carb. spacer theory - Hot Rod Forum : Hotrodders Bulletin Board -- Hot Rod Forum

Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
lost password?   |   register now

LinkBack Thread Tools
  #1 (permalink)  
Old 05-02-2004, 10:58 AM
onecoomofo's Avatar
Last photo:
Join Date: Jan 2004
Location: Houston, TX
Age: 34
Posts: 155
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
carb. spacer theory

So what exactly happens when you had a carb spacer to a vehicle? Doesn't it give it less torque but more top end? And doesn't it require bigger jets to accomidate for the bigger distance the air/gas has to travel?

I would really appreciate someones expertise

Sean S.

Reply With Quote Quick reply to this message
Sponsored Links
  #2 (permalink)  
Old 05-02-2004, 11:26 AM
camaroman7d's Avatar
Last photo:
Join Date: Dec 2003
Location: Vacaville, California
Age: 49
Posts: 2,246
Wiki Edits: 0

Thanks: 3
Thanked 10 Times in 10 Posts
Different combos will want different things. It is not possible to say what a certain spacer will do on every engine. There are basically to styles/types of spacers (open and 4 hole). There are also different types of intake manifolds so depending on the combination of the two the effect can be different.

Typically they don't really "add" power, they adjust the range at which your power band will be. An open spacer adds plenum volume so if you have a manifold that is slightly to small an open spacer will help, otherwise it usually will raise the RPM level at which the engine makes power.

A 4 hole spacer should add torque, or lower the range that the torque is made. With a 4 hole the carb gets a stronger vacuum signal (over an open spacer).

Of course there is a lot mor to it than this, it is basically a tuning tool to get the most out of your combo or adjust the power band. There are all kind of them out there, some claim big gains. They also come in different heights and materials. In some case a phenolic spacer is the best choice, because it keeps the heat from being transfered to the carb (one case is when using a Weiand Stealth intake) I have fixed several cars with this intake that had hot start problems, add the phenolic spacer and the problem is solved.

It is a trial and error type of thing, don't expect huge gains. You might pick up a few HP/ft lbs, but don't expect 50HP.

That is the basics, like I said there is a lot more to it.

Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 05-02-2004, 11:27 AM
Join Date: Apr 2004
Location: Cassville,MO
Posts: 976
Wiki Edits: 0

Thanks: 42
Thanked 68 Times in 64 Posts
The spacer give the intake more plenum volume making the intake appear bigger than it is to the engine. Sometime with real short intakes it helps the fuel make a smooth turn into the runners. Often a 4 hole spacer rather than an open spacer will limit your bottom end torque loss.
Sometime they get put on just because the speed shop has them for sale and somebody seen someone else use one.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 05-02-2004, 12:41 PM
Croz's Avatar moderator
Last photo:
Join Date: Jul 2002
Location: Oklahoma
Posts: 465
Wiki Edits: 0

Thanks: 0
Thanked 4 Times in 4 Posts
There is quite a bit of info about this here.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 05-03-2004, 09:26 AM
Technical Support Barry Grant
Last photo:
Join Date: Jul 2003
Location: Dahlonega, GA
Posts: 1,503
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
Carburetor Spacers

Spacers installed between the carburetor and intake manifold can be used to overcome a problem in the design of the engine (too big or small of an intake, carburetor, cam, heads, etc), or to help fine tune the engine to your specific combination. There is not a end all be all better or worse with a spacer, it's a matter of what your specific combination requires.

As a rule of thumb, a 4-hole carburetor spacer will increase the air velocity through the engine at lower speeds, increasing the bottom end torque, throttle response, and moving the power band down a little.

Conversely an open spacer will decrease the air velcoity at low speeds, taking some of the torque away, but it will increase the higher end HP, and raise the Power band up a little.

With either of these the thicker the spacer the more of an effect they will have.

Your best option with spacers, is to run the vehicle without a spacer to start with, and then use a spacer to tune for what you are looking for out of the engine combination.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 05-03-2004, 12:52 PM
1BAD80's Avatar
The Smell of Nitro in the morn
Last wiki edit: How to adjust valves Last photo:
Join Date: Jun 2001
Location: Mich
Posts: 2,423
Wiki Edits: 2

Thanks: 0
Thanked 3 Times in 2 Posts
Luv the smell of NITRO in the morning.
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Please select your insurance company (Optional)


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools

Posting Rules
You may 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

All times are GMT -6. The time now is 01:37 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999 - 2012. All Rights Reserved.