My Willys 3A and 3B Community
3A, 3B, DJ Technical Knowledge Base => "Modifications"-- Technical Questions, Answers, Incites => Topic started by: garage gnome on March 03, 2013, 09:01:41 PM
-
I decided to finally do this mod I've been thinking about to my '53, dual carbs. I had two YFs and plenty of time. So here it is. I got two YF repop air horns that I'll tie into the original air cross over tube.
http://www.youtube.com/watch?v=sUMFx9gbDIQ
(http://i748.photobucket.com/albums/xx125/willyscjmj/4DF7928D-6A7C-4244-8503-4821D5E64269-5421-00000DA15E58442E.jpg)
(http://i748.photobucket.com/albums/xx125/willyscjmj/DCDA3A0F-9374-4A37-AFB7-A4E19D9A46CE-5421-00000DA5A35A815C.jpg)
(http://i748.photobucket.com/albums/xx125/willyscjmj/IMG_1236.jpg)
-
Hmmmm I'm surprised no one responded to this here. Anywho, I hooked up the choke and throttle cables. The chokes work perfectly together. I was running it again today and I noticed that when I revved it up, the engine rocks the jeep side to side a bit. I really think the lead came alive with this. I can't wait to put my OD back together and take if for a test run!
(http://i748.photobucket.com/albums/xx125/willyscjmj/D24611E9-5FE2-410E-BCEC-1760F39934B2-6045-00000E97333C7787.jpg)
-
I like it ! Details on how you did it ?
-
Nice setup Nate. You might want to think about running the fuel supply line over the top of the fuel filter to keep from having vapor lock issues. It's best to keep fuel lines as far away from the exhaust manifold as possible.
I will be interested if it increases the power output and acceleration or will it bog out if the throttle is opened fully at take off. Keep us updated.
Have you thought about making progressive linkage for the carbs?
-
The thought of a progressive linkage did cross my mind, but I decided to keep it simple. The fuel line is pretty far away actually. Is no different than where the float bowl of the WO would be. The fan also blows a nice breeze by it too and out the rear hood gap. ;)
Kenny, I traced the gaskets to make my flanges and just cut some tubing with 45s on the ends. Putting the equalizer in was the hardest. You have to keep the two block flanges in the same plane as well as the carb flanges. I also used an Fhead exhaust manifold to keep it clean looking.
-
Gnome - I haven't posted mainly because I'm not that smart a mechanic (I'm still at the "Put Tab A into Slot B" level) and wasn't even sure why someone would put 2 carbs on the engine?? :P I guess it's more power, but wouldn't that just red line it all that much faster?
Sure looks cool tho!
-John
-
Yes, the reason is more power. But how does it make more power? Well, its not the delivery of more fuel, that would cause the engine to run rich and that would be bad. This is the gist of it. This allows the engine to breath better. It all has to do with these things called venturis, where the fuel and air mix and the amount of air flow. Try only breathing through a straw only while running or exercising. You'll notice it is rather difficult to keep up with the air your body needs. Same principle applies to an engine. By letting more air flow easily, you will have more performance. This is also why people put 4 barrel intakes on V8s and yank off the 2 or 1 barrels. The engine gets all choked up.
This is a very simplified explanation. There are a bunch more factors and such that I know a little about from working with my hit and miss engines. It is all very complex.
One other thing I noticed too is, it starts much better too. It started great before, but it is even better now! Usually when it is cold, I'll have to choke it and leave it half choked with the throttle on a bit until it warms up. However with the two carbs, I choke it all the way and it fires right up as soon as I turn the key and I can turn the chokes off all the way and it will stay running. �:o Then when it is warm, I can turn the key and it will fire up right away. Just the way I like engines to start. �8-)
-
Do you have two choke knobs to pull or did you somehow link the chokes?
Did I read it right the manifolds are straight tubing with angle cuts on the ends? I'm surprised you didn't get a couple of u bends and make a curved manifold. of course we all know this is just a prototype for the new polished cast aluminum dual carb setup you will be offering the discerning flathead owner soon. ;)
Nice work Nate. I still think you need to paint the lettering on the head for even more power.
-
If you look closely, there is a piece of wire between the two carbs and at the second one, you can see the choke cable sticking out. At the rear carb, there are two pieces of wire going into the cable clamp for the choke.
Yes, the tubing is cut and 45s and welded to make a 90. I thought about a bend, but it is so tight there that I don't think it would have worked. Haha, I don't think I'll be getting aluminum ones made anytime soon. ;D That would cost a small fortune I think!
But my engine is Pontiac blue! That is better than Chevy orange! :P
-
GG - thanks for the explanation. Makes perfect sense. Now I are a little undumber.... :D
-
Nice work Nate. I was thinking the same thing as Carl on the fuel line and manifold heat.
I want to see your air horns.
