Type 4 rebuild questions |
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Type 4 rebuild questions |
mepstein |
Nov 19 2018, 08:14 PM
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#1
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914-6 GT in waiting Group: Members Posts: 19,223 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. |
Mark Henry |
Nov 19 2018, 08:58 PM
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#2
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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. |
mepstein |
Nov 19 2018, 09:39 PM
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#3
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914-6 GT in waiting Group: Members Posts: 19,223 Joined: 19-September 09 From: Landenberg, PA/Wilmington, DE Member No.: 10,825 Region Association: MidAtlantic Region |
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. |
Chris914n6 |
Nov 20 2018, 01:20 AM
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#4
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Jackstands are my life. Group: Members Posts: 3,302 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.... |
BeatNavy |
Nov 20 2018, 06:05 AM
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#5
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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. |
Racer |
Nov 20 2018, 07:05 AM
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#6
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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?
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saigon71 |
Nov 20 2018, 07:08 AM
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#7
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Senior Member Group: Members Posts: 1,995 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. |
Literati914 |
Nov 20 2018, 09:35 AM
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#8
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Senior Member Group: Members Posts: 1,428 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. |
914Sixer |
Nov 20 2018, 09:42 AM
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#9
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914 Guru Group: Members Posts: 8,863 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.
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GregAmy |
Nov 20 2018, 10:07 AM
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#10
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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. |
yellowporky |
Nov 20 2018, 10:26 AM
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#11
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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 |
Alapone |
Nov 20 2018, 11:09 AM
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#12
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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>?
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Racer |
Nov 20 2018, 11:22 AM
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#13
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Senior Member Group: Members Posts: 787 Joined: 25-August 03 From: Northern Virginia Member No.: 1,073 Region Association: MidAtlantic 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. 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) |
mepstein |
Nov 20 2018, 01:01 PM
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#14
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914-6 GT in waiting Group: Members Posts: 19,223 Joined: 19-September 09 From: Landenberg, PA/Wilmington, DE Member No.: 10,825 Region Association: MidAtlantic 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. Yea, my mistake. @sirandy |
914Sixer |
Nov 20 2018, 01:13 PM
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#15
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914 Guru Group: Members Posts: 8,863 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.
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thelogo |
Nov 20 2018, 02:40 PM
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#16
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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 |
Jamie |
Nov 20 2018, 02:41 PM
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#17
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Senior Member Group: Members Posts: 1,025 Joined: 13-October 04 From: Georgetown,KY Member No.: 2,939 Region Association: South East States |
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) |
mepstein |
Nov 20 2018, 02:50 PM
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#18
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914-6 GT in waiting Group: Members Posts: 19,223 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. |
JOEPROPER |
Nov 20 2018, 04:24 PM
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#19
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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.
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TravisNeff |
Nov 20 2018, 05:03 PM
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#20
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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? |
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