Porting a saw without cutting squish

[MustangMike]

Brian, both my 044 #1 and MS440 have no port work, but run like ported saws. Both have timing advance and base gasket delete, with the resulting squish at 20/1000 and 19/1000, respectively.

I think it depends on the cylinder you start with, and the saw. I would like to find another 044 or 440 to see if I can replicate my results with these mods, but nothing has come across my way since, although the saw Al did seems very similar.

 

[Keith Gandy]

Brian, both my 044 #1 and MS440 have no port work, but run like ported saws. Both have timing advance and base gasket delete, with the resulting squish at 20/1000 and 19/1000, respectively.

I think it depends on the cylinder you start with, and the saw. I would like to find another 044 or 440 to see if I can replicate my results with these mods, but nothing has come across my way since, although the saw Al did seems very similar.

440 and 460s do well with a base gasket delete because they build good compression

 

[Mattyo]

None of my port jobs have squish band cut. I cut the cases (chassis) most often on the bridgeport to optimize squish while still retaining a gasket. Then adjust the ports as needed. Its just the way I do it.... and has worked well. The compressions #'s can't compete with what mastermind or Jmssaws gets, but the saws do have a bump in performance

 

[jmssaws]

Anymore my high compression 066 is 185lb
It's simply not needed but a by product of fixing the exhaust timing.
That's a lot of why the better stock timed cylinder run better and lowering makes intake duration to big,much past 160 is to much for how I do and filling them just don't work like the real thing.

 

[jmssaws]

The cylinder on my 064 is a mahle decomp 066 cylinder that's 99.5 stock and with a 020 squish has 175lbs of compression.
The cylinder is completely untouched and will run with most ported ones.

 

[MustangMike]

440 and 460s do well with a base gasket delete because they build good compression

Keith, as you know, when you delete the base gasket you are doing much more than just improving compression and tightening the squish band (both of which are good).

You also increase the length of both the compression stroke and power stroke, and increase intake duration. I imagine these changes work much better with some cylinders than with others, depending on where the original #s are, including the transfers.

I did not put a degree wheel on these two saws, so I'm kinda just flying by the seat of my paints, but I try to do what works, and it seems to have worked.

And thank you for your encouragement to do it, I would not have done it w/o that. You advised me that the resulting squish usually works out quite well, and it did in both cases.

 

[jmssaws]

020 doesn't change everything timing much but a 44 or 46 can use the extra dab of intake and exhaust.
There both saws that usually have good stock timing.

As for the stroke being longer I'm not sure I follow. Stroke never changes but chamber cc's does.

 

[mdavlee]

020 doesn't change everything timing much but a 44 or 46 can use the extra dab of intake and exhaust.
There both saws that usually have good stock timing.

As for the stroke being longer I'm not sure I follow. Stroke never changes but chamber cc's does.

He meant compression stroke from the exhaust closing to TDC I'm guessing? More intake can help the 44 usually since they're sometimes 68-72 stock.

 

[mdavlee]

Could do the ole Gypo port job of 1 mm up and down

 

[jmssaws]

He meant compression stroke from the exhaust closing to TDC I'm guessing? More intake can help the 44 usually since they're sometimes 68-72 stock.

Right on
Most of them I've done are 68-70
The last 460 was 72
Both need some intake

 

[junkman]

Brian, both my 044 #1 and MS440 have no port work, but run like ported saws. Both have timing advance and base gasket delete, with the resulting squish at 20/1000 and 19/1000, respectively.

I think it depends on the cylinder you start with, and the saw. I would like to find another 044 or 440 to see if I can replicate my results with these mods, but nothing has come across my way since, although the saw Al did seems very similar.

I had an early 044 10mm with a ks jug that ran real good ,had 170 psi with a gasket delete ,no timing advance ,just a triple port muffler and the gasket delete done ,it was angry sounding ,and pulled a 32 inch bar fine ,did not spool up like my hybrids ,but ran real good .

 

[jmssaws]

I sometimes spend 4 hours just on the transfers maybe 7 or 8 hours total just on the ports,then the muffler takes a good bit of time and the ignition advance and then run a tank through tuning and making sure it's alright.

Cutting the chamber is a 10 min job.

My 046 has nothing but enough off the base for 020 and the rest is ported a good lick,runs good but not like one that's had the chamber cut.

 

[MustangMike]

My earlier one (a Black Lever SN 120******) does not run as strong as my newer one (a Red Lever saw SN 126******).

I know at some point in time Stihl increased the width of the intake port and the HP rating from 5.1 to 5.4. I'm wondering if any knows the corresponding date or SN for this change? Perhaps that has something to do with it.

 

[DND 9000]

This change was descriped in TI 44.2000 for 044 and 046 engines.

on 044 flush handle version from serial number 1 48 533 494
on 044 wrap handle version from serial number 1 48 532 794
on 046 flush handle version from serial number 1 46 085 314
on 046 wrap handle version from serial number 1 46 086 124

 

[MustangMike]

OK, thanks, so that is not the answer, as those are SNs for 12 mm saws.

I think my 044 #1 is just a freak of nature, it is a very strong running non ported saw.

 

[MustangMike]

I printed that and will retain it for future use, thank you very much for that detailed information.

 

[DND 9000]

OK I found a other serial number break in an IPL. 10mm piston pin was used (according to a US 044 IPL) up to serial number X 29 583 701. There is also a TI note (16.1994) but in this TI is a other serial number break, and I think that there is the german serial number break in it. Sorry it`s not really clear and I think Information between Germany and the US are often different.

 

[Al Smith]

Could do the ole Gypo port job of 1 mm up and down

That was a hoot when it happened .Believe it or not that 044 ran real good in spite of the shape it was in when I ran at a GTG. That thing had been through the ringer when I got my hot little hands on it .