Engine and Transmission Tech

The plan is to run a rebuilt Cater AFB 400 Carb on the Rover engine. But other than fabricating a base to fit on to the 4 1/4" opening what other options are there? Does anyone know of an air cleaner that has the base opening of 4 1/4" instead of the usual 5 1/8"? The only thing I can think of is to fit a ring of metal cut to the 4 1/4" interior opening with a bit larger than the 5 1/8" exterior diameter and attach it to an after market base. Any ideas? Thanks~

Michelle, I'm assuming you don't have or can't find an oem. 4 1/4" base ? Many times they have more refined, radiused inlet than some aftermarket cleaners. Trim off unnecessary metal, find suitable,hi-flow filter/top. Clean an mean ? roverman.

Art, I bought it from a fella on the MG Board and it didn't come with any oem base and so far I haven't been able to locate one at all. Right now I have a dropped base but it is a 5 1/8" opening. I haven't been able to find anything that would work at all with it. I emailed K&N to see if they have anything in a set that has that diameter base opening but I doubt they do. My husband wondered what opening the VW and such had but I don't know.

Perhaps clue lies with carb. ? OEM. ? If so, what cars used it ? May "some" 215's ? D&D any help ? roverman.

I searched the number and I beleive it was OEM to the Buick in the day from what I could tell. I talked to Mark over there and he had nothing that would work with it in his stock and no idea where to find something. Jegs sells a step up from that size to the standard but that raises it even higher under the hood which is why I am trying to figure out a way to get it lower.

Someone must make an adapter similar to the attached ebay listing

[cgi.ebay.com]

Otherwise it would be a simple matter of cutting an appropriate size ring in metal.

Got silver lining ? "If" you make it, why not "drop It" ? Since 51/8" is surrounding 41/4", leaving room to drop ? roverman.

Well that is my idea, to make a ring with the appropriate sizing and attach it to the base plate. I have a drop base to work with that is already dropped close to 2", I will have to try and modify it around the top of the carb to give clearance to the locations that need it.

> The plan is to run a rebuilt Cater AFB 400 Carb on the Rover engine.
> But other than fabricating a base to fit on to the 4 1/4" opening what
> other options are there?

I don't think you have a 400 CFM Carter AFB if your carb uses the 4 1/4"
diameter filter base. While the first version of the Carter AFB used
the smaller air 4 1/4" filter base (shared by the Carter WCFB and Rochester
4GC carbs), they were not flow rated. Instead they were grouped by venturi
and throttle bore diameters. The 400 CFM AFB's were models 9400 and 9410
were second generation AFB's which use the standard 5" 1/8" diameter air
filter base.

> I searched the number and I beleive it was OEM to the Buick in the day from
> what I could tell.

The Buick 215's and 300's used Rochester 4GC carbs which did have the
smaller 4 1/4" base. Perhaps you have a 4GC and not an AFB?

> Does anyone know of an air cleaner that has the base opening of 4 1/4"
> instead of the usual 5 1/8"?

The street rod shops should have what you want. Try these guys:

www.offyonline.com
[www.thehotrodcompany.com]

If you're looking for an original Buick air cleaner with the 4 1/4" base,
I probably have one around here. Let me know if you want me to look.

Dan Jones