The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > General Truck Forums > Engine & Drivetrain

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 10-08-2015, 08:10 PM   #26
Justins76
OutOfMyMind & I'llNeverKnowWhy
 
Justins76's Avatar
 
Join Date: Apr 2004
Location: Another world, some other time
Posts: 672
Re: Tuning carb with a Vacuum Gauge

When tuning a carb with a vacuum gauge, should the transmission be in Park or Drive?
__________________
-Justin-Out of my mind and I'll never know why
1976 Chevrolet Silverado C10 350 4bbl / TH350 Big10 longbed
1986 Pontiac Firebird T-Top 5.0L TPI 700R4 WS6
1992 Pontiac Firebird T-Top 5.0L TBI 700R4
My cardomain page

I don't like to save, it's more fun to spend!!
Justins76 is offline   Reply With Quote
Old 10-08-2015, 08:29 PM   #27
cableguy0
Senior Member
 
Join Date: Apr 2000
Location: Delta,Pa
Posts: 14,950
Re: Tuning carb with a Vacuum Gauge

Quote:
Originally Posted by Justins76 View Post
When tuning a carb with a vacuum gauge, should the transmission be in Park or Drive?
Park. Being in gear puts the engine under load which will lower the vacuum readings.
__________________
Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member.
cableguy0 is offline   Reply With Quote
Old 10-08-2015, 08:29 PM   #28
RyansToy
Registered User
 
RyansToy's Avatar
 
Join Date: Aug 2015
Location: Nova Scotia Canada
Posts: 145
Re: Tuning carb with a Vacuum Gauge

The manual is in neutral, so I would think the auto should not be loaded (in gear).
__________________
1968 GMC truck
910 Trim (Canadian)
127" WB
3 on the Three Trans (Saginaw SM330)
250 ci L6 Engine
HEI ignition (early 80s L6)
RyansToy is offline   Reply With Quote
Old 10-08-2015, 09:05 PM   #29
prostreetC-10
My Carbon Footprint
 
prostreetC-10's Avatar
 
Join Date: Oct 2008
Location: Orygun
Posts: 5,527
Re: Tuning carb with a Vacuum Gauge

Quote:
Originally Posted by cableguy0 View Post
Park. Being in gear puts the engine under load which will lower the vacuum readings.

That and it also requires you to run along side the truck which can be tricky.
prostreetC-10 is offline   Reply With Quote
Old 10-08-2015, 09:21 PM   #30
cableguy0
Senior Member
 
Join Date: Apr 2000
Location: Delta,Pa
Posts: 14,950
Re: Tuning carb with a Vacuum Gauge

Quote:
Originally Posted by prostreetC-10 View Post
That and it also requires you to run along side the truck which can be tricky.
Your supposed to stand on the bumper or sit in the engine bay. I thought that was required when working on an old truck.
__________________
Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member.
cableguy0 is offline   Reply With Quote
Old 10-08-2015, 09:28 PM   #31
prostreetC-10
My Carbon Footprint
 
prostreetC-10's Avatar
 
Join Date: Oct 2008
Location: Orygun
Posts: 5,527
Re: Tuning carb with a Vacuum Gauge

Quote:
Originally Posted by cableguy0 View Post
Your supposed to stand on the bumper or sit in the engine bay. I thought that was required when working on an old truck.
Hey on a serious note, have you seen those things that you almost lay against and they curve over the front of the truck. Looks like it would really save the back of the knees. Saw one on TRUCK U. I remember weekends where I was hunched over that truck for hours and could hardly walk the next day. I too am a fan of just climbing on into the bay and making yourself comfy! lol
prostreetC-10 is offline   Reply With Quote
Old 10-08-2015, 09:33 PM   #32
cableguy0
Senior Member
 
Join Date: Apr 2000
Location: Delta,Pa
Posts: 14,950
Re: Tuning carb with a Vacuum Gauge

Quote:
Originally Posted by prostreetC-10 View Post
Hey on a serious note, have you seen those things that you almost lay against and they curve over the front of the truck. Looks like it would really save the back of the knees. Saw one on TRUCK U. I remember weekends where I was hunched over that truck for hours and could hardly walk the next day. I too am a fan of just climbing on into the bay and making yourself comfy! lol
Absolutely have used one. Its called a truck creeper. They are fine if your in the same spot for a long while but Im stubborn and move a lot. They do work well but for stuff where your constantly back and forth climbing up and down to grab another tool etc is worse than just being uncomfortable. Also if your drinking the required amount of beer you wont stay hunched for hours because between drinking the beer, getting the beer and going to pee you have plenty of time to stretch.
__________________
Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member.
cableguy0 is offline   Reply With Quote
Old 10-11-2015, 01:49 AM   #33
71_Burb
Registered User
 
Join Date: Aug 2015
Location: Los Angeles Ca
Posts: 34
Re: Tuning carb with a Vacuum Gauge

