Re: Bob Dunn timing question

michaelmps · Post by **michaelmps** » Tue Apr 29, 2008 9:34 am

'I centered both mag indexs prior to pulling the mags and did not move
the prop . After mag overhaul, I restabbed and it worked well for the
right but not Quite correct with the left. I would like to find out
how to verify the engine is at 25 degress BTDC and try and stab the
left mag again. I do not see any Index marks on the Crank. I guess
thats what I am asking. Aside from the index mark on the mags. How
can I verify 25 BTDC..

Michael'

Tom Downey · Post by **Tom Downey** » Tue Apr 29, 2008 1:37 pm

'Manufacture a piston stop that will fit the spark plug hole (I used
and old spark plug and a 1/2" rod) Place the piston stop in the spark
plug hole while the engine is at bottom dead center on #1 compression
stroke. Attach a degree wheel to the prop shaft?prop and set at any
position, carefully turn the engine in the direction of rotation,
until the piston stop is touching the piston. mark the degree wheel at
that position. rotate the engine backwards until the piston stop is
touching the piston again, mark the degree wheel again. TDC is half
way between your 2 marks. on the side of the degree wheel that you
have not turned the engine.

rotate the degree wheel on the shaft until TDC is indicated by the
degree wheel pointer, lock it down and rotate the engine backwards
until 25 degrees is indicated. stab the mag at "point opening" for #1
plug.

--- In fairchildclub@yahoogroups.com, "michaelmps"
wrote:

>
> I centered both mag indexs prior to pulling the mags and did not

move

> the prop . After mag overhaul, I restabbed and it worked well for

the

> right but not Quite correct with the left. I would like to find out
> how to verify the engine is at 25 degress BTDC and try and stab the
> left mag again. I do not see any Index marks on the Crank. I guess
> thats what I am asking. Aside from the index mark on the mags. How
> can I verify 25 BTDC..
>
> Michael
>

'

rangerrobertmn · Post by **rangerrobertmn** » Wed Apr 30, 2008 6:48 am

'Tom,

We do it exactly like you do, but instead of a 'degree wheel', we use
an electronic 'smart level' taped to the prop. When at TDC, we set
the level to ZERO, then turn the prop 'til it reads 25. Old eyes can
read inch high digits, easier than 'tiny' marks on a 'degree wheel'.

Also, someone should have mentioned the unique 'rubber ring' between
the mag and the mag-drive is really a 'vernier' adjuster. It adjusts
in 2/3 degree increments. It seems that you rotate it about 15
degrees in order for it to mesh with the mag-drive, but all that
effort resulted in 2/3 degree change. Very frustrating until you
figure out what is happening, but very precise. I wish all mags were
like that.

Bob Waldron
1939 Fairchild 24 K
Sky Harbor airpark
Webster, MN

--- In fairchildclub@yahoogroups.com, "Tom Downey"
wrote:

>
>
> Manufacture a piston stop that will fit the spark plug hole (I used
> and old spark plug and a 1/2" rod) Place the piston stop in the

spark

> plug hole while the engine is at bottom dead center on #1

compression

> stroke. Attach a degree wheel to the prop shaft?prop and set at any
> position, carefully turn the engine in the direction of rotation,
> until the piston stop is touching the piston. mark the degree wheel

at

> that position. rotate the engine backwards until the piston stop is
> touching the piston again, mark the degree wheel again. TDC is half
> way between your 2 marks. on the side of the degree wheel that you
> have not turned the engine.
>
> rotate the degree wheel on the shaft until TDC is indicated by the
> degree wheel pointer, lock it down and rotate the engine backwards
> until 25 degrees is indicated. stab the mag at "point opening" for

#1

> plug.
>
>
> --- In fairchildclub@yahoogroups.com, "michaelmps"
> wrote:
> >
> > I centered both mag indexs prior to pulling the mags and did not
> move
> > the prop . After mag overhaul, I restabbed and it worked well

for

> the
> > right but not Quite correct with the left. I would like to find

out

> > how to verify the engine is at 25 degress BTDC and try and stab

the

> > left mag again. I do not see any Index marks on the Crank. I

guess

> > thats what I am asking. Aside from the index mark on the mags.

How

> > can I verify 25 BTDC..
> >
> > Michael
> >
>

'

Bob Haas · Post by **Bob Haas** » Wed Apr 30, 2008 7:48 am

'VERY GOOD! B.H.

