Author Topic: Pre-cup cracks  (Read 1598 times)

March 07, 2009, 10:29:06 am

turbosyncrobus

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Pre-cup cracks
« on: March 07, 2009, 10:29:06 am »
Some of the pre-cups on the TD head that I'm planning to use have one or two very slight hairline cracks radiating out from the flame hole, how bad is this? They don't look too bad, and none of the cracks is anymore than about 5 or 6 mm long.



Reply #1March 07, 2009, 02:21:37 pm

maxfax

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Pre-cup cracks
« Reply #1 on: March 07, 2009, 02:21:37 pm »
I asked my machine shop guy the same thing the other day..   To quote "I guess it wouldn't hurt as long as they don;t get worse, but I generally replaced them to be sure" He's generally pretty fussy about things such as questionable cracks so I was kinda surpirsed that he even left the option open to reuse them..

I'll appreciate any other input as well, but I think I'll replace mine as Murphy and his band of law officers find me frequently...

Reply #2March 07, 2009, 05:25:11 pm

subsonic

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Pre-cup cracks
« Reply #2 on: March 07, 2009, 05:25:11 pm »
If you where tearing it all down and planning on dumping a bunch of cash into the engine to turn it into a daily high boost, high (for a diesel) rpm machine I would say do it.  If you are just going to run slightly higher boost and fuel I would say just run em.  I have seen lots of very small cracks in the precups.    Do you have any pictures?
2009 Jetta TDI Loyal edition, 6-spd. 16V 2.0CR


1985 VW Golf 5-spd, 4-door, 1.6NA  Bought from orig. owner in Savannah with 42,000 miles.
"Making the jump NA to TD" slow but sure.

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Reply #3March 07, 2009, 08:00:13 pm

maxfax

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Pre-cup cracks
« Reply #3 on: March 07, 2009, 08:00:13 pm »
Mine will be a daily driver NA, but I'm replacing damn near everything else in the thing... What's a few more bucks...

Reply #4March 09, 2009, 07:26:01 pm

turbosyncrobus

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Pre-cup cracks
« Reply #4 on: March 09, 2009, 07:26:01 pm »
No pics yet but I'll try tomorrow or wed. the engine is at my shop and I can't get there much during the week. But I also figured that they would be good enough for a few thou while I rebuild the TD motor for my Syncro, then I will get a rebuild for that one and use that head on the caddy...delayed gratification!