Just read the thread .... Great useful info that I'm gonna use over the weekend and make some tweeks ..
71_Burb is offline   Reply With Quote
Old 10-17-2015, 10:24 AM   #34
ranger danger
Registered User
 
ranger danger's Avatar
 
Join Date: Jan 2015
Location: Vacaville CA
Posts: 896
Re: Tuning carb with a Vacuum Gauge

I picked up a vacuum gauge last week. Its an Ashcroft 1850. I plan on band clamping a hook on it so I can hang it from the hood. I hope its big enough!
Attached Images
 
__________________
1969 C20 Suburban "Rez Dog"
Rebuild America one testicle at a time.
US Army 1977-1979 12B Combat Engineer
US Navy 1979-1983 Gunners Mate Guns (GMG)
NRA Life Member

Unrestrained Children in back seats cause Accidents.
Unrestrained Accidents in back seats cause Children.
ranger danger is offline   Reply With Quote
Old 10-17-2015, 01:53 PM   #35
prostreetC-10
My Carbon Footprint
 
prostreetC-10's Avatar
 
Join Date: Oct 2008
Location: Orygun
Posts: 5,527
Re: Tuning carb with a Vacuum Gauge

The threads below are so you can actually BOLT it to the hood! Kind of like the Pontiac GTO hood tach.
prostreetC-10 is offline   Reply With Quote
Old 10-17-2015, 02:01 PM   #36
ranger danger
Registered User
 
ranger danger's Avatar
 
Join Date: Jan 2015
Location: Vacaville CA
Posts: 896
Re: Tuning carb with a Vacuum Gauge

Quote:
Originally Posted by prostreetC-10 View Post
The threads below are so you can actually BOLT it to the hood! Kind of like the Pontiac GTO hood tach.
The threads below are for the vacuum line.
__________________
1969 C20 Suburban "Rez Dog"
Rebuild America one testicle at a time.
US Army 1977-1979 12B Combat Engineer
US Navy 1979-1983 Gunners Mate Guns (GMG)
NRA Life Member

Unrestrained Children in back seats cause Accidents.
Unrestrained Accidents in back seats cause Children.
ranger danger is offline   Reply With Quote
Old 10-17-2015, 02:14 PM   #37
ranger danger
Registered User
 
ranger danger's Avatar
 
Join Date: Jan 2015
Location: Vacaville CA
Posts: 896
Re: Tuning carb with a Vacuum Gauge

Ok I got the new gasket installed with a LIGHT layer of grease like suggested.
First is a pic of the old gasket, about construction paper thick.
Then the location I got vacuum from (off the manifold, next to the vacuum for the trans.)
Then a pic of the gauge at 1900 RPM's. Dead steady at 21.5"
Then a pic of the gauge at 700 RPM's. Vibrates between 18" and 18.5"
Attached Images
    
__________________
1969 C20 Suburban "Rez Dog"
Rebuild America one testicle at a time.
US Army 1977-1979 12B Combat Engineer
US Navy 1979-1983 Gunners Mate Guns (GMG)
NRA Life Member

Unrestrained Children in back seats cause Accidents.
Unrestrained Accidents in back seats cause Children.
ranger danger is offline   Reply With Quote
Old 10-17-2015, 02:16 PM   #38
ranger danger
Registered User
 
ranger danger's Avatar
 
Join Date: Jan 2015
Location: Vacaville CA
Posts: 896
Re: Tuning carb with a Vacuum Gauge

The new gasket is a Felpro thats about 1/4" thick.
__________________
1969 C20 Suburban "Rez Dog"
Rebuild America one testicle at a time.
US Army 1977-1979 12B Combat Engineer
US Navy 1979-1983 Gunners Mate Guns (GMG)
NRA Life Member

Unrestrained Children in back seats cause Accidents.
Unrestrained Accidents in back seats cause Children.
ranger danger is offline   Reply With Quote
Old 10-17-2015, 03:31 PM   #39
ranger danger
Registered User
 
ranger danger's Avatar
 
Join Date: Jan 2015
Location: Vacaville CA
Posts: 896
Re: Tuning carb with a Vacuum Gauge

Ok after slight adjustments to the carb air screws, the vacuum is vibrating between 18.9" and 19.1". Not to bad.
__________________
1969 C20 Suburban "Rez Dog"
Rebuild America one testicle at a time.
US Army 1977-1979 12B Combat Engineer
US Navy 1979-1983 Gunners Mate Guns (GMG)
NRA Life Member

Unrestrained Children in back seats cause Accidents.
Unrestrained Accidents in back seats cause Children.
ranger danger is offline   Reply With Quote
Old 10-18-2015, 01:16 PM   #40
prostreetC-10
My Carbon Footprint
 
prostreetC-10's Avatar
 
Join Date: Oct 2008
Location: Orygun
Posts: 5,527
Re: Tuning carb with a Vacuum Gauge

