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anthonimartini
Joined: 17 Feb 2020
Posts: 240
Location: portland oregon
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 Posted: Sat Mar 27, 2021 3:02 am Post subject: ideolas compression calc |
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recently somebody posted a mirror to dans old compression calculator. i need this tool to finalize some calculations before i order parts. anybody have that link?
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ive saved alot of 924's
current:
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83 944
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formerly known as turbellion, lost password. |
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Cedric
Joined: 27 Aug 2004
Posts: 2807
Location: Sweden
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anthonimartini
Joined: 17 Feb 2020
Posts: 240
Location: portland oregon
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| Posted: Sat Mar 27, 2021 9:52 am Post subject: |
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i have that one i thought there was another version that had a option for the 931and vw flattop combo. is was hosted bu thewayback machine i think.
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ive saved alot of 924's
current:
79 MochaSchwartz 931
83 944
87 924S
Instagram @anthoni.jpeg
formerly known as turbellion, lost password. |
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jacobroufa
Joined: 18 Nov 2016
Posts: 531
Location: Belvidere, IL
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| Posted: Sun Mar 28, 2021 2:17 am Post subject: |
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I own the 924.terribly.fun domain -- I snagged a bunch of the calcs off of Dan's site before it went down. Let me look and see if I can find the one you're talking about...
If you go to the index by the way, you can see all that is there. http://924.terribly.fun has a listing and it is mostly spreadsheets. The code for the calculator was some wysiwyg generated thing; there might be an option commented out that I can try to find.
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1980 Porsche 931
1981 Porsche 924 Weissach |
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safe
Joined: 18 Mar 2017
Posts: 703
Location: Sweden
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| Posted: Sun Mar 28, 2021 7:23 pm Post subject: |
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| anthonimartini wrote: | | i have that one i thought there was another version that had a option for the 931and vw flattop combo. is was hosted bu thewayback machine i think. |
Just change the piston dish volume to 0 and the compression height to that of the flat tops.
But the calculator is just an approximation. For accurate numbers you will have to measure actual parts on the actual engine.
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/Magnus, Stockholm Sweden
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Porsche 924 -79 NA, EFI and Turbo.
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Porsche 911 -77, 3.2 Targa
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anthonimartini
Joined: 17 Feb 2020
Posts: 240
Location: portland oregon
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| Posted: Mon Mar 29, 2021 2:22 am Post subject: |
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yeah i have ordered a burette so i can see what my head volume is. im ordering the 88mm pistons on monday. ill rough assemble my engine soon and see what it actually is. if the compression is too low ill get the block decked. this is all going on a block that has bad std bores so it needs to be bored out to 88 first. it seems i hit a dead end on using the bmw rods with the big end being way too narrow. i could probably run them with no real ill effect but im just going to lighten to stock rods and rebush.
_________________
ive saved alot of 924's
current:
79 MochaSchwartz 931
83 944
87 924S
Instagram @anthoni.jpeg
formerly known as turbellion, lost password. |
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Mike9311
Joined: 14 Dec 2004
Posts: 1798
Location: Chicago-ish
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| Posted: Thu Apr 29, 2021 12:19 am Post subject: |
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When doing a piston also think about crevice volume before the top ring
looks like this. The outer ring around the bowl
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1980 931 since 1989
1981 Ideola 931 Club Sport
1982 931 Entwicklungsfahrzeug
1979 924 NA ohne 650 mit 471
1982 931 Red Resurrection - 951 IC
1982 931 parts car / resurrection?
1980 924 NA (R&D lightweight)
1982 931 wana-be GTR race car |
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