Jason builds a plane

it's the little things that count

11/3/2018

0 Comments

 
It's safe to say that any flying machine is a collection of parts that are strategically placed and assembled to enable one to fly.

​Although this is true, it's the little things that get accomplished over the course of a building project that make the difference in not only getting the plane built, but improves the overall quality and performance of the end product.  It also contributes to the philosophy I spoke of last August on my blog: ( a-little-here-a-little-there).

​
​Today I decided to pull out the Corvair heads and have a closer look at them.
​
​You might recall that these heads are 110hp versions from a 1966 car.  They are just as I received them from the seller - not filthy but certainly not clean either!
Picture
Picture

​Any engine that is more than 50 years old is bound to be grimy.  Air cooled engines like the Corvair have many, many cooling holes factory cast in between the head fins.  Being small, they trap everything.  Not good as the GM engineers counted on these being clear for optimum cooling.  What the GM engineers didn't consider is that casting aluminum or other metals sometimes leaves "flash" where the moulding halves join up during the casting process.  Either it was considered to costly to remove the flash or maybe they decided it was good enough.  What I have experienced however is the massive range of acceptable "flash" tolerances - some heads have so much the cooling holes are almost closed over.  With a small amount of dirt in there, they are effectively closed to cooling air.

​Here is a look at the cleaner of the two heads.  I've put a lightbulb behind to ease the viewing:

Picture

​As you can see, the cooling holes are many and this head seems quite good.  Some minor flash to clean up but generally good.

​The 2nd head, despite being from the same casting lot as the first is terrible! I could only find one hole that was clear and even then it was almost closed over from flash:
Picture

​


Took an hour with a combination of small files and old steak-knives, but I managed to clean out the majority of the gunk from the cooling holes. 

Picture
This picture really shows how much flashing can be removed from the holes, maximizing air flow and therefore cooling capacity. It also shows just how grimy this head is.... yuck.
Picture
Here is a picture about 10 minutes into the process. Lots of cleaning and flash removal to be done.

Both heads really do need a good pressure wash before I'll be able to remove all the flashing, but this was a good start.  Removing the flashing is very important and goes a long way to improving cooling of the heads.

It's these little things that take time, but make a world of difference and counts towards the goal.  Along those same lines, my father Jim and I have been working on an important submission regarding my mentor Barry.  I don't want to say much yet but it's a little thing that also counts for something.   Stay tuned for more on this shortly.
0 Comments

    New here? Try starting at:

    blog #1

    Author

    Husband, father and 911 dispatcher.  Long time pilot with a licence that burns a hole in my pocket where my student loan money used to be.  First time aircraft builder. Looking to fly my own airplane.

    Categories

    All
    Airframe
    Airport
    Avionics
    Decisions
    Engine
    Interior
    Keep Looking
    Mentor
    Milestone
    Mission
    Motivation
    Paperwork
    Philosophy
    Priorities
    Scrounging
    Tools
    Ultralights
    Welcome Aboard
    Workshop

    Archives

    January 2023
    December 2022
    November 2022
    October 2022
    September 2022
    August 2022
    June 2022
    May 2022
    April 2022
    March 2022
    February 2022
    January 2022
    December 2021
    November 2021
    October 2021
    August 2021
    July 2021
    June 2021
    May 2021
    April 2021
    March 2021
    February 2021
    January 2021
    November 2020
    October 2020
    September 2020
    August 2020
    July 2020
    June 2020
    May 2020
    April 2020
    March 2020
    February 2020
    January 2020
    December 2019
    November 2019
    September 2019
    August 2019
    June 2019
    May 2019
    April 2019
    March 2019
    February 2019
    January 2019
    December 2018
    November 2018
    October 2018
    September 2018
    August 2018
    June 2018
    April 2018
    March 2018
    February 2018
    January 2018
    December 2017
    November 2017
    October 2017
    September 2017
    August 2017
    July 2017
    June 2017
    May 2017
    April 2017
    February 2017
    January 2017
    December 2016
    October 2016
    September 2016
    August 2016
    July 2016
    June 2016
    May 2016
    April 2016
    March 2016
    February 2016
    January 2016
    December 2015
    November 2015
    October 2015
    September 2015

    RSS Feed

    build log

    Item Hours
    Engine 39
    Tail 151
    Wings 726.5
    Fuselage 239
    Interior 5
    Controls 11.5
    Avionics 27
    Other 66
Powered by Create your own unique website with customizable templates.