Show full size 924Board.org
Discussion Forum of 924.org
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
 Technical FAQ924 FAQ (Technical)   Technical924 Technical Section   Jump to 924.org924.org   Jump to PCA 924 Registry924 Registry

Turbo bypass valve

 
Post new topic   Reply to topic    924Board.org Forum Index -> 931 Tech.
View previous topic :: View next topic  
Author Message
knobby  



Joined: 23 May 2011
Posts: 43
Location: Cincinnati,Ohio
PostPosted: Fri Oct 26, 2018 8:34 am    Post subject: Turbo bypass valve Reply with quote
I just got my turbo back from Majestic and have to replace the bypass valve gaskets myself because they thought that they were NLA!
Anyway I need help with the piston orientation.
I think the piston crown faces the opposite side to the vacuum elbo.
There are two slots on the crown and I need to know if they need to be oriented in a specific way or doesn’t matter.
Also a slot cast that is visible from the underside of the piston.
Any help appreciated as I’d really like to get this right before installing it this weekend.
_________________
81 RED 931 S2(daily driver),81 WHITE 931 S2(not currently drivable).
Cincinnati,Ohio
Back to top
View user's profile Send private message
924RACR  



Joined: 29 Jul 2001
Posts: 8803
Location: Royal Oak, MI, USA
PostPosted: Fri Oct 26, 2018 9:46 pm    Post subject: Reply with quote
Per the parts manual, the piston looks to be installed with the flat face opposite the inlet elbow (boost sensing line from intake), or facing the RHS of the car... and the spring on the LHS of the car/on the vacuum elbow side... make sense? Sounds like what you were expecting for orientation.

Can't offer any ideas regarding rotational orientation, sorry.

Definitely want to get that sorted now; I made the mistake of getting it backwards, and had to fix in-car, which sucked (but was just barely doable)...
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype
Back to top
View user's profile Send private message Send e-mail Visit poster's website
Carrera RSR  



Joined: 08 Jan 2010
Posts: 2309
Location: Somerset, UK
PostPosted: Sun Oct 28, 2018 12:15 am    Post subject: Reply with quote
Not aware of orientation of the slots. I don’t believe it matters. Had mine in and out twice and did not consider this. There is nothing to stop the piston spinning except spring friction anyhow.
_________________
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
Back to top
View user's profile Send private message
knobby  



Joined: 23 May 2011
Posts: 43
Location: Cincinnati,Ohio
PostPosted: Mon Oct 29, 2018 1:02 pm    Post subject: Reply with quote
I eventually spoke to the tech at Majestic who confirmed that the rotational orientation of the piston slots was vertical when he disassembled the turbo but John stated that it did not matter.
Any way I installed it this weekend and am very happy with it!
Thanks for your replies,much appreciated!
_________________
81 RED 931 S2(daily driver),81 WHITE 931 S2(not currently drivable).
Cincinnati,Ohio
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    924Board.org Forum Index -> 931 Tech. All times are GMT + 10 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group