Tim
-
I finished the air horn today. I'll take some pictures once the paint has finished drying.
-
Here's the air horn. Nothing too technical. Just two Fhead air horns welded together and a piece of old cross-over tube sticking out.
(http://i748.photobucket.com/albums/xx125/willyscjmj/12407011-4B69-46C0-B6CC-29734B246518-6593-00000F8F253267DB.jpg)
-
This is one of the coolest projects I've seen here. Can't wait for the test run video.
-
Me too! I'm hoping I can this weekend. The machine shop said my OD shifter forks should be done sometime this week. Hopefully it will be cold this weekend and my road will be frozen.
-
Nice man, can't wait to see how it runs!
-
Hello GG, It never even occurred to me that that might be possible. I have run many multiple carb rigs on big block Pontiacs and small block Chevys, but never through an oil bath air cleaner. Can't wait to see how it performs. Good Luck
-
Thanks guys!
I like to try ideas that are totally new and out of the box. I also try to make them look as factory as possible and if I want to switch back to original, I can very easily. None of my oem stuff got modified. I was the first one to build a flatty with a coil spring suspension. Now some people are doing the mod. Maybe more will do this?
This jeep has taken a severe turn. I wanted to make it the best, most original jeep around. Durning the project though, I upgraded brakes to 10", put in 12v and turn signals. Then after I drove it for a while, I did a dual mc conversion and OD. But then I upgraded to a supersonic head and now this. I honestly think the ole Lhead came alive with this one. It's kind of becoming my hot rod so to speak.
I do love the looks that the Pontiac tripowers give to an engine!
-
Here it is all completed! Now if my OD was fixed... �>:( If I do say, it looks like a factory piece!
(http://i748.photobucket.com/albums/xx125/willyscjmj/FC8837F3-DF1F-44AF-BE12-BC0079A13A70-6973-0000106124D01BCA.jpg)
-
Awesome! Love the horn setup.
Tim
-
Thanks Tim!
-
That air horn setup looks completely and totally stock. Great job.
-
So are you going to put that engine on a dynamometer?
We need to know if dual carbs will up the horsepower of the L-head to match the F-head. :)
That 72 HP F-head is a real powerhouse. ;)
-
(http://i1075.photobucket.com/albums/w428/cbnichols/IMG-1.jpg) �
This is the last small block I used to play with late at night on the edge of town 8-). �If you decide to take a look at a progressive linkage, I got my parts from a place called HotRodCarbs.com. �Check out his web site if your interested. �He can hook up anything from the old Man-a-fre 4 carb setup to six 2 barrels so he should have something for your two. �I'm getting that old feeling back that usually means I WANT more carbs!! �Standing By, Terry
-
Nate, that did turn out really nice-very sanitary. Before and afer dyno tests would be even nicer.
You do realize you are now on that slippery mod slope with your stocker!!
My last venture into multiple carbed vehicles was a long, long time ago with a 60 ElCamino and the 350 hp version of the 348 that we had warmed over with 12:1, wicked solid lifter cam, and a balance job. Ran pretty good for a rather heavy vehicle.
These days, I think fuel injection is a much better option, especially for an off road vehicle.
-
Yeah, the dyno would have been nice. I really don't want to change it back. ;)
Don't worry John, it won't be getting any more modified than this. And it isn't stocker. I had a few mods before this. ;)
-
Don't worry John, it won't be getting any more modified than this.
Famous last words. ;D
-
Ok, ok, maaaybe it won't be the last mod I do to it. I'll probably leave it like this for a few more years until I get the urge to tweak something else that could be improved or given the cool factor. 8-)
-
Seems to me your next step would be a turbo. :o
Or maybe switch the whole thing over to fuel injection. ;)
-
Nah, that stuff is too complex. ;)
-
[size=24]Tomorrow...[/size] duhn duhn duhnnnnnnnnnn......
I will be able to take it for its first test drive!!!!!!!!!!!!! [smiley=2vrolijk_08.gif]
-
Ok, so I took of for a little test run down our driveway and up the road. I noticed a difference. I cannot recall if I could take off from a stop in second gear, high range before. I tried it and it didn't mind it. I can take off in 1st with just a little above an idle. I know with my '49, I have to rev it way up to take off in 1st high range. I can't remember how high I used to have to rev it up. I'll really know how much better it is when I can really drive it up some hills and on a flat road.
-
I took it for its first test run on Monday. I noticed a difference right away. It had better power and got up to 55-60 easier (even though I had an issue). A lot less screaming from the engine too. I had a couple problems which I had to work out. I wasn't getting wide open throttle, so I modified the linkage yesterday. I'll see how it does today afternoon. Hopefully, it is much better!