_____

From: fairchildclub@yahoogroups.com [mailto:fairchildclub@yahoogroups.com]
On Behalf Of rangerrobertmn
Sent: Wednesday, April 30, 2008 8:49 AM
To: fairchildclub@yahoogroups.com
Subject: [fairchildclub] Re: Bob Dunn timing question

Tom,

We do it exactly like you do, but instead of a 'degree wheel', we use
an electronic 'smart level' taped to the prop. When at TDC, we set
the level to ZERO, then turn the prop 'til it reads 25. Old eyes can
read inch high digits, easier than 'tiny' marks on a 'degree wheel'.

Also, someone should have mentioned the unique 'rubber ring' between
the mag and the mag-drive is really a 'vernier' adjuster. It adjusts
in 2/3 degree increments. It seems that you rotate it about 15
degrees in order for it to mesh with the mag-drive, but all that
effort resulted in 2/3 degree change. Very frustrating until you
figure out what is happening, but very precise. I wish all mags were
like that.

Bob Waldron
1939 Fairchild 24 K
Sky Harbor airpark
Webster, MN

--- In fairchildclub@
yahoogroups.com, "Tom Downey"
wrote:

>
>
> Manufacture a piston stop that will fit the spark plug hole (I used
> and old spark plug and a 1/2" rod) Place the piston stop in the

spark

> plug hole while the engine is at bottom dead center on #1

compression

> stroke. Attach a degree wheel to the prop shaft?prop and set at any
> position, carefully turn the engine in the direction of rotation,
> until the piston stop is touching the piston. mark the degree wheel

at

> that position. rotate the engine backwards until the piston stop is
> touching the piston again, mark the degree wheel again. TDC is half
> way between your 2 marks. on the side of the degree wheel that you
> have not turned the engine.
>
> rotate the degree wheel on the shaft until TDC is indicated by the
> degree wheel pointer, lock it down and rotate the engine backwards
> until 25 degrees is indicated. stab the mag at "point opening" for

#1

> plug.
>
>
> --- In fairchildclub@

yahoogroups.com, "michaelmps"

> wrote:
> >
> > I centered both mag indexs prior to pulling the mags and did not
> move
> > the prop . After mag overhaul, I restabbed and it worked well

for

> the
> > right but not Quite correct with the left. I would like to find

out

> > how to verify the engine is at 25 degress BTDC and try and stab

the

> > left mag again. I do not see any Index marks on the Crank. I

guess

> > thats what I am asking. Aside from the index mark on the mags.

How

> > can I verify 25 BTDC..
> >
> > Michael
> >
>

[Non-text portions of this message have been removed]'

Michael Denest · Post by **Michael Denest** » Wed Apr 30, 2008 8:21 am

'I use a buzz box and Time Rite indicator. Before I start mag timing, I check the mag points for the proper gap of .012" to .015". Then I find the #1 cylinder compression stroke to set the card for TDC. I then back the blade off then bump the prop in the direction of rotation and listen for the buzz box. When I get the tone, I check the card to see where 25° BTDC is and adjust the coupling as necessary. I do each mag individually then do a final check on both mags. Takes me about 1 hour to do both mags.
ATS has the Time Rite available but it's several $$$$. If you do a lot of engines, it's a great investment.

Mike

Quando omni flunkus moritati
(If all else fails, play dead)
- "Red" Green

----- Original Message ----
From: rangerrobertmn
To: fairchildclub@yahoogroups.com
Sent: Wednesday, April 30, 2008 8:48:45 AM
Subject: [fairchildclub] Re: Bob Dunn timing question

Tom,

We do it exactly like you do, but instead of a 'degree wheel', we use
an electronic 'smart level' taped to the prop. When at TDC, we set
the level to ZERO, then turn the prop 'til it reads 25. Old eyes can
read inch high digits, easier than 'tiny' marks on a 'degree wheel'.

Also, someone should have mentioned the unique 'rubber ring' between
the mag and the mag-drive is really a 'vernier' adjuster. It adjusts
in 2/3 degree increments. It seems that you rotate it about 15
degrees in order for it to mesh with the mag-drive, but all that
effort resulted in 2/3 degree change. Very frustrating until you
figure out what is happening, but very precise. I wish all mags were
like that.

