Chamfering the bottom of cylinders.
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Chamfering the bottom of cylinders.
Is it a must to chamfer the bottom of the cylinders in a block that has been bored? The block is a std deck big block with 4.25 stroke, srp pistons and 6.385" rods. I already assembled the bottom end before i noticed that not all of the cylinders have a chamfer att the bottom.
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Re: Chamfering the bottom of cylinders.
Where the gauge point for the piston is located @BDC and how much skirt protrusion is a big factor. But generally speaking you never want to start a knife fight between iron and aluminum, if you catch my drift.
Re: Chamfering the bottom of cylinders.
It will most likely roll the aluminum up on the pistons and then you'll get some nice scuff marks on your cylinder walls.
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Re: Chamfering the bottom of cylinders.
Does the edge feel sharp? If not sharp, it should be O.K.Berserk wrote: ↑Tue Mar 06, 2018 2:24 pm Is it a must to chamfer the bottom of the cylinders in a block that has been bored? The block is a std deck big block with 4.25 stroke, srp pistons and 6.385" rods. I already assembled the bottom end before i noticed that not all of the cylinders have a chamfer att the bottom.
Automotive Machining, cylinder head rebuilding, engine building. Can't seem to quit
Re: Chamfering the bottom of cylinders.
Breaking the edges of all machined sharp finishes is a good habit to get into. It makes handling a lot kinder on the fingers.
A buzz around the bottom of the bore with a die grinder and finish with a flap wheel will do the trick.
Cheers.
A buzz around the bottom of the bore with a die grinder and finish with a flap wheel will do the trick.
Cheers.
Re: Chamfering the bottom of cylinders.
A de-burring tool perhaps followed by a little rub with say 80 grit would also work and might be possible without disassembly for access and with care would leave no grindings that would require disassembly. Only a slight chamfer is necessary.
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Happy is he who can discover the cause of things.
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Re: Chamfering the bottom of cylinders.
Break the sharp edges so they don't FEEL sharp. That seems to be enough.
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Re: Chamfering the bottom of cylinders.
I deburr and radius every machined surface especially bores with reciprocating motion going on like lifters and pistons. Sharp edges are also stress risers for cracks
Re: Chamfering the bottom of cylinders.
I have found Noga BS2010 deburring blades to be amongst the best on CI ,but you can get some pretty tough old aged blocks and heads that require a more aggressive approach with power tools.
Cheers.
Cheers.
Re: Chamfering the bottom of cylinders.
Does a sharper edge vs any radius wipe any splashed oil off skirts better and with a more favorable result?
Re: Chamfering the bottom of cylinders.
I say we leave the task of oil control to the oil ring...
Felix, qui potuit rerum cognscere causas.
Happy is he who can discover the cause of things.
Happy is he who can discover the cause of things.
Re: Chamfering the bottom of cylinders.
Yes, oil on the skirts is a good thing, just as long as it doesn't make it past the rings. Imagine what a dry piston skirt would look like after 8000rpms.
Re: Chamfering the bottom of cylinders.
Yes the sharper edge does a better job at wiping oil, along with aluminum from the piston.