The CJ3A Page CJ3B.info

Post reply

Warning: this topic has not been posted in for at least 120 days.
Unless you're sure you want to reply, please consider starting a new topic.

Note: this post will not display until it's been approved by a moderator.

Name:
Email:
Subject:
Message icon:
Verification:
Type the letters shown in the picture
Listen to the letters / Request another image

Type the letters shown in the picture:
Write the word between words Jeep from this JeepWILLYSJeep?:
How many slot has a GPW grill?  7 - 9 - 11:

shortcuts: hit alt+s to submit/post or alt+p to preview


Topic Summary

Posted by: garage gnome
« on: April 11, 2013, 02:54:33 PM »

I think that is a replacement from an auto parts store. Just good info to have in this thread so if the question does come up, we have the answer.
Posted by: athawk11
« on: April 11, 2013, 02:29:32 PM »

In a different thread, Nate asked for some photos of this fuel pump. �I don't want to cloud up what is right or wrong in a 3A. �I want to emphasize that, to my knowledge this is [size=14]NOT[/size] an original fuel pump in a 3A. �This is just another style you might find in yours. �This is a single action flat top fuel pump that was found in a early '49 3A. �Additionally, the engine is a 3A, but the front engine mount plate is a 2A. �

Tim

 






Posted by: garage gnome
« on: April 03, 2013, 08:51:19 AM »

Correct, unless you need decreased fuel pressure.
Posted by: Kenny_Kustom
« on: April 03, 2013, 08:18:30 AM »

Quote
The CJ-3A 647911 Fuel and Vacuum Pump is designed to be mounted using two 638737 Gaskets and one 647669 Spacer.


So, with fuel pump alone ( no vac) you don't use the spacer?
Posted by: garage gnome
« on: April 03, 2013, 07:35:53 AM »

Thanks Bob. Mine didn't have the spacer, so someone had it off one time or another.
Posted by: Bob W
« on: April 03, 2013, 06:27:26 AM »

The CJ-3A 647911 Fuel and Vacuum Pump is designed to be mounted using two 638737 Gaskets and one 647669 Spacer.
Posted by: garage gnome
« on: April 02, 2013, 06:52:38 PM »

The original one on my '49 didn't use one, nor did I put one in. The only one I found it on what the double action glass bowl pump from the 3B Fhead. The original double action on my '53 didn't have one. Bob, should there have been one on my '53?
Posted by: gmcjr
« on: April 02, 2013, 02:57:57 PM »

Quote
Hmmm... So.... Without any vac. Should i use it or not ? I have a weber carb..

The factory specs for fuel pressure are 2 1/2 to 3 3/4 psi, and enough volume to pump a half pint within 20 strokes of the pump.
I would try with the spacer first (just to err on the side of caution), and see how close it comes to the factory specs. If it doesn't work, remove the spacer. Then if its too much pressure for the carb, you might need a regulator.
 You don't want to be climbing a steep grade and have the carb run dry halfway to the top � ;)

I 'm 90% sure the single action glass bowl pumps didn't use the spacer, but I could be wrong too. Hopefully, somebody else will chime in......
Posted by: Kenny_Kustom
« on: April 02, 2013, 01:03:10 PM »

Hmmm... So.... Without any vac. Should i use it or not ? I have a weber carb..
Posted by: gmcjr
« on: April 02, 2013, 11:47:07 AM »

Quote
The PO put an electric pump on my 3A.
I ordered a glass bowl pump, no Vac.
I also got a spacer for it. Do I need to put the spacer on?


If I remember, the spacer only applied originally to the double action pumps. As GG said, you can put one on the glass bowl pump to reduce fuel pressure if needed, but it can reduce fuel pump volume as well.
Posted by: garage gnome
« on: April 01, 2013, 08:58:03 AM »

You only need it if you are running a solex carb. It will work with the carter though. As stated above, the spacer saves on wear and tear on the diaphragm.
Posted by: Kenny_Kustom
« on: April 01, 2013, 08:52:17 AM »

The PO put an electric pump on my 3A.
I ordered a glass bowl pump, no Vac.
I also got a spacer for it. Do I need to put the spacer on?
Posted by: maximushuntermus
« on: March 20, 2013, 09:37:09 PM »

Oooops never mind I just missed reading the previous post, Duh !!!!
Posted by: maximushuntermus
« on: March 20, 2013, 09:36:01 PM »

Is there any significance to the 1/8" plate? Does it being there or not change the pump rate?
Posted by: gmcjr
« on: March 20, 2013, 08:14:01 PM »

Good Job GG! Lots of good info! One thing I can add, if the original double action fuel pump had a 1/8" spacer between it and the block, and it doesn't get reinstalled, you will have insanely high fuel pressure (I had 10-12 psi, if I remember right. Not good, especially with a solex carb.) and not to mention extra stress on the pump diaphragms. I learned this the hard way.......sometimes p/o's are not very nice