Carburetor spacer for 258? - JeepForum.com
 2Likes
Reply
 
LinkBack Thread Tools
post #1 of 17 Old 08-21-2020, 04:03 PM Thread Starter
andysbarker
Registered User
 
andysbarker's Avatar
1980 CJ5 
 
Join Date: Sep 2012
Location: Caledonia
Posts: 180
Carburetor spacer for 258?

So, I have a 0.75” “thick carburetor spacer. I’ve had it for years, left over from a different project. I had no idea that I still owned it, and I just re-discovered it today. It will fit on the Jeep; I have plenty of room to move the carb up.

From what I know, they only offer benefits. More horsepower and torque. I couldn’t find any reason not to add it. But, I’m thinking if they’re so great, why doesn’t everybody have them?

Is this worthwhile to add? Or is there any reason why it should not be added?

It will take a little effort to make the change. I’ll at least need some longer mounting studs and another gasket. I’ll probably go over the top and replace other things just so they look better while I’m at it. So I don’t want to go through the process if there’s no benefit to it or if it will have negative results.

I am running a Holley truck avenger carburetor and an Offenhauser intake manifold.

Attached Thumbnails
67FBD5E0-5FF1-47CF-89FA-52516FF64440_1598047365485.jpg   8450ED4E-D621-47DD-BEC3-7489EF2CF3EA_1598047391082.jpg  
andysbarker is offline  
Sponsored Links
Advertisement
 
post #2 of 17 Old 08-21-2020, 04:43 PM
pedal2themetai
Registered User
1956 CJ5 
 
Join Date: Apr 2015
Location: Boise
Posts: 1,808
HI That's not a spacer its an adapter. Looks like to go from a spread bore carb to a square bore intake. your Holley is a square bore I believe. Q-jets are spread bore carbs and mostly GM products.
good luck
tim
pedal2themetai is offline  
post #3 of 17 Old 08-21-2020, 04:46 PM
pedal2themetai
Registered User
1956 CJ5 
 
Join Date: Apr 2015
Location: Boise
Posts: 1,808
HI After looking at it again it for going with a square bore carb to a spread bore intake. Your holding it upside down.
good luck
tim
pedal2themetai is offline  
 
post #4 of 17 Old 08-21-2020, 04:56 PM Thread Starter
andysbarker
Registered User
 
andysbarker's Avatar
1980 CJ5 
 
Join Date: Sep 2012
Location: Caledonia
Posts: 180
Wow. It sure is an adapter. Surprised that I didn’t notice that. Thanks!
andysbarker is offline  
post #5 of 17 Old 08-21-2020, 05:52 PM Thread Starter
andysbarker
Registered User
 
andysbarker's Avatar
1980 CJ5 
 
Join Date: Sep 2012
Location: Caledonia
Posts: 180
I still wouldn’t mind hearing if a spacer is a good upgrade. The cost is low enough, and I enjoy working on the Jeep, and I need a project. And I’ve got spacers on my mind.
andysbarker is offline  
post #6 of 17 Old 08-22-2020, 12:09 AM
BagusJeep
Registered User
 
BagusJeep's Avatar
1981 CJ7 
 
Join Date: Jul 2009
Location: Bali
Posts: 8,537
The spacer is only worth it if it is a heat insulator, the originals were a phenolic resin compound.

Phenolic resin base compound - 20 W/m-K
Aluminium - 200 W/m-K


If you have an aluminium manifold, it is quite a good heat conductor. The spacer will reduce the rate of heat transfer to the carb.

BagusJeep lives in Bali with far too many 4x4s:
1981 CJ7 258ci - Bagusjeep
1984 CJ7 258ci - Puthijeep
1981 J20 258ci - Gladys
1951 Willys CJ3A/MB/M38 - Little Willy
1995 Cherokee 4.0 - CHEROKEE
1980 Land Rover Series III 109" troop carrier - ROVER
BagusJeep is offline  
post #7 of 17 Old 08-22-2020, 10:10 AM
hp_lovecraft
Registered User
1981 CJ5 
 
Join Date: Sep 2009
Location: Maine
Posts: 1,393
Quote:
Originally Posted by BagusJeep View Post
The spacer is only worth it if it is a heat insulator, the originals were a phenolic resin compound.
The factory phenolic spacer on my 77 engine was about 1/2". I noticed that the spacer for a 81+ engine was about 1".

Kinda odd since the 81+ engines no longer have the exhaust attached to the intake.

But I've been having hot start issues for years, so I put on the 1" spacer.... and it seems a little better. 1" is also the absolute max, as the aircleaner now rubs on the hood a little.
hp_lovecraft is offline  
post #8 of 17 Old 08-22-2020, 03:13 PM
JEEPFELLER
Registered User
 
JEEPFELLER's Avatar
1977 CJ5 
 
Join Date: Dec 2015
Location: Western
Posts: 1,356
Garage
The spacer may aid you in a different way than you think.

Your spacer may need modifying, but in the end, your carburetor operation will be a bunch more efficient.

