Folks dig the 3x1...

Varilux

Well-known member
We attended our local Mustang club's first show of the year last night. Usually there are only a couple first gen Mustangs there, but eight showed up this time! As my son and I walked the show, I noticed 3 of the 8 were inlines and commented "Well, we aren't going to get any votes for being a six tonight!" Additionally, there was an unrestored '67 with only 28k miles on display- which I assumed would win our class (I think it came in on a trailer). Additionally, they had a 289 '65 convertible GT in original special order "Dusk Rose" that really stood out.

Anyway, as the night went on I was just amazed at how many people were interested in the 3x1 setup. Prior to installing the Offy, I'd get at least 4-5 comments per show along the lines of "When are you going to put a 302 in there?" In the two years the Offy has been under the hood, I can't recall a single comment other than "That is a really cool six!" and "I've never seen a tri-power six." At this show, I probably answered more questions than ever on the triple carbs, and had lots of "Kudos for not pulling the six" comments.

At the end of the evening, they awarded 3 class awards and 1 class winner to the first gens. They listed off the class awards, and we weren't on the list, and my son said "I can't believe we didn't get anything..." Then they called our name for the class winner!

I know there's a 3x1 build thread currently active, and all I can say is the 3x1 really seems to change people's perspective of the six! It certainly makes all the fiddling you have to do with the linkages worth it (now if I could only get that front carb's linkage to stop sticking... :^). If you've ever considered the Offy, go for it- it will definitely fill your conversation card during shows!
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They do…
"...lots of "Kudos for not pulling the six" comments."
is mine as well (Tri or not).
Keep'er goin bro! & congrats!
(y)
BTW: thnx 4 da pic, really like the paint choice
(4get 'dusy rose' - looks 'pink')
 
Gorgeous car. You certainly deserve that prize. Keep the six; keep the faith, brothers.
 
Howdy Varilux:

Very nice ride. Kuddos!! How about some more pictures of the engine- especially the linkage. Thanks, in advance.

Adios, David
 
How about some more pictures of the engine- especially the linkage. Thanks, in advance.

More than happy to post pics of the linkage- heaven knows it is embossed on my brain. It took all of a couple hours to install the head and hook up the fuel supply lines, but I've easily spent 80+ hours fiddling with the linkage to get it just right.

Here is the Offy setup plumbed and sitting on the bench (ah the innocence of that moment- little did I know the hours of frustration that were about to occur :unsure: ). In fact, I couldn't even lower the head onto the engine at first (because the front carb's fuel line caught on the A/C hoses).
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Issue #2 was also immediately evident. The front carb rod was unable to travel far enough forward due to the A/C compressor. Given that I do not have power steering, I would LOVE to figure out how to relocate the A/C compressor to the driver's side of the engine. It has been a constant challenge (e.g., had to adjust the mount to install the header). Solving the problem involved shortening the front rod of the Offy and relocating the compressor forward (there are two "Vs" on the pulley, so I went from using the front to the back- happily, this also solved a squealing issue I had).
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The next issue had to do with the angle the carb rods were held at. The kit caused a "V" pattern to the rods, which just didn't seem to work, plus it would have required carb linkage rods that would be <1" long (completely impractical). After some thinking, this was easily solved with some aluminum "U channel" from Lowes (its back where they have the metal rods and metal bars). The U fits perfectly over the rectangular pivot mount on the Offy adapter, and- with a couple of holes- you can put the pivots at whatever height you like. The linkage rods still needed to be exceptionally short, so I created them from the components shown in the last picture.
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At this point, I had things basically "working," but driving the car was VERY frustrating. The throttle activation bar (that long bar that goes from the gas pedal to the center linkage) just had to go for several reasons. First, the header interfered with the bar (it could not travel down far enough to allow the center carb to return to idle). With a single carb this wasn't a problem because I could adjust the linkage rod shorter, but with the Offy, the center linkage rod was already as short as it was going to go. The second issue is the extra return springs for the three carbs created an issue where the bar would try to "deflect" towards the passenger shock tower rather than push the throttle up. Finally, as the throttle was engaged, the bar would occupy the same space as the center carb's pivot. After messing with it for months, I finally decided to bite the bullet and convert to a cable throttle. I purchased a '69 gas pedal, drilled a few holes to relocate the pedal mount, and yes- this was definitely a better solution. Additionally, the mount for the rear carb's pivot (the U piece I had fabbed earlier) provided the PERFECT mount for the end of the cable. For the first time, I was really really glad I had installed the 3x1. If I could go back and change any part of the process, I would have converted to the cable throttle as I was swapping the head. It would have probably cut at least 75% of the time from this project.
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And that brings us to current status. The drive is just great- at about 60% throttle, you feel the resistance on the pedal increase and- assuming you push through it- you get pushed back in your seat as the secondary carbs kick in. The only remaining issues are the front carb slider keeps hanging up once the car is hot (really frustrating, because the idle will hang up at 2000 RPMs and you have to goose it to get it to kick down). I noticed there is a bit of some sticky stuff on the rod, but I think I need to take the "slider" (the part attached to the pivot that glides on the rod) off and smooth out the entrance holes a bit. The other thing is I cannot find a center throttle rod that is short enough (so I have fabbed one with some bar and clips- but I don't like the appearance of the clips and am worried they could pop off). I ordered a Ford tractor linkage that is 2.25", and it is so cloooose, but it really needs to be 2.00" in length. One of these days, I'm going to see if a shop can cut the center, and reweld it together.
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I am a rank amateur in the garage, so if you have ANY kind of mechanical prowess, you can easily do this project (and probably spend a lot less time doing it than it has taken me). As mentioned before, simply adding three carbs really changes the whole show experience. Just pop the hood up, and wait for people to start seeking you out to ask questions and make comments!
 
