Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > 1- Porsche Technical Forums > 911 / 930 Turbo & Super Charging Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered User
 
Join Date: Jul 2006
Location: S. Florida
Posts: 7,234
Minimum intake manifold stud thread engagement question

When installing CIS aluminum injector blocks with phenolic plastic heat insulators and extra gaskets needed the top of the 930 pancake intake manifold ends up about 10mm higher.

Is it OK to just thread the original intake manifold studs in about 9-10 mm less to keep sufficiant thread engagement for the manifold nuts?
Would there be enough thread engagement of those studs in the cylinder heads to still torque the intake manifold nuts on the studs to 18 foot pounds without ripping the threads out of the heads?
Or is standard procedure to buy approximately 10-12mm longer intake manifold studs?
If you need longer studs where do you get them?

Also, I'm guessing eliminating the 3 intake manifold gaskets needed to include the heat insulators would give you some stud length back and then using a sealant like hondabond 4 with no gaskets seems like it might work if the surfaces are flat and clean?

Lastly, not using the heat insulators at all would keep the same total thickness and hight as the stock injector blocks so thread engagement would be the same. I think I read going without the heat insulators when using aluminum injector blocks will transfer and heat soak the CIS injectors too much and vaporize the fuel in them after shut down or while driving, is this true? would it cause misfiring on hot startup and while driving?

thanks in advance for any answers...
Old 04-07-2014, 10:52 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Registered User
 
pete3799's Avatar
 
Join Date: Nov 2008
Location: Vermont
Posts: 6,308
Garage
Just a heads up......my exhaust studs ( installed by the PO) were only threaded into the head 3/8 of an inch and two of them pulled the treads out of the head. Same 18 foot pound torque.
__________________
Pete
79 911SC RoW
"Tornadoes come out of frikkin nowhere. One minute everything is all sunshine and puppies the next thing you know you've got flying cows".- Stomachmonkey
Old 04-07-2014, 11:51 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
beancounter
 
jwasbury's Avatar
 
Join Date: Jan 2008
Location: Weehawken, NJ
Posts: 3,318
what aluminum injector blocks are you using? I bought a set from Turbokraft when I was doing my engine build. They came with heat insulators, but the stack height with the insulators was the same as the factory plastic blocks. I used OE gaskets only on the top and bottom of the stack, used a light coating of Loctite 574 between the aluminum block and the plastic heat insulator.
__________________
Jacob
Current: 1983 911 GT4 Race Car / 1999 Spec Miata / 2000 MB SL500 / 1998 MB E300TD / 1998 BMW R1100RT / 2016 KTM Duke 690
Past: 2009 997 Turbo Cab / 1979 930

Last edited by jwasbury; 04-07-2014 at 12:56 PM..
Old 04-07-2014, 12:54 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Registered User
 
Join Date: Jul 2009
Location: Ontario
Posts: 1,763
studs

Get a length of threaded rod, and cut your own to desired length. If you have trouble finding metric ready rod, I could send you a piece. Philip
__________________
87 930 GHL/Rarlyl8/Garretson/GT3582R/1 Bar/Wevo shift, mounts/Meth inj/LM-2/Custom Fuchs/Carrera intake manifold/Xtreme Carrera heads P&P/3.4/DR 993SS cams/ Mahl/Pauter/JE/Niresist/ARP/twin COP/8.25:1/KEP stage 2/twin tials/close 2,3,4th. MS3Pro Evo 500+ HP, BTSOMP Dyno
Old 04-07-2014, 01:30 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Registered User
 
Join Date: Jul 2006
Location: S. Florida
Posts: 7,234
I don't know who made them, there's no markings on them. They look a lot like the TK injector block casting but not exactly the same. They had a rough sand cast finish on the outside of them when I got them but I sanded them smooth and polished them shiny when i got them so they look really good.

They have 40mm holes and I've already ported the heads and intake manifold to match them. I bought them for around $250 used here on the forum around 6 years ago.

They are the same thickness top to bottom as the stock plastic 930 injector blocks but then when you add the 6.35mm plastic heat insulators I have and one of the approximately 2mm thick gaskets that came with them between the head and block it goes up to about 8.3 mm before installation.

