Old McCulloch with Pipe

[T.Roller]

In a purpose to design the pipe I made a check of exhaust timing.
This shows 0 degree for the exhaust port begins to open, ;
View attachment 77669

and 160 degrees for closing. ;
View attachment 77670

But one failure was that I did not make a check on her transfer port timing . Instead I put 150 degrees for this parameter which gave me this design below as a result, ;
View attachment 77671
Chy

So cool

 

[Mastermind]

Did someone yell for me?

 

[Czed]

Good morning and thanks StumpShot, I am heading out for job now, will come in the evening later,

Happy birthday chy.

 

[Stump Shot]

Did someone yell for me?

Yes, thought you should know about the possibility of an electronic timing advance.

 

[Mastermind]

Yes, thought you should know about the possibility of an electronic timing advance.

Very intriguing....

 

[chy_farm]

So cool

Thanks Dave!

Yes, thought you should know about the possibility of an electronic timing advance.

Very intriguing....

Thanks Steve,
and Happy birthday Randy! hope you have a very nice day. I always appreciate your support to us, which allows us to keep our quest going for better and fun retrofitting of old saws.
Chy

 

[chy_farm]

Happy birthday chy.View attachment 77688

Good morning my friend, sorry for being late here to say thanks to you. Time flies....there are still many fun projects undone, lol.
Chy

 

[Czed]

Good morning my friend, sorry for being late here to say thanks to you. Time flies....there are still many fun projects undone, lol.
Chy

Same here but not so much fun flooring to do.
I have several customers saws to fix as well.
What you do takes much longer.
Modern saw's are easy to fix usually.

 

[chy_farm]

------160 degrees for closing. ;
View attachment 77670
But one failure was that I did not make a check on her transfer port timing . Instead I put 150 degrees for this parameter which gave me this design below as a result, ;
View attachment 77671

So I made a check again on a 795 in my hand, to see the transfer port timing/angles.

1st, exhaust port begins to open at zero degree below;


2nd, transfer port begins to open at 20 degrees in addition to the 1st. ;


3rd, transfer port begins to close at 140 degrees. So 140 - 20 = 120 degrees for transfer port angle. ;


4th, exhaust port begins to close at 160 degrees.


These new data allow me to try a reverse-calculation to the pipe I previously fabricated for 740, and it gives me results as below including its optimum velocity of rotation as 8660rpm.


Chy

 

[chy_farm]

Same here but not so much fun flooring to do. I have several customers saws to fix as well. What you do takes much longer. Modern saw's are easy to fix usually.

You seem to be a carpenter my friend, if I am not too wrong that job is what I really wanted to do when I was very young, and once worked for a friend who ran a carpenter's office for some two years. It's a good reminiscing of the day, glad this friend still is a good friend of mine. Chy

 

[p61 western]

You seem to be a carpenter my friend, if I am not too wrong that job is what I really wanted to do when I was very young, and once worked for a friend who ran a carpenter's office for some two years. It's a good reminiscing of the day, glad this friend still is a good friend of mine. Chy

Glad to see all of this stuff in a thread over here Chy.

 

[chy_farm]

Glad to see all of this stuff in a thread over here Chy.

Good afternoon Mike you seem to have a very nice one, Pioneer P61 I am green for that! lol. Actually we seldom see that big one here, the largest one of this series was P40 so far on a local auction here. I know it's a wonderful saw of the day!
Chy

 

[p61 western]

Good afternoon Mike you seem to have a very nice one, Pioneer P61 I am green for that! lol. Actually we seldom see that big one here, the largest one of this series was P40 so far on a local auction here. I know it's a wonderful saw of the day!
Chy

It's a saw that my grandpa bought brand new, and left it to me when he passed away. That was what started my addiction lol. Did you get the p40 from the auction Chy? I think that it's neat that they do show up there.

 

[chy_farm]

It's a saw that my grandpa bought brand new, and left it to me when he passed away. That was what started my addiction lol. Did you get the p40 from the auction Chy? I think that it's neat that they do show up there.

No Mike not yet, I saw P40 at least three times on a auction here, but the seller who posted one reasonably clean did not give any reply to me to what I asked on her, so quit it lol.

