Author Topic: Another use for your Dial Indicator--Finding TDC with it  (Read 8080 times)

March 30, 2010, 12:43:56 am

AudiVWguy

  • Veteran

  • Offline
  • ***

  • 433
Another use for your Dial Indicator--Finding TDC with it
« on: March 30, 2010, 12:43:56 am »
A couple of years ago when I installed the 16v lightened flywheel I found out it didn't have the right TDC mark. Here's what I did to check TDC. Rotate the engine to the TDC mark on the flywheel (cyl #1). Pull the #1 injector. Loosen the nut on the glow plug a little. Unscrew the glow plug most of the way out to get it out of the way. Extend your dial indicator with a piece of coat hanger or similar of metal. Preload to about 2.5 mm. Now, rotate the crank. the dial indicator will stop at TDC, and then move again as you pass that point. In my case, TDC on the dial was not correct on the flywheel (the pointer in the transmission hole). I made a new mark with my Dremmel tool and was good to go.This is critical for very accurate pump timing.
I hope this helps.
Cheers,
-JB











 


81 Caddy
NA to TD
Giles Superpump "There is no Substitute"
Meth/H2O Inj, BFI, 3" Ext.
8 lb. flywheel, Oil Cooler
11" Corrado Brakes

86 Audi 5K TQ (For Sale)
2000 Miata SE (Track project)

Reply #1March 30, 2010, 12:51:16 am

Vincent Waldon

  • Global Moderator
  • Veteran

  • Offline
  • ****

  • 3255
    • My collection of HOWTOs
Re: Another use for your Dial Indicator--Finding TDC with it
« Reply #1 on: March 30, 2010, 12:51:16 am »
Good one... thanks for posting... "don't have a reliable mark on my flywheel" comes up often.

Moved to the FAQ section. ;)
Vince

Edmonton, Alberta, Canada
2001 silver TDI Jetta Malone Stage 1.5 , 2001 blue TDI Jetta SBIII 216s Malone Stage 3, 1970 Bay Window bus

Gone but not forgotten: 1969/1971 Beetles, 1969/1974 Westies, 1979 Rabbit, 1986 TD Jetta, 1992 gas Jetta, 1994 TD Jetta

Reply #2March 30, 2010, 01:16:26 am

lovinthedeez

  • Veteran

  • Offline
  • ***

  • 489
Re: Another use for your Dial Indicator--Finding TDC with it
« Reply #2 on: March 30, 2010, 01:16:26 am »
i've never seen a magnetic vise like that before.  that's awesome ;D
location:  ashland, oregon US

Reply #3March 31, 2010, 10:01:40 am

moTthediesel

  • Junior

  • Offline
  • **

  • 194
Re: Another use for your Dial Indicator--Finding TDC with it
« Reply #3 on: March 31, 2010, 10:01:40 am »
That's a great tip!

I have a hybrid flywheel on my engine (Kennedy A/C VW) and I've never been absolutely sure of my TDC mark. This winter I made a "mental note" to check it before I put the head back on.

Of course, as we all know, "mental notes" are not worth the paper they're not written on, which lead to another Homer Simpson "DOHH!" moment shortly after torquing the head  >:(
'82 LandCruiser Diesel Conversion
4Cylinder 3B/KKKturbo/AudiIntercooler(gone, BNF)
'92 Dodge/Cummins D350 Getrag Dually
356 w/Quantum 1.6TD (73 mpg!)
'85 BMW 524td (Der Komisar) 
'00 Jetta TDI 5spd

Reply #4September 08, 2010, 04:16:06 pm

vako

  • Junior

  • Offline
  • **

  • 187
Re: Another use for your Dial Indicator--Finding TDC with it
« Reply #4 on: September 08, 2010, 04:16:06 pm »
will it be possible to use this method on 1.9td (aaz)? because am going to use suzuki flywheel on my engine and i will no more have tdc mark on it. 

Reply #5May 16, 2015, 09:08:33 pm

goomicoo

  • Newbie

  • Offline
  • *

  • 2
Re: Another use for your Dial Indicator--Finding TDC with it
« Reply #5 on: May 16, 2015, 09:08:33 pm »
Doesn't the piston linger at TDC for a couple of degrees of crank movement?

Reply #6May 16, 2015, 11:55:29 pm

vanbcguy

  • Administrator
  • Veteran

  • Offline
  • *****

  • 2831
  • Personal Text
    Vancouver, BC
Re: Another use for your Dial Indicator--Finding TDC with it
« Reply #6 on: May 16, 2015, 11:55:29 pm »
Yes. You're better off using something as a piston stop (say a valve) and then turning the crank till it makes contact, marking, turning it back the other way till it makes contact, marking again. True TDC will be directly in the center of your two marks.
Bryn

1994 Jetta - AHU M-TDI - Jezebel Jetta
2004 Jetta Wagon - 1.8T - Blitzen

Reply #7May 17, 2015, 02:48:59 pm

libbydiesel

  • Global Moderator
  • Veteran

  • Offline
  • *****

  • 3401
Re: Another use for your Dial Indicator--Finding TDC with it
« Reply #7 on: May 17, 2015, 02:48:59 pm »
I've used the liquid and clear tube method a couple times and find it to be incredibly accurate and very easy.  That way just one glow plug or injector needs to be removed.  Glow plug #4 is easiest and has the same crank TDC as #1.