I notice that it looks like the fuel bowl vents are welded up on your carbs, is that something you did, and how is it affecting you accelerator pump operation?
 
Howdy Back Varilux:

And thank you, thank you, thank you. Great photos and great problem solving. I'm hoping you'll continue to take us along on your progress. 3 X 1s are the BOSS!

Please explain how you got the header and the AC pump to get along. Nice solution to move the AC pump forward for linkage clearance. Did that add clearance to the front of the header?

Why are you using the SCV with all three carbs? I seem to recall that you are using a distributor with a ported vacuum source for the vacuum advance?? What source are you using for the vacuum advance from the carb(s)to the distributor?

One more favor. I can't quite make out the accent strip on the side. One more photo please.

I can see that the choke valve and lever on the center carb. Are you thinking manual choke? Or??

This is an absolutely delicious project. Thanks for sharing and feel free to gloot all you want. You are my hero.

Adios, David
 
yes, my additional kudos, esp 4 some1 who claims to "not be a mechanic". U certainly have advanced to "Shade Tree Mechanic I" with this project.

I too am inexperienced (except for vehicles I've owned). U mentioned a small problem in drivability ("stumble" or something). Wondering if it's related to the shorter length of link to primary carb v the 2 end ones as seen in photo 1?
 
I notice that it looks like the fuel bowl vents are welded up on your carbs, is that something you did, and how is it affecting you accelerator pump operation?
When it was time to get the carbs, I ordered all three from a rebuilder in California (I'm sure I have the receipt if anyone wants the info). I described my project, and they said they knew just what I needed and would send out the set (which I think cost right around $850 for all three). I received them with the carb vents closed off, and everything seems to work fine. They used the "middle venturi size" (apparently there are three sizes available on the 1100). I should also mention that the head was sourced from a gentleman that goes by "1hotvega" on eBay. Apparently, he does a lot of inline six work (I've seen others here who have sourced heads from him). He used a head with the largest valves, with heavy duty valve springs, and he mounted the Offy adapter. All I had to do was hook up the carbs, linkages, fuel lines, etc. I've been really happy with the head he provided (after initial install, I blocked off the front and rear carbs, and just having the improved head provided a noticeable increase in power... in fact, I could swear the exhaust note was a bit lower).

I did have a couple issues with the center carb they provided, however. One of the issues was the carb they provided was for an automatic. For a couple months, I had an issue with the idle wanting to "hang open" for a couple seconds after letting off the gas- which was really annoying. I finally compared the new 1100s against my previous carb, noticed the center carb had an extra lever, did some reading, and discovered it had a dashpot (which I understand is usually found on automatic trans cars). I disconnected the dashpot, and no longer have the issue.

The "stumbling" I encountered was during braking. When coming to a hard stop, the car would stumble and sometimes stall. I finally took apart the center carb and discovered the float setting was way too low (which caused the needle valve to close too early resulting in very low levels of fuel in the bowl). When I was braking, the fuel would slosh away from the pickup tube and the car would stall. I reset the float, and that problem is completely resolved. I would very much like to find 2" throttle rods. As mentioned, the shortest I've found are 2.25" from a Ford tractor (which are slightly too long). If anyone knows of a super short throttle rod, please shoot a link my way!

