Inliners International Forums General Discussion Hi Performance Multi carbs

Any recomendations on what one barrel carbs to run in a dual carb L6 application? Any thing to stay away from? The engine I have is a 230 Cu In Mopar Flattie that I have found a cool Manifold for. First time setting one of these up and looking for any info I can find.

That is one fine looking flathead!
I am reading in Weertman's new book [excellent] "Chrysler Engines" and it appears the 1958 230 came with a 2v carb, I dont know the CFM but it might be a good reference point.

I would think either Carter W-1 or YF would work if you have the clearance, there was a shorter Carter RBS? but two of these might be too much cfm. I like the Rochester B/BC/BV ok too, there's a small, medium, and large CFM of those. I have not had good luck with the later Rochester Monojet (late 60s).

What compression and cam do you have inside?
Nice picture, nice induction setup!

I was looking at the Carter W-1 and that seems pretty straight forward. I haven't checked compression yet as the head has has .075 taken off. After my vacation I'll get out the burret and check it out.

Carter YFs are plentiful, easy to rebuild, come in several sizes, and work well.

By the way - nice engine!

I would seriously consider welding a piece of tubing to the bottom of that intake manifold for water heat. It will make for a much better running engine. Nice bikes too!

Hey man that does look nice! I always recommend using the Carter B&B's. That's what I run on mine anyway. They are also plentiful, any Dodge or Plymouth late 40's to early 50's has one. Two of them seem to work fine.

I've been thinking about experimenting with a couple of YF's too. Have fun with it!

Who built the manifolds? Really slick.

Moose55 built it. I was on vacation down in Daytona this past week. I went to the Turkey run and picked up a couple carbs I think will work.

Any comments or advice?

Yea, Who's that girl on the wall?

Looks like Miss December

Its my exwife she liked to hang out everywhere LOL

I've never used Rochesters on any of my stuff before, mostly because the throttle arms are made for up and down movement. But anything can be adapted to anything. To use those I would first turn them 90 degrees, and then make new/find different arms that are 90 degrees from those to allow them to move fore and aft.

The linkages I put on my own stuff have a cross shaft with two arms and links to connect the arms to the carbs, and the carbs together.

I tried to post a picture but I'm not sure how... any suggestions?

I was thinking about that last night and this morning and think
I have a way around the up and down action. I'm gonna mock something up tonight.

As far as posting, I set up a photobucket account and use the add image feature there. I upload the photo, save it, then select the IMG offering, save then paste into my post here.

Tom Langdon sells some weber carbs with adapters that would work great on that engine.

Here is a link..
http://www.stoveboltengineco.com/acartpro/category.asp?catcode=33

Focus guys! :-) on the engine!

This weekend I'm gonna try and set up my linkage. McMaster Carr delivered a LH thread tap today so I can set up the actual connecting rod between carbs. I've got in mind to remove the Idle adjustment from the rear carb and once the carbs are in sync with RH/LH Heims, do all the idle adjust from the front carb. My carbs are manual choke and I'm gonna set the cable up to the front carb and run wire linkage for the choke butterflies. Pulling the front choke will atvivate the fast idle of the front carb with the linkge raising the idle of the rear carb. I'm gonna drill and tap both carb bases for a vacuume nipple to be able to sync the carbs using a pair of vacuume gages. Once sync'ed I'll lock the Heims with jam nuts. I'll also use one of these points to get my ignition advance, with a cap over the unused nipple.

Any comments or things I'm forgetting? This is the first car multi carb set-up I'm trying, but I've done a ton of multi-carb motorcycles. A motor is a motor, right?

Not quite.

Any of the multi carb motorcycles I have run don't have a balance tube, so for synchronisation you could use some variation on vacuum gauges (ie, mercury manometers).

If you already have a Uni Syn (or equivalent) then you should be good.

Look over to the left in our Tech tips area and at the multi rottenchester section. Should give you all you need. I gotta say again, you seriously need manifold heat.If you don't, it will always run rich, get bad mileage and be a dog to drive. It would be easier to mount them directly to the manifold 180 from how they're sitting and bend the fuel lines to fit.

Manifold heat is a good thing to have, and with those head pipes running less than 1/2" from the intake log, you've got it. My personal experience has shown that it's not a problem running sets similar to this through the Massachusetts winters for the past few years.

I'd say just get it running and synced pretty close and see how you like it!

Moose, I haven't pestered you, but have you had to change jets in what your running? I've figgered out a way of getting aroud manifold heat (copper tube covered by insulating wrap) but the reduced carb signal concerns me. It is is definatly drunk out tonight, so if I'm out in left field let ne know.......

I couldn't see how close the pipes were to the manifold, at 1/2 inch I'm with Moose in just sync em and see how it runs. Don't bother with the copper tube, it doesn't work that well (it's been done). In the tech section under "IMPROVING DRIVEABILITY WITH MULTIPLE ROCHESTERS" You will find all you need to know to make them work better, jetting tips and all that. You'll have to get it running to see what you need for jets. I had two on my '41 Chevy (235 W/split exhaust) and after the mods, they ran better and got better mileage than the single did!

I've never been one for "ultimate" tuning. I've never really had enough time for that. I have two kids car seats in the back of my '55(I'm a stay-at-home dad), so reliability is very important to me. As far as I'm concerned, I just want my motor to start every time, be somewhat more efficient(both in power and mileage), and look cool.

I leave the jets alone. My thought is that the carb meters the amount of fuel to the amount of air going through it. Period. Possibly by having the lower vacuum signal will change the mixture at idle, but thats what the idle mixture screws are for, right? I feel like at wide open throttle, a properly functioning carb will do its job. If it is a little more rich, then the more free flowing exhaust will help to properly move that out and make more power from the extra fuel.

Hope everybody's feeling OK this morning...
Moose

Thanx guys...