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R924T
Joined: 17 Sep 2007
Posts: 3
Location: Sweden
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 Posted: Tue Oct 09, 2007 9:48 pm Post subject: |
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I know the pistons have been used before, but never in a NA configuration? only turbo and supercharger. But there have been a lot of posting about it. Does someone know what kind of pistons the 924D engine used, im building an similar engine. Would be nice to met Racing some time, live in sweden too  |
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simsport
Joined: 06 Nov 2002
Posts: 573
Location: UK Warrington
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| Posted: Wed Oct 10, 2007 3:48 am Post subject: Pistons |
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Ok, Im sold on these...can someone just confirm the code if I wanted to buy some. I wanted the number/description of these pistons. I know thay are VWType1, 87/88mm depending on current bore size but not sure of the correct item number with AA or is it also Bugpack?
Thanks a lot.
Simon
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Blown is always best! |
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leadfoot
Joined: 11 Dec 2002
Posts: 2222
Location: gOLD cOAST Australia
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Racing
Joined: 27 Apr 2004
Posts: 374
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| Posted: Mon Oct 29, 2007 8:02 am Post subject: |
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No offense,and for the sake of simplicity only guys.
R924;
E inget större problem.
Bor,å har verkstan min,i Göteborg.
Sen en tid tebax skojar jag ju mest med 16v cossie mercorna.
Nu e det iofs en stund sen jag spika i 931;orna,men om jag kan hjälpa dig så e det bara att säga till.Kikar om inte annat in här då å då.
Känner även gubbar som Sven å Utzon mfl..-för vad d e värt.
Om du vill ha tag i mig för att fråga ngt finns jag på 0737-189010 dagtid.
Jesper |
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Topls82
Joined: 08 Feb 2021
Posts: 57
Location: Chicago
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| Posted: Sun Apr 23, 2023 5:02 am Post subject: Pistons |
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Anyone have updated info on the flat head VW type pistons in 931 ?
Please share specs and mods needed
Thanks
Frank |
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Mike9311
Joined: 14 Dec 2004
Posts: 1678
Location: Chicago-ish
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| Posted: Tue May 23, 2023 1:36 am Post subject: |
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These are the old pictures of the Utzon build which i am pretty sure are the VW units. Edit: I will say I am now highly interested in these too since I am no longer that interested in quench for a turbo build (which is a hard 180 for me). I am still digging if I have any more info
_________________
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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Cedric
Joined: 27 Aug 2004
Posts: 2614
Location: Sweden
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| Posted: Tue May 23, 2023 2:45 am Post subject: |
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Why would you skip the quench area ? our engines aren't exactly fast burners as it is?
_________________
1980 924 Turbo
www.instagram.com/garagecedric/ |
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Mike9311
Joined: 14 Dec 2004
Posts: 1678
Location: Chicago-ish
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| Posted: Tue May 23, 2023 7:33 am Post subject: |
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| Cedric wrote: | | Why would you skip the quench area ? our engines aren't exactly fast burners as it is? |
If I could do it close at around 1mm then I would do it but the quench pad could become very limited with all the porting and, in particular, the chamber work I have come across. If I would copy it to lessen the blow back on the long side radius flow of the port it seems like there isn't much pad area left. I have also seen the application of a radius from flat to chamber (Vizard). What is actually left and how affective will it be? I don't want to end up with lazy quench but that, supposedly, is only if you are actually applying quench with too large a gap (too thick of a gasket)
_________________
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
Last edited by Mike9311 on Wed May 24, 2023 1:25 am; edited 1 time in total |
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72rallye
Joined: 08 Apr 2023
Posts: 16
Location: San Diego, CA, USA
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| Posted: Tue May 23, 2023 1:19 pm Post subject: Euro NA pistons in 931 S2 |
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FWIW, I used a different route. Two of my 931 S2 pistons were cracked below the top piston ring. I didn't want to spend much money, and after some consideration bought a set of used Euro NA pistons.
The compression ratio of this combination calculates to 7.8:1, smack dab in the middle of the S1 and S2 engines. Since the bore is the same, one only needs to hone, but not machine the cylinders.
The engine runs fine with the new pistons, but I haven't had a chance to drive the car, yet. Also, until the WUR problems are sorted out it would be unsafe to use any boost.
I looked through the archives, but couldn't find any information on this setup. Maybe, because it's an obviously bad idea. |
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Mike9311
Joined: 14 Dec 2004
Posts: 1678
Location: Chicago-ish
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| Posted: Wed May 24, 2023 1:30 am Post subject: Re: Euro NA pistons in 931 S2 |
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| 72rallye wrote: | FWIW, I used a different route. Two of my 931 S2 pistons were cracked below the top piston ring. I didn't want to spend much money, and after some consideration bought a set of used Euro NA pistons.
The compression ratio of this combination calculates to 7.8:1, smack dab in the middle of the S1 and S2 engines. Since the bore is the same, one only needs to hone, but not machine the cylinders.
The engine runs fine with the new pistons, but I haven't had a chance to drive the car, yet. Also, until the WUR problems are sorted out it would be unsafe to use any boost.
I looked through the archives, but couldn't find any information on this setup. Maybe, because it's an obviously bad idea. |
That is an interesting way of approaching the problem. Not necessary a bad idea. Just an idea especially when funds are limited. Just keep us updated on how it runs
When safe runs an NA the way he does so successfully, we know these engines work, NA or Turbo
_________________
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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