A Change of Plans; Engine Plans, That Is

A couple of weeks ago, I told the story of how I went down every trail I could find in attempt to find plans for an engine I wanted to build.  It's an inline four cylinder from a 19-teens tractor called a Holt 75.  I thought it looked cool - I have a video of one running  This is the picture I took of one in 2015 that got me searching for the plans to build one. 

The conclusion of that story is that the plans were copyright to a company called Coles Power Models that's no longer around.  I concluded by saying that I ran across references to another inline four cylinder engine called a Panther Pup (video from the NAMES show in Detroit at the end of April) and bought the plans from Little Machine Shop. 

In the intervening weeks, a chance at the plans for the Holt 75 has resurfaced.  It's a bit of a story, but a model maker on the Home Model Engine Machinist's Forum bought the prints some years ago and built one.  Before he started he found other builders and asked them what the trouble spots were in the plans and then he improved on them.  He has gotten approval to sell his upgraded prints and is working on improvements to the engine.  The model pictured above uses castings for the intake and exhaust manifolds, at least, and I believe these new plans will replace them with manifolds made entirely from bar stock.  He expects to have his prints available "August to September", which I read as "next fall". 

Given that, I decided to put the plans for Panther aside, and instead build the Webster that I was originally considering for my first internal combustion engine.  I intend to follow the Webster with the Holt 75.  Do I build the Panther Pup or sell the booklet?   Don't know.  No harm keeping it for now.

Between last night and today I've begun the process of sourcing parts to build a Webster.  I haven't bought everything, but between what I have and what's on order, I should be able to get a good start on it before I need to get more materials.  

YouTuber PatPending's Webster. 

The Webster is the most often recommended design for a First IC Engine.  Which isn't to say that I don't expect to make mistakes, just that the design is supposed to be fairly simple and forgiving.  I actually could have made my Oh-Fish-Ul first part for the Webster today; it's just cutting a piece of 1/2" steel rod to length for the crankshaft.