Cadillac & LaSalle Club Discussion Forum

Cadillac & LaSalle Club Forums => Want To Buy - Parts => Topic started by: Caddyholic on April 12, 2020, 05:17:41 PM

Title: 4jet primary cluster
Post by: Caddyholic on April 12, 2020, 05:17:41 PM
One of the brass tubes fell out of my primary cluster on a Rochester 4jet. Downs anyone have a spare tube, cluster or parts carb to sell?
Title: Re: 4jet primary cluster
Post by: The Tassie Devil(le) on April 12, 2020, 08:15:53 PM
Can't you just push it back in?   Or, have you lost it?

Bruce. >:D
Title: Re: 4jet primary cluster
Post by: Caddyholic on April 12, 2020, 09:05:24 PM
One of the small brass tubes fell out and I lost it.
Title: Re: 4jet primary cluster
Post by: Cadman-iac on April 13, 2020, 12:18:25 AM
You should be able to find one of these fairly easily.  A Rochester 2 barrel carb with the small bore has the same primary venturi cluster tubes in it. I have dozens of them, for 2 and 4 barrel carbs. But I'm in Arizona.
If you can't find one anywhere, let me know,  I'll send you one. No charge. Just let me know the length of the remaining one, and if it sticks out through the top as well. Some did, some didn't.
Here's a couple of pictures that show the tubes on both the 2 and 4 barrel venturi clusters. The tubes are the same,  but the clusters themselves are different.

The second picture shows the longer tubes that extend above the cluster. These are typically only in a 2 barrel,  but I thought I had seen it before in a 4 barrel once too, so I'm showing it to you just in case.
HTH,
Rick
Title: Re: 4jet primary cluster
Post by: fishnjim on April 13, 2020, 10:47:13 AM
There's a primary and secondary cluster, so you need to know which one.
See catalog cut.
I thought there's a exploded diagram in rebuild manual, but only in the 2 GC?   Might be in my books.   I'm more familiar with carter and have some parts for those.   I got a '58 Rochester core but saving to sell with the manifold.
I have the 4GC rebuild manual electronic, if need.   It's also available to download from Mike's Carbs.
Would need the carb number or year to match.
Title: Re: 4jet primary cluster
Post by: Cadman-iac on April 13, 2020, 11:03:30 AM
That's right TJ, but i was only referring to the small tube that he lost. Those are just an air bleed tube to help atomize the fuel. The larger tubes are the pick up or feed tubes to the venturis.
I would just pull out one of the small ones for him if he can't find one nearby.

Rick
Title: Re: 4jet primary cluster
Post by: Cadman-iac on April 13, 2020, 02:49:54 PM
Jim,
There are two packed and ready to send. Hopefully i can get them to the post office today or tomorrow.
Posting this here because I can't post a picture in a personal message.
What I use to install one of these tubes with is just a very small brass vacuum hose connector. It fits down over the end of the tube and against that shoulder so it doesn't mess up the end of the tube. You want that opening to remain the same shape and size as it is now.
Here's a picture of what I'm talking about. You can probably use a plastic vacuum connector, as you're only going to do this hopefully just once.  But I've gotten this one off of an old Cadillac vacuum hose harness for the climate control. You may even have one on your own car that you could use for this.
Just be careful and be sure not to drive it in too far. Use a gage of some kind and measure the other side first.
If it doesn't feel like it would stay in place, you can use a little punch to lightly close the opening in the venturi cluster where the tube goes. That will help keep it from falling out again.
This is actually a common occurrence with these carbs.
Let us know how the repair goes after you get these.

Rick