See Posts 13-15 in this link.

https://www.jeepforum.com/forum/f8/c...oblem-4406705/

----JEEPFELLER
JEEPFELLER is offline  
post #9 of 17 Old 08-22-2020, 06:46 PM
BushPusher77
Registered User
1977 CJ7 
 
Join Date: Dec 2015
Location: Rochester
Posts: 304
Garage
Or may be just a simple CARBURETOR ADAPTER 2 TWO-BBL TO 4 FOUR-BBL INTAKE MANIFOLD THROTTLE FLANGE PLATE
Attached Images
 
BushPusher77 is offline  
post #10 of 17 Old 08-22-2020, 08:55 PM
BagusJeep
Registered User
 
BagusJeep's Avatar
1981 CJ7 
 
Join Date: Jul 2009
Location: Bali
Posts: 8,537
Just a note for BBD owners reading this, the top side of the phenolic spacer has cut outs that match the cut outs in the carb base gasket which connect to slots in the base of the carb (it is not flat for a reason). This is an integral part of the carb function, do not ever put a solid gasket under it (with no cut outs, or the one seen in many kits with the cut outs on the short sides as they will not match the spacer) or try to use gasket maker in these areas or rebuild without the spacer. Not using the spacer will degrade performance of the carb.

Pics below are of an original, top side followed by bottom. Also pics of gaskets you find in kits and an original BBD, note the slots on the base.

Spacers are now available for the BBD, repro:

https://www.ebay.com/itm/OEM-JEEP-CJ...-/124015829004
Attached Thumbnails
spacer.jpg   spacer bot.jpg   spacer gasket.jpg  
Attached Images
 

BagusJeep lives in Bali with far too many 4x4s:
1981 CJ7 258ci - Bagusjeep
1984 CJ7 258ci - Puthijeep
1981 J20 258ci - Gladys
1951 Willys CJ3A/MB/M38 - Little Willy
1995 Cherokee 4.0 - CHEROKEE
1980 Land Rover Series III 109" troop carrier - ROVER
BagusJeep is offline  
post #11 of 17 Old 08-25-2020, 08:55 AM Thread Starter
andysbarker
Registered User
 
andysbarker's Avatar
1980 CJ5 
 
Join Date: Sep 2012
Location: Caledonia
Posts: 180
Quote:
Originally Posted by hp_lovecraft View Post
Quote:
Originally Posted by BagusJeep View Post
The spacer is only worth it if it is a heat insulator, the originals were a phenolic resin compound.
The factory phenolic spacer on my 77 engine was about 1/2". I noticed that the spacer for a 81+ engine was about 1".

Kinda odd since the 81+ engines no longer have the exhaust attached to the intake.

But I've been having hot start issues for years, so I put on the 1" spacer.... and it seems a little better. 1" is also the absolute max, as the aircleaner now rubs on the hood a little.
I currently don’t have any spacer. The carb is bolted directly to the aluminum intake manifold with a standard gasket between them. The gasket is paper, maybe 1/16” thick.

It sounds like perusing a spacer may be a good idea.
Attached Thumbnails
D0D5DFA0-E4B8-4F24-8CF4-FB5048D4B3D1_1598367485566.jpg  
pedal2themetai likes this.
andysbarker is offline  
post #12 of 17 Old 08-25-2020, 11:00 PM
JEEPFELLER
Registered User
 
JEEPFELLER's Avatar
1977 CJ5 
 
Join Date: Dec 2015
Location: Western
Posts: 1,356
Garage
I'm not sure everyone knows what happens with "Our Carbs"

with the way they have to mount.

I have a 258 with a 390 Holley.

I made an explanation pic.

The carb must sit as level as possible, as ours mount perpendicular to the engine block.

Without compensating to make it level this is what happens.

Our engine "squats" on the cockpit side. In turn, the barrels in the carb sit "one High" and the other "Low"

The engine slant would not matter much if the carb sat parallel with the engine---but it don't!

It's hard enough to tune as perfect as possible, without attempting to compensate for an constantly unlevel fuel level (I've tried--it don't work!)!

Best thing going for me was to have a solid spacer machined to make my carb sit level. Better Performance was now obtainable!

See how much my carb leaned backwards in my pic?

----JEEPFELLER
Attached Thumbnails
wedge carb (2)EXPL.jpg  
uptillnow likes this.
JEEPFELLER is offline  
post #13 of 17 Old 08-26-2020, 12:42 PM Thread Starter
andysbarker
Registered User
 
andysbarker's Avatar
1980 CJ5 
 
Join Date: Sep 2012
Location: Caledonia
Posts: 180
I get it. Makes complete sense.

I’m not sure if being slightly off of level is an issue for me. I’m running the “Truck Avenger” which is designed specifically for off-road. It is advertised as allowing for 40 degree climbing, 30 degree side hill maneuvers and nose-down descents with no hesitations, stalling and flooding typically associated with carbs in an off-road environment.
andysbarker is offline  
post #14 of 17 Old 08-26-2020, 12:48 PM
pedal2themetai
Registered User
1956 CJ5 
 
Join Date: Apr 2015
Location: Boise
Posts: 1,808
HI tho that is true of the Avenger Carb if your motor is already tipped it takes from those degrees and it is talking about front to back tipping of the carb while your carb is mounted sideways.
Just an FYI
tim
pedal2themetai is offline  
post #15 of 17 Old 08-26-2020, 02:14 PM Thread Starter
andysbarker
Registered User
 
andysbarker's Avatar
1980 CJ5 
 
Join Date: Sep 2012
Location: Caledonia
Posts: 180
Sounds good. I like what JEEPFELLER has done. I plan to pursue a spacer as a thermal insulator and to correct the carb to level with the ground.
I didn’t know that plastic spacers were part of the original parts for thermal insulation. I’ve always had my carb bolted directly to the aluminum intake manifold with the standard paper gasket.
andysbarker is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the JeepForum.com 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 e-mail address for yourself.



Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



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 Off
Pingbacks are On
Refbacks are On

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