Aren't the SE pistons forged? Forged pistons typically require more clearance than the stock cast pistons.

In the automotive world as a general rule-of-thumb, where cast pistons run at approx. .001 clearance, forged pistons in the same motor run around .004 clearance.

 

They offer the SE pistons in various flavors and sizes and offer standard, big and bigger bore cylinders for the installation. I would guess the cylinders are the constant and if there is any variation in clearances it would be in the OD of the piston.

For my problem install I used forged 10.5:1 purchased through ebay as new in an opened for pictures package but found the rings provided most likely were not SE. The next set of pistons came with a set of SE rings and in a different package. I have rebuilt many motors and this was the first set of compression rings I could bend like a pretzel. The rings were flexing up and down in the groove, damaging the ring groove and cutting the cylinder wall resulting in the damage you have in your pictures.

Did you purchase a new set of pistons and rings or did someone screw you out of your SE rings like my seller did me?

 

no, the SE pistons are cast... and yes, i got them direct from harley

i brought a cylinder to the local indy that did my case work and he's insisting that the pistons were too tight...told him i did a quick measurement with a feeler guage and that it was indeed tough to get a .001 in there... said to bring down a piston and jug tomorrow and he'd do a more accurate measurement

i'm leaning toward too tight

regardless, gonna go .020 over on a set of wiseco forged and be done with it

 

Tried my darnest to find clearance instructions for the SE casts and no in stone specs, found that SE TC and Evo should be set at .0025 but once again not in stone, I know that forged pistons are set at .003 in Wiseco's. S&S cast pistons are all over the place in specs according to the piston number so not a good referance either.

Defintley a heat issue and if it was running lean, you should of heard the marbles of detonation to do that, lower bearing problems will scuff a piston on the exhaust side of the piston but piston scuffing is uniform by pictures.

 

.003 to .005 on forged here,thats after using a sunnen hone machine or equvilant to get a straight bore.I thought the se were the same as the keith black pistons and they were allways .002 to .003 here but I like my stuff a little looser than most.it seems instructions on the keith black were .001 which is t-i-t

 

indeed, 97.... scoring is uniform (front and rear of both pistons- same with jugs)....checked everywhere as well for specs on clearance, so just referred to manual on stock pistons (this could be a bad reference, though)

indy very much dislikes the SE pistons... says they're spec'd to fit too tight... wiseco forged pistons fit loser at .003-.005 as you say, pete

...and you could be right, the SE pistons might be spec'd out to between .002 -.003, but i'll be damned if i can find the info anywhere

 

There's no doubt the pistons were installed too tight, or you had a 50/50 oil/sand mix in the engine. The coating is scuffed right off of the sides. The bore could also be tapered. All to often a shop will install parts without reading instructions or doing the proper research. We alway read the instructions as most manufacturers don't notify us personally when they make changes. The clearance on a piston has many variable like composition, usage, and engine bore to name a few.
John

 

yeah i figured maybe a contaminant, john... but i did a thorough scavenger oil change before i tore things down, but nothing.... inspected oil, ran my hands and fingers through it to feel for grit or something

this is upsetting considering i had a very reputable person do the work ....oh well, live and learn

 

Js, every engine builder can have a bad day. Unfortunately it's the customer that gets hurt the most. You need to make sure none of the particles that came off of the pistons is still in the engine or your problems will get worse once you fire it up again.
John

 

i know, john... i'm not losing my mind over it

any suggestions on how to get out what oil is left in case without having to pull it from the frame and split it?

gonna pull the oil tank and have a buddy clean it out this weekend... gonna pull gear cover and inspect everything, clean it out... but case?....hhhmmmm

any ideas?