Bob Waldron
1939 Fairchild 24 K
Sky Harbor airpark
Webster, MN

--- In fairchildclub@ yahoogroups. com, "Tom Downey"
wrote:

>
>
> Manufacture a piston stop that will fit the spark plug hole (I used
> and old spark plug and a 1/2" rod) Place the piston stop in the

spark

> plug hole while the engine is at bottom dead center on #1

compression

> stroke. Attach a degree wheel to the prop shaft?prop and set at any
> position, carefully turn the engine in the direction of rotation,
> until the piston stop is touching the piston. mark the degree wheel

at

> that position. rotate the engine backwards until the piston stop is
> touching the piston again, mark the degree wheel again. TDC is half
> way between your 2 marks. on the side of the degree wheel that you
> have not turned the engine.
>
> rotate the degree wheel on the shaft until TDC is indicated by the
> degree wheel pointer, lock it down and rotate the engine backwards
> until 25 degrees is indicated. stab the mag at "point opening" for

#1

> plug.
>
>
> --- In fairchildclub@ yahoogroups. com, "michaelmps"
> wrote:
> >
> > I centered both mag indexs prior to pulling the mags and did not
> move
> > the prop . After mag overhaul, I restabbed and it worked well

for

> the
> > right but not Quite correct with the left. I would like to find

out

> > how to verify the engine is at 25 degress BTDC and try and stab

the

> > left mag again. I do not see any Index marks on the Crank. I

guess

> > thats what I am asking. Aside from the index mark on the mags.

How

> > can I verify 25 BTDC..
> >
> > Michael
> >
>

____________________________________________________________________________________
Be a better friend, newshound, and
know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ

[Non-text portions of this message have been removed]'

Bob Haas · Post by **Bob Haas** » Wed Apr 30, 2008 11:41 am

'This is the proper way to set the mags oh the Ranger Engines,
works every time! Bob H.

_____

From: fairchildclub@yahoogroups.com [mailto:fairchildclub@yahoogroups.com]
On Behalf Of Michael Denest
Sent: Wednesday, April 30, 2008 10:21 AM
To: fairchildclub@yahoogroups.com
Subject: Re: [fairchildclub] Re: Bob Dunn timing question

I use a buzz box and Time Rite indicator. Before I start mag timing, I
check the mag points for the proper gap of .012" to .015". Then I find the
#1 cylinder compression stroke to set the card for TDC. I then back the
blade off then bump the prop in the direction of rotation and listen for the
buzz box. When I get the tone, I check the card to see where 25° BTDC is
and adjust the coupling as necessary. I do each mag individually then do a
final check on both mags. Takes me about 1 hour to do both mags.
ATS has the Time Rite available but it's several $$$$. If you do a lot of
engines, it's a great investment.

Mike

Quando omni flunkus moritati
(If all else fails, play dead)
- "Red" Green

----- Original Message ----
From: rangerrobertmn
To: fairchildclub@ yahoogroups.com
Sent: Wednesday, April 30, 2008 8:48:45 AM
Subject: [fairchildclub] Re: Bob Dunn timing question

Tom,

We do it exactly like you do, but instead of a 'degree wheel', we use
an electronic 'smart level' taped to the prop. When at TDC, we set
the level to ZERO, then turn the prop 'til it reads 25. Old eyes can
read inch high digits, easier than 'tiny' marks on a 'degree wheel'.

Also, someone should have mentioned the unique 'rubber ring' between
the mag and the mag-drive is really a 'vernier' adjuster. It adjusts
in 2/3 degree increments. It seems that you rotate it about 15
degrees in order for it to mesh with the mag-drive, but all that
effort resulted in 2/3 degree change. Very frustrating until you
figure out what is happening, but very precise. I wish all mags were
like that.

Bob Waldron
1939 Fairchild 24 K
Sky Harbor airpark
Webster, MN

--- In fairchildclub@ yahoogroups. com, "Tom Downey"
wrote:

>
>
> Manufacture a piston stop that will fit the spark plug hole (I used
> and old spark plug and a 1/2" rod) Place the piston stop in the

spark

> plug hole while the engine is at bottom dead center on #1

compression

> stroke. Attach a degree wheel to the prop shaft?prop and set at any
> position, carefully turn the engine in the direction of rotation,
> until the piston stop is touching the piston. mark the degree wheel

at

> that position. rotate the engine backwards until the piston stop is
> touching the piston again, mark the degree wheel again. TDC is half
> way between your 2 marks. on the side of the degree wheel that you
> have not turned the engine.
>
> rotate the degree wheel on the shaft until TDC is indicated by the
> degree wheel pointer, lock it down and rotate the engine backwards
> until 25 degrees is indicated. stab the mag at "point opening" for

#1

> plug.
>
>
> --- In fairchildclub@ yahoogroups. com, "michaelmps"
> wrote:
> >
> > I centered both mag indexs prior to pulling the mags and did not
> move
> > the prop . After mag overhaul, I restabbed and it worked well

for

> the
> > right but not Quite correct with the left. I would like to find

out

> > how to verify the engine is at 25 degress BTDC and try and stab

the

> > left mag again. I do not see any Index marks on the Crank. I

guess

> > thats what I am asking. Aside from the index mark on the mags.

