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Welcome Area OnlyNew Member Welcome Area Only. Be sure to pop in here and introduce yourself & let us know what Harley Davidson you own. Save your bike related questions for the proper area.
Real quick, short and sweet...i've gotten a ton of excellent advice from this and I appreciate everyone who takes the time to help another out. This is my first post here and i apologize in advance if it's in the wrong "forum". People seem to get their panties in a bunch over such a trivial thing but s*** happens. So moving on, I have a 77 Ironhead stroker and I let my son take it last summer for a weekend ride. Apparently some oil had drained out and in the process the Piston had slapped into the valve and squashed where one of the grooves for the piston rings go. The ring was in about 30 pieces, I was able to retrieve all of it however if there's no other damage to the piston on the top or the sides except for words crushed. I filed it and now a ring fits and they're fine. I priced new pistons and it seems the stock ones are only $41 and the stroke Pistons are about 280 for half the material. Since there's no other visible damage to this piston that I have now and the ring roof seems to be functioning properly is it okay just to slide that back in there and run it or should I sit at 300 bucks and put a new one in? What could really happen if I run the old one? What can really happen if I run the old piston? Just bad compression? And if that's the case then I'll go ahead and get a new one but I'd like to try the one I have now.
The picture is from before I filed the ring groove
Bad idea? Yes a bad idea ... Replace the piston ... Just because the ring groove has been "repaired" doesn't mean the integrity of the piston hasn't been compromised ... It has ... It could ( and more than likely will ) crack and destroy itself ... I'd never put that back in ... Just my.02˘ worth ... Good Luck
Hope you continue to enjoy your ride here with us on the HDFORUM.
Only as a suggestion, but very important, create a signature line similar to mine with your year, model, and all the letters Harley assigned to your bike. It will appear at bottom of your post.
You can also add a favorite picture to the signature line.
Doing this will be helpful if you ask a question or someone asking a question. All Harleys aren't the same with many changes and variations over the years.
Above since this is welcome area. No biggie but you will get more replies if you need them probably in tech area.
I will say, a ring seals as it gets pushed out to the cylinder wall and down to lower face. That lower face is damaged. So your going to loose compression.
That lower face is usually what wears as an engine wears out and that is one of a few ways pistons are inspected. The groove width.
It's best to replace it and hit the cylinder with a hone to break glaze . Be sure to cut ridge ring for sure if there is one at top of cylinders. New rings in new pistons will be damaged hitting it.
Good luck.
Wants some more opinions, copy and paste it here in a new thread.
Welcome from Spartan Country, Michigan! I tell a lot of new comers to the forum to get: Factory Service manual and the Parts manual. Take to an office supply store and have them put a spiral binder in place of the glued binder. That will let the manuals lay flat on your bench. Get a three ring binder and record all your maintenance, repairs, accessories, etc. This will be a great reminder of what was done when. And great material to pass along to the new owner should you sell and upgrade. Also know how large your fuel tank is, a rough idea of your range per tank, and record your fuel usage. I have an app called Simply Auto that I record all my fuel used. I use the odometer and use the fuel gage as reference only. I reset the odometer to zero on fill ups, and I know I can safely get 200 miles on a tank on around town riding, and upwards of 230+ on trips.
Congratulations on your first post to HDF,
to the forum.
1. If you removed material, you have changed the balance of the piston and that will affect the crank, rod and other balance of the engine.
2. As stated, the piston may have damage not visible.
3. The ring groove is now wider and the piston ring will hammer the upper and lower part of the groove because of the extra space.
4. Do it right or you may be rebuilding the entire engine.
As pointed out, this is the wrong spot for technical questions. This is the OPs first post, so I think this post can be considered his introduction post and the OP can now go to the Ironhead section of the forum and get more technical replies. I suspect that those replies will be the same as those here; the integrity of the piston and ring seal has been compromised and the piston replaced. https://www.hdforums.com/forum/ironhead-66/
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Ironhead piston smashed
