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Engine Specific Info and Questions => IDI Engine => Topic started by: SR Heer on August 28, 2012, 07:36:50 am
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I have 3 flywheels that I can mate up with the 1.6TD that I am putting into 82 Caddy.
A stock diesel weighing in at 13.6 lbs,
a gasser weighing in at 10.8 lbs
and a lightened gasser weighing in at 7.2 lbs.
Othere than setting and marking TDC is there such a thing as good and bad when it comes to using lightened flywheels for VW 1.6 and 1.9TDs? What is advantage and or risk if any in using lightened flywheel in these motors?
If it is ok - which would you use to couple up with TD motor?
Thanks for your time!
Stephen
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A lightened flywheel will allow the engine to rev faster giving a different perception of power (engine power output/torque does not actually change). A lightened flywheel will result in increased vibration especially at idle.
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I think the general feeling from members is that right around 9lbs was ok for our diesels. Less and the vibrations were bad. If you use a Gass flywheel make sure to mark TDC as some of the gasser flywheels didn't have an actual TDC mark, but one that was 6*BTDC. 6 isn't much but enough to cause problems if you are off at all with the rest of the timing. Valves could smack etc.
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I would consider a lightened flywheel for the 1.6td. These are quicker and potentially higher reving engines than the 1.9's, in which I would definitely stick to stock weight.
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one thing ive noticed, is that a lighter flywheel takes away from the torque big time..
the actual native torque of the engine, not the torque you get once boost picks up..
my engines were dogs with light flywheels.. made them drive like gassers.
i took the light digi gasser flywheel (12 pounds) and swapped it out for a 19 pound AAZ/ABA flywheel..
it took off much easier, and burned rubber alot better with the heavy wheel.
once you get the heavy wheel spinning, you dont stop it..
my 86 Audi Coupe GT has a really heavy flywheel as well.. you can tell. it takes seconds for it to rev up and down. and it also needs no throttle to take off at an idle. the flywheel must weigh 30 pounds EASY.. i was just in there to do a clutch, and i was amazed at how HUGE the flywheel on the 2.2L 5 cylinder is..
BUYER BEWARE: you may lose most of your low end torque and make your diesel feel more like a gasser!
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I put an 8lbs on my NA AAZ and I loved it. The head was ported, giles pump, long runnner intake and 4:2:1 exhaust. It revved great and it feels fast. Never been dynoed or anything but it's a blast to drive. Great power all the way bottom to top of the RPM range.
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I put an 8lbs on my NA AAZ and I loved it. The head was ported, giles pump, long runnner intake and 4:2:1 exhaust. It revved great and it feels fast. Never been dynoed or anything but it's a blast to drive. Great power all the way bottom to top of the RPM range.
that would prolly respond a bit differently, being n/a and all..
and wasnt your engine in a light-ass mk1?
you guys can do what you want with your flywheels, but my experiences and preferences leave me with heavy flywheels..
i LOVE the torque...
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http://www.uucmotorwerks.com/flywheel/there_is_no_torque_loss.htm
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http://www.uucmotorwerks.com/flywheel/there_is_no_torque_loss.htm (http://www.uucmotorwerks.com/flywheel/there_is_no_torque_loss.htm)
Real data is, well, real ;)
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and wasnt your engine in a light-ass mk1?
MK2 2 door Golf
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U lose a bit of drivability and idle quality but technically you would gain torque although obviously it won't feel that way
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i loved my (approx) 6 pounder on my old 1.6td...revved up nice..needed some throttle to get off the line
BEWARE: if you use a 210mm fw,the tdc timing mark is NOT correct...you need to fashon up a piston stop to go thru the injector hole..then rotate the engine in each direction and mark the flywheel in each spot...split the difference thats your new tdc mark......yes that got me scratchin my head when i went to change my belt later down the road....
oh also on my tdi m that fw was really awesome,and i rechecked the mark and it was ok..but the tdi piston stop was easier to make from a glow plug and a bolt....the idi was a pita.....i think i was able to fish and jam some 12 ga wire thru the prechamber into the piston area...its a pita tho
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For an easy piston stop on either IDI or TDI engines you can stick a shim between the cam and a lifter.
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yea good idea on the shim for cam....
the tdi glowplug/6mm stud works ok for them,but i like your shim deal better for the idi's
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what size shim because if too thick one can stop before TDC - maybe I invision on how to incorrectly - can you explain = thanks!
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You want it to stop before TDC, make a mark, roll it the other way, mark.
True TDC is halfway between the two.
With the piston hang time around TDC, just marking where it is at the top isn't as accurate.
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shim size doesnt matter too much.thats the point.you are using the valve as a piston stop actually....put in the shim and rotate the engine one way and make a mark on the fw where it stops....then rotate the engine in the opposite direction and mark the fw again(both times using the tdc mark thats on the bellhousing)
after you have a mark on the fw from the forward and backward rotation,take a measuring tape or equivalent and measure the distance between the 2 marks you made...do the math and split that measurement in half...thats your true tdc.......
actually the thicker the shim you use the harder it may be to get a measuring tape in the bellhousing hole....
to be honest ive always measured mine with the trans out or on a stand.....a useful tool is to cut a big chunk out of an old transmission that has the top 2 bolts and the tdc mark on it and bolt it to your engine.
so in summary: shim the cam on #1 cyl,rotate one way,mark fw,rotate opposite way,mark fw again..measure that distance and split it in half and make your" new" tdc mark