Part Two: The Intake Port

[drf256]

Pics

Too late.

The throttle plate is 283mm2

Tomorrow night. I'll post stock vs mine. They look exactly the same.

 

[Deets066]

Too late.

The throttle plate is 283mm2

Tomorrow night. I'll post stock vs mine. They look exactly the same.

Wonder how a sawwould run with the exact same area as the throttle plate? I bet it would suck

 

[huskihl]

Too late.

The throttle plate is 283mm2

Tomorrow night. I'll post stock vs mine. They look exactly the same.

Just a little shout out to you. Once I started squaring intake ports to mimic yours, my saws ran noticeably better than previous ones that were more rounded on bottom and the sides. Sorry to confuse you more, lol

 

[Hedgerow]

It's hip to be square..

 

[srcarr52]

It's hip to be square..

Square filed!

 

[Deets066]

Maybe I could square up my intake ports with a double bevel

 

[mdavlee]

Square for more performance. Round for longevity and fuel usage

 

[Hedgerow]

Square filed!

Harrumph!!!

 

[Hedgerow]

I wanna see an intake port you can shove a golf ball down.

 

[Hedgerow]

A square golf ball..

 

[huskihl]

Maybe I could square up my intake ports with a double bevel

Finally found a use for Save Edge

 

[mdavlee]

A square golf ball..

The 880 is close. I think a 346 piston would fit.

 

[Hedgerow]

Finally found a use for Save Edge

I've gone through so many save edge files, you'd think I owned stock in the freaking company.

 

[mdavlee]

Vallorbe FTW

 

[drf256]

Who said round?

The 262 has a nearly perfect intake stock. It's already near to edges of the skirt factory. It's already square with rounded edges. It's 66% of bore width stock.

Would I leave a Stihl 026/036/044 stock width? No.

An o46/460-maybe. I've seen some jugs with huge perfect intake ports-the most variations I've seen in any Stihl jug.

The intake opening is nearly double the area of the carb bore. Any bigger and I'll flow the same and lose vacuum signal. This saw has the 87 carb as well. The roof is untouched.

Every saw is different.

Factory



Modified

 

[Deets066]

Who said round?

The 262 has a nearly perfect intake stock. It's already near to edges of the skirt factory. It's already square with rounded edges.

Would I leave a Stihl 026/036/044 stock width? No.

An o46/460-maybe. I've seen some jugs with huge perfect intake ports-the most variations I've seen in any Stihl jug.

The intake opening is nearly double the area of the carb bore. Any bigger and I'll flow the same and lose vacuum signal. This saw has the 87 carb as well.

Every saw is different.

Factory

View attachment 68531

Modified
View attachment 68532 View attachment 68533

Nothin wrong with that Al

 

[drf256]

The 262XP has a plated intake port in most cases. It ain't easy to grind as the plating extends about 8mm into the port on some jugs.

 

[drf256]

Here's a few Stihl intakes.

A 10mm 044

 

[drf256]

2 Stihl 046/460

This one has around 20% more port area than the second.

Unfinished



Finished



Smaller port with rounder edges



Guess which one makes the same WOT rpm free spooling and more rpm in the cut? Which one losses the least rpm when you dawg it in and pull up on the handle hard?

 

[drf256]

Doesn't the 10mm 044 port modified look a lot like a stock 262 intake?

Another point to remember on dual ring Stihl pistons. The right sided roof area, as you look at the port the direction I posted a pic of, is where the bottom ring gap sits at BDC. I leave that corner more rounded to make sure it stays tucked.

Like Deets exhaust port he posted, a trapezoid can work here as more flow happens on the floor than the roof. Opposite an exhaust port.