Stihl 026 Stock / Ported Comparison Pics

I get a lot of guys asking questions about port work. I'm building a really nice 026 for a member and thought I would show a stock jug side by side with a ported jug. This would be a great thread to throw out any questions about porting. If I can't answer them there are many guys here that can.

In this shot you can see that I didn't really enlarge the intake much, just smoothed out the casting lines and blended it out.



I just take the lip out of the lower transfers on a mild work saw. I don't find it necessary to open them any more on a work saw of this size.



I spend much more time on the upper transfers than the lowers. Here I've widened these as much as possible, and raised them a few degrees as well.



The exhaust port gets quite a bit of work. I widen the port, and increase the outlet size as well. On this saw the port is already fairly high (164° duration - 98° from TDC) so it's not been raised at all.



The shiny spot in the center of the exhaust port is the plating, like I mentioned above this port is at the stock height, only widened.

I increased the intake port timing 10° from 144° duration. It would require lowering the intake port about 3/32". Rather than making the port that much larger I cut some length from the piston skirt.





If there's any interest I'll add some more to this thread. I would love to see some other guys post some pics here as well.

Good work and a good thread Randy.

This is just what i needed to see , it clears up alot.

subscribed.

very informative. thanks for posting this Randy! this couldn't come at a better time for me as i am wanting to get some work done to an 026. i read on another thread where some fellas felt it was best to leave the lower transfers alone because they thought rather firmly that it helped keep the torque stronger through the rpm range. this of course was for a true work saw. i noticed you did some moderate work to the lower transfers here so i was wondering if i could get your thoughts on the matter. please don't think i'm calling you out or anything, i'm just a FNG trying to learn.

Great thread, I like the before and after pics, they tell the story well.

Mastermind, how does one port for torque versus rpms? I understand the need to keep the exhaust lower for torque, but how are the transfers and intake ports adjusted for torque?

Rep sent, good job.

Nice work Randy. And very generous of you to share.

Al.

chopperfreak2k1 said:

very informative. thanks for posting this Randy! this couldn't come at a better time for me as i am wanting to get some work done to an 026. i read on another thread where some fellas felt it was best to leave the lower transfers alone because they thought rather firmly that it helped keep the torque stronger through the rpm range. this of course was for a true work saw. i noticed you did some moderate work to the lower transfers here so i was wondering if i could get your thoughts on the matter. please don't think i'm calling you out or anything, i'm just a FNG trying to learn.

Click to expand...

I just removed the lip from the bottom of the port, it has to help with flow.

Log Hogger said:

Great thread, I like the before and after pics, they tell the story well.

Mastermind, how does one port for torque versus rpms? I understand the need to keep the exhaust lower for torque, but how are the transfers and intake ports adjusted for torque?

Click to expand...

I've found that raising the upper transfers a few degrees with other mods allows an engine to hold the rpm in the cut. The higher the exhaust and transfers go in relation to each other the high the rpm seems to go. I'm sure that there's a point when it starts going the other way though. Too much exhaust without the compression to support it and an engine is just a screamer that has no useable torque.

I tried to reply this morning, got my pictures loaded and hit submit to see '' sorry the server is to busy at this time.'':msp_sad:

I was just gonna add a few pictures to go with Randy's since he said we could add some . I don't have a stock jug to compare too, but Ill give what I got.

Heres a ms460 Ive been working on, coming together slowly but surely. You can see where I unshrouded the lowers, and blended back into the existing port. The uppers were raised to 118ATDC, and only widened toward the intake a little, due to the piston ring end pins.



Exhaust port was raised to 100, from 101. If this saw was destined for a popup, id probably raised the exhaust a little more. Polished it up good too. Shaved .010 off the base for a .021 squish with the OEM base gasket.


The intake was lowered to 80, most of it was trimmed off the skirt. Looks like I need to take some more pictures :msp_sad:. I may take some more before I get it all put back together and start a thread on it if anyone is interested. ??

Here's a little trick I've picked up for the 026. The squish band hits just the edge of the piston when the base gasket is ditched, this allows it to clear, and raises compression a BUNCH.





This shot shows how much the muffler must be milled out to fit now.



This is a clean saw. DSS sent this saw here in exchange for some port work.

Did I mention I do port work for trades???

I just so happen to have an ole 026 and this is an great comparison. Awesome work Randy!

Matching the exhaust gasket.







I've used the largest fuel line and filter that would fit here. Can't have it staving for fuel.






Thanks for the pics Durand. Damn fine looking work. I would love to see more.

For those of us who understand little about porting, the side by side pictures really help.

026

I see Randy the Mastermind has met another saw. Nice looking work and great pictures. Keep them comming. Rick!

A shameless plug with the card.



A new starter pawl never hurts a thing.





This I mention that this was a clean saw???

I hope you enjoy it Wes.

Thanks for the pics. Its been a good while since anyone has posted up there porting work.

Outstanding.

And the carb is a ????

How do you do the transfer work? Will a dremel fit, or do you have a 90 degree one.
Perfect timing, I am doing an 026 now as a gift and will port it. I have never messed with transfers before.
and if all works well, I will do my old 026 the same way later.