Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

thy rod no longer comforts me
#1

as promised, here are some shots of the rods that bent when i hit 7psi boost. please realize that the reading of amount of boost on a gauge is only a reading of what the engine could not take in. a more efficient engine will make more power, but show less boost than a less efficient one. so, if you have a crap motor, it will show higher boost numbers than a better engine, but not make any more power. this is how many manage to run higher boost numbers. they really aren't making as much boost as they think.



notice that where the rods bent is NOT where porsche reinforced them. these are the 1R rods. the 2R rods are reinforced down where the connecting nuts are, and not up at the top where these bent. it does not matter which of the OEM rods you have. they will all bend when you exceed their load limits. this is a designed in failure component. most engine designers choose the rods as the give item. it's generally less damaging and less expensive to repair than other things, like the crank or block.



the first shot shows all 4. the only straight rod is the one on the left. not entirely certain it is straight either.



   

   

   

   



here is a shot of one of the pistons. note the wear from scraping the side of the bore. they were all pretty much the same. this is what happens when a rod bends like this.



   
Partial Post: Please Login or Register to read the full post.

94 Midnight Metallic Blue Cab Porsche 968 w/deviating cashmere/black interior and WAY too many mods to list - thanks to eric for creating www.968forums.com



"It isn't nearly as expensive to do it right as it is to do it wrong."
Reply
#2

Interesting!
Partial Post: Please Login or Register to read the full post.
Reply
#3

lol - yeah - i had some other, more interesting and colorful words to describe it, but decorum prevents me from sharing
Partial Post: Please Login or Register to read the full post.

94 Midnight Metallic Blue Cab Porsche 968 w/deviating cashmere/black interior and WAY too many mods to list - thanks to eric for creating www.968forums.com



"It isn't nearly as expensive to do it right as it is to do it wrong."
Reply
#4

Ouch!
Partial Post: Please Login or Register to read the full post.
Reply
#5

Bent is not good, of course. But they didn't fail, which is a positive thing. In a fresh motor what is the boost expected from the DS1 SC?
Partial Post: Please Login or Register to read the full post.
Reply
#6

I'm guessing that my pistons look like that as well. At least you have your cylinder walls still!
Partial Post: Please Login or Register to read the full post.
Reply
#7

uh - no - i had to bore them out and put in oversized pistons. that was a whole new adventure too.
Partial Post: Please Login or Register to read the full post.

94 Midnight Metallic Blue Cab Porsche 968 w/deviating cashmere/black interior and WAY too many mods to list - thanks to eric for creating www.968forums.com



"It isn't nearly as expensive to do it right as it is to do it wrong."
Reply
#8

Interesting read

The title chosen was a very skillful "play on words"...
Partial Post: Please Login or Register to read the full post.
Reply
#9

lol - i never said they were good jokes. i only said they were plentiful.
Partial Post: Please Login or Register to read the full post.

94 Midnight Metallic Blue Cab Porsche 968 w/deviating cashmere/black interior and WAY too many mods to list - thanks to eric for creating www.968forums.com



"It isn't nearly as expensive to do it right as it is to do it wrong."
Reply
#10

Were you running over the normal factory rev limit at times on the dyno?



Are the 951 forged rods a fix in your opinion, rather than going after market?
Partial Post: Please Login or Register to read the full post.
Reply
#11

no on revs.



i know some people feel the 951 rods are an option. i have also heard they need a modification in order to work. the problem i have with that idea is twofold. first, modifying a highly stressed part is always dicey. second, why not run a stronger and lighter rod if you are changing? the cost difference is negligible if you are already replacing them. balancing will still be required. makes no sense to me to use something less than what i can have, with no performance advantage to it.
Partial Post: Please Login or Register to read the full post.

94 Midnight Metallic Blue Cab Porsche 968 w/deviating cashmere/black interior and WAY too many mods to list - thanks to eric for creating www.968forums.com



"It isn't nearly as expensive to do it right as it is to do it wrong."
Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)