New domain: www.Speed-Talk.com

The forum is currently running on the new domain and server. The old domain will remain active for a short while to forward any (less frequent) visitors.
IMPORTANT: Update your bookmarks to https://www.speed-talk.com/forum/

Recommend me stone grits

General engine tech -- Drag Racing to Circle Track

Moderator: Team

Post Reply
AC sports
Pro
Pro
Posts: 217
Joined: Mon Jun 03, 2013 6:25 am

Recommend me stone grits

Post by AC sports » Tue Sep 10, 2019 7:01 am

I've decided to invest in a new rigid type hone to: correct any machine shop errors, straighten out slightly tapered/out of round bores, de-glaze and plateau finish cylinder walls.
I build a variety of vintage, mainly 4 cylinder Euro engines, for either street or historic racing. I use all sorts of ring types. Cast, Chrome, SS, as well as the newer nitrited/moly slim type supplied with forged pistons. Cylinders are almost always cast iron.
Given this is not something ill do often, i figure there is no point spending on a dedicated machine, so have been looking at the Lisle 15000 unit for use on a high torque, low speed drill.
My question is what grit stones do i need to cover the above?
Also is it acceptable to use a couple dozen strokes of a flexhone after finishing with stones, to achieve a plateau finish? I'm seeing lots of conflicting info here.

User avatar
modok
Guru
Guru
Posts: 2227
Joined: Sun Jun 06, 2010 1:50 am

Re: Recommend me stone grits

Post by modok » Tue Sep 10, 2019 7:20 am

I'd have to ask what stones are available for it, I don't know.
I don't believe in going finer than 220 for a base finish, with the exception of moly faced rings.
Although most moly faced rings can also work great on a 220 base finish, if you plateau it. .

User avatar
modok
Guru
Guru
Posts: 2227
Joined: Sun Jun 06, 2010 1:50 am

Re: Recommend me stone grits

Post by modok » Tue Sep 10, 2019 7:31 am

https://www.lislecorp.com/specialty-too ... inder-hone
If it was me, I'd get the 180 and 280

500 might be REALLy fine, only would use that as plateau for super skinny or moly, pre-lapped rings.

the 80 course, would only really NEED that if there is more than .003" to remove.

AC sports
Pro
Pro
Posts: 217
Joined: Mon Jun 03, 2013 6:25 am

Re: Recommend me stone grits

Post by AC sports » Thu Sep 12, 2019 6:02 am

Since only 180 and 280 grit are available, Could i plateau a 280 grit stone finish, with a 280 or 320 grit flexhone and leave it at that for moly rings? what about conventional types? or could i plateau straight over the 180 grit?
Ive been told the flexhone will finish finer than a similar grit stone.

User avatar
modok
Guru
Guru
Posts: 2227
Joined: Sun Jun 06, 2010 1:50 am

Re: Recommend me stone grits

Post by modok » Thu Sep 12, 2019 9:46 pm

for most applications, hone virtually all the way to size with the 180, then do a limited number of strokes with the 280, just enough to "hone the hone marks", probably only be 10-20 strokes. You can experiment and see how many strokes it takes to "get to the bottom" and then do about 1/3 of that. Kind of the same as sanding paint....how much does it take to remove all the scratches from the last step, do 1/3 of that. you want to even out the surface but NOT remove the deeper scratches.

in order to plateau with a rigid hone, the cylinder needs to be straight. Ok duh, but actually that's kinda tricky. Even to the point that when you switch stones, the pressure needs to be the same, so the distort the cylinder the same way.

The straightest a cylinder will EVER be is just after you honed it, and that's when you need to do it. IMO this gives you a surface that is better AND straighter than otherwise possible. Cannot be done tomorrow or next week.

The flex hone will follow the existing surface even if it isn't perfect, which is a good thing and a bad thing.

to make it simple, What happens with a normal singe stage finish?
180-220 is the OLD standard, and break-in sometimes took awhile, but it was, normal.
280 grit and what happened in my experience, is it broke in QUICK, but in sometimes wore out prematurely.
Sometimes if too much the hone marks are worn out it starves of lubrication, other times it's ok, really depends on the rings and the cylinder and how much it wears and how picky the rings are about lube.

I've used a flex hones and brush hones a few times, didn't like it. results were mixed. You will have to ask others for advice on those.
Doing a base finish with 220 aluminum oxide soft, then plateu with 280 silicon carbide, I have, believe it or not, 0% problems.
I mean, that's impossible, I know, for humans to have 0% problems, but so far that's how it's been, so far, out of thousands. Must be some luck involved.

User avatar
modok
Guru
Guru
Posts: 2227
Joined: Sun Jun 06, 2010 1:50 am

Re: Recommend me stone grits

Post by modok » Thu Sep 12, 2019 10:07 pm

And that would be for d-wall or older metric width rings...... like, npr's chrome faced, or industrial HD, cast iron grant, or even Hastings moly.

Post Reply