An interesting way to set timing. - Team Camaro Tech
Tech 2000 Our previous General Forum
Replies ONLY - no new topics.

 
LinkBack Thread Tools Display Modes
post #1 of 11 (permalink) Old Jul 28th, 01, 08:59 PM Thread Starter
Senior Tech
 
Join Date: Jun 2001
Location: Birmingham Mi,
Posts: 142
Post

Hey all,
I got 1 question for all of u:
I was talking to the dude at the trans shop, and he was telling me the best way to set engine timing is to run the engine at 1200 rpm in park, witht the vacum advance on the distributor plugged, and put a vacum gauge to manifold vacum, and to turn the distributor until u get the highest reading, and that is where u should put the timing at, and that I should ignore the timing marks on the engine. Is this true???
Joshua Leslie is offline  
Sponsored Links
Advertisement
 
post #2 of 11 (permalink) Old Jul 28th, 01, 09:36 PM
Senior Tech
Cameron
 
Join Date: Oct 2000
Location: Lexington, KY
Posts: 771
Post

I personally don't see how that could be true. In order to get a higher vacuum reading, you would have to increase the engine speed without moving the throttle position. This would mean that you would set the timing for the highest idle speed. I am almost positive that this would advance the timing too much. You could try it and see then put a timing light on it to see what the actual timing was. Who knows, the guy may be right.
Cameron is offline  
post #3 of 11 (permalink) Old Jul 29th, 01, 01:15 PM
Team Member
John
 
JohnZ's Avatar
 
Join Date: Sep 2000
Location: Washington, Michigan USA
Posts: 7,728
Post

That's why the guy works in a transmission shop, not an engine shop. Timing is set with a timing light, not a vacuum gauge. Hope he doesn't breed.....

------------------
JohnZ
'69 Z28 Fathom Green
JohnZ is offline  
 
post #4 of 11 (permalink) Old Jul 29th, 01, 02:52 PM
Senior Tech
 
Join Date: Jul 1999
Location: Metro Chicago
Posts: 235
Post

Ditto!
Silver69 is offline  
post #5 of 11 (permalink) Old Jul 30th, 01, 06:00 AM
Senior Tech
 
Join Date: Jun 2001
Location: Houston Tx.
Posts: 2,646
Post

Say you need 37 deg. of total timing for best performance. How in the world would you know where your total timing is??? The guy is full of it!

------------------
67RS STREET CAR, 502 PUMPGAS, HYD. ROLLER, TH350 w/ATI 10" 12-BOLT w/373 - [email protected] ON MOTOR, ET-STREETs w/MUFFLERS
67RS502 is offline  
post #6 of 11 (permalink) Old Jul 30th, 01, 06:46 AM
Senior Tech
 
Join Date: Jun 2001
Location: Concord, CA, USA
Posts: 142
Post

Sounds like the right procedure for adjusting your idle mixure screws, but not the timing....




------------------
Son's 67-327, Dad's twistin' wrenches again after 25 yrs.
Dans67 is offline  
post #7 of 11 (permalink) Old Jul 30th, 01, 09:52 AM
Senior Tech
Gary
 
Join Date: Sep 2000
Location: Kirkville,N.Y., U.S.A.
Posts: 957
Post

Be afraid, Very afraid!
Gary Dorion is offline  
post #8 of 11 (permalink) Old Jul 30th, 01, 09:19 PM
 
Join Date: Apr 2001
Location: Oakdale Ca
Posts: 12
Post

Well guys this method of setting timing is older than all of us, actually I believe it is done at an idle and this gives you your best running at idle, as a matter of fact if you do this to a stock engine and you check it with a timing light it is very close to factory spec makes you wonder how thay get a factory spec. but once you change cams, intakes and all that you timing requirements change.
If you would like to get the most out of your engine like me, find where you engines max timing is (where it runs the best and is not detonating) lets say 37 deg and then find you optimum idle vacuum timing lets say 17 deg then you set your mechanical advance for 20 deg, and then you come back and find the curve (springs) that work best and you will have your ignition system set up good.
Some of these old time methods still have there place in the electronics age
1968DON is offline  
post #9 of 11 (permalink) Old Jul 30th, 01, 09:48 PM
 
Join Date: Jul 2001
Location: franklin, tn
Posts: 16
Post

38* no more -38 Degrees o.k. never lock it down higher than that.
jbracer921 is offline  
post #10 of 11 (permalink) Old Jul 31st, 01, 04:59 AM
Senior Tech
 
Join Date: Oct 2000
Location: Greenville,SC,USA
Posts: 177
Thumbs up

Adjusting timing and carb with a vacuum gauge is accepted practice in drag racing. But you would still have to ensure that total advance does not cause run-on or detonation. I quess the 1200rpm start point is to negate the vacuum advance from affecting the initial setting. If a car is only used in parades and parking lots you probably don't need it.
MY10secSS is offline  
post #11 of 11 (permalink) Old Jul 31st, 01, 05:23 AM
DjD
Retired
Dennis
 
DjD's Avatar
 
Join Date: Apr 1999
Location: Fortuna, CA
Posts: 26,419
Garage
Post

I don't run in drag racing circles and I'm not a mechanic by trade but IMO if you're gonna use a vacuum guage to set your timing you might as well do it buy ear and look for the highest idle!! Setting the initial timing on anything but a stock vehicle to factory spec's doesn't cut it. Total mechanical timing requires a timing light! A vacuum guage is used to adjust the idle mixture. When there are millions of cars in the world and they have been around for a century or so you will find many things will have been tried...

It was my understanding that timing is locked on drag cars and timing curves and vacuum advance are not used... Mind you there are various classes and the closer you get to street it might be different!!

------------------
...Dennis
'69 RS Convertible w/SS trim
'96 Z28SS #1679 of 2410
"The Club"
DjD is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Team Camaro Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.



Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome