Not So Fun Facts Stihl 1108 Series Cases and Cylinders

[295 tramp]

Many of you know I'm building a rear handle Stihl S-10 for Dave.
Doing custom and restoration work comes with many challenges.
Working on the project tonight I ran into problems fitting the cylinder on the case.
1108 series cases I thought were all the same, unfortunately I was wrong.
The S-10 top handle and S-10 rear handle saw is built on a 08 1108 series case.
All 08 parts will fit a S-10 top or rear handle saw except the case gasket.
08 and top handle S-10 have 5 bolt holes around the fuel tank.
A rear handle S-10 has 6 bolt holes around the fuel tank.
The differences are in the cases and cylinders.


Here's a early model 08 and top handle S-10 case.

My problem at first was the jug wouldn't fit on the case.
I'm using a 47 mm jug on a early model case that used a 44mm jug.
No worries I'll just grind a little off where the jug goes into the case, problem solved.
The jug fit and all the bolt holes matched.

I thought I was home free to keep on building and then I grabbed the rear handle.
the handle has 2 bolts that fastens to the top and 1 that fastens at the bottom of the case
Hey!! there's no bottom hole in the case for the handle.
I knew at that moment I was Screwed.
Not only no hole in the bottom , the area where it mounts is wider.

Here's a 1108 series case for a rear handle S-10


Notice the same part #s like the first set of cases and it has the hole for the bottom handle mount.
It gets better.

 

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Here's another case with different part #s.


I think this case is off a 08s.
It has the bottom hole for the handle mount.
It's setup for a chain brake and notice the extra bosses around the clutch area at 5 and 7 o'clock.

It's getting late and I have school tomorrow .
I talk about the cylinders tomorrow.

 

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Here's 3 cylinders from left to right that are for a 08 and top handle S-10, 08s, and rear handle S-10.
The cylinder on the left uses the same intake block that is on a 07 for a Tillotson HL.
The Center and right cylinder use a Tillotson HS.
Notice the shark fin on the top of the rear handle S-10



Here's a look at the exhaust, the only difference was the early production 08 and top handle S-10.
08 and top handle S-10, Mahle 44ZD4, exhaust 24.8mm x 16.4mm.
08s, Mahle 47ZN1+A4, exhaust 27.6mm x 16.4mm
Rear handle S-10, Mahle 47ZD2, exhaust 27.6mm x 16.4mm


Left - 08 and top handle S-10 open ports and plated bore.
Center - 08s closed ports and plated bore.
Right - rear handle S-10 open ports and a plated iron bore.
This where my first setback was using the 08s 47mm cylinder on the 08 early model case
that used the 44mm cylinder.

 

[Definitive Dave]

Beautiful work Randy.
There is very little good info out there on these models beyond the generic IPL.
Until I found that rear handle version amongst a bunch of saws from a local shop, I always assumed they were just fat little heavy turds.
To me the rear handle version is a lot cooler looking.
There is a crazy amount of attachments for the o8/08s as well, everything from rail grinders to 2 man earth augers to outboard motors, makes them a fun collectible and the 08s was made at least until the mid 90's in some parts of the world.
Thanks for taking on this project, you rock!!