Jerry Hey wrote:
I spent about 5 hours trying to chop down the 2 inch 180 degree sweep.
The plan was to cut a section out of the bend which would cause an out
of round condition which I would repair by welding in material and then
grinding to get back to round. It started out well and I soon had the
two inch runner hugging the top of the engine. The problem came when I
could not quite maneuver the tig torch far enough into the tube to
deposit material as far back as needed for fairing out the new radius.
It would have been so easy to do with J & B weld (J & B whiskey
would have also come in handy) but the last step of welding the two
halves back together prevented that. I will spare you the details. I
abandoned the effort as a no go.
So where to go from here. I see three possible solutions. One is to
use a smaller diameter intake runner. The 1.5 o.d. runner has a 2.5
radius and would fit nicely. There would have to be a reducer with an
internal taper to connect up soothly with my 2" o.d. throttle bodies
but that is not a big deal. The question how does that size runner
effect performance? I do like getting the fuel to the cool side.
The second possibility is to use the off the shelf 2 inch bends and
lean them over. As you said, I only need to lean them 20 degrees to
get clearance. However, to lean them even 20 degrees, I have to either
cut down or relocate the water pump. I have wanted to cut down the
water pump anyway just on esthetic principles. But this solution may
not apply well to other installations especially those that need to lay
down the runners a lot further.
The third possibility is the Russell Manifold. It is starting to look
better all the time.
In looking for a solution, I would like to choose one that works for
every application and not just mine.
To me, if the 1.5 inch runners will work, then that is the way to go.
If not, then the Russell manifold would be the second choice.
I do want to ask about the possibility of a carbon fiber 180 degree
bend. I am thinking of something we can clamp the straight aluminum
legs into. Is this feasible?
Jerry
I agree with you on the Russell manifold and I am doing further work on it.
Hopefully I can get the plenum box straight up and down. Hang on more to come.
BTW To calculate the center line length of a 3 inch center line radius bend
multiply the angle by .0524. For an example a 45 degree bend center line
length would be 2.356 inches long.
BTW jerry cut down the length of the TB's as every little bit helps.
You don't need the hose barbs on the the prototype since the manifold
is under vacuum almost all of the time. All you need is 5/8 of an inch
hose barb.
Paul Lamar
This is it. Uses a 6.5 by 4 by 4 Zero box with alternator flapper.
Bends 45, 180, 90, degree front tube.
Bends 20, 90 degree back tube.
Move the starter up as far as possible.
Adjust the length by moving the whole works closer or further
from the engine. You can also adjust the length by moving the
plenum forward. Moving it aft is not possible.
The neck bone is connected to the back bone and the back bone is connected
to the hip bone etc., etc., etc., so don't make any other changes.
Everything fits under the stock cowl.
Current length is about 20 inches.
Paul Lamar
This is a breakthrough in intake manifolds. we have been fighting over the
top for years. All made possible by the P-port. This will probably even
fit in a Lancair 360.
Thanks Russell.
Paul Lamar
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