Go Back   Third Generation F-Body Message Boards > Tech Boards > Tech / General Engine
Register Forgot Password?

Tech / General Engine Is your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
Sponsored by Weld Racing
Click Here

Welcome to ThirdGen.org!
Welcome to ThirdGen.org.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, join the ThirdGen.org community today!

Removing Vacuum Advance and timing question...

Thread Tools Search this Thread
Old 05-06-2006, 11:49 AM   #1
Join Date: Jan 2006
Posts: 441
Car: 85' TA
Engine: 355 Carbed
Transmission: Built 700r4

Classifieds Rating: (0)
Removing Vacuum Advance and timing question...

first question-
what is the best way to go about removing vacuum advance?

Can i just not hook it up? I would love to be able to jb weld the vacuum advance assembly shut and go on. Is this possible? or maybe wiggle loose after time?

second question-
I was recomended 18* initial timing, and 36* at full throttle. Does the mechanical linkage only have 18* travel? or will i have to limit the travel it takes?

third question-
With a 355, cam is .520/.544 lift and 234/244 duration @.050. I have a edelbrock performer rpm, and a Speed demon carb, what are your recoomendations as to initial timing for best responce, as well as keeping it streetable.

I did have a previous post about timing, and thats where the 18* was suggested. If it stands, then great.
12SecondTA is offline vBGarage Page   Reply With Quote
Old 05-06-2006, 12:08 PM   #2
Senior Member
Join Date: Dec 2001
Location: Klamath Falls Or 97603
Posts: 976

Classifieds Rating: (0)
You can unhook the vacume from the advance and plug the vacume source. You'll need to check your total mechanical advance, I think they vary. I know my mechanical advance is 24* and I want to limit it to 16 -18*. You'll need a timing tape or one of those fancy timing lights to accurately check. With your base up that high you'll need a better starter than the stock one. FBird88 has a couple real good posts on here about that stuff. I also think there was something about using the vacume advance for better miliage when there was little load on the engine( cruising speed). Hopefully someone smarter chimes in.
350, 200 cc Pro Action heads, XE274 cam, RPM Airgap intake, T5, 4.10 posi.
rjmcgee is offline vBGarage Page   Reply With Quote
Old 05-06-2006, 09:32 PM   #3
Supreme Member
Sonix's Avatar
Join Date: Jul 2004
Location: Calgary, AB, Canada
Posts: 10,763
Car: 1982 Trans-Am
Engine: 355 w/ ported 416s
Transmission: T10, hurst shifter
Axle/Gears: 10 bolt, true-trac, 3.73

Classifieds Rating: (1)
yea, I certainly wouldn't get rid of vacuum advance, your highway mileage will suck, your plugs will carbon up fast, etc.

You just need to dial in the right timing curve. I'd recommend an MSD 960001 or whatever it is, the fully adjustable vacuum can. You can limit your max vacuum advance, change what vacuum level it comes in on, and that kit comes with mechanical advance springs, to choose when that starts coming in, and when it finishes.

You may want to hook up your vacuum advance to manifold vacuum, that'll give you more advance at idle. Or you can use ported, and bump up your base timing, then weld your mechanical advance slot shorter. (IMHO manifold vacuum is easier ) however you may end up with your manifold vacuum giving you a hunting idle, kinda depends on the motor. Best bet is to try a few combinations and see what works best for you.

that timing (18 base, 36 total) is probably a good starting point. I think stock mechanical is around 20* travel. Lots of different ways to skin the cat here.
oh right, and say you went 18* initial (that's mostly a guess and check thing), then 36* "total" (that's pretty much the same for most SBC motors.), then you could use around 52* at cruise. Yes, that's right 50* degrees of timing at cruise. If you had that much at WOT you'd ping, but at light loads like cruising, it's ok. Hence, vacuum advance.

Last edited by Sonix; 05-06-2006 at 09:35 PM. Reason: Automerged Doublepost
Sonix is offline vBGarage Page   Reply With Quote
Old 05-06-2006, 09:32 PM
1992 Camaro

Paid Advertisement


Go Back   Third Generation F-Body Message Boards > Tech Boards > Tech / General Engine

234244, 244, 355, advance, cam, carbs, demon, duration, hook, initial, removing, run, taking, thirdgen, timing, vacuum
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not 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 Off
Pingbacks are Off
Refbacks are Off


1982 Camaro '82 || 1983 Camaro '83 || 1984 Camaro '84 || 1985 Camaro '85 || 1986 Camaro '86 || 1987 Camaro '87 || 1988 Camaro '88 || 1989 Camaro '89 || 1990 Camaro '90 || 1991 Camaro '91 || 1992 Camaro '92

All times are GMT -5. The time now is 11:25 PM.

All content copyright 1997 - 2014 ThirdGen.org. All rights reserved. No part of this website may be reproduced without the expressed, documented, and written consent of ThirdGen.org's Administrators.

Emails & Contact Details