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Stihl 084 and 088

GeorgeWLogger

GeorgeWLogger

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I am wondering what is the differance in the two models? The specs. are the same on both.
Model Displacement (cm³) Power(kW/HP) Weight (kg)


STIHL 084 121.6 6.3/8.6 9.4
STIHL 088 121.6 6.4/8.6 9.9

Was it changed to meet emissions/EPA Regulations? Or is there major internal differences in the two powerheads?
 
kdhotsaw2

kdhotsaw2

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stihl084/088

Hello George,
The 088 and the 084 are the same sized motors but there are considerable differences inside. the 088 develops more power than the 084 does when they do stock. the factory changed a number of the things we were doing on our woods modifications, all for the better. they changed the combustion chamber volume from 13.5 cc to 11.5 cc. they lowered the squish clearance from .043 to .034. both these mods increased compression. they changed the transfer duct so it is now a straight shot into the barrel. the tonsil that hung dowm into the 084's inlet duct is now gone. they increased the exhaust duration slightly and changed to a slightly larger cast aluminum muffler. Also went to the newer fiberglass flywheel. probably has 1-1.5 more foot pounds of torque. also the lower transfer area in the case is larger so you can process more air-fuel mixture. all in all the 088 is a better saw
i have 2 new 088's left to modify if anyone is interested. put in a photo of one of my 084's making a .9 second cut in a 8 by 8 cant
ken
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530-589-2744
 
Ryan Willock

Ryan Willock

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Ken, what is the biggest bar that a stock 088 can effectively pull in the softwoods out your way??? i've seen pics of people running 72'' bars but was wondering:angel:
 
kdhotsaw2

kdhotsaw2

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northern calif
088 bar length

hello ryan,
up on the north coast in california in the redwoods they are currently using up to 8 ft bars with skip chain . lots of 4-5 foot bars used on that sized saws. we should check with uncle Art(Art Martin) , I think he used to use longer bars than that when he was falling up there
That is a 28 inch bar i'm using in the photo to test that size racing chain but normally use my 17 inch bar. can get the cutting time downto .6 seconds with that sized bar and chain with a pipe fitted to the 084 stihl. that particular saw now belongs to none other than the legendary gypo logger john lambert
ken
 
kdhotsaw2

kdhotsaw2

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85
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northern calif
stihl 084

Hello George,
The original stock 084's just didnt run all that great stock. when we modified them they ran very well. they were designed 10-15 years before the 088's came out. Stihl realized that they could make power by changing some of thier port timing figures and some of the bottlenecks in their 084 designed saw without losing any of their dependability so they incorporated many of the features we put in our modified saws. viola! more torque, more cutting power. the hp and torque figures are almost the same but the two saws don't run the same, the 088 has 10-15 more power stock and 35-40 % more power modified.
ken
[email protected]
530-589-2744
 
mtngun

mtngun

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Sometimes an 8 1/2 year old post is a gem, like this one.
+1

kdhotsaw2 said:
the combustion chamber volume from 13.5 cc to 11.5 cc. they lowered the squish clearance from .043 to .034. both these mods increased compression. they changed the transfer duct so it is now a straight shot into the barrel. the tonsil that hung dowm into the 084's inlet duct is now gone. they increased the exhaust duration slightly
If true, that's good data.

The compression ratio on my 084 was indeed lame, in stock form.

084 transfer duct looks just like other Stihls to my eye.

084 exhaust duration about 170 degrees, dunno why it would need to be increased.
 
Man of $tihl

Man of $tihl

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+1


If true, that's good data.

The compression ratio on my 084 was indeed lame, in stock form.

084 transfer duct looks just like other Stihls to my eye.

084 exhaust duration about 170 degrees, dunno why it would need to be increased.

The comp on my stock 084 is about 140 psi. What is the norm?
 
what-a-stihl

what-a-stihl

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084

I'm building a 084 now and I just purchased a gas tank/handle assembly but after reading this post it sounds like a 088 should be the saw to build. Is the handle/tank the same between the two? Or if I do build the 084 are there any mods i should do as I'm building it? thanks
 

w8ye

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I have a stock 084 with a .404 full compliment chain X 30" bar.

I use it to buck big trunks. It pulls the chain just fine. I run the mixture at the 2/4 point.

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