-
Took it for another ride and I love this mod. I'm not sure how my wallet will like it though. ;D It seems to be about the same on gas though. I'll see. There is this one show I go to and I fill at this one gas station when I leave. By the time I get there, I have about an 1/8 of a tank left.
I have never driven a jeep with an Fhead, but I would say this Lhead will give one a good run for its money.
-
I know a progressive linkage came up earlier in this thread. On my 327 I could go anywhere on just the center carb with 280 cfm but when I punched it and brought in the end carbs we went to 840 cfm and the race was on. The end carbs had their idle circuits all plugged up so they basically just dumped fuel. From what you have written though, on the Lhead much of the benefit of the extra carb might be on the low end of the power curve so maybe a progressive linkage wouldn't help conserve that much gas. I have a second carb and intake manifold standing by so keep reporting on what you find. Are you just adjusting the idle mixture and speed on the original carb?
-
What do you mean by original carb? I'm not using WOs, I'm using YFs. The intake is a custom piece, I didn't use the original one at all. I am adjusting the air/fuel mixtures on both and the rear one sets the idle.
-
Gotcha. I shouldn't post things at 2:11 A.M. Got carried away with the whole idea and the results you are getting from it. I could just sell what I have and be ready to buy the "kit" when you have it on the market :).
-
I'm in love with this mod. A huge difference in power. I finally finished tweaking it so it is just right. I'm going up hills in 3rd gear where before I had to shift into 2nd. I got it up to 65 mph too! What a big difference!
I'm going to wager it has the same or more HP than an Fhead.
-
Just a random thought. I wonder if a 2 barrel carb would accomplish close to the same upgraded performance?
-
If you are thinking about the 2bbl Weber Kit from Quadratec, I would say not. Why? Well, it uses the stock intake and exhaust manifolds. The intake still chokes air flow down to the stock WO size where the carb base is. It is like having a piece of 2" pipe, that restricts down to 1/2", then back up to 2".
The Lhead exhaust manifold is inefficient. The heat riser flap is a huge air block and it is not as smooth flowing as the Fhead one, which is what I used. I read on JP magazine's site that the Fhead exhaust manifold is one of the most efficient designs.
These are the things I noticed while I was comparing the parts side-by-side.
Plus, I am running a decked supersonic head and electronic ignition. I didn't drive it after putting the supersonic head on (did that early winter), so I don't know how much that helped.
-
So Nate, �after a month or so, what is the verdict? � How * is it?
zeke
-
I love it! I think I might be getting the same or better MPG too.
-
Excellent.... Do you have any pics of the intake when it was unassembled? Like I might want to steal your design if you are not gonna make some for sale?
Zeke
-
Are you an experianced fabricator with some machining experianced? If not, I would not recommend doing this mod. There are lots of places for vacuum leaks to form and alignment is a big issue.
To answer your question, the pictures I have in this thread are all I have.
-
Thanks, let me know if you decide to mfg them.
Zeke
-
Sweet Mod Nate
-
This is one of the coolest projects I've seen here. Can't wait for the test run video.
Me two...No pun intended ;)
-
Nate: what did you use for your flanges on the block? Just got my block apart and may want to fool around a little with dual carbs, have 2 WO's (I think). Thanks!
-
Traced the gaskets on a piece of steel and cut with a plasma cutter.
-
Would be interesting to find a way to compare your dual carb setup to the Weber 32/36 progressive 2 barrel I am planning. I'll be using an aluminum manifold made from 2) aluminum pipe elbows and an aluminum box milled out of a small block of aluminum. I am also building a header for the engine and will have the header flange (going to be 3/8" T) pass over the intake ports and the Intake manifold will bolt to it to make it easy for the two different metals to expand. Instead of trying to use one bolt to hold two different metals. I'll be running a fresh air intake system that will put the Air cleaner ahead of the raditator just below the hood. I'm working on some sort of high water baffle or possibly a way to reroute the air intake for deep water.
I love how clean and simple your dual carb setup is. VERY Hot Roddy
-
I like it! It looks pretty stock too.
-
It is two year later. Does it still work? Have you made more? Will you make more? Am sure there are a lot of us who want some additional power but don't want to butcher their Willys.
-
I gave up on the dual WO's. I could not make Ted run right on them. The dual YFs on Red jeep work great still.
-
Lost something. As I was trying to say, I am sure there are a lot of us who do not want to replace their go devil engines but want some more power. What do you recommend?
-
On my red '53, I put supersonic head and dual YF carbs from an F head. That makes awesome power and have no complaints.
On my '49 3A, Ted, I put dual WOs after rebuilding the engine. I could not get that one to run right. I made new jets and converted the oil bath air cleaner to a paper one. I went back to one and put the oil bath back together. I wanted to use WOs because of how they can be cleaned on the trail.
-
Henry J's had the same engine with the Super Sonic head and they had a 2bbl carb on a manifold designed for the 2bbl carb.