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morghen
Joined: 21 Jan 2005
Posts: 8880
Location: Romania
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 Posted: Wed Jan 30, 2013 10:53 pm Post subject: |
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looks great, but i think you could have went for 12:1 
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ideola
Joined: 01 Oct 2004
Posts: 15548
Location: Spring Lake MI
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| Posted: Thu Jan 31, 2013 12:32 pm Post subject: |
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| morghen wrote: | | looks great, but i think you could have went for 12:1 |
There weren't any off-the-shelf pistons that would get me there, plus it's a little too close to the edge for my preference. According to materials I've read, the D-Prod racers were running anywhere from 11.5:1 to 13:1, but at the expense of rebuilds every 8 hours of run time.  Sure, I could do custom pistons, but the point of this exercise is to use all off-the-shelf components to see what can be done.
I am planning some pretty aggressive ignition advance once I get the EDIS installed. I can get to 11.5:1 with a .027" Cometic gasket, so I think the motor should be quite...healthy 
Here's tonight's progress...
Head studs:
Head and water pump installed:
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erstwhile owner of just about every 924 variant ever made |
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924-76
Joined: 05 Jun 2006
Posts: 1475
Location: Ontario, Canada
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| Posted: Thu Jan 31, 2013 8:20 pm Post subject: |
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| ideola wrote: | Head studs:
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What torque specs are you using on those studs?
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1976 924 N/A ROW SOLD
1980 931S
1981 931 Part car RIP |
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ideola
Joined: 01 Oct 2004
Posts: 15548
Location: Spring Lake MI
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| Posted: Thu Jan 31, 2013 10:20 pm Post subject: |
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| 924-76 wrote: | | What torque specs are you using on those studs? |
I'm using the instruction sheet that came in the package, which says to use the ARP assembly lube, and then torque to 90 ft lb in three successive stages, following the factory tightening sequence. I started at 45 ft lb, then did 70 the second time around, and finished up at 90.
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morghen
Joined: 21 Jan 2005
Posts: 8880
Location: Romania
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| Posted: Thu Jan 31, 2013 11:14 pm Post subject: |
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8 hours? did they have the distributor backwards?
Will you dry sump it? please do.
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ideola
Joined: 01 Oct 2004
Posts: 15548
Location: Spring Lake MI
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| Posted: Fri Feb 01, 2013 1:57 am Post subject: |
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| morghen wrote: | | 8 hours? did they have the distributor backwards? |
No, but I'm sure they were running aggressive advance, and running constantly between 5500-7000 RPM (by some accounts, even higher!). So those motors at 13:1 were really stressed. Required a rebuild after each race weekend.
| morghen wrote: | | Will you dry sump it? please do. |
Not this one. It's going to be a street car, so very hard to justify the expense. I am putting an Accusump in the Club Sport though, and still have the dry sump for the UWB motor
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ideola
Joined: 01 Oct 2004
Posts: 15548
Location: Spring Lake MI
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| Posted: Thu Mar 28, 2013 5:24 am Post subject: |
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Long block is now completed.
High-amp [URL="http://garage.ideola.com/prod-ElectricsUpgrades.html#QualityPower"]direct fit replacement alternator[/URL]:
[URL="http://garage.ideola.com/prod-ExhaustUpgrades.html#931ENKhttp://garage.ideola.com/prod-ExhaustUpgrades.html#931ENK"]Locking Stage8 Exhaust Hardware[/URL] and [URL="http://garage.ideola.com/prod-ExhaustUpgrades.html#Headers"]MSDS Header[/URL]:
Vibratechnics "Fast Street" replacement motor mounts:
[URL="http://garage.ideola.com/prod-EFISolutions.html#36-1TW"]Ideola's 36-1 Trigger Wheel[/URL] for EFI and Programmable Ignition conversions:
[URL="http://garage.ideola.com/prod-EngineMods.html#weber"]Redline-Weber 45DCOE Carb Conversion[/URL]:
[URL="http://garage.ideola.com/prod-EFISolutions.html#DBOP"]Ideola's Distributor Block-off Plate[/URL] and Coil Pack Mount for Programmable Ignition conversions:
Natural Aluminum powder coat and high-temp black ceramic exhaust coatings:
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GeorgeV
Joined: 14 Mar 2010
Posts: 306
Location: Brisbane, Australia
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Carrera RSR
Joined: 08 Jan 2010
Posts: 2309
Location: Somerset, UK
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| Posted: Thu Mar 28, 2013 6:56 pm Post subject: |
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Dan, you seem to have the same OCD issues I have! 
