taper in cylinders

[SoonToBeDSM06]

I am rebuilding my spare 6 bolt at school and I came up with a few problems. My teacher is a mustang guy so its hard to believe some of the things he says. The FSM indicates that the taper must be less than .001". I measured the cylinders like 5 times and I came up with dead even or .001". Take note that there is glaze on the walls still and it has not been honed. The engine has 20K original miles on it and something went though the oil which destroyed the bearings and left a few scratches on my a couple of my crank journals.

Can those cylinders be honed for .001"? I know that might be a lot of I can't trust a V8 guy.
And I'm not sure what to do about this rod journal since its a little scratched. I have seen ppl turn theres and be fine but I might just get another crank. The thrust surface on the counterweight of the crank seems a little uneven too from the wear. I'll try and get pics of the crank if you want them.

Thanks guys

 

[GVR4592]

Honing the cylinder by hand won't remove the taper if that's what you're asking. If it's within specs and it's not going to be a race engine, you are probably fine. Sounds like your crank needs replaced though.

 

[92redman]

That's not right, less than .001" taper is what you would shoot for on a refinished cylinder. You can have taper .005" depending on what you are doing with the engine. Straightness, however, should not exceed .001". The more critical spec is out-of-round, that is what will kill your rebuild.

 

[SoonToBeDSM06]

I will re-check out of roundness and taper today in several places. I just want a stock build with the same pistons so I don't want to bore it but if I do then I will have to deal with it I guess. I will have all the specs I find today in another post. Thanks

 

[92redman]

If you can still see the cross-hatch all the way around, you should be good to go especially with the low mileage. There were threads on here recently that you may want to search for about honing, it seems that some people think it's better to not hone the cylinders if you are putting cast rings back in. Personally, I have no experience because I have only used chrome and moly rings.

 

[GVR4592]

I've always rehoned the cylinders when replacing rings and I have always had great success with it.

 

[SoonToBeDSM06]

Ok I re-checked the taper and out of round and have some numbers but not with me for every cylinder. The out of round never went above .001" and it was only .001" on like 1 cylinder. We can only measure in the thousanths with our tools. The taper was dead on since he taught me how to properly use the telescoping gauges. So .001" is the most I see on any measurment and hopefully I can just rebuild this motor with new bearings and rings. I still see the cross-hatch very clearly so I just need to deglaze it and looks like I will be good. Now just gotta find another crank ### .010 undersize even doesn't sound safe on this sensitve engine. Thanks you guys.

What grit and type of hone should I use?