 slightly more than stock rebuild, 1.8 L Jet |
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| swood |
 Feb 11 2003, 04:08 PM
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#1
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Senior Member  Group: Members Posts: 1,839 Joined: 6-February 03 From: Strong Beach Member No.: 251 Region Association: None  |
Am I correct in assuming that if I do a stock rebuild ('75 1.8 Ljet) but bore the 93mm barrels to 96mm and use 96mm KB pistons, the CR would be affected? More specifically, does that slightly larger comustion area alter the CR thereby requiring mods to the deck height or head?
I plan on having the heads rebuilt and cc'd to have each chamber match and to be able to calculate the CR. Is it reasonable to shoot for 8:1 or so and run 91 octane pump gas? I'm trying to figure out all the calcs to make sure what I'm going to have done will work out. Deck Height: Is this a function of calculating the CR, or is it set first and the combustion chamber modified to arrive at a predetermined CR? By the way, my case is split and I'm going to have the machining done as soon as I can confirm the numbers. Thanks guys! Steve |
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Replies(1 - 8)
| Mueller |
Feb 11 2003, 04:12 PM
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#2
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914 Freak! Group: Members Posts: 17,146 Joined: 4-January 03 From: Antioch, CA Member No.: 87 Region Association: None 
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I had the same setup on my first 914...1.8 with a big bore kit...stock FI (L-Jet)....no problems
Yes, the compression is raised a bit when going to the bigger bore Before I installed the Megasquirt I was running a stock 1.8 L-Jet on my Euro spec 2.0 (flat top pistons, higher than norm compression compared to the slightly dished regular Euro pistons) No problems with this setup as well. |
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| bernbomb914 |
 Feb 11 2003, 08:13 PM
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#3
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one of the oldest Farts on this board Group: Benefactors Posts: 1,873 Joined: 29-December 02 From: Temecula, CA Member No.: 36  |
Mike did this change make a noticeable differance in street performance? Was it easy to drive for a daily driver. What HP do you think it produced?
Bernie (IMG:style_emoticons/default/aktion035.gif) |
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| Mueller |
Feb 12 2003, 12:29 PM
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#4
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914 Freak! Group: Members Posts: 17,146 Joined: 4-January 03 From: Antioch, CA Member No.: 87 Region Association: None
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This was my first 914 so I had no benchmarks....I can tell you the first drivers ed event I went to both of my instructors had healthy 2.0 914's and thought I had a "very strong" 2.0....
When I told 'em it was a stock 1.8 with a big bore, both where very impressed |
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| swood |
Feb 13 2003, 06:58 PM
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#5
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Senior Member Group: Members Posts: 1,839 Joined: 6-February 03 From: Strong Beach Member No.: 251 Region Association: None |
That's SWEET! Ok then, I'm goin fer it. Now I'm looking at the stock grind cam vs. the Web Cam #73 grind to see how much variance it has. That might help goose it up a bit too. Of course I'll have that restrictive exhaust to contend with...
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| Mueller |
Feb 13 2003, 07:07 PM
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#6
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914 Freak! Group: Members Posts: 17,146 Joined: 4-January 03 From: Antioch, CA Member No.: 87 Region Association: None
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Get rid of the exhaust at the same time..it's easy to backdate to the early style...
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| swood |
Feb 13 2003, 07:13 PM
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#7
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Senior Member Group: Members Posts: 1,839 Joined: 6-February 03 From: Strong Beach Member No.: 251 Region Association: None |
what about the O2 sensor (i think) in the muffler? does it just get disconnected?
Can you tell me what exh setup would work best? and I mean just finding a used set up for starters (manifold to tailpipe) |
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| Mueller |
Feb 13 2003, 07:26 PM
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#8
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914 Freak! Group: Members Posts: 17,146 Joined: 4-January 03 From: Antioch, CA Member No.: 87 Region Association: None
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O2 sensor??
You shouldn't have one unless someone added one...that wire is for the cat converter to give you a heads up if it's too hot......(???) one wire correct? I will have a complete setup for sale soon.....it's off an early 2.0 from when i did the same exact swap...I used to have a '75 2.0 which uses the identical exhaust as the 1.8... I have no more use for it with my newest car since I am going to a header...(and I have the '74 2.0 exhaust if I change my mind....like that has never happened before, LOL) |
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| swood |
Feb 13 2003, 08:45 PM
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#9
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Senior Member Group: Members Posts: 1,839 Joined: 6-February 03 From: Strong Beach Member No.: 251 Region Association: None |
yep. one wire. just a temp sensor? Yeah, let me know when your ready to sell what you have, I'd like to see what you got. and how much. that doesnt sound good...
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