Looks fantastic and I'm sure it'll sound great at full chat. Whats your anticipated red line, 7000?
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1980 931 - forged pistons, Piper cam, K27/26 3257 6.10 hybrid turbo, 951 FMIC, custom intake, Mittelmotor dizzy & cam pulley, H&S exhaust, GAZ Gold, Fuch'ed, Quaife
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Then www.924board.org/viewtopic.php?t=31252 |
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Rasta Monsta
Joined: 12 Jul 2006
Posts: 11723
Location: PacNW
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| Posted: Fri Mar 29, 2013 12:53 am Post subject: |
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I like that coil mount, nice piece.
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- WeiBe (1987 924S 2.5t) - 931 S3
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ideola
Joined: 01 Oct 2004
Posts: 15548
Location: Spring Lake MI
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| Posted: Fri Mar 29, 2013 9:59 am Post subject: |
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| Carrera RSR wrote: | Dan, you seem to have the same OCD issues I have!
Looks fantastic and I'm sure it'll sound great at full chat. Whats your anticipated red line, 7000? |
LOL, too funny...I am still a bit miffed that one out of my four transmission plugs was gold while the other three are silver! No way to know what you're going to get when you order from the wholesaler, so I've resisted the urge to order more to get them to match 
I don't plan to spend much time beyond 6500 RPM, but this setup should have no trouble going to 7000, given the big valve head, Stage1 cam, heavy duty springs, and the lightweight Sten Parner solid lifters. I can't wait until May, which is how long it's going to take before I can drop this thing in and even come close to firing it up!!!
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Carrera RSR
Joined: 08 Jan 2010
Posts: 2309
Location: Somerset, UK
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| Posted: Fri Mar 29, 2013 5:24 pm Post subject: |
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When you do fire it up Dan, we expect a video with quality audio. I'll then run it through my sound system for full effect!!
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1980 931 - forged pistons, Piper cam, K27/26 3257 6.10 hybrid turbo, 951 FMIC, custom intake, Mittelmotor dizzy & cam pulley, H&S exhaust, GAZ Gold, Fuch'ed, Quaife
Now www.924board.org/viewtopic.php?t=34690
Then www.924board.org/viewtopic.php?t=31252 |
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vatoisimo
Joined: 31 Aug 2008
Posts: 134
Location: Kent, Wa
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| Posted: Tue Apr 16, 2013 11:20 am Post subject: |
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| ideola wrote: | | the_mad_electrician wrote: | | What pistons would the N/A use? |
Not sure what you're asking...this will be a normally aspirated build...I'm just using the 931 head because of the superior port design and flow, plus the better quench arrangement.
If you wanted to use an NA head with these rods, there are several different alternative piston choices resulting in various distances "down the hole", I'd have to go back and look at my notes to figure out which would be best. It also depends somewhat on what CR one wanted to achieve... |
looks like i might have to pull my "good" motor apart because of low compression in 2-3-4 holes. Do you think that I could drop in high compression jugs without upgrading the rods? |
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ideola
Joined: 01 Oct 2004
Posts: 15548
Location: Spring Lake MI
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| Posted: Wed Apr 17, 2013 12:07 am Post subject: |
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| vatoisimo wrote: | | looks like i might have to pull my "good" motor apart because of low compression in 2-3-4 holes. Do you think that I could drop in high compression jugs without upgrading the rods? |
Yes, you can do this, but there are no "off-the-shelf" options for aftermarket cars as in the build documented in this thread. But if your cylinder bores are within spec (i.e. 86.5mm and not out of round), the cheapest route to achieve this would be to acquire some used 931 pistons. Depending on your deck height, with an NA head, 931 S1 slugs will yield somewhere in the vicinity of 9.7:1 (or greater) CR. 931 S2 slugs with NA head will yield 10.6:1 or greater. Just be aware, this will make the motor an interference design.
The other option would be to get custom-spec Diamond pistons, which can be done in any CR with appropriate valve reliefs for normal NA or big valve setup.
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flosho
Joined: 01 Jul 2004
Posts: 3155
Location: Eau Claire, Wisconsin
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| Posted: Sat Apr 20, 2013 3:45 am Post subject: |
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Dan, did you ever release aftermarket off the shelf fitments for our cars?
Otherwise I will just tell you that I'm looking to do the offset crank grind, longer rods and 88mm pistons to put me at/around 9.0-9.5:1 and I'd like valve reliefs, but it is not realistic, then I'll live with the interference.
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