guy with a chainsaw
ArboristSite Member
So .96 ring gap
Pioneer Holiday 1100G
- Thread starter Jasonrkba
- Start date
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One mm is about .039 is it not? I am old school and only function in thousands of an inch.
guy with a chainsaw
ArboristSite Member
Sounds Right well I will let you know when I got it running
If your measurement of the keeper pin was accurate at .039 then add .008 to it then a ring gap of .047 - .050 would be acceptable I would think, at least that is how I approach this stuff. The keeper pin may have worn down some from when new and the manual would be written using new parts for reference, that is why mechanics need to measure every part being resused on a rebuild.
guy with a chainsaw
ArboristSite Member
Ok thanks your a life saver
Don`t think of myself as that but thanks. I just watched a young fellow that does not have much extra cash do a rebuild on a straight 6 Ford 300, he did not measure his crank but just went ahead and installed new inserts/rod bearings. Said his dad had rebuilt many 6`s and knew what he was doing. I offered Plastigauge and or my micrometers but they refused, saying it was a waste of time, the truck made 35 miles before the crank tore the inserts out and the rods destroyed the crank, now looking for a replacement crank and possibly rods for a 300 six cylinder.
guy with a chainsaw
ArboristSite Member
Sounds like pride got in the way/ I did get the rings gaps right but I did not look at the size of the bore un till now I'm dumb for sure bore is 44.2mm the rings where to big even when I filed them ordering the right ones see you in a week or so
Note to anyone who is reading this 46mm rings do not fit in a 44mm head
Note to anyone who is reading this 46mm rings do not fit in a 44mm head
A.C.195
ArboristSite Lurker
I'm looking for one of those white holiday saws in great shape if anyone has one for sale.
guy with a chainsaw
ArboristSite Member
Ok I'm back got the right rings now but they have tapered ends like modern rings they fit I filled the ends to get the right gap thank you for so much help.
Ring are caber very nice ring for cheap
Ring are caber very nice ring for cheap
guy with a chainsaw
ArboristSite Member
Saw now cuts better new idle is a little bit better ring gap is at 100tho and compression is a bit higher at 31psi I do not know why tho can crankshaft seals or read valves do any thing to compression or maybe a bad tester gauge or are the rings still breaking in
I'm running a 20in bar and a 8 tooth sprocket
I'm running a 20in bar and a 8 tooth sprocket
Crank seals and reed valves does nothing for compression. Compression is all cylinder seal between the piston and cylinder wall and occurs after the top ring passes the exhaust port. Ring gap of .100 is far too excessive, the compression is leaking out through that gap. That much ring gap sounds to be about .050 larger than necessary to clearance even the ring keeper pin you say is in the piston. A set of rings with .020 gap is worn, a set with .025 and larger is totally worn out.
guy with a chainsaw
ArboristSite Member
Good to know so with the horizonal rings that I filed down to get flat ends do they make rings for old school pistons with vertical pins that are new of so send a link 44.2mm is the size of the bore
No need to file the ring ends completely flat, you only need to file enough off to get proper ring end clearance from the keeper pin in the piston. A set of 44.3 Cabers would be about right. Caber rings from DLA engine parts in Greece are easy enough to attain.
https://www.dlastore.com/cylinders-pistons/individual-piston-rings/piston-ring-44-3
guy with a chainsaw
ArboristSite Member
Ok gotcha but why go 44.3 over 44.2on the rings I got the 44.0 when I got them from DLA
As far as finding new rings with square cut ends, I have not seen any. They may be out there somewhere but I have not seen them on Hastings or Caber ring sites for many years.
You need to file them for proper gap so go any size you can find, 44.3 was the closest ring that came up in my search, no one uses these old ring sizes these days so pickings are slim. If you can get 44.2 so much the better.
guy with a chainsaw
ArboristSite Member
Okey dokey I will see what I can find
guy with a chainsaw
ArboristSite Member
guy with a chainsaw
ArboristSite Member
Is this what you where looking at
That is what came up when I ran a search, when filed the ring ends will be blunt enough to fit the ring end keeper well enough, only file them enough to get the .050 ring end clearance when fitted square in the cylinder. That should be plenty of clearance when fitted on the piston and yet provide much better compression.
