Ignition Timing

[FL SAAC]

Wow.

So no one here adjusts the curve on their mechanical advance.

cant believe the "experts" did not bring ,this up previously

excellent point you bring up and how about retinkering with the carb after the adjustments

[pbf777]

cant believe the "experts" did not bring ,this up previously

    I think if one were to utilize a "timing light", versus just twisting the distributor about and attempting to listen for 'ping' not having any real idea of what they are actually doing, this subject would lets' say . . . . "come to light"! 

    Scott.

[Coralsnake]

So much for chat gpt responses

 

[Bob Gaines]

Wow.

So no one here adjusts the curve on their mechanical advance.

I would say 2/3 of the time it needs help.  Maybe because it is all gummed up inside or maybe (more likely) it has been monkeyed with in the past by someone who just sticks a different spring inside.  I would plug the vacuum advance, set an adjustable timing light at around 35-36 degrees and set it to that at full advance (whatever engine speed that is) and see what you have. 

Just to remind Jim of who I have mucho respect for of ability is that a stock 67GT500 does not have a vacuum advance.

[Lincoln tech]

Listening for ping while at idle , retinkering with the carb ??   Good thing we are not talking about airplanes here    

[FL SAAC]

[/quote]Just to remind Jim of who I have mucho respect for of ability is that a stock 67GT500 does not have a vacuum advance.
[/quote]

Y'all gota realize that a bunch of these old cars don't have their original components in it

So that explains vaccum advances appearing that should not be there.

Or in my case you look at our cars and they have the vacumm advances in place.

But you can't see the B.B. inside the vacuum control hose plugging it up.

Plus our cars are fully advanced and of course by EAR

[pbf777]

Listening for ping while at idle , retinkering with the carb ??  Good thing we are not talking about airplanes here    

    Well . . . . with my Lycoming 540, 260 H.P. "strait-valve", the O.E.M. ignition timing value is 25 degrees (B.T.D.C.), though with testing I established that "best performance" was had by advancing to 28 degrees, but not more; and don't ask me how I know that!     And I also swapped out the MA-4-5 carburetor for a MA-6 which presents a larger venturi bore and the example being a helicopter application carb also richer fuel settings. 

    O.K., it isn't my fault!  Somebody else injected "airplanes" into the conversation, I'm just following their lead!   

    Scott.

[JohnSlack]

Listening for ping while at idle , retinkering with the carb ??  Good thing we are not talking about airplanes here    

    Well . . . . with my Lycoming 540, 260 H.P. "strait-valve", the O.E.M. ignition timing value is 25 degrees (B.T.D.C.), though with testing I established that "best performance" was had by advancing to 28 degrees, but not more; and don't ask me how I know that!     And I also swapped out the MA-4-5 carburetor for a MA-6 which presents a larger venturi bore and the example being a helicopter application carb also richer fuel settings. 

    O.K., it isn't my fault!  Somebody else injected "airplanes" into the conversation, I'm just following their lead!   

    Scott.

And yet I resisted

[pbf777]

And yet I resisted

    Such control, . . . . but then, that's what comes with being a "Sr. Member"!   

    Scott.

[Lincoln tech]

Listening for ping while at idle , retinkering with the carb ??  Good thing we are not talking about airplanes here    

    Well . . . . with my Lycoming 540, 260 H.P. "strait-valve", the O.E.M. ignition timing value is 25 degrees (B.T.D.C.), though with testing I established that "best performance" was had by advancing to 28 degrees, but not more; and don't ask me how I know that!    And I also swapped out the MA-4-5 carburetor for a MA-6 which presents a larger venturi bore and the example being a helicopter application carb also richer fuel settings. 

    O.K., it isn't my fault!  Somebody else injected "airplanes" into the conversation, I'm just following their lead! 

    Scott.

At least it sounds like you know what you're talking about , unlike ,,,,, 

[JohnSlack]

And yet I resisted

    Such control, . . . . but then, that's what comes with being a "Sr. Member"!   

    Scott.

On the Rare Bear the ignition system actually had a circuit that allowed you to retard the timing as you got into Cruise, not that we ever "cruised", however the airlines and the military DID use the cruise circuit. There were two sets of points in the distributor one set, the standard set was the advanced set that were normally used for ignition. The retard circuit would select the retarded points which if I remember correctly were 5° retarded. The ultimate feature that we were going to use this system for was that a pressure switch would be in circuit with the nitrous oxide that when the switch sensed pressure it would be automatically retarded 5°. Of course there would have been a manual override switch so that the retard circuit could be overridden at speed if needed.

Think about that with your R-3350 powered swamp boat. I do still have the manuals and part numbers.


John

[pbf777]

At least it sounds like you know what you're talking about ,,,,, 

     Mannn . . . . Maybe, I should go into politics!   

     Scott.

[pbf777]

On the Rare Bear the ignition system actually had a circuit that allowed you to retard the timing as you got into Cruise, . . . .

    Now see, us here Red Neck's, for those who'd bin think-in' they'd be needed it, we dun' have dee-vised our own "add-justable" timing capable ignition system on these little "Piper-Popper" motors; this here by utilizing spring-clamp loading on the magnetos (2 ea.) hold-down/retention fixturing, preset stops against the housings, and cable-pull attachments. Shazam!

    But then, most dun figured there rarely is a "cruise" scenario pushing that there boat hull through the water (after all water is thicker than air  ) or over the ground (as takes more pushin' when you's ain't got no wheels!   ), but still might prove useful with N2O! But then most of even the dumbest of us here Red Neck's dun have heard of "MSD" (available with "adjustable timing retard")   

    And speaking of "cruising", and how it really isn't relevant in this venue either, this is another reason for utilizing the "helicopter" carburetor, as it doesn't have the fuel "economizer valve" as common in the others for fixed-wing aircraft, which just causes lean instances as mounted to the airboats.   
   

Think about that with your R-3350 powered swamp boat. I do still have the manuals and part numbers.

    Yeah, . . . . . I do still have my R3350 ("A" series"), but I kinda gave up on trying to put it on a boat.  This actually because by the time I came up with a boat hull and a prop(s), I realized that too many of the road and highway bridges that we encounter wouldn't have the clearance for it to go under! At least not when the water is high!    

    So I decided to be a "bit" more realistic, . . . . . I have reduced the size of things by changing direction and going with the R1820 (-82WA @ 1525 H.P.); which ought to have enough "push", and which I just happen to have a couple of! 

    O.K., I know, maaaan . . . .have we ever gotten lost!  But again, I was just following someone else's lead; but this time that of even a "Sr. Member"! Ya' can't blame me!

    Scott.     

[shelbydoug]

Wait...are you calling me, "an adjustable timing retard"? I resemble that remark.

[FL SAAC]

Think about that with your R-3350 powered swamp boat. I do still have the manuals and part numbers.



    O.K., I know, maaaan . . . .have we ever gotten lost!  But again, I was just following someone else's lead; but this time that of even a "Sr. Member"! Ya' can't blame me!

    Scott.     

Got s friend that has a swamp air boat, they call him tater

Scott, Scotty, Scotto, listen to buddha
neva eva follow a Senior Señor

"No one saves us but ourselves. No one can and no one may. We ourselves must walk the path."
Buddha

Walk alone and make your own path. Be yourself.
Him

Continuing on this interesting thread, I would still do it by ear...