Quote:
Originally Posted by ranger danger View Post
The threads below are for the vacuum line.
Way to take the humor right out of it.......
prostreetC-10 is offline   Reply With Quote
Old 10-18-2015, 01:19 PM   #41
prostreetC-10
My Carbon Footprint
 
prostreetC-10's Avatar
 
Join Date: Oct 2008
Location: Orygun
Posts: 5,527
Re: Tuning carb with a Vacuum Gauge

I'm sorry but that gauge is freaking hilarious. The guys on the space station said your vacuum is just under 22 hg. No matter if it works though!
prostreetC-10 is offline   Reply With Quote
Old 10-18-2015, 01:24 PM   #42
ranger danger
Registered User
 
ranger danger's Avatar
 
Join Date: Jan 2015
Location: Vacaville CA
Posts: 896
Re: Tuning carb with a Vacuum Gauge

Quote:
Originally Posted by prostreetC-10 View Post
I'm sorry but that gauge is freaking hilarious. The guys on the space station said your vacuum is just under 22 hg. No matter if it works though!
Ya its big but I can see it!
__________________
1969 C20 Suburban "Rez Dog"
Rebuild America one testicle at a time.
US Army 1977-1979 12B Combat Engineer
US Navy 1979-1983 Gunners Mate Guns (GMG)
NRA Life Member

Unrestrained Children in back seats cause Accidents.
Unrestrained Accidents in back seats cause Children.
ranger danger is offline   Reply With Quote
Old 10-18-2015, 09:56 PM   #43
crazy longhorn
Fabricate till you "puke"
 
Join Date: Jun 2002
Location: Ill
Posts: 9,403
Re: Tuning carb with a Vacuum Gauge

Quote:
Originally Posted by ranger danger View Post
Ya its big but I can see it!
I love it....this old mans eyes can see it Longhorn
__________________
69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....
crazy longhorn is offline   Reply With Quote
Old 10-18-2015, 10:12 PM   #44
ranger danger
Registered User
 
ranger danger's Avatar
 
Join Date: Jan 2015
Location: Vacaville CA
Posts: 896
Re: Tuning carb with a Vacuum Gauge

Hanging under the hood of the truck, it looks like one of those clocks we used to have in school (45 years ago). You could see it from the back of the room. Every agonizing minute of it!!
__________________
1969 C20 Suburban "Rez Dog"
Rebuild America one testicle at a time.
US Army 1977-1979 12B Combat Engineer
US Navy 1979-1983 Gunners Mate Guns (GMG)
NRA Life Member

Unrestrained Children in back seats cause Accidents.
Unrestrained Accidents in back seats cause Children.
ranger danger is offline   Reply With Quote
Old 10-18-2015, 10:42 PM   #45
crazy longhorn
Fabricate till you "puke"
 
Join Date: Jun 2002
Location: Ill
Posts: 9,403
Re: Tuning carb with a Vacuum Gauge

Well, I have to ask....did it fix the problem? Longhorn
__________________
69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....
crazy longhorn is offline   Reply With Quote
Old 10-19-2015, 05:53 AM   #46
ranger danger
Registered User
 
ranger danger's Avatar
 
Join Date: Jan 2015
Location: Vacaville CA
Posts: 896
Re: Tuning carb with a Vacuum Gauge

Quote:
Originally Posted by crazy longhorn View Post
Well, I have to ask....did it fix the problem? Longhorn
Well it fixed the vacuum leak but, it did not fix the trans problem. Clinebarger suggested a few things that basically said its time for a trip to the trans shop. I broke the tachometer while replacing the wiper switch. I ordered a new one. Once it gets here and installed, off we go to visit the tranny boys!
__________________
1969 C20 Suburban "Rez Dog"
Rebuild America one testicle at a time.
US Army 1977-1979 12B Combat Engineer
US Navy 1979-1983 Gunners Mate Guns (GMG)
NRA Life Member

Unrestrained Children in back seats cause Accidents.
Unrestrained Accidents in back seats cause Children.
ranger danger is offline   Reply With Quote
Old 10-19-2015, 12:47 PM   #47
prostreetC-10
My Carbon Footprint
 
prostreetC-10's Avatar
 
Join Date: Oct 2008
Location: Orygun
Posts: 5,527
Re: Tuning carb with a Vacuum Gauge

Quote:
Originally Posted by ranger danger View Post
Ya its big but I can see it!
I used to laugh when guys couldn't read the LIST number on their Holley without glasses. I am now that guy!!
prostreetC-10 is offline   Reply With Quote
Old 10-19-2015, 05:29 PM   #48
SierraMtns
Registered User
 
SierraMtns's Avatar
 
Join Date: Jun 2014
Location: Shingle Springs, CA
Posts: 869
Re: Tuning carb with a Vacuum Gauge

I like watching these guys. Here is a video on tuning with vacuum gauge.


https://www.youtube.com/watch?v=X0uEMeDVxaA
SierraMtns is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

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

Forum Jump


All times are GMT -4. The time now is 04:19 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com