|
|
|
|
| Author |
|
|
Registered
Join Date: Sep 2002
Location: dfw tx
Posts: 3,957
|
Why don't they bush the tensioner stud?
I have an early 85 944 I picked up from my Brother, who abandoned it when it broke the tensioner stud and bent all the valves. I'm bringing it back to life now.
Today, I picked up an "updated stud and nut" to replace it, and unfortunately, it already had it and it still failed. Now granted, bad bearings in one the pullies could cause a lot of side loads on the stud, which is probably what happened. But as I look at the setup, it seems those side loads have the leverage to snap the stud because there is nothing supporting the stud out near the tensioner itself, because it is hanging out almost an inch from the block where it is threaded. Wouldn't a bushing put between the stud and the front sealing cover give the stud the support it needs? Just a thought anyway. I'd appreciate the advice from those who know these cars better.
__________________
72 914 2056: 74 9146 2.2: 76 914 2.0 |
||
10-27-2006, 09:14 AM
|
|
|
Registered
Join Date: Nov 2004
Location: ronkonkoma ny 11779
Posts: 2,024
|
just by the mechanics of it yes, it would help to alleviate the load.
Under "normal" circumstances it is not needed. Where did you get the updated stud, I have to do the job in my car soon?
__________________
83 944....bye bye 85.5 euro spec 944, 5sp (she's gone....  74 914...hasta LA Vista baby 87 924s....don't let the door hit ya 68 912.......see ya! |
||
|
10-27-2006, 09:51 AM
|
|
|
Registered
Join Date: Sep 2002
Location: dfw tx
Posts: 3,957
|
It was a special order item thru Zim's here in Bedford TX but any dealer or Porsche facility can probably get them. I would think Pelican could get them, too. It was about $16 for both the stud and nut.
If you need the part no's i can get them off the receipt.
__________________
72 914 2056: 74 9146 2.2: 76 914 2.0 |
||
|
10-27-2006, 11:27 AM
|
|
|
Registered
|
Never should be enough shear on the tensioner stud to bend it. I've seen them stripped out of the block or even crack because of over tightening the pulley.
When the depth of a studs threads is the same as the threads major cross section (diameter) there is no streagth in shear (sideways loads) Two cross sections deep is minimal. Three is optimal.
__________________
Hugh - So Cal 83 944 Driver Person NOT a 'real' Porsche -- Its Better!!!! When was the last time you changed your timing and balance belts and/or cam chain and tensioner? New Users please add your car's year and model to your signature line! Never break more than you fix! |
||
|
10-27-2006, 01:01 PM
|
|
|
Registered
|
Definitely a lot of cars run a very long time with the design that is there. If a stud shears, then something else is wrong and proper maintenance probably wasn't done to the motor. With this engine, it is very important to do the proper maintenance....meaning replace belts, rollers, water pump often. Can't really stress that enough. It's good you are bringing this one back to life though. It will be a really fun car for you.
__________________
Tom 1990 944S2 Cabriolet 2002 Chevy Silverado 2500HD 2003 Maroon Ford F350 dually |
||
|
10-27-2006, 02:58 PM
|
|
|
Registered
Join Date: Sep 2002
Location: dfw tx
Posts: 3,957
|
in my reading here I realize belt tension and maintenance is critical on this engine, more so than most. I'm just looking to try to keep this semi-catastrophic failure from happening again.
I am definately looking forward to driving it!
__________________
72 914 2056: 74 9146 2.2: 76 914 2.0 |
||
|
10-27-2006, 06:41 PM
|
|
|
1983 Porsche 944 2.5 liter
