Dual SOLEX carbs on a 230 flat six?

[papajohn]

Has anyone ever tried running two Solex carbs, (stock type from Willys flatfender Jeeps) on a dual intaked flathead six?

 

 

They are cheap and easy to find new, and have a nice vintage look to them.

[Don Coatney]

Has anyone ever tried running two Solex carbs, (stock type from Willys flatfender Jeeps) on a dual intaked flathead six?

 

 

They are cheap and easy to find new, and have a nice vintage look to them.

Being cheap and easy to find new, and having a nice vintage look is nice but this does not answer the more important questions. What is the flow rate in CFM's? What is the base configuration and throttle orientation? In other words how does the throttle linkage connect? ETC?

[greg g]

just about any carb can be made to fit with materials, money and ability. Got a picture?? I looked at a pair of SU's from a 3 liter Triumph, but I then found a Fenton Intake and used two stock style carbs.

[papajohn]

Not sure of the cfm, but if one will power a 134 cube 4 cylinder, 2 should be enough for a 230 six Cyl. Flange looks the same and i think orientation is same.

[Lumpy]

I can tell you what works very well on the 230, because I done did it. I'm running two B&B single barrel carbs which both came off of 170 slant sixes.

 

I don't know how much more power they produce, but they certainly run "better" than the single carb, and get better gas mileage. The set up gets really good mileage. Low end, off idle performance/response is probably better than the stock carb, and certainly better than running two bigger carbs, such as two stock carbs.

 

All I did to tune them in, was to put slightly weaker springs in/under the "power valves", the ones that rise when vacuum is low and lift the needle jet up in the main jet. In other words I just had to lean them a bit. I've been running them for almost ten years and they run perfect, starts easy, (have a choke cable to each one) and I've never had a problem with them. And...great "wow" appeal when I pop the hood.

 

I'm not sure exactly which Solex's were on the older Willy's jeeps, but if they came off the flat four, two of them may indeed be close to ideal, as are the B&B's. On a low revving motor, which is a flathead to boot, be sure to think small. Remember it is always better to under carb, than to over-carb. At worst, too little carburation will act as a rev limiter at high or peak, or near peak RPM, but too much carb and throttle response will suck, tuning will be difficult, and you may never get it truly tuned in.

 

If you wanted pics of my B&B set up, I could probably do that. Or I'd try!

 

ken.

[greg g]

You talking about 2 of these homely things??

http://i.ebayimg.com/t/Carburetor-Solex-Design-L-Head-41-53-Willys-CJ2A-CJ3A-/09/!CCVGrU!!Wk~%24(KGrHqV,!g8E0fWQq1!mBNKyBRuFM!~~_35.JPG

[Lumpy]

Don't know if that's what he's talking about...but that's beautiful in it's homeliness....that would look great on a homely flathead six!! Certainly has that vintage "nuts and bolts" look. !

Although, that almost looks like something off a VW. ??

ken.

Edited January 24, 2014 by Lumpy

[papajohn]

Those are the ones. I guess they "ugly" but vintage.

[Lumpy]

I don't think they're ugly...the have...CHARACTOR!

Thinking more about twin solex's off a jeep being sized right for the engine, in a dual application, I think that the rule of thumb being that if one carb fed a 134 inch engine, than two should be in the ball park for an engine up to 268 inches, as you mentioned. So they might be, or are probably pretty ideal. I'm sure there's a lot of wiggle room, as 2X170=340, which in theory makes my twin B&Bs way more than enough for a 230...but they work perfectly, and the engine displays no characteristics of being over-carbed. So, there's more variables, and dynamics going on than that, but still, a good place to start.

If the carbs you get do indeed come off of flatheads, I think they might be even closer to being tuned in, or easier to tune in than my B&B's, which were easy. I say that because tuning a carb for a flathead is a bit different than the same carb on the same size OHV engine, and mine came off a OHV. I just used a Bendix carb off a 74 inch OHV engine, on a 74 inch flathead engine, and I had to lean it out quite a bit. (with an adjustable mainjet, that was kind of easy) My point being there's different dynamics between flats and OHV's that effect carb tuning, and if you use carbs off a flathead, I'm thinking you might just be right on to begin with. Pretty slick. Of course I won't mention that nothing ever works out the way it should.

Just a thought. Good luck.

ken.

[Don Coatney]

I see rule of thumb has come up a few times lately. That is one of those sayings that has been around for hundreds of years and the meaning has been misconstrued over the years. Below is the best definition I could find for the true meaning of rule of thumb From Wikipedia, the free encyclopedia

.

 

It is often claimed that the term's etymological origin lies in a law that limited the maximum thickness of a stick with which it was permissible for a man to beat his wife. British common law before the reign of Charles II permitted a man to give his wife "moderate correction", but no "rule of thumb" (whether called by this name or not) has ever been the law in England. Such "moderate correction" specifically excluded beatings, allowing the husband only to confine a wife to the household.

