can we have basic porting term thread?

[cobey]

What to measure?
I know how to find TDC
So intake open /close?
Blow down?
Exhaust open / close?

 

[cobey]

Just want a list of significant
Timing events to measure

 

[Sty57]

View attachment 9876

I got that in PDF form

 

[cobey]

Made me a reminder

 

[SixGun]

What to measure?
I know how to find TDC
So intake open /close?
Blow down?
Exhaust open / close?

Exhaust open#,
Transfer open#.
(The difference between exhaust and transfer open is your blow down.)
Intake open # ( measured in degrees before TDC )
These are your starting numbers, duration can be calculated from here

 

[cobey]

Exhaust open#,
Transfer open#.
(The difference between exhaust and transfer open is your blow down.)
Intake open # ( measured in degrees before TDC )
These are your starting numbers, duration can be calculated from here

Good info thanks

 

[SixGun]

To find duration,
Exhaust or transfer open # subtracted from 180 multiplied by 2 equals duration#
Example- (180- 100=80) ( 80 x 2 = 160) exhaust opening at 100* has a duration of 160*
To go from duration to open # , do math in reverse.
For intake, simply multiply open# by 2

Guys, please correct me if I'm wrong

 

[cobey]

Should I get a 3/8 or 1/2 chuck?

 

[jmssaws]

Half

 

[Hedgerow]

Good info thanks

This is how you get to know the saw you're about to work on.
Sometimes you have to figure out what the original designer had in mind for it, before you can make improvements.
There are other factors to consider also, as #'s that make an awesome 372 will not help your cause on a 7900 or 044.

 

[cobey]

Got a chuck

I know it is ugly and dirty
Next time I'll clean up better
I got ahead of myself

I have to put it together and check squish
And get the clutch off

 

[czar800]

Congratulations your hooked

 

[cobey]

Probably be a couple day's before
I get numbers ,
I might have to teach tomorrow night

 

[cobey]

It's a head banger without the gasket,
022 ish with it. I have half a thought
Of putting it together and seeing
It everything works before
I do more

 

[huskihl]

It's a head banger without the gasket,
022 ish with it. I have half a thought
Of putting it together and seeing
It everything works before
I do more

That's a good #. Check a few places and if using solder, roll the flywheel over TDC a bunch of times to get a better reading

 

[cobey]

That's a good #. Check a few places and if using solder, roll the flywheel over TDC a bunch of times to get a better reading

I'm gonna order a couple base gaskets
To make sure I measure everything
With the gasket I'm going to use

 

[lumberjackchef]

Half

Yep..the first one I made was 3/8 and it wouldn't work on my big saws on the clutch side.

 

[lumberjackchef]

View attachment 10004
Got a chuck
View attachment 10005
I know it is ugly and dirty
Next time I'll clean up better
I got ahead of myself

I have to put it together and check squish
And get the clutch off

What is that dirty thing Cobey? Looks like one of my canola'd up carving saws lol!

 

[cobey]

What is that dirty thing Cobey? Looks like one of my canola'd up carving saws lol!

It was an 024 carcass
The 254 isn't much cleaner

 

[Fairways_and_Greens]

Such great info. Are these from a book or hand drawings?