The last two valves on my W5 won't stay in adjustment. After ten minutes of running the gap disappears. I've set them three times as has a professional restorer. He thinks the valves may be receding into the block. Anyone have any ideas what may be happening? And how to fix it?

Where Are You From? Greenbrae CA

Do You own a car built by Durant? 1925 Star

Hi Vence,

We had a similar problem on a later continental 6 that was being used as an auxeliary engine, would adjust the valves and after running for a short time the valves would need re-adjusting....We found that the valves were "mushrooming" from getting too hot from running to lean of fuel mixture...On this engine we had to drill the hi speed jet in the carburetor....I would suspect something along this line, possiably an intake manifold leak or something that would give you a lean mixture on #4 cylinder.

Where Are You From? Leavenworth, WA / Yuma, AZ

Do You own a car built by Durant? '25 Flint H-40 2door / '25 B-40 Touring / '29 D-40 Coupe / '23 A-22 Touring

I was just thinking Vince, It is possiable if you have been running a tight valve for any length of time you could be getting a burned valve(s)....Make sure that you have valve clearance and give it a compression check and see how #4 checks out against the rest of the cylinders.

Where Are You From? Leavenworth, WA / Yuma, AZ

Do You own a car built by Durant? '25 Flint H-40 2door / '25 B-40 Touring / '29 D-40 Coupe / '23 A-22 Touring

Good Morning. What is the engine's mechanical state at this point? Has it recently been rebuilt? More specifically, have the valves/seats been reconditioned/replaced in the recent past? Does the valve adjustment mechanism lock appropriately?

Where Are You From? Hyattsville Md

Do You own a car built by Durant? Yes

The engine was rebuilt before I got it so it likely doesn't have hardened seats. Its a strong runner and I've put 3000 miles on it. I judt drove it ten miles at 45 mph with the engine running smoothly. No missing.

My restorer and I both believe we got the lock nut tight.

Where Are You From? Greenbrae CA

Do You own a car built by Durant? 1925 Star

Vince: If it were my engine I would start the detective work and see what is different about the valves/lifters that continue to go out of adjustment verses the ones that don't. Possible that you have a mix of valve manufacturers and those valves are inferior. Mark the screw adjustment relative to the lifter that it screws into to verify that it is not moving. Compare the valve seats and valve faces to the valves that stay in good adjustment. If you continue to run the engine with zero valve clearance, it will eventually burn those valves. Just some ideas to try to solve the problem.

Where Are You From? Hyattsville Md

Do You own a car built by Durant? Yes