Why the need to change?

[JTT3]

Surfing the web looking for an aluminum intake and chanced upon this. Measurements are good. So why?

[Wayne Sheldon]

To put in a larger generator, or one with maybe an oil pump behind it.

[Wayne Sheldon]

It would really mess up the "Y" flow pattern. The number 3 and 4 cylinders would run stronger and richer than cylinders 1 and 2. If someone wanted to do this for some reason, it would work a bit better if the triangle "Y" was turned end for end to compensate somewhat for the change in flow distance.

[Wayne Sheldon]

That of course would require turning the bottom piece around.

[Jerry VanOoteghem]

Some folks feel that 1 & 2 tend to run richer than 3 & 4. Maybe this was an attempt to "correct" that?

[Wayne Sheldon]

Jerry V, Interesting idea!

[DHort]

why take a chance. call Langs or Snyders

[ThreePedalTapDancer]

On the other hand, I would guess that it was to provide more clearance for an oddball magneto adapted to a Bosch front plate unit or similar. The DU4 already is pretty close to the manifold, other larger magnetos would probably touch. But definitely for something being driven on the side of the engine that was touching stock manifold.

IMG_2791.jpeg (98.4 KiB) Viewed 2746 times

[Craig Leach]

My thinking is that the 1-2-4-3 firing order is off so far that the manifold is of little concern. No modern inline 4 cylinder engines use that
firing order????? I may be full of bravo sierra but I thought that firing order of Winfield's 2 up 2 down had much to do with firing order?
Craig.

[38 coupe]

With the typical four cylinder crankshaft for balance reasons cylinders 1 and 4 are opposite in stroke to cylinders 2 and 3. All options for firing order has cylinders 1 and 2 fire next to each other, and cylinders 3 and 4 fire next to each other. Any inline four with a normal crankshaft and only two intake ports is going to struggle to have identical charge in the adjacent cylinders (1 & 2, 3 & 4). Modern engines deal with that by having individual intake passages for each cylinder. The 2 up, 2 down method achieved alternating intake pulses for more even intake charge, at the cost of horrific vibration acceptable only in a race car.

[Les Schubert]

My 2 up 2 down crank (and cam and rods). If you look at the counter weights vibration is not likely to be a problem!

[Les Schubert]

Another solution to the limitations of the T firing order. I have had great success with!

[Craig Leach]

An other way to accomplish this. http://www.nwvs.org/Technical/MTFCA/Art ... eRacer.pdf
http://www.youtube.com/watch?v=5bnTC7WXsGA
Craig

[Les Schubert]

Craig
I’ve thought about doing that by chain driving the camshaft

[ModelTWoods]

Another thought: Was/Is this manifold advertised to be an aluminum intake manifold (if that is what you are seeking)? It looks like whomever modified it cut it and reassembled it using brass to braze the pieces together. You don't braze aluminum. You can braze cast iron, and sandblasted cast iron can give the appearance of aluminum. I saw this on EBAY when it was first offered and thought the same thing as others; someone modified this manifold to move the carburetor further back. i didn't think about it upsetting the flow characteristics, but I'm sure that's true.

[Craig Leach]

Hi Les,
That's a good idea but wouldn't the sprockets have to be rather small so the chain would clear the casting hump? I seen some of Kurt Wrights
antics making a 6 cylinder model T engine. Could you reform a cam to fire 1-3-2-4 or 1-4-2-3? leaving the ports the same. Or even cut it & turn
the cam around so it turned backwards? Then swap the ports? Then add Multi-Lifts. Just food for thought.
Have a great day.
Craig.

[Les Schubert]

Craig
If you don’t run the generator, then it shouldn’t be a problem. I have too many other projects so I won’t be doing it.
Have a great day