View previous topic :: View next topic |
Author |
Message |
Juho
Joined: 03 Oct 2018 Posts: 391 Location: Finland
|
Posted: Wed Aug 25, 2021 11:08 pm Post subject: Decking block |
|
|
How much you can deck the block? Timing belt issues? I need to shave off 1.5-2.5mm for desired compression. |
|
Back to top |
|
|
safe
Joined: 18 Mar 2017 Posts: 631 Location: Sweden
|
Posted: Thu Aug 26, 2021 6:50 am Post subject: |
|
|
Yes, you need a shorter belt. One tooth I think. _________________ /Magnus, Stockholm Sweden
=======================
Porsche 924 -79 NA, EFI and Turbo.
Porsche 931 -79
Porsche 911 -77, 3.2 Targa
Porsche 911 -69, 3.6, Coupe |
|
Back to top |
|
|
Juho
Joined: 03 Oct 2018 Posts: 391 Location: Finland
|
|
Back to top |
|
|
safe
Joined: 18 Mar 2017 Posts: 631 Location: Sweden
|
Posted: Thu Aug 26, 2021 5:54 pm Post subject: |
|
|
Not sure. I have friend who has decked the block 1.5mm, I know he runs a shorter belt, but I don't know where he gets it. Its a bit tight to get on the engine, you really don't have to tension the tensioner... _________________ /Magnus, Stockholm Sweden
=======================
Porsche 924 -79 NA, EFI and Turbo.
Porsche 931 -79
Porsche 911 -77, 3.2 Targa
Porsche 911 -69, 3.6, Coupe |
|
Back to top |
|
|
Juho
Joined: 03 Oct 2018 Posts: 391 Location: Finland
|
Posted: Thu Aug 26, 2021 6:30 pm Post subject: |
|
|
Could you ask him what belt he runs? |
|
Back to top |
|
|
safe
Joined: 18 Mar 2017 Posts: 631 Location: Sweden
|
Posted: Thu Aug 26, 2021 7:14 pm Post subject: |
|
|
Juho wrote: | Could you ask him what belt he runs? |
Yes.
He says,1 tooth shorter, he gets them from Mittelmotor.
Mottelmotors webshop really really sucks if you cant find it, so you might have to call them or email, but they suck at email too... _________________ /Magnus, Stockholm Sweden
=======================
Porsche 924 -79 NA, EFI and Turbo.
Porsche 931 -79
Porsche 911 -77, 3.2 Targa
Porsche 911 -69, 3.6, Coupe |
|
Back to top |
|
|
Juho
Joined: 03 Oct 2018 Posts: 391 Location: Finland
|
Posted: Thu Aug 26, 2021 9:21 pm Post subject: |
|
|
safe wrote: | Juho wrote: | Could you ask him what belt he runs? |
Yes.
He says,1 tooth shorter, he gets them from Mittelmotor.
Mottelmotors webshop really really sucks if you cant find it, so you might have to call them or email, but they suck at email too... |
Have to email them, they might just be selling audi belts at a higher cost? |
|
Back to top |
|
|
Juho
Joined: 03 Oct 2018 Posts: 391 Location: Finland
|
Posted: Thu Aug 26, 2021 9:31 pm Post subject: |
|
|
Found it on the shop, 50 euros for one belt might have to look in to the audi belts because i have a feeling they might be selling them at a higher cost. |
|
Back to top |
|
|
TJC
Joined: 04 Apr 2010 Posts: 828 Location: Central-ish Arizona, USA
|
Posted: Fri Aug 27, 2021 12:36 am Post subject: |
|
|
It would seem to me that perhaps the best source would be to contact your favorite belt manufacturer directly rather than going through some middleman to discover which size belt you need to purchase. They would most likely have all the specifications and with a little work they may provide you with the proper belt part number so you may go shopping for the best deal.
