1950 Bentley engine project

YYCHM

(Craig)
Premium Member
Against your better judgment eh..... You're having way too much fun with this:D
 

Brent H

Ultra Member
@John Conroy : so how many of this guy's children now have to call you "DAD" or what kinda price are ya getting for arms, legs, kidneys etc????? (seriously I need to know for my next job) ...LOL

I can see why you "reluctantly" agreed - wow.....more power to you brother - some great work at keeping the head intact as you wrestle with corrosion.

On the ship we have had success with fitting up a bubbler system and glycol - basically submerge the unit over some copper tube with perforations and attach some air with a control valve and peculate until ready. We used to use this carbon remover stuff until one of the oilers showed up with three legs - had to stop that practice quick (LOL) (old days)

nice pics of your mill set ups and thought process documentation - Kudos!
 

John Conroy

member
Premium Member
Thanks for your comments guys. I really am enjoying most of this battle, you can only self isolate for so long before you go crazy. My friend is a gear head but is formally trained as a neurosurgeon. My wife worked with him for 20 years while he was chief of Pediatic Neurosurgery at the Stollery. He is a brilliant but down to earth guy and loves to learn so it's fun to pass along some of the knowledge I gained during 40 years in my trade.

Kevin, I use the CLR at full strength. It dissolves the white calcium deposits and loosens the oily sludge àlso. It can also attack some aluminum alloys so you have to be watchful.

There is so much corrosion in the block that I'm not sure it will be usable.

The head really does not need much more work, the valve guides are in good shape so I'm going to grind the valve seats and possibly flycut the head gasket surface if it needs that. If the block is junk we will have a good head to sell. Then we go to plan B. We have a nice small block Chevy that would power the old Bentley nicely
 
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PeterT

Ultra Member
Premium Member
Nice work. Lots of unique setups & remedial solutions there. Looks like your better judgment was already gazing ahead into the future LOL.
I think this demonstrates that 'restoration' can be quite a different animal that rebuilding or re-assembling.

I was going to ask about threads & fasteners in general - is everything old school Brit (Whitworth, BSF...)? What about even 'common' things like spark plugs, fluid caps, oil filter?

Interesting looking pistons, long aspect ratio by modern standards. I've noticed that on older aircraft engines of that era too. I was never clear why though. Seems like oil control & compression was still in concentrated in the top crown area around the rings, so why so much skirt length below? Maybe heat dissipation or related to materials at the time to maintain shape?

Does the owner have much in the way of documentation like shop/maintenance manuals?
 

John Conroy

member
Premium Member
Thanks Peter, we have copies of the manuals. A lot has been learned about engine design since 1950 but even the pistons of that era could be quite different in design based on the design intent. These engine were designed to be smooth and quiet. Power was achieved through displacement, not rpm. You would think that they would have been able to get away with more piston to cylinder clearance with those long piston skirts but the clerance spec is .0012-.0015" which is pretty consistant with modern engines. Those long pistons maintain their shape when hot where modern short skirt pistons are designed knowing the clearnce will change when heated because the mass of the piston is so different around it's circumference.
If you're interested in engine design, motorcycles have always been about performance and have seen huge changes in piston design over the years. There are alot of great articals written by Kevin Cameron on the subject. This one breifly discusses piston design.

https://www.cycleworld.com/modern-motorcycle-piston-crowns-and-combustion-chambers/
 
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turner

Active Member
John
Very interested in this project, thinking about the SBC install if the block is not salvageable. The car excites me, and even though I am a chevy fan...I would like to plant a seed. A unique car with a unique substitute under the hood would retain if not elevate the value of the ride. Falconer V12 ? There is just something about having something no one else has. The part I enjoy about working for friends/free is spending their money! Todd T.
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