Nonetheless, belief in the existence of a "rule of thumb" law to excuse spousal abuse can be traced as far back as 1782, the year that James Gillray published his satirical cartoon Judge Thumb. The cartoon lambastes Sir Francis Buller, a British judge, for allegedly ruling that a man may legally beat his wife, provided that he used a stick no thicker than his thumb, although it is questionable whether Buller ever made such a pronouncement. The Body of Liberties adopted in 1641 by the Massachusetts Bay colonists states, “Every married woman shall be free from bodily correction or stripes by her husband, unless it be in his own defense from her assault.” In the United States, legal decisions in Mississippi (1824) and North Carolina (1868 and 1874) make reference to—and reject—an unnamed "old doctrine" or "ancient law" by which a man was allowed to beat his wife with a stick no wider than his thumb. For example, the 1874 case State v. Oliver (North Carolina Reports, Vol. 70, Sec. 60, p. 44) states: "We assume that the old doctrine that a husband had the right to whip his wife, provided that he used a switch no larger than his thumb, is not the law in North Carolina." In 1976, feminist Del Martin used the phrase "rule of thumb" as a metaphorical reference to describe such a doctrine. She was misinterpreted by many as claiming the doctrine as a direct origin of the phrase and the connection gained currency in 1982, when the U.S. Commission on Civil Rights issued a report on wife abuse, titled "Under the Rule of Thumb

[Lumpy]

And I always thought that it meant that those with opposing thumbs....ruled.

k.

[Lumpy]

Here's a couple pics of my B&B set up, looks a little "busy", but it sure works. The fuel pressure regulator you can see in the bottom of the pic helped a lot as far as getting them tuned in. I have an electric fuel pump, and for some reason the carbs didn't like the pressure it was running at. Dropped it down a few PSI and she's been happy ever since.

 

 

ken

Edited January 26, 2014 by Lumpy

[Lumpy]

There they is from the other side. Chrysler Ace marine engine.

Edited January 25, 2014 by Lumpy

[Lumpy]

And of course a vacuum gauge and choke cable for each carb.

Edited January 25, 2014 by Lumpy

[Frank Elder]

Obviously you have studs instead of bolts holding the head on your engine.....They don't look like they would hold torque properly to me without a few threads protruding past the nuts, how long have you been running them like that?

[Plymouthy Adams]

I have had first hand experience with the studs and I personally would never use them on any engine of my own...the items being marketed for the Plymouth flathead in actual use I find the class of fit a bit questionable..I do not think they are of proper length...

[Niel Hoback]

 I have about 10-12 head bolts that look like that on mine. They are tapped for the ground cable.

[Lumpy]

Believe it or not, those aren't studs and bolts, those are bolts which have threads in the bolt heads. ?? That's what was on the engine when I got it. That is actually a Chrysler ACE marine engine, so maybe that has something to do with it. ?? The engine was found in a warehouse in Pullman Washington, someone had ordered it for a boat, perhaps an old Chris Craft or something, and never paid up. Then it found it's way into Lumpy.

I promise I would never run short studs on an engine.

So...??

ken.

[Frank Elder]

 I have about 10-12 head bolts that look like that on mine. They are tapped for the ground cable.

That's a lot of grounding bolts on one head then.

Edit. Just read lumpys post, he really had a lot of those bolts in his extra box huh!

Edited January 26, 2014 by Frank Elder

[Niel Hoback]

   Apparently a rebuilder saved up a bunch and got rid of them all at once in my head.  That explains the rattle I hear when I shake my head.  I do have unlimited grounding capabilities.

[Don Coatney]

And of course a vacuum gauge and choke cable for each carb.

I am running a single choke cable for both carburetors. I also was going to question the head bolt/stud issue but I see it has been resolved. I am using two of the drilled and tapped head bolts for my carburetor linkage.

 

 

[Lumpy]

Well now I question the head bolt issue, because that engine was fresh in a crate. But I never paid it no mind before. I know it is a Chrysler Marine ACE engine, it has the data plate and everything riveted to the block. (it's very "bitchen", but under the intake and exhaust manifolds, no way to get a pic) Now for the first time I'm thinking that maybe it WAS a ACE engine, that someone used for a rebuild. Just happened to have it around for some reason. ??? (and happened to have a box of those bolts) Not that it matters...it's one good running, smooth running engine. I had assumed that someone had had it shipped from Chrysler Marine. I will have to do some research on those engines. It's possible that Chrysler Marine also rebuilt their engines, but I can't imaging them using a hodge-podge of those bolts.

 

Anyhow...wow Don, that is one well done clean dual carb application you have. Beats the heck out of mine, although I prefer the smaller carbs. Even so, yours is definitely "better". !! Your linkage is so nice. Did you fabricate that? I salute you, to say the least. My linkage, or the basic package came with the manifold, which is an Offenhauser.

 

All my tuning issues were very minor, I probably spent the most time getting my linkage to work to my satisfaction. For some reason it was real sensitive to return spring tension, and just where I put them. Too little and I had trouble getting my idle down, too much and I had to stand on the gas pedal. So I experimented quite a bit changing the geometry, you can see that on some of my levers I have multiple holes that I played with quite a bit. But it does work well and to my satisfaction now.

 

Again, BRAVO! That is NICE. That is CLEAN. I'm impressed. PaPa John, you go to Don for any further advice!!!

 

ken.

Edited January 26, 2014 by Lumpy

[Don Coatney]

I just looked at your pictures again and noticed several return springs on both carburetors. Did you use a flow meter to synchronize your carburetor linkage? Pictured below is the flow meter I used. This adjustment has nothing to do with idle or mixture adjustment. It only insures that both butterflies are in sync and flow the same amount of air by adjusting the linkage for each carburetor. I also had to add a stiffer return spring but I only use one spring connected to the linkage on top of the head and not to the carburetors as pictured below.

 

 

 

[Don Coatney]

Another question? You mentioned that you have a vacuum gauge for each carburetor. Not sure why but are you measuring ported vacuum or manifold vacuum? If ported what port did you use and do you have a vacuum advance distributor in this engine? And if you do have a vacuum advance how is it connected?

[Plymouthy Adams]

two carbs from the smaller flathead Studebaker as found in the Champion lineup has been reported as properly jetted from the factory to act as a matched pair of carbs for the flathead Plymouth....