The center carb also came from the shop with a choke- but there was no way it was going to fit on the Offy adapter with the choke spring housing on there. So, I took the housing off and used a spring to hold the choke open. I would VERY MUCH like to hook up a manual choke, and someone on another forum posted a really cool manual choke conversion kit for the 1100- but did not provide a link. If anyone knows of a good manual choke kit for the 1100, I would be eternally grateful! The weather rarely gets all that cold in Dallas (and when it is, I'm probably not driving the Mustang anyway), so the choke isn't really all that necessary. However, it normally does take a minute or so for the idle to even out once I start the car.

It appears as if there are SCVs on the front and back carbs, but the ports are closed off behind the valve- so they aren't doing anything. The center carb appears to be a later 1100 that does not have threading for the SCV. I draw vacuum from the manifold (there's a small square bolt that can be removed- that's where I'm drawing vacuum from).

So what's next? Well forced induction would be way super cool- but I believe the fabrication / installation of such a system is WELL beyond my technical abilities (that would be Shadetree Mechanic 3.0 :^)! The garage that installed the clutch was amazed at how well the 3 carb setup seems to work in my car- no real issues at idle once it is warmed up, and you can really feel the kick when the secondary carbs come on (knock on wood).

If you want to hear the car run (and don't mind some Joe Walsh along with it), there's a video of my car at this link (about mid-way through I get on it a bit- sounds kinda like an old Jaguar to me): https://www.youtube.com/watch?v=zwoxE4JZaeE
 
thats a nice triple carb congratzz,, i love the triple carbs,i got build one of myself. a vieuw years back i post alot pictures here
on this forum bubba was a great help for me,
greetzz from the Netherlands JD.

(watch the links below if you like it)
 
"...greetzz from...JD…."
welcome back, good 2 C U again.
What do the locals think of the triple?
How bout the American Metal (stang I should say)?
 
Please explain how you got the header and the AC pump to get along. Nice solution to move the AC pump forward for linkage clearance. Did that add clearance to the front of the header?


At least in my case, the #1 tube of the header needed to go right where the rear edge of the compressor was mounted. The "fix" involved modifying the A/C bracket (which is rather large and provides a mount for both the compressor and the alternator). You have to cut the bracket and weld in a section to move the compressor out towards the fender (towards the battery). As I recall, you just have to move things about 1.5" or so. At first, it also appeared that the starter was going to interfere with tube #6, but we were eventually able to get it to fit by simply elongating the mounting bolt holes on the header flange (you just need to move it forward about 1/4" and it fits perfectly).

Not quite sure which accent stripe you are looking for a picture of- just describe what you're looking for and I'll post another pic.

Thanks,
Pete
 
I hope it performs as good as it looks. Very nice.
 
Wow, very nice. Just a few comments/questions.

1) it looks like you are actually drawing ported vacuum off the side off the center carb, but you said you were drawing off the intake manifold so where do you have the ported carb line going?

2) I'm struggling a bit to totally understand the issue you have with the short length of the center rod to the carb... one thing I notice a little different postion-wise on your setup vrs one I used to run is the center "inverted V" linkage piece on your car doesn't seem to start from a vertical position, yours starts a bit "pulled back" so you would need a shorter center rod up to the carb and would potentially have less motion to pull back to wide open throttle? On mine all the pivots including the center were very vertical and I was able to use all three of the carb rods that came with the Offy linkage. Not sure why the difference here. I ran an Autolite 1100 in the center and a Holley 1904 at each end but that shouldn't make any difference.

Scott
 
Hello Pete,
As mentioned thanks so very much for all the pics. You've certainly been a big help and inspiration to me thus far. Well deserved award, and your boy is one lucky kid!

My 3x1 is on hold while the tub gets redone, but I've decided to use the time to build this 200 block I have. I need to find the specs for the acceptable tolerances in the cylinder bores, crank journals etc first and foremost. I have a glimmer of hope that the guy was telling the truth and it does have low miles, just developed some sludge. Maybe I'm just a dreamer ;) but if we weren't, we wouldn't put multiple carbs on a six now would we?

I think I will also look up 1hotvega and have him build a head for me and attach my Offy adapter. Quite sure he's a member here but cant remember his username.

Jeff
 
If memory serves me correctly, I think he's cleverly hidden as "1hotvega" on here. He's usually got 1 or 2 heads for sale up on ebay so maybe try pinging him through there too. :beer:
 
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