How

> > can I verify 25 BTDC..
> >
> > Michael
> >
>

__________________________________________________________
Be a better friend, newshound, and
know-it-all with Yahoo! Mobile. Try it now. http://mobile.

yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ

[Non-text portions of this message have been removed]

[Non-text portions of this message have been removed]'

michael Steiger · Post by **michael Steiger** » Sat May 10, 2008 5:33 pm

'That is what I did because it sounded logical with out timing marks and you say the same thing. Great! I did it and all checks well. Thanks for all the help! Everyone is great on thes site! I hope I can help someone oneday.

Bob Haas wrote: This is the proper way to set the mags oh the Ranger Engines,
works every time! Bob H.

_____

From: fairchildclub@yahoogroups.com [mailto:fairchildclub@yahoogroups.com]
On Behalf Of Michael Denest
Sent: Wednesday, April 30, 2008 10:21 AM
To: fairchildclub@yahoogroups.com
Subject: Re: [fairchildclub] Re: Bob Dunn timing question

I use a buzz box and Time Rite indicator. Before I start mag timing, I
check the mag points for the proper gap of .012" to .015". Then I find the
#1 cylinder compression stroke to set the card for TDC. I then back the
blade off then bump the prop in the direction of rotation and listen for the
buzz box. When I get the tone, I check the card to see where 25° BTDC is
and adjust the coupling as necessary. I do each mag individually then do a
final check on both mags. Takes me about 1 hour to do both mags.
ATS has the Time Rite available but it's several $$$$. If you do a lot of
engines, it's a great investment.

Mike

Quando omni flunkus moritati
(If all else fails, play dead)
- "Red" Green

----- Original Message ----
From: rangerrobertmn
To: fairchildclub@ yahoogroups.com
Sent: Wednesday, April 30, 2008 8:48:45 AM
Subject: [fairchildclub] Re: Bob Dunn timing question

Tom,

We do it exactly like you do, but instead of a 'degree wheel', we use
an electronic 'smart level' taped to the prop. When at TDC, we set
the level to ZERO, then turn the prop 'til it reads 25. Old eyes can
read inch high digits, easier than 'tiny' marks on a 'degree wheel'.

Also, someone should have mentioned the unique 'rubber ring' between
the mag and the mag-drive is really a 'vernier' adjuster. It adjusts
in 2/3 degree increments. It seems that you rotate it about 15
degrees in order for it to mesh with the mag-drive, but all that
effort resulted in 2/3 degree change. Very frustrating until you
figure out what is happening, but very precise. I wish all mags were
like that.

Bob Waldron
1939 Fairchild 24 K
Sky Harbor airpark
Webster, MN

--- In fairchildclub@ yahoogroups. com, "Tom Downey"
wrote:

>
>
> Manufacture a piston stop that will fit the spark plug hole (I used
> and old spark plug and a 1/2" rod) Place the piston stop in the

spark

> plug hole while the engine is at bottom dead center on #1

compression

> stroke. Attach a degree wheel to the prop shaft?prop and set at any
> position, carefully turn the engine in the direction of rotation,
> until the piston stop is touching the piston. mark the degree wheel

at

> that position. rotate the engine backwards until the piston stop is
> touching the piston again, mark the degree wheel again. TDC is half
> way between your 2 marks. on the side of the degree wheel that you
> have not turned the engine.
>
> rotate the degree wheel on the shaft until TDC is indicated by the
> degree wheel pointer, lock it down and rotate the engine backwards
> until 25 degrees is indicated. stab the mag at "point opening" for

#1

> plug.
>
>
> --- In fairchildclub@ yahoogroups. com, "michaelmps"
> wrote:
> >
> > I centered both mag indexs prior to pulling the mags and did not
> move
> > the prop . After mag overhaul, I restabbed and it worked well

for

> the
> > right but not Quite correct with the left. I would like to find

out

> > how to verify the engine is at 25 degress BTDC and try and stab

the

> > left mag again. I do not see any Index marks on the Crank. I

guess

> > thats what I am asking. Aside from the index mark on the mags.

