Bentley BR2

[joerom]

Hello,
Thanks for the info, but I already have steel keyway stock..With being 1/3 scale, I am going heavier on everything that I can..
Did it mess up your engine bad..Things like that can really spoil your day..

 

[joerom]

I am working on the cams still, and getting closer to being done..The pictures below show this..The cam rings were drilled and cut to tooth height on the lathe, and then the book suggests finishing by hand with a file..I used a Dremel and did it that way..You already have the proper spacing and height, so it is a simple matter to do the nose..I ended up doing the same for the cams, and it came out very well, and works smooth..The cam looks blotchy because I case hardened it and that is as far as I got with the cleaning..The eccentric still needs more drilling and keyway put in, as does the cam ring...…

 

[joerom]

I wanted to make the top plate that holds the upper bearing on the eccentric shaft before I finished the upper cam..I needed to change it from the drawings because of the way this was being built in 1/3 scale by the original builder..So I decided I wanted to make the top plate as an attachment to the front propeller housing..The very top of the plate is flush to the top of cam housing and will secure the cam plates in the final position..In the following pictures you will see what I mean...…

 

[joerom]

I have done a little more on the BR2..I finished the cam gears and cam plates..They have been case hardened and look blotchy..I think all the oil passages have been reworked and associated parts also reworked. I need to put studs at various places and I think that is it for this phase..I think it may be time to make the lifters..

 

[joerom]

I was just down in the basement working on this, and finally realized that the other part built BR2 that I have is not going to get done..I am getting older and I still have a lot of projects to do, so I think it is time to sell the other..I do want to finish this one and will keep posting here until it is done, but doing 2 of them is a pipe dream so the other to go...…..

 

[Cessnadriver]

Hi I would be curious to know what you would sell the unfinished projects for?

 

[bobden72]

I was just down in the basement working on this, and finally realized that the other part built BR2 that I have is not going to get done..I am getting older and I still have a lot of projects to do, so I think it is time to sell the other..I do want to finish this one and will keep posting here until it is done, but doing 2 of them is a pipe dream so the other to go...…..

Me too.

 

[joerom]

I may have spoken too soon...……..

 

[joerom]

I have decided to put up for sale the extra part built BR2 that I have for sale in the sale section here.....I know I will never finish the other one I have being that I turn 74 this year, and am getting too slow with too many projects...Reality has a way of stepping in......…….

 

[Les99]

I have decided to put up for sale the extra part built BR2 that I have for sale in the sale section here.....I know I will never finish the other one I have being that I turn 74 this year, and am getting too slow with too many projects...Reality has a way of stepping in......…….

Hi Joerom,
Just out of interest, how much are you asking for the second Bentley?
Cheers,
Les

 

[joerom]

Hello,
Please go down to the
Buy / Sell / Trade
section here, and all the info is there...…….
Joe

 

[joerom]

When I took on this project, I thought I may have some problems along the way..I wanted to make the tappets, but could not figure how they were installed, being the eccentric shaft for the cam gears was already made and assembled with the ball bearing installed..I fooled with it for a while and just could not see how it was done, because the ball bearing on the eccentric shaft was mounted with a circular plate that was held down with screws, that could not be accessed when the tappets were installed..When I was downstairs fooling with it today trying to make sense of it, I discovered that the eccentric shaft was held on by a thin collar in the back, that I thought was just the shaft that was pressed on..It was done so well, that I just did not see this when trying to figure it out..So now I see how it is done and it is a simple matter to make the tappets and install them, and lastly install the eccentric shaft with the nut..I had made a dummy tappet to see how this all works, and it does..I just have to make the tappets now and I can proceed with the project..So, actually there never was a problem, other than me!

 

[58tux]

[see below]

 

[58tux]

Math of the Bentley BR2 cam. The outer cam rings attached to the crankcase have 18 teeth. The cams have 16 teeth, For each turn of the cam rings the internal cam will make 1 1/8 turns. Being this is a four cycle engine for all cylinders to fire the engine must make two revolutions. So when the engine makes two turns the cams will make 2 1/4 turns ( 2 X 1 1/8). There are four lobes on each cam, so 2 1/4 X 4 = 9.

Here is an animation of the cams drawn in Fusion 360 (click on image below):

 

[joerom]

I started work on the tappets..I decided to make the stems from ground rod and then silver solder the bottom to it..The stems needed a concave depression in one end to accept the ball end on the pushrod...I did not have a ball end mill that size so I ground one up from a drill bit..I first center drilled the end in the lathe, and then followed with my reground ball mill..It worked well..Then I needed to make the lower portion which will contact the cam, and drilled it for the stem..It will need to be ground to size and shaped...That will be silver soldered on the end, and the other end cross drilled for the thimble that needs to be made yet.....

 

[joerom]

I am writing to let everyone know that I have not given up on this engine..I am still very much interested in finishing it..It is just that I got involved in converting a mill to CNC to use down the line, and that is where I am right now..The conversion progress is posted on this site, and I hope to soo be finished, at which point I will get right back to working on the BR2, and the Gipsy Major...…………….

 

[joerom]

I have gone as far as I can go with the CNC conversion until I get some better weather to paint the cabinet, so I am back on the BR2..I have made the thimbles for the valve lifters..These will need to be swaged to retain the ball end in the lifter and also cross drilled for attaching to the end of the lifter..I am getting closer to being able to assemble the crankcase into an assembly that looks like a BR2...This is still a very impressive engine to me and look forward to the day I can actually spin it for the first time...………

 

[byawor]

I remebered this post and finally found it. It answers my problem with the cams I think. Thanks for posting\Bob

 

[imsteamer21]

hi guys - im building the ageless engines br2- my question is that they call for a propellar of 42" diameter - is this correct - i was thinking that it should be closer to 24" - any ideas thanks fred

 

[byawor]

Blackmore plans spec prop at 23 3/8 so I guess your guess is right