Block Cylinder Wear......Give it to me striaght!

[stroker87]

Ok pulled the rotating assembly out today and had a good look at every thing

The block had the same wear in all the cylinders all about the same one with a little more, I dont think the rings was file fit, the bearings are toast and I think the crank might need to be turned it has some marks

is this normal to have this wear in all the cylinders like this with low miles? I included one of the crank (the worst one)

 

[grumpyvette]

Its really difficult to judge from the pictures, almost everything posted falls into the commonly seen wear category, but,it appears the ring gaps were not correctly set up (possibly a bit to tight)and the piston to bore clearance might have been a bit off, (rocking in the bore slightly)but the wear pattern seems to indicate the block was not honed with deck plates,(possibly not exactly round, but Id point out again all the above might have been ok, and the wear was mostly the result of crud in the oil, Id say that simply because the wear seems localized to the thrust wall areas) notice the wear on thrust wall seems to be more pronounced, (that might have been aggravated with the metallic crud in the oil getting scrubbed on the bore wall by the rings, and by metallic crud trapped between the piston skirt and bore wall. remember crud in the oil will tend to drain along the rings to the low side and that's the thrust wall, so it tends to increase wear)
but there's not a thing that a hone job or a bore and hone job and new rings and pistons,can,t easily cure, and Ive seen far worse!, your machine shop can measure and tell you but ID suspect that a good hone with deck plates and new rings and possibly pistons might be all that's required, if it does need to be bored go with the minimum over size (depends on what your machine shop finds when measuring) btw the micro grooving on the crank further indicates crud in the oil and Id bet the bearing surfaces are scratched a bit also

http://www.realclassic.co.uk/techfiles/ ... 31600.html

http://www.babcox.com/editorial/ar/eb110242.htm

http://books.google.com/books?id=-MooN2 ... 6#PPA55,M1

http://www.daros.se/technical/faq.htm#01

http://books.google.com/books?id=Ro3_4p ... t&resnum=8

http://www.enginebuildermag.com/Article ... ishes.aspx

http://www.aa1car.com/library/honing98.htm

 

[stroker87]

the piston to bore clearance might have been a bit off, (rocking in the bore slightly)

Grumpy so your thinking the bore was a touch to big for the pistons?

Yes the bearing surfaces are scared some more then others but all are going in the trash

 

[grumpyvette]

the piston to bore clearance might have been a bit off, (rocking in the bore slightly)

Grumpy so your thinking the bore was a touch to big for the pistons?

Yes the bearing surfaces are scared some more then others but all are going in the trash

there's other causes than the piston being undersized, for the bore, some piston skirt designs won,t expand to the correct dimensions until the engine reaches full operational temperatures, the material used in the piston it self, has a big effect, example, forged pistons normally require more clearance than a similar hyper eutectic piston would, and piston pin location in the piston, and rod length , and stroke ratio,also effects that, check with the piston manufacturer on the design clearance

 

[stroker87]

the rotating assembly is a Eagle "kit" that they sell with the SRP pistons so I would "think" that piston pin location and rod length are correct???

 

[grumpyvette]

the rotating assembly is a Eagle "kit" that they sell with the SRP pistons so I would "think" that piston pin location and rod length are correct???

your correct,but like I pointed out, that wear indications fall, into the commonly seen range, and metallic crap in the oil, or on the rings could account for much of that wear
one reason IM a huge fan of several magnets installed in engine,MOLY assembly lube,and the use of shrapnel screens in lifter galleries and good oil filters, being changed and inspected frequently

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