if im removing the cylinders on a stock 80" evo....I should quick hone and replace the rings when not replacing the pistons, right? im around 35000 miles..or should I replace the pistons?
are these what I need to replace the rings?
http://www.ebay.com/itm/Hastings-Sta...VW7KVK&vxp=mtr

 

At least replace the rings. If I was doing it, which I did in July, I would go with the 10 to 1 pistons, it made a world of difference with mine, power wise.

 

I'm going to do this sometime too...maybe next winter...my 99 has less than 20K on it..I want to do the 10:1 piston swap

should you wait to order rings an pistons until you remove the jugs an check for how they're wearing...I don't know how likely it is the cyl wear an will need to be trued.

 

anything else needed to be done with moving up in compression like that? doing the lifters and a ev27 cam also....

 

You really need to take some measurements to know if you need new pistons. You need an inside Mic to check to see if the holes are round and size. And then an outside Mic to see if theb pistons are a match for the holes. Even if you are going to a higher compression pistons you still need to know first what size the holes they're going in are. There are other things to check for as well such as a ring ridge.

 

... and you need to know the proper area to measure ... pistons are not "perfectly" round.

 

800screws, yes if not replacing pistons just hone check end gaps .018"-.022". If you want to go to new piston@10:1 you will most likely need to bore. Original cast piston require more clearance than forged pistons. Plus you want go make sure there is no taper in the cylinders. I believe Scott@ Hillside stocks the pistons, Wiseco...... He'll bore and set them up for you and probably sqaure up the base of the cylinder. Very important...

 

Plus you want go make sure there is no taper in the cylinders ... a bore gauge will tell you this. Good info here. Ridge at top of cylinder has to be removed. It will break new rings. Ring grooves/lands will need to be cleaned and inspected. Any carbon will bind the rings and "tweaked lands' will bind the rings. There's a lot to consider. Bumping up the compression will/could effect the performance of your cam choice. Think it through BEFORE jumping in. Good Luck

 

OP, I ll just chime in hear on post#5. If your your looking at top-end upgrade or just ring job consider just a few things. I'll try to be as short as possible. Like always for the DYI person, the HD service manual is very helpful...

First; like mentioned determine that your jugs first are round and within the recommended clearances for just new rings. A glaze breaking hone process may be all that's needed to restore a cross hatch pattern on the cylinder wall providing they are round. Check for ridge also at the top of each jug. This can can be cut if needed with a ridge reamer. It's critical that your finish honing remains within allowed tolerances otherwise your looking at replace or rebore the old cylinders.

Second; check by OD micrometer your pistons for wear measured at the piston skirt. If ok reuse. After removing the old piston rings the piston ring lands should best be cleaned of carbon build up. A ring regroving tool carefully, works well for this making ring replacement simple. Check new rings installed end gap.

This is just scratched the surface. To go this deep, you should also be looking at things like wrist pin to piston wear and crank pin wear. Cylinder heads givin a thorough inspection as well.

In some cases it's more cost effective to just go with new parts and be done. This minimizes the amount of machine work of old parts.

Either way you go, good luck!
Hope this has helped some.

 

im going to have them bored to new pisons