Then once you know the standardized belt number and are sure that it works properly you may tell the world...or keep it to yourself, buy up a supply of shorter belts and resell them as at a huge profit to compensate for the bit of time and effort put into sourcing them in the first place...like Mittlemotor, perhaps! _________________ '95 BMW 318i/5 ..."Pearl"
'87 Porsche 944 NA... "Liebchen"
'02 Porsche Boxster..."Sunbeam"
'04 BMW X3..."Xander"
Still on the Prowl!
www.ttrs1.com |
|
Back to top |
|
|
DZGunner
Joined: 18 Nov 2014 Posts: 191 Location: Great white north
|
Posted: Mon Oct 04, 2021 3:49 am Post subject: |
|
|
You keeping the stock internals with this compression ratio upgrade? _________________ 1979 924 (Daily driver EFI)
1979 924 Sebring
1977 924
1977 924 (Parts) |
|
Back to top |
|
|
Juho
Joined: 03 Oct 2018 Posts: 391 Location: Finland
|
Posted: Mon Oct 04, 2021 3:12 pm Post subject: |
|
|
no, 931 head vw flat tops, forged rods |
|
Back to top |
|
|
Mclaren924
Joined: 13 Oct 2021 Posts: 199 Location: California
|
Posted: Fri Aug 09, 2024 11:46 am Post subject: |
|
|
Juho wrote: | no, 931 head vw flat tops, forged rods |
You ever get around to milling the block Juho? I'm thinking about taking 2.5 mm off with a 931 head and stock na bottom end. Seen multiple people mention taking 2.5 off or .100 thou but nobody posts afterwards. Will be intercooled ethanol only of course and even then will be spicy. Will be checking piston to valve clearance tonight with a degree wheel and checking springs. They say 2mm clearance for intake and 2.5 mm for exhaust so will see how much can really be had. Dumb question maybe but what about head bolts, i assume they would no longer fit stock ones and would need different bolts/studs? _________________ 1980 931 "Salt" Bucket wannabe racer (not started)
1979 924 "Pepper" Restoration (almost done)
1980 924 "Donnie" (Parts car)-DEAD
1977 924 Slicktop "Pennie" Bucket turned Silver Spoon |
|
Back to top |
|
|
924RACR
Joined: 29 Jul 2001 Posts: 8846 Location: Royal Oak, MI, USA
|
Posted: Fri Aug 09, 2024 9:54 pm Post subject: |
|
|
I would be surprised at a need for different head fasteners - but I would think it would be obvious that you'd want the ARP studs for that build. Pretty sure there's enough play with those to not have to worry. Just make sure you clean the threads in the block fully, which should be part of the job anyway... _________________ Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype |
|
Back to top |
|
|
Mclaren924
Joined: 13 Oct 2021 Posts: 199 Location: California
|
Posted: Sat Aug 10, 2024 2:37 am Post subject: |
|
|
924RACR wrote: | I would be surprised at a need for different head fasteners - but I would think it would be obvious that you'd want the ARP studs for that build. Pretty sure there's enough play with those to not have to worry. Just make sure you clean the threads in the block fully, which should be part of the job anyway... |
Yeah I'm debating how far I want to take this build. I'm thinking skim both head and block and throw in a cometic but the headstuds will add a decent price increase. Debating if the stock pistons will even be able to handle enough boost for the head to lift. What head stud setups do you guys normally run? It really is a science experiment to see what the bottom end can handle when compression is cranked up and boost is fed to it. Ultimately I'm looking for a "cheap" way to get a more responsive and powerful motor with less boost. In the end I'll probably feed it as much as it can handle to see it's true potential or lack there of. Forged pistons and rods with big bore is what everybody wants but that's 3k at least before you start getting into other parts needed to round out the build.
Will be calling machine shops today to get quotes on decking and surfacing of mating surfaces. Hoping to have head and block done for around 3-400$ we shall see... I'm often surprised at costs now. _________________ 1980 931 "Salt" Bucket wannabe racer (not started)
1979 924 "Pepper" Restoration (almost done)
1980 924 "Donnie" (Parts car)-DEAD
1977 924 Slicktop "Pennie" Bucket turned Silver Spoon |
|
Back to top |
|
|
924RACR
Joined: 29 Jul 2001 Posts: 8846 Location: Royal Oak, MI, USA
|
|
Back to top |
|
|
|