Flex hone for deglazing/honing cylinders

Flying Torquewrench · 03-05-2021, 11:46

As per my project thread I am replacing the piston rings on my RD28T. To help bed in the rings the bore should be honed or deglazed.

I have already decided that I will not be honing it in the traditional sense. The traditional way is the three pronged honing tool and send it up and down the cylinder bore. There are several reasons for not using this method:

1) The bores are currently not 100% straight and therefore this tool with not get to the low spots.
2) It takes off more metal and therefore increasing the bore diameter, which in turn results in the new rings being closer to the outer limit.
3) The tool needs to be held perfectly otherwise the top (or bottom) of the stones grinds off more metal.

I am looking at using a Flex hone. This will follow the contours of the cylinder and makes sure that every bit of the cylinder gets deglazed. Cast iron rings will be used on the pistons as these are a little bit more flexible to seal an out of round cylinder compared to a more modern equivalent.

Has anybody used a flex hone?

03-05-2021, 11:46	#1
Flying Torquewrench Senior Member Join Date: May 2011 Location: Worcestershire Vehicle: Nissan Patrol Y61 2.8TD Posts: 1,152	Flex hone for deglazing/honing cylinders As per my project thread I am replacing the piston rings on my RD28T. To help bed in the rings the bore should be honed or deglazed. I have already decided that I will not be honing it in the traditional sense. The traditional way is the three pronged honing tool and send it up and down the cylinder bore. There are several reasons for not using this method: 1) The bores are currently not 100% straight and therefore this tool with not get to the low spots. 2) It takes off more metal and therefore increasing the bore diameter, which in turn results in the new rings being closer to the outer limit. 3) The tool needs to be held perfectly otherwise the top (or bottom) of the stones grinds off more metal. I am looking at using a Flex hone. This will follow the contours of the cylinder and makes sure that every bit of the cylinder gets deglazed. Cast iron rings will be used on the pistons as these are a little bit more flexible to seal an out of round cylinder compared to a more modern equivalent. Has anybody used a flex hone?