
post Nov 20 2018, 01:01 PM
Post #14


914-6 GT in waiting
***************

Group: Members
Posts: 19,213
Joined: 19-September 09
From: Landenberg, PA/Wilmington, DE
Member No.: 10,825
Region Association: MidAtlantic Region
QUOTE(Literati914 @ Nov 20 2018, 10:35 AM) *

Posted in the classifieds?, you amateur (IMG:style_emoticons/default/poke.gif)

I do kind of envy the built 1.7, they can be quick/high revving engines AND gas mileage! I like that.


Yea, my mistake.
@sirandy
User is online!Profile CardPM
Go to the top of the page
+Quote Post
914Sixer
post Nov 20 2018, 01:13 PM
Post #15


914 Guru
*****

Group: Members
Posts: 8,859
Joined: 17-January 05
From: San Angelo Texas
Member No.: 3,457
Region Association: Southwest Region
My bad, I got on the wrong info line. 88 hp was for the 73 2.0. 76 hp is for the 1.7.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
thelogo
post Nov 20 2018, 02:40 PM
Post #16


Senior Member
***

Group: Retired Members
Posts: 1,510
Joined: 6-April 10
Member No.: 11,572
Region Association: None
If your stick in with djet = stay bone stock

If you want to go above 60-70-80 hp

Then djet wont get you there
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Jamie
post Nov 20 2018, 02:41 PM
Post #17


Senior Member
***

Group: Members
Posts: 1,025
Joined: 13-October 04
From: Georgetown,KY
Member No.: 2,939
Region Association: South East States
QUOTE(914Sixer @ Nov 20 2018, 11:13 AM) *

My bad, I got on the wrong info line. 88 hp was for the 73 2.0. 76 hp is for the 1.7.


Stock 73 was/is rated at 80 HP. (IMG:style_emoticons/default/driving.gif)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
mepstein
post Nov 20 2018, 02:50 PM
Post #18


914-6 GT in waiting
***************

Group: Members
Posts: 19,213
Joined: 19-September 09
From: Landenberg, PA/Wilmington, DE
Member No.: 10,825
Region Association: MidAtlantic Region
I already have 94mm Mahle P&C's, 2.0 crank and a FI cam kit. I'm wondering if any of those things will make a difference if I rebuild the engine. If it's little to none, or not a combo that will work, I won't bother. If I could get another 15hp, well that's a 20% increase on that engine so It would be worth it to me.

I have a 250lb weight reduction planned (on paper) so a little boost with a much lighter car would make it fun.
User is online!Profile CardPM
Go to the top of the page
+Quote Post
JOEPROPER
post Nov 20 2018, 04:24 PM
Post #19


The answer is "no" unless you ask...
***

Group: Members
Posts: 1,184
Joined: 21-November 15
From: White Plains New York
Member No.: 19,387
Region Association: North East States
I think you're right about looking at HP increases in percentage vs. looking at actual "big" numbers. When you are starting off with a relatively low HP number, I think it's unreasonable to look for high HP numbers with stock FI. I think 20% is a terrific goal and will be very noticeable.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
TravisNeff
post Nov 20 2018, 05:03 PM
Post #20


914 Guru
*****

Group: Members
Posts: 5,082
Joined: 20-March 03
From: Mesa, AZ
Member No.: 447
Region Association: Southwest Region
The CA spec 73 1.7 was 72 HP, lower than the 1.8 believe it or not.

I wonder if you could build a 2.0 liter engine and use the 1.7 djet?
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
« Next Oldest · 914World Garage · Next Newest »
 

3 Pages V  1 2 3 >
Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 

Display Mode: Standard · Switch to: Linear+ · Switch to: Outline

Track this topic · Email this topic · Print this topic · Subscribe to this forum

- Lo-Fi Version Time is now: 16th April 2024 - 12:36 PM
Invision Power Board v9.1.4 © 2024  IPS, Inc.
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 ...