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#62122 06/24/2006 9:54 PM | Joined: Jul 2005 Posts: 71 Member | | Member Joined: Jul 2005 Posts: 71 | What is the principle behind setting ignition timing to the highest vacuum gauge reading (instead of timing light, pinging etc)? | | |
#62123 06/24/2006 10:57 PM | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | Ken,
Where did you read or hear those instructions? What engine and year?
It is OK to set your carburetor fuel mixture to the maximum vacuum reading at the desired idle speed.
Tim | | |
#62124 06/24/2006 11:08 PM | Joined: Jul 2005 Posts: 2,031 Shop Shark | | Shop Shark Joined: Jul 2005 Posts: 2,031 | fyi gentlemen::
http://www.stovebolt.com/bboard/cgi-bin//ultimatebb.cgi?ubb=get_topic;f=2;t=011381;p=1#000000
Jim & Caroline
The highway is for gamblers, better use your good sense."
Gooday-that's my 1¢ answer due to the lousy economy ~ cause I ain't got - no . mo . doe
Every Shaver | Now Can Snore | Six More Minutes | Than Before ... | Half A Pound for Half a Dollar | Spread On Thin | Above the Collar || BURMA-SHAVE
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#62125 06/26/2006 4:16 AM | Joined: Apr 2005 Posts: 50 Wrench Fetcher | | Wrench Fetcher Joined: Apr 2005 Posts: 50 | It is acceptable to set ignition timing using a vacuum gauge.
Adjust the distributor until you get the highest vacuum reading and then back off the adjustment 2 in.Hg.(inches Mercury) from highest reading.
Example: if highest reading is 21 in.Hg...
Adjust until 19 in.Hg is reached.
This method is similar to timing by ear (pinging), although you are looking at a vacuum gauge rather than detecting evidence of pinging.
Timing using a vacuum gauge is a way to set the timing according to what type of fuel is being used and other engine modifications. Also if the timing marks are gone or harmonic balencer has slipped or flywheel marks are not visible, this method can be used.
Hope this helps. | | |
#62126 06/26/2006 10:07 AM | Joined: Jul 2005 Posts: 71 Member | | Member Joined: Jul 2005 Posts: 71 | Thanks for the responses!
Tim - No particular engine; I read of this on a post here, a week or so ago, but hadn't heard of this method previously, & wondered if it was correct or not- I've always used a light and/or ear.You never stop learning! | | |
#62127 06/26/2006 1:19 PM | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | Adam,
Thanks for the information on the technique. I am going to give it a try as soon as the rain stops.
The results with a slightly modified 261 should be very interesting (I have guessed that the original timing mark was not appropriate).
Now I will adjust both the timing and the carburetor mixture with a vacuum gauge.
Tim | | |
#62128 06/26/2006 11:52 PM | Joined: Feb 2006 Posts: 395 Shop Shark | | Shop Shark Joined: Feb 2006 Posts: 395 | I use the gauge all the time but just back off one number...doc | | |
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