Model Engine Maker

Engines => From Plans => Topic started by: gldavison on August 17, 2020, 02:49:16 AM

Title: Build pictures of GB 4 cylinder overhead value engine
Post by: gldavison on August 17, 2020, 02:49:16 AM

Some members wanted to see a build thread on my construction of Geroge Britnell's 4 cylinder overhead value engine. I did not take any pictures of actual machining setups. So here you go with what I have so far.


This is the first group picture I took.
  (https://listerengine.com/coppermine/albums/userpics/10038/normal_4cyl_parts.jpg)   


The con rods are bronze. I just happen to have a section of bronze bushing stock 3"OD X 1-1/4" ID left over from repairing a dozer years ago. I cut a slice off and milled to the proper thickness. Then I draw a 3" circle in cad with id of 1-1/4" and placed 4 rods and caps in that circle. The code was generated in Fusion360 and they were cut on my home made CNC router. You can see that machine here. http://www.gldpages.com/CNCRouter.htm

 (https://listerengine.com/coppermine/albums/userpics/10038/normal_Rods.JPG)

 
After they were cut out I used a rotary table to do the profiling.
 (https://listerengine.com/coppermine/albums/userpics/10038/normal_Rods1.JPG)   


The rocker arms were constructed in same manner as the rods and profiled on RT.
 (https://listerengine.com/coppermine/albums/userpics/10038/normal_20191121_165052.jpg)   
 

Here is the value and tappet cover.
(https://listerengine.com/coppermine/albums/userpics/10038/normal_20191127_111135.jpg)   

And here we have the spark plugs.
(https://listerengine.com/coppermine/albums/userpics/10038/normal_20191119_100749.jpg)

This is the last group picture I took.
(https://listerengine.com/coppermine/albums/userpics/10038/normal_20191006_154902.jpg)

The timing gear cover and distributor cap were also CNC'd on my router.

Title: Re: Build pictures of GB 4 cylinder overhead value engine
Post by: nj111 on August 17, 2020, 08:02:14 AM

Very nice, you are getting on well with that project.

Title: Re: Build pictures of GB 4 cylinder overhead value engine
Post by: Johnmcc69 on August 17, 2020, 03:41:09 PM

 :ThumbsUp:
WOW! Nice work!
 :popcorn:

 John

Title: Re: Build pictures of GB 4 cylinder overhead value engine
Post by: ddmckee54 on August 17, 2020, 06:51:12 PM

Gary:

I like your CNC router.  What are you using to control it and what kind of travel speeds can you get out of it?

I'm currently working on a CNC router that will be similar in size to yours'.  The design for my router is very loosely based on the MPCNC and I am curious about the performance of your machine.

FYI - I tried the link on your homepage to your CNC foam cutter, but it didn't work.

Don

Title: Re: Build pictures of GB 4 cylinder overhead value engine
Post by: tvoght on August 17, 2020, 10:08:34 PM

That looks great Gary. Been wondering how you are doing. Pretty good I'd say.  --Tim

Title: Re: Build pictures of GB 4 cylinder overhead value engine
Post by: gldavison on August 18, 2020, 01:07:49 AM

Well, I guess since some fellows got me posting, I just as well keep it up until this project is finished. Today I finished the exhaust pipe flanges. Here I m profiling on the RT.

(https://listerengine.com/coppermine/albums/userpics/10038/normal_20200816_1618055B15D.jpg)

And the finished product.

(https://listerengine.com/coppermine/albums/userpics/10038/normal_IMG_0673.JPG)

Title: Re: Build pictures of GB 4 cylinder overhead value engine
Post by: gldavison on August 18, 2020, 01:10:35 AM

Hi Tim,

All's well here. Looking forward too Rapid City.

Title: Re: Build pictures of GB 4 cylinder overhead value engine
Post by: gldavison on January 05, 2021, 03:56:52 PM

Time for an update on this little engine. I decided not to make a radiator when I found this on Walmart's website. $27 and free shipping, just couldn't turn it down. It’s for a 4” (120mm) computer fan.

(https://listerengine.com/coppermine/albums/userpics/10038/thumb_120mm_radiator.jpg)


As you can see, there is no fill neck. So got out my radius gauges and measured the radius on the tank. Then I drew up a model in a 3D CAD program.

(https://listerengine.com/coppermine/albums/userpics/10038/normal_Radiator_fill_neck.jpg)

Machining the fill neck.
(https://listerengine.com/coppermine/albums/userpics/10038/normal_20200905_093315.jpg)

And the radius
(https://listerengine.com/coppermine/albums/userpics/10038/normal_20200905_093246.jpg)


Next we need a radiator cap.
(https://listerengine.com/coppermine/albums/userpics/10038/normal_20210104_150409.jpg)

(https://listerengine.com/coppermine/albums/userpics/10038/normal_20210104_150517.jpg)

I use coarse sandpaper to sand the paint off of the tank at the top and proceeded to a fix the aforementioned part with J-B Weld. After the JB cured out, drill a hole  thru the new fill neck into the tank. And the finished product.
(https://listerengine.com/coppermine/albums/userpics/10038/normal_IMG_0677.JPG)
(https://listerengine.com/coppermine/albums/userpics/10038/normal_IMG_0678.JPG)



I 3D printed the fan shroud.
(https://listerengine.com/coppermine/albums/userpics/10038/normal_IMG_0676.JPG)

Title: Re: Build pictures of GB 4 cylinder overhead value engine
Post by: Admiral_dk on January 05, 2021, 08:46:53 PM

Great conversion of the radiator - I really like the transformation  :cheers:

Have you assembled the engine yet ?

Per

Title: Re: Build pictures of GB 4 cylinder overhead value engine
Post by: crueby on January 05, 2021, 10:14:46 PM

Love the look of the radiator, never knew they made ones that small.

Title: Re: Build pictures of GB 4 cylinder overhead value engine
Post by: Art K on January 06, 2021, 02:15:46 AM

Gary,
Glad to see that you are doing well and being productive as well. The engine looks great.
Art