Chainsaw Repair
Husqvarna - Stihl - Poulan - Jonsered - Dolmar chainsaws and more => Husqvarna => Topic started by: chainsman1 on February 24, 2014, 06:58:05 am
-
I ve seen a 357 with a 272 top end, anyone have even seen a 254 with a 272 top end? Maybe it would be too much work to make it fit....
The biggest it could go could be with a 262 top end?
-
IIRC, the 254 has a shorter stroke that the rest of the members of that family. (I remember SawTroll reminding me of that a short while back) So that lets the rest of the family out. The 272 cylinder also has a spigot or flanged base that fits down into the crankcase, the 254 and the rest of the family use flat based cylinders.
So, unfortunately I think you re out of luck. If and only if you could put the 272 top end on a 254 the cost to do so would be more than just buying a 272 and rebuilding that.
-
IIRC, the 254 has a shorter stroke that the rest of the members of that family. (I remember SawTroll reminding me of that a short while back) So that lets the rest of the family out. The 272 cylinder also has a spigot or flanged base that fits down into the crankcase, the 254 and the rest of the family use flat based cylinders.
So, unfortunately I think you re out of luck. If and only if you could put the 272 top end on a 254 the cost to doso would be more than just buying a 272 and rebuilding that.
Actually the stroke is the same, but the con rod is shorter than on the 262 and 257. ;)
-
Well I stand corrected on Stroke vs. Connecting Rod. However I do not think either of the two options are worthwhile. Although trying to get a 262 top end to work would be an interesting puzzle. Expensive but interesting.
-
@KRL....."..The 272 cylinder also has a spigot or flanged base that fits down into the crankcase, the 254 and the rest of the family use flat based cylinders..."
I've just pulled the cylinder off the 254 I bought and it has a spigot flanged base, the cylinder extends about 6mm into the crank case. Is it possible that it is not a 254 cylinder? The only numbers I can find on it are 45 ZN7 W2, cast onto the edge of the mounting flange (with MSHLE cast on the opposite side). This saw may be a mongrel. It has the wrong clutch cover. I'll make a separate post about that.
Cheers,
Gregg
-
Wow, it appears that I have been wrong twice in this thread. After looking about the internet it appears that the 154 and 254 indeed use the same cylinder and they both DO have a spigot! See the attached. I appologize for leading you astray!
I guess I should turn in my Husqvarna badge!
-
At the risk of being wrong three times in this thread; the 254 and the 272 both have a stroke of 34mm. That being said, we have to take into account what Troll said about same stroke but different length connecting rod. I have not been able to find the difference in length of the 254XP and 272XP connecting rods.
However, here is my supposition the differing length rods will most likely throw the port timing of the saw off.
-
IIRC, the 254 has a shorter stroke that the rest of the members of that family. (I remember SawTroll reminding me of that a short while back) So that lets the rest of the family out. The 272 cylinder also has a spigot or flanged base that fits down into the crankcase, the 254 and the rest of the family use flat based cylinders.
So, unfortunately I think you re out of luck. If and only if you could put the 272 top end on a 254 the cost to doso would be more than just buying a 272 and rebuilding that.
Actually the stroke is the same, but the con rod is shorter than on the 262 and 257. ;)
if the con rod is shorter,maybe the piston pin to crown height is taller?
-
i got 76mm between cylinder bolt holes across the jug (center to center)on a 272 cylinder. anybody knows the mesurements of a 254 cylinder?
the spiget is 56mm in diameter
-
The 254XP piston is 45mmd,x20mmch,x39mmoa
The 272XP piston is 52mmd,x24mmch,x40.5mmoa
Both use a 12mm pin but of differing lengths.
-
@KRL....."....Wow, it appears that I have been wrong twice in this thread. After looking about the internet it appears that the 154 and 254 indeed use the same cylinder and they both DO have a spigot! See the attached. I appologize for leading you astray!....
I guess I should turn in my Husqvarna badge!...."
I'm sure you're just kidding. Trying to keep an old saw going, this forum was like an oasis in the desert. So thanks to all the people who contribute here.
-
It just occurred to me that you may also have a problem with the 272 piston at 40,5mm oah having the skirt hitting the crank throws at BDC. When I mess with these kinds of frankensaws I try to have 2mm clearance between the skirt and the crank.
-
IIRC, the 254 has a shorter stroke that the rest of the members of that family. (I remember SawTroll reminding me of that a short while back) So that lets the rest of the family out. The 272 cylinder also has a spigot or flanged base that fits down into the crankcase, the 254 and the rest of the family use flat based cylinders.
So, unfortunately I think you re out of luck. If and only if you could put the 272 top end on a 254 the cost to doso would be more than just buying a 272 and rebuilding that.
Actually the stroke is the same, but the con rod is shorter than on the 262 and 257. ;)
if the con rod is shorter,maybe the piston pin to crown height is taller?
Or the cylinder is sitting lower relative to the crank?
I don't know the details.
-
Or the cylinder is sitting lower relative to the crank?
I don't know the details.
Yes, I agree that is also a possibility. We would need to know the deck height from crank shaft center, as well as the actual length of the rod from crank pin center to piston pin center (I think? ???). In order to try to figure it out. None of these measurements can I find anywhere, I can't even find anything from HVA stating the deck height.
-
Both cylinders are flanged, but the flange for the 272 cylinder will not fit into the 254 crankcase; the opening is just too small.
It could be done, with a lot of time and machine work. I doubt it would be worthwhile to anyone but an absolute fanatic.