John Laudano's Carburetor

 Thank you again. I built one. Next will be the rest of the engine.

A few photos are attached.

John

On Monday, October 7, 2024 at 09:01:57 AM EDT, John Laudano <john.laudano@att.net> wrote:

Thank you Allen. 

the world misses guys like your dad.

John

Missing dimension on Throttle plans?

Q: Hi Allen.  I recently purchased plans for the 2 Jet throttle carburetor.  On page 2 in the front view, hole # 5 & 6 I need a location for.   I couldn't find it on the drawing.  Is #6 hole for the set crew for the spray bar?  I understand that the carburetor can be enlarged for bigger engines.  What formula do I use to enlarge it for a 2 1/2" bore slow speed engine?  Thanks for your reply - Norman Stauffer



A: Hi Norm.  If Dad were still alive, I'm sure he could definitively answer your questions.  I was a computer programmer/analyst by trade, but do have some mechanical skills, so I'll give it a try:

I believe hole#5 location is shown in the "Left Side View", the center being .270" from the top, and .505" from the bottom.  Hole#6 is simply aligned with hole#5 and drilled all the way thru.

I must admit these plans are a bit of a challenge to visualize because of the odd shape, plus all the holes and passages.  I surmise that once you build the main "block" and drill the large cylinder holes
that the smaller holes and details will be easier to ascertain.

To answer your last question, according to paragraph 2 of Dad's construction notes, the throttle bore should be 25% of the piston diameter, so for a 2.5" bore engine, the throttle size should be .625

Hope this helps...

Allen

Throttle hole dimension question

Malcolm from Great Britain had sent me an email question about the 2-Jet throttle plan pages included in the V-Twin plans:

Q: On sheet 27 left side view there are 2 holes .100. from top and .570 from top and .265 from right hand edge.
I can't work this as to size, depth, threaded etc.  Can you help me with this?



A: Hi Malcolm.  Page 27, looking at the "Left Side View", I'll call the top hole #1, and the bottom hole #2. These are the two holes you inquired about .

For hole#1, the dimension reference is shown to the left of the "Top View": Drill .070 thru and tap 2-56.  Looks like you drill until you "T" into the larger .140 hole at a 90 degree angle.

For hole#2, the dimension reference is shown to the left of the "Front View": Drill .043 dia into fuel inlet, then drill .070 dia x .200 deep and tap 2-56.

This may sound childish, but try cutting out the Top View, Left Side, Front View, and Right Side, then tape them together to form a basic 3-D model, then I think it will mentally come together much clearer.

Hope this helps...

Jerry's Original "Howell" 2-Jet Throttle

"It is small in physical size, very adjustable and not nearly as difficult to build as it looks. The configuration and size of mounting flange (or a spigot) at the base of the unit is easily modified to suit your engine requirements. The two threaded holes at the top are for mounting an air filter (included in the plans) if desired. Otherwise, a trumpet shape velocity stack may be used instead - or your own special treatment." - Jerry Howell