 

[chy_farm]

This is very intriguing Chy, we were discussing here on the forum how to do such a thing a while ago, no one here with the needed electronics background could be found. Might be you are that someone with the right technical know how. Please keep us informed on the progress of this. Also do you think an adjustable version could be possible? ---------

Good evening Steve, some years ago I found a program scripted in assembly language for the PIC, a micro controller I mentioned above, here quoted the header of this program and the link to it.
;***************************************************************************
;******
;****** Digital ignition for 2 stroke engines. SPORTDEVICES 1/9/2005
;******
;******
;****** Digital parts: PIC16F84
;******
;******
;****************************************************************************

list p=16F84a
#include p16F84a.inc
radix dec

__CONFIG _WDT_OFF & _XT_OSC
;******
;****************************************************************************

(link here)
http://www.sportdevices.com/ignition/ignition16.asm

I think we have to give some modification to this, hope you like it!
As far the adjustable version for this program, not impossible but need some outer terminal to input new data, sounds better if iPhone or some other interface were available in this purpose! But I am not so skilled to accomplish this goal though, lol.
Chy

 

[Stump Shot]

Good evening Steve, some years ago I found a program scripted in assembly language for the PIC, a micro controller I mentioned above, here quoted the header of this program and the link to it.
;***************************************************************************
;******
;****** Digital ignition for 2 stroke engines. SPORTDEVICES 1/9/2005
;******
;******
;****** Digital parts: PIC16F84
;******
;******
;****************************************************************************

list p=16F84a
#include p16F84a.inc
radix dec

__CONFIG _WDT_OFF & _XT_OSC
;******
;****************************************************************************

(link here)
http://www.sportdevices.com/ignition/ignition16.asm

I think we have to give some modification to this, hope you like it!
As far the adjustable version for this program, not impossible but need some outer terminal to input new data, sounds better if iPhone or some other interface were available in this purpose! But I am not so skilled to accomplish this goal though, lol.
Chy

Hey Chy, so if I were to give a copy of this information to an elecromalogical type of person they should be able to make a 5 degree advance out of it? @Mastermind You see this Randy?

 

[chy_farm]

Hey Chy, so if I were to give a copy of this information to an elecromalogical type of person they should be able to make a 5 degree advance out of it? @Mastermind You see this Randy?

Good morning Steve,
it is only my presumption that this program seems to be scripted for something like karts than saws we use. I can see at least three stages of the timing there, 'spin<5000rpm', '5000rpm< spin <15000rpm' and 'spin>15000rpm'. So I think we have to add some modification to this, like 'spin<5000rpm', '5000rpm< spin <10000rpm', '10000rpm< spin <13500rpm' and 'spin limit>14000rpm'.
It seems not a few try-and-error should be there when we go further on this.
Chy

p.s. Now going out for job, will be home in the evening.

 

[p61 western]

Good morning Steve,
it is only my presumption that this program seems to be scripted for something like karts than saws we use. I can see at least three stages of the timing there, 'spin<5000rpm', '5000rpm< spin <15000rpm' and 'spin>15000rpm'. So I think we have to add some modification to this, like 'spin<5000rpm', '5000rpm< spin <10000rpm', '10000rpm< spin <13500rpm' and 'spin limit>14000rpm'.
It seems not a few try-and-error should be there when we go further on this.
Chy

p.s. Now going out for job, will be home in the evening.

Good morning Chy, have a great day.

 

[chy_farm]

Good morning Chy, have a great day.

Good evening Mike, had a very busy day at our office today, comfortable under air-conditioned rooms but seemed very hot outside. Came home 21:00 and seeing messages of your guys.
Chy

 

[chy_farm]

I wrote;

---------
These new data allow me to try a reverse-calculation to the pipe I previously fabricated for 740, and it gives me results as below including its optimum velocity of rotation as 8660rpm.

So if I want her run faster than this velocity 8660rpm with a pipe, the pipe should be like this ;

One in the upper is the previous pipe, lower a new design for 13000rpm. This tells the comparison between the two.
Chy