2 into 1 Manifold

[Doug79]

I'll tell you from talking to him he runs a 36 on his xs. Not saying you can't run a 38, but it might be a bit big.

when you said a 38 might be a little big I was looking at the bike and the down tube looked too close to the cylinder head so I got my tape out. As near as I can tell, the down tube is 4 1/2" from the carb mounting surface. The stock carb is 4 1/4' long that leaves 1/4" for an intake manifold. obviously a no go. This is 79 Special 650, is there something different about this frame? I can't see how any manifold/carb combination is going to fit without replacing the single down tube with a BSA type dual tube setup. Man, it's always something. Fortunetily I haven't purchased anything yet and won't until I get this figured out.

 

[figure8]

when you said a 38 might be a little big I was looking at the bike and the down tube looked too close to the cylinder head so I got my tape out. As near as I can tell, the down tube is 4 1/2" from the carb mounting surface. The stock carb is 4 1/4' long that leaves 1/4" for an intake manifold. obviously a no go. This is 79 Special 650, is there something different about this frame? I can't see how any manifold/carb combination is going to fit without replacing the single down tube with a BSA type dual tube setup. Man, it's always something. Fortunetily I haven't purchased anything yet and won't until I get this figured out.

Sorry, what I meant was the carb may be to big to properly run the engine. Some people on here have tried running vm38's on an xs with not great results. However, running a single carb may negate that issue. Sorry for the confusion.

 

[Doug79]

initally i knew what you meant. but it got me looking at the bike and that is when I noticed how little room there is for any type of single carb.. Hopefully, I'll be smarter after I talk to Wes at counterbalance. However on the other side, if i'm not mistaken, the engine now runs with two 38mm carbs so it seems to me that running both cylinders with one 38mm card should work..Just thinking out loud.

 

[weaselbeak]

Running 2 38s, yes, but those are CV carbs. VM38 is a slide pull. Big difference.

 

[Doug79]

AH, I see I have more reading to do..Thanks

 

[schioler]

I have a 2 in 1 manifold The bike runs good
But at low reps its rough. I Would not recommend a 2 in 1 if your in The City - its for The highway

 

[chizler62]

Interestingly I've just dove in looking around for a 2 into 1.
Anyone purchase one of these? I would build you one for free to see it in person?

 

[chizler62]

 

[CoconutPete]

The one from Counterbalance looks to have a small difference in run length between the distance to each cylinder from the carb.

That one looks to have a HUGE difference in run length.

 

[Doug79]

Home made and has been coated but not tested. It will run a 389 [TR-6] series Amal carb. I was uncomfortable with unequal runner length that I saw on the manifolds for sale. The frame had to be modified to use this so I really hope it works.

 

[figure8]

Home made and has been coated but not tested. It will run a 389 [TR-6] series Amal carb. I was uncomfortable with unequal runner length that I saw on the manifolds for sale. The frame had to be modified to use this so I really hope it works.

Can you post a pic on how you modified the frame?

 

[Doug79]

I just boxed out the down tube. The second picture shows how the frame mod. is covered by the side covers.
P.S. I did save the down tube piece just in case my back yard engineering proves to be flawed.