Subarutex Posted August 16, 2005 Share Posted August 16, 2005 I just got my block back from being re-ringed, and having 2 pistons replaced. It has been rehoned, but lacks the pretty crosshatch i've seen on other blocks. The engine assembler (Subaru Tech 20+ yrs) said I could use some light sandpaper to put a slight crosshatch on it. So... how should I go about doing this? Looking for cheap and easy. Time consuming is ok. Quote Link to comment Share on other sites More sharing options...
iamtheq Posted August 16, 2005 Share Posted August 16, 2005 http://buy1.snapon.com/catalog/item.asp?P65=&tool=&item_ID=11786&group_ID=1589&store=snapon-store&dir=catalog or http://buy1.snapon.com/catalog/item.asp?P65=&tool=&item_ID=11804&group_ID=1592&store=snapon-store&dir=catalog Quote Link to comment Share on other sites More sharing options...
NorthWet Posted August 16, 2005 Share Posted August 16, 2005 The "pretty crosshatch" is a product of the honing process... so what did his honing job leave for markings? The hone marks are intended to help the compression rings "seat", and are more important for chrome-faced rings than moly-filed rings. It might be an idea to find out what type of rings were installed, and whether the type of hone job matches the ring type. I see no reason to go after the cylinder walls with sandpaper. Either the hone job was done right or it wasn't. Quote Link to comment Share on other sites More sharing options...
KStretch55 Posted August 16, 2005 Share Posted August 16, 2005 Your cylinders were bored to make them round again, since over time they become slightly oval shaped. Now, you need to run a hone through them. Go to Schucks, Harbor Freight, NAPA and buy a hone (there's two types, one looks like the object in the previous post with a bunch of stone balls on it and one has more rectangular shaped stones mounted on springloaded arms. Generally, the stone ball type is cheaper and does just as good of a job.) Don't buy the Snap-On one, it's waaaay overpriced. It only takes a few minutes so they last a long time. Basically, follow the directions that come with it. You put it in an electric drill and run it in and out of the cylinders while the drill turns. You want a nice 45 degree (if I recall correctly) crosshatch pattern. It doesn't take long at all. The reason for the crosshatch pattern is to give oil a very small place to flow and to help the rings seat. Quote Link to comment Share on other sites More sharing options...
All_talk Posted August 16, 2005 Share Posted August 16, 2005 Just a couple of notes: As Pat said the hone job from the machine shop should have the cross hatch. The solid stone (3 arm) hones are used for sizing and squaring, while they will do a fine job crosshatching a new or rebored cylinder, they don’t work well for de-glazing/crosshatching when just re-ringing. I’d recommend the ball type (sometimes called a bead hone) for most home shops. There is a bit of a trick to pacing the up and down of the drill to the rotation speed to get a good crosshatch (hint: turn it pretty slow), practice on an old block if you can. And you should check the piston to bore clearance and the ring end gap before going crazy with the hone (specially with the 3 arm type). Gary Quote Link to comment Share on other sites More sharing options...
Subarutex Posted August 17, 2005 Author Share Posted August 17, 2005 Your cylinders were bored to make them round again, since over time they become slightly oval shaped. Now, you need to run a hone through them. Go to Schucks, Harbor Freight, NAPA and buy a hone (there's two types, one looks like the object in the previous post with a bunch of stone balls on it and one has more rectangular shaped stones mounted on springloaded arms. Generally, the stone ball type is cheaper and does just as good of a job.) Don't buy the Snap-On one, it's waaaay overpriced. It only takes a few minutes so they last a long time. Basically, follow the directions that come with it. You put it in an electric drill and run it in and out of the cylinders while the drill turns. You want a nice 45 degree (if I recall correctly) crosshatch pattern. It doesn't take long at all. The reason for the crosshatch pattern is to give oil a very small place to flow and to help the rings seat. My cylinders were not bored, they were honed. It does have a slight crosshatch to it, just not as perfect as when I bought the block new. The block has 150 miles on it since its last full rebuild. The hone that is on is functional, however it is not the good 45 degree crosshatch. It seems I can't use the balls with the pistons in, so i'll just continue to follow directions given by my Tech and use some fine grit sandpaper by hand. Quote Link to comment Share on other sites More sharing options...
Subi81 Posted August 18, 2005 Share Posted August 18, 2005 Here is what a power honed block looks like minus pistons. I agree with NorthWet if the machine shop said they did the hone, then you shouldn't have to do anything else. Good luck Quote Link to comment Share on other sites More sharing options...
ShawnW Posted August 18, 2005 Share Posted August 18, 2005 Really shouldnt be doing anything to the cyl walls now that the pistons are installed unless you want to take em back out. The grit created would cancel out any productive gain you do to them and hopefully the pistons are sized to the block properly and enlarging anymore wouldn't be good either. Quote Link to comment Share on other sites More sharing options...
KStretch55 Posted August 19, 2005 Share Posted August 19, 2005 Most definitely agree with ShaunW!! You'll do more damage than good if the cylinders are installed when you try to scuff the walls up. You won't be able to remove all the grit, nor will you be able to scuff the lower end of the cylinder. Quote Link to comment Share on other sites More sharing options...
MorganM Posted August 20, 2005 Share Posted August 20, 2005 Northwet already spoke the truth on this. Either the machine shop honed them properly or they didnt. You said you talked to the machinist that did it and mentioned he has lots of experience with Subaru engines. If he is satisfied with the hone on the cylinder walls then it's go time. If you are not satisfied with his hone job then you need to take out the pistons and do it to your satisfaction. Quote Link to comment Share on other sites More sharing options...
Subarutex Posted August 20, 2005 Author Share Posted August 20, 2005 It was not a machinist that honed it, it was the Subaru Technician that did. It was just with one of the handheld deals. And, it is fine. Engine is already together about to go back in... Quote Link to comment Share on other sites More sharing options...
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