I'd like to use one of those gaskets between the block and insulator and then it becomes about 10mm added on. These gaskets will squish down a little and how much is unknown until I do it.
I could probably just use the creamy consistancy hondabond 4 sealant I have between the insulator and the block with no gasket and then it would only be about 8 mm after installing them and squishing down the gasket in the process.
That'll probably work fine.
Old 04-07-2014, 01:40 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered User
 
TurboKraft's Avatar
 
Join Date: Mar 2005
Location: Phoenix, AZ
Posts: 2,506
Pic of aluminum block?
__________________
Chris Carroll
TurboKraft, Inc.
Tel. 480.969.0911
email: info@turbokraft.com
http://www.facebook.com/TurboKraft - http://www.instagram.com/TurboKraft
Old 04-07-2014, 02:30 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
Registered User
 
Join Date: Jul 2006
Location: S. Florida
Posts: 7,234
Here's pic of an original plastic injector block and one of the aluminum 40mm ones I have side by side. You can see they are the same hight top to bottom.
Then a pic with one gasket and an insulator block under the aluminum one to show the hight increase and a pic of the gaskets and insulator blocks I plan to use if they work out.



Old 04-07-2014, 02:52 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Registered User
 
TurboKraft's Avatar
 
Join Date: Mar 2005
Location: Phoenix, AZ
Posts: 2,506
To the original question: Minimum intake manifold stud thread engagement question
As a rule of thumb, minimum safe depth is Diameter x 1.5.
An M8 fastener should thread in 12mm deep.
__________________
Chris Carroll
TurboKraft, Inc.
Tel. 480.969.0911
email: info@turbokraft.com
http://www.facebook.com/TurboKraft - http://www.instagram.com/TurboKraft
Old 04-07-2014, 02:52 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
Registered User
 
TurboKraft's Avatar
 
Join Date: Mar 2005
Location: Phoenix, AZ
Posts: 2,506
Seeing that photo, I'd machine material off the bottom of the block.

The insulator's outer profile should allow it to drop through the fan shroud and sit atop the head gasket
Then the block sits atop it and the fan shroud, like the stock plastic block does.

You may have to cut a small notch in the insulator's bore, that's it.
__________________
Chris Carroll
TurboKraft, Inc.
Tel. 480.969.0911
email: info@turbokraft.com
http://www.facebook.com/TurboKraft - http://www.instagram.com/TurboKraft
Old 04-07-2014, 02:55 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)
Registered User
 
Join Date: Jul 2006
Location: S. Florida
Posts: 7,234
FWIW, I just snapped some more pics.





Old 04-07-2014, 03:21 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #10 (permalink)
Registered User
 
TurboKraft's Avatar
 
Join Date: Mar 2005
Location: Phoenix, AZ
Posts: 2,506
Yes, I think machining off the base, notch the insulator:



__________________
Chris Carroll
TurboKraft, Inc.
Tel. 480.969.0911
email: info@turbokraft.com
http://www.facebook.com/TurboKraft - http://www.instagram.com/TurboKraft
Old 04-07-2014, 03:38 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #11 (permalink)
Registered User
 
Join Date: Aug 2008
Location: S. Florida
Posts: 321
Hey Jim,

I used the aluminum injector blocks with just gaskets and everything is fine, no starting or heat soak issues, everything normal as can be. Studs had enough thread top and bottom like factory. Hope this helps.
Old 04-07-2014, 04:53 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #12 (permalink)
 
Registered User
 
proffighter's Avatar
 
Join Date: Aug 2007
Location: Switzerland
Posts: 2,179
Garage
Using an insulator is highly recommended in my eyes. I shaved the bottom of my injector blocks for the amount of the insulators to get same height at the end





__________________
Roland

930 Turbo '81 Too many modifications to list
Old 04-08-2014, 12:43 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #13 (permalink)
Registered User
 
T77911S's Avatar
 
Join Date: Oct 2006
Location: MYR S.C.
Posts: 10,197
Quote:
Originally Posted by zcoker View Post
Hey Jim,

I used the aluminum injector blocks with just gaskets and everything is fine, no starting or heat soak issues, everything normal as can be. Studs had enough thread top and bottom like factory. Hope this helps.
my mechanic friend said that is the way his are.


i would leave the studs threaded all the way in. mine are threaded to the top of the last thread on the studs. you dont want to pull a stud.
__________________
86 930 42kmiles [__] RUNNING:[__] NOT RUNNING: ____77 911S widebody: SOLD
88 BMW 325is 200K+ SOLD
05 BMW 330CI 130K:: [__] RUNNING: [__] NOT RUNNING:
08 VOLVO V70 190K:: [__] RUNNING: [__] NOT RUNNING:
90 B2200[__] RUNNING:[] NOT RUNNING:__2000 MER E320 WAGON [] WRECKED:[]RUNNING:
Old 04-08-2014, 04:02 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #14 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 10:17 PM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.