cylinder damage
Thread Starter
Melting Slicks
Joined: Sep 2003
Posts: 3,050
Likes: 2
From: Orange Ct
cylinder damage
I have the heads off and found several scratches in one cylinder wall. Since the scratches extend above where the rings move, there must have been something in the cylinder. The compression read ok and it was not smoking before I tore it down. My first impulse is to ignore it. I could rebuild it now or wait and see if and when it starts smoking and then rebuild or crate it. No real difference except my time and labor. It’s not the original motor. Any other opinions?
http://i1.tinypic.com/n5q8t3.jpg
http://i1.tinypic.com/n5q92x.jpg
http://i1.tinypic.com/n5q8t3.jpg
http://i1.tinypic.com/n5q92x.jpg
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Leakdown test?
Can't tell how deep scratches are from pix? Can u feel them with ur fingers?
A leakdown test should show all good cyls at least at 75% of test press (70-90psi) and all cyls within 10% of each other. This is the best and fastest way to determine condition of cyl sealing and detect if those scratches are doing harm.
Well a compression test is much better at locating a problem between rings and vlvs but if that cyl had good compression without smoke then most likey not a major problem. Clean'r up with alcohol wipes and vacuum an' bolt back together - try leakdown test to verify. There are oil supplement sealers availible though only molibdimum and teflon products is what i would recommend to use if u feel the need.
If not smoking and good compression then only u can determine if rebuild is timely. Eng miles? Eng still in or out of car?? Optimum c.r. and pistions?
Hope this helps ya w1.
cardo0
A leakdown test should show all good cyls at least at 75% of test press (70-90psi) and all cyls within 10% of each other. This is the best and fastest way to determine condition of cyl sealing and detect if those scratches are doing harm.
Well a compression test is much better at locating a problem between rings and vlvs but if that cyl had good compression without smoke then most likey not a major problem. Clean'r up with alcohol wipes and vacuum an' bolt back together - try leakdown test to verify. There are oil supplement sealers availible though only molibdimum and teflon products is what i would recommend to use if u feel the need.
If not smoking and good compression then only u can determine if rebuild is timely. Eng miles? Eng still in or out of car?? Optimum c.r. and pistions?
Hope this helps ya w1.
cardo0
Thread Starter
Melting Slicks
Joined: Sep 2003
Posts: 3,050
Likes: 2
From: Orange Ct
Thanks Cardo. I can feel the scratches with my finger and the last compression test about 3k miles ago showed all cylinders within 10lbs of each other. The motor is still in the car and has about 50k on it. I'm going to ignore it and see what happens.
Bob
Bob
Large Impressive Member
Joined: Jul 2003
Posts: 65,811
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From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
If they are indeed just light scratches and not scoring, you should be okay to run it a while. You might want to do a leakdown test when you get it back together just so you'll have a better idea of where you stand and can plan accordingly.
Le Mans Master
Joined: Feb 1999
Posts: 5,877
Likes: 1
From: Park Ridge IL
The cylinder wall scoring doesn't look like enoguh justification to rebuild the engine yet, especially if all your compression/leakdowntesting is good. However, I'm curious about the two scratches on the top of the piston, shown in the first picture. Are they cracks/fractures?
Thread Starter
Melting Slicks
Joined: Sep 2003
Posts: 3,050
Likes: 2
From: Orange Ct
They are scratches. The color of the deepest part of the scratches seems to be about the same as the ridge area. This makes it appear that it was this way for awile. I could find no missing metal from the heads so it's a mistery of what did it.
Drifting
Joined: Jun 2005
Posts: 1,824
Likes: 1
From: Middleboro Massachusetts
Whatever caused this most likely happened during intake manifold installation or head installation the first time. Sometimes working around an open carb. with an oily rag picks up very small debris and gets deposited. Hopefully it found it's way out through the exhaust. I would like to know what the rings on that piston look like for a piece of mind, but that is a ball buster. If you said the compression is good, I think you will be ok. If you have mileage over 50K, you may be able to use an additive to help fill in the scratches and restore, if any loss in compression, no pun intended. Good luck with it and hope it works out well without too much additional fuss.
