ZR-1 Net Registry Forums - LT5 valve guide failures

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- - LT5 valve guide failures (http://zr1.net/forum/showthread.php?t=31135)

grahambehan

11-05-2019 02:28 PM

LT5 valve guide failures

3 Attachment(s)

Found on a recent teardown

Graham

billschroeder5842

11-05-2019 07:16 PM

Re: LT5 valve guide failures

Yikes- that is scary!

XfireZ51

11-05-2019 07:35 PM

Re: LT5 valve guide failures

Graham,

Any sense on the cause of failure? Are these OEM?

grahambehan

11-06-2019 07:48 AM

Re: LT5 valve guide failures

Quote:

Originally Posted by XfireZ51 (Post 300653)

Graham,

Any sense on the cause of failure? Are these OEM?

Valve guides are stock. From the uneven tool marks on the end of the guides, they were over stressed whilst being knocked back to perform the port work then knocked back into position. After that it was just a matter of time.

Graham

XfireZ51

11-06-2019 08:31 AM

Re: LT5 valve guide failures

Thx Graham. Any outward signs, ie oil burning, spark plug coloring, indicative of a problem here?

grahambehan

11-06-2019 08:42 AM

Re: LT5 valve guide failures

Quote:

Originally Posted by XfireZ51 (Post 300672)

Thx Graham. Any outward signs, ie oil burning, spark plug coloring, indicative of a problem here?

No comments from the owner re that, although it has heavy carbon deposits. The actual reason for taking it apart was, no compression on cyl 7 due to the parts of valve guide passing through the cylinder.

Graham

Jagdpanzer

11-06-2019 04:38 PM

Re: LT5 valve guide failures

Graham,
Do you have any experience with the VG 19292/00 aluminum bronze valve guide SI International makes for the LT5 cylinder head?

Sent from my iPhone using ZR-1 Net Registry

grahambehan

11-06-2019 04:48 PM

Re: LT5 valve guide failures

Quote:

Originally Posted by Jagdpanzer (Post 300688)

Graham,
Do you have any experience with the VG 19292/00 aluminum bronze valve guide SI International makes for the LT5 cylinder head?

Sent from my iPhone using ZR-1 Net Registry

No sir, not in LT5 applications, but al bronze should be fine.

Graham

rkreigh

11-12-2019 09:06 AM

Re: LT5 valve guide failures

on the old LSV we saw 3 guides that had noticeable wear after 106k. The other thing was the idler shaft for cam chains.

That was a bit of a surprise. Thanks Phil for all your help on this!

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