S-PAutomotive.com

Author Topic: TDI Piston Ring Placement and Rod Bolt Reuse....?  (Read 5480 times)

January 18, 2007, 05:49:39 am

jimbote

  • Junior

  • Offline
  • **

  • 168
TDI Piston Ring Placement and Rod Bolt Reuse....?
« on: January 18, 2007, 05:49:39 am »
I'm building an ALH "parts bin" engine wondering what the correct piston ring placement is ....and has anyone reused rod or maincap bolts in an ALH? .....I know the manual says "always replace"......but has anyone "foolishly"  taken the chance on this.....if not I may be the guinea pig!...... :shock:



Reply #1January 19, 2007, 01:37:17 am

hillfolk'r

  • Veteran

  • Offline
  • ***

  • 1532
TDI Piston Ring Placement and Rod Bolt Reuse....?
« Reply #1 on: January 19, 2007, 01:37:17 am »
i didnt chance the rod bolts or main cap bolts
i think the rod bolts were cheap,like 3 or 4 or maybe 5? bucks a piece??
 for the replacement main cap bolts,i went with a raceware stud kit for 155
what do you mean correct ring placement??
if i remember right the top ring is 1.75mm wide,the 2nd is 2mm and the oil ring is like 3mm
Throttle cables ftw

Reply #2January 19, 2007, 03:07:05 am

jimbote

  • Junior

  • Offline
  • **

  • 168
TDI Piston Ring Placement and Rod Bolt Reuse....?
« Reply #2 on: January 19, 2007, 03:07:05 am »
thanks for the reply hillfolkr'......what I mean by ring placement is how are they supposed to be "clocked"......of course you don't want to line up the gaps.....anyone know how they should be staggered? e.g. bottom ring gap at three o'clock second compression at five ....etc....

Reply #3January 19, 2007, 12:50:03 pm

RabbitGTDguy

  • Veteran

  • Offline
  • ***

  • 1274
TDI Piston Ring Placement and Rod Bolt Reuse....?
« Reply #3 on: January 19, 2007, 12:50:03 pm »
Couple tips...

Never reuse OEM harware :) I.E. rod bolts, mains, etc...all should be replaced. Dealer prices as already mentioned aren't that bad and are well worth the security of having new hardware in there. There is a debate about rod bolts...supposedly being able to be torqued twice in their service life...but I wouldn't...
Its all factory stretch stuff...def. replace for the price.

As for the rings, depending on the ring manufacturer they will provide you with instructions. Goetze I know does...and they recommend the rings clocked... 90 degrees off each other on proper installation. If memory serves me correctly without looking!

Joe
1979 Rabbit mTDI crazy $*(\%& bunny...
1972 VW Westfalia
2009 VW Tiguan SE 2.0T (Wife's car)
2001 Audi TT 225 Quattro Roadster (something newer :) )

Reply #4January 20, 2007, 12:25:04 am

hillfolk'r

  • Veteran

  • Offline
  • ***

  • 1532
TDI Piston Ring Placement and Rod Bolt Reuse....?
« Reply #4 on: January 20, 2007, 12:25:04 am »
Yea i think its 90 degrees
id have to grab my ring install chart
i think i went by what total seal said to do
i think they said 120 degrees,starting from the top....
close enough,,as long as the ring gaps are opposing each other
Throttle cables ftw

Reply #5January 21, 2007, 12:45:55 am

jimbote

  • Junior

  • Offline
  • **

  • 168
TDI Piston Ring Placement and Rod Bolt Reuse....?
« Reply #5 on: January 21, 2007, 12:45:55 am »
thanks for the advice.....did I mention that this is a parts bin motor?.....anyway.....I figured the top two should be at least 120 apart but when I took the pistons out I noticed on more than one piston a consistent pattern .....the top two ring gaps only fifteen degrees apart....followed by the oil ring another fifteen degrees counterclockwise from the second and lined up perfectly with one of the the divots just below and to the side of the pin....also on the one high mileage motor I noticed a trail of oil stain coming from the divot that had the oil ring gap above it.....it would make sense for the gap to be there so oil vapor could get to the rings.....on the ALH piston there are no oil "vapor" holes under the skirt as in the IDI engines.....I'm sure the rings were lined up that way for a reason....I'll post pics of one of the piston that suffered catastrophic damage that "locked" the rings into the factory position via "land crushing" force......also I'm reusing the pistons and rings from one engine in another block.....around 30k miles .....like new ring end gap.....

Reply #6January 22, 2007, 10:04:30 pm

hillfolk'r

  • Veteran

  • Offline
  • ***

  • 1532
TDI Piston Ring Placement and Rod Bolt Reuse....?
« Reply #6 on: January 22, 2007, 10:04:30 pm »
rings spin or turn in actual use,so sooner or later,the gaps do line up once in a while
but yea id oppose the oil ring gaps 180
Throttle cables ftw

 

S-PAutomotive.com