How

> > can I verify 25 BTDC..
> >
> > Michael
> >
>

__________________________________________________________
Be a better friend, newshound, and
know-it-all with Yahoo! Mobile. Try it now. http://mobile.

yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ

[Non-text portions of this message have been removed]

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---------------------------------
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[Non-text portions of this message have been removed]'

Michael Kelly · Post by **Michael Kelly** » Tue May 13, 2008 6:59 am

'Ther is a timing mark but you have to take the prop and nose bowl off.It is an arrow cast into the front case under the prop shaft.
Keep 'Em Flying1
Mike Kelly

________________________________

> To: fairchildclub@yahoogroups.com
> From: michaelmps@yahoo.com
> Date: Sat, 10 May 2008 16:33:38 -0700
> Subject: RE: [fairchildclub] Re: Bob Dunn timing question
>
>
> That is what I did because it sounded logical with out timing marks and you say the same thing. Great! I did it and all checks well. Thanks for all the help! Everyone is great on thes site! I hope I can help someone oneday.
>
> Bob Haas wrote: This is the proper way to set the mags oh the Ranger Engines,
> works every time! Bob H.
>
> _____
>
> From: fairchildclub@yahoogroups.com [mailto:fairchildclub@yahoogroups.com]
> On Behalf Of Michael Denest
> Sent: Wednesday, April 30, 2008 10:21 AM
> To: fairchildclub@yahoogroups.com
> Subject: Re: [fairchildclub] Re: Bob Dunn timing question
>
> I use a buzz box and Time Rite indicator. Before I start mag timing, I
> check the mag points for the proper gap of .012" to .015". Then I find the
> #1 cylinder compression stroke to set the card for TDC. I then back the
> blade off then bump the prop in the direction of rotation and listen for the
> buzz box. When I get the tone, I check the card to see where 25° BTDC is
> and adjust the coupling as necessary. I do each mag individually then do a
> final check on both mags. Takes me about 1 hour to do both mags.
> ATS has the Time Rite available but it's several $$$$. If you do a lot of
> engines, it's a great investment.
>
> Mike
>
> Quando omni flunkus moritati
> (If all else fails, play dead)
> - "Red" Green
>
> ----- Original Message ----
> From: rangerrobertmn
> yahoo.com>
> To: fairchildclub@ yahoogroups.com
> Sent: Wednesday, April 30, 2008 8:48:45 AM
> Subject: [fairchildclub] Re: Bob Dunn timing question
>
> Tom,
>
> We do it exactly like you do, but instead of a 'degree wheel', we use
> an electronic 'smart level' taped to the prop. When at TDC, we set
> the level to ZERO, then turn the prop 'til it reads 25. Old eyes can
> read inch high digits, easier than 'tiny' marks on a 'degree wheel'.
>
> Also, someone should have mentioned the unique 'rubber ring' between
> the mag and the mag-drive is really a 'vernier' adjuster. It adjusts
> in 2/3 degree increments. It seems that you rotate it about 15
> degrees in order for it to mesh with the mag-drive, but all that
> effort resulted in 2/3 degree change. Very frustrating until you
> figure out what is happening, but very precise. I wish all mags were
> like that.
>
> Bob Waldron
> 1939 Fairchild 24 K
> Sky Harbor airpark
> Webster, MN
>
> --- In fairchildclub@ yahoogroups. com, "Tom Downey"
> wrote:
>>
>>
>> Manufacture a piston stop that will fit the spark plug hole (I used
>> and old spark plug and a 1/2" rod) Place the piston stop in the
> spark
>> plug hole while the engine is at bottom dead center on #1
> compression
>> stroke. Attach a degree wheel to the prop shaft?prop and set at any
>> position, carefully turn the engine in the direction of rotation,
>> until the piston stop is touching the piston. mark the degree wheel
> at
>> that position. rotate the engine backwards until the piston stop is
>> touching the piston again, mark the degree wheel again. TDC is half
>> way between your 2 marks. on the side of the degree wheel that you
>> have not turned the engine.
>>
>> rotate the degree wheel on the shaft until TDC is indicated by the
>> degree wheel pointer, lock it down and rotate the engine backwards
>> until 25 degrees is indicated. stab the mag at "point opening" for
> #1
>> plug.
>>
>>
>> --- In fairchildclub@ yahoogroups. com, "michaelmps"
>> wrote:
>>>
>>> I centered both mag indexs prior to pulling the mags and did not
>> move
>>> the prop . After mag overhaul, I restabbed and it worked well
> for
>> the
>>> right but not Quite correct with the left. I would like to find
> out
>>> how to verify the engine is at 25 degress BTDC and try and stab
> the
>>> left mag again. I do not see any Index marks on the Crank. I
> guess
>>> thats what I am asking. Aside from the index mark on the mags.
> How
>>> can I verify 25 BTDC..
>>>
>>> Michael
>>>
>>
>
> __________________________________________________________
> Be a better friend, newshound, and
> know-it-all with Yahoo! Mobile. Try it now. http://mobile.
>
> yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ
>
> [Non-text portions of this message have been removed]
>
> [Non-text portions of this message have been removed]
>
> ---------------------------------
> Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now.
>
> [Non-text portions of this message have been removed]
>
>
>

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