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Stuck broken valve


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Remove the tappet covers

Remove the offending valve retaining pin, cup and spring.

Cut the valve stem at the base of the guide.

Remove the cam follower and plug the hole in the block.

Try to (Carefully) prise up the remaining valve part.

Perhaps using two screwdrivers.

A piece of flat aluminium plate under each screwdriver might act as a cushion on the valve seat but you may find you need to replace the valve guide and recut the seat.

If it will only come up a little way then cut the head off and drive it down 

Good luck.

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Hopefully the valve is bent below the guide and cutting the lower portion of the shaft will do the trick.

I take it you have already removed the spring and cup? 

If the cam shaft is jammed on and the cam follower is hard up against the valve then perhaps try to rotate the engine backwards a little to ease any pressure.

Back off the tappet adjustment to allow for clearance to remove the cam follower and spring.

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     It seems unlikely that the stem would bend below the guide.  

     I would soak it down with 50/50 acetone/ATF and give the valve head a good jolting with a brass or hardwood drift and, (without brutal force), attempt to raise it with the camshaft.  Jolt the valve while there's some upward force from the cam.  Work it back and forth.  Add a shim between the valve stem and lifter to raise it further.

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I started out using a piece of wood, but I slowly started using more and more force until I made it worse. As far as rotating the engine backwards, do you think I could just jack up a wheel and turn it backwards in gear?  The motor only needs to spin backwards a quarter of an inch just enough to take the pressure off the camshaft. 

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I was able to remove the valve retaining pin. I also moved the motor back so pressure is taken off the camshaft. I tried hammering it in to break the rust free but that did not work. Now it’s almost flush. I will need two original valves. I accidentally hit another valve and it is bent. On the valve it says DB and has three holes on top for lapping. 
 

I don’t want to drill it out. With the valve in the way I can not remove the spring. Prying does not work it only bends the stem. I have been spraying atf and acetone daily   

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Hmmm. Time for an expert. You could try soaking it in the best penetrating fluid ever made. Its probably not obtainable or maybe never invented yet.  Next, you could try oxy acetylene, and heat the shit out of it. Might work.

 

See if you can fit the spring again in order to un adjust the cam follower adjuster. Thus may allow you to remove the camshaft, then drop the cam follower down [ after you have removed the burrs at its top edge ]. This will save you from ruining the camshaft.

 

If all else fails, remove the engine and give it to someone who can machine it out for you on their industrial drill press.

 

We once had a jap car in our workshop were the cylinder head had corroded onto the cylinder head studs. Even chain-blocking the cylinder head up in the air for a few days  with the cars front  wheels off the ground, we could not budge it.  We threw that engine away and fitted a replacement.

 

You have a problem there mate.

 

Best of luck.

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     Have you screwed the valve adjustment all the way in and put the cam at zero lift for that valve?

     If, (what's left of), the valve is seated, driving it downward will do no good.  That valve is about as crusty as they get.  It looks as though the engine was running on three cylinders at the end of it's last gasp  It's safe to assume that the seat is toast and that in the usual expanding project syndrome you will end up replacing all the exhaust valves at the least.

     A coupling nut such as this    https://www.lowes.com/pd/Hillman-2-Count-0-375-in-Zinc-Plated-Standard-SAE-Regular-Nut/3013470?cm_mmc=shp-_-c-_-prd-_-hdw-_-ggl-_-LIA_HDW_126_Fastening-_-3013470-_-local-_-0-_-0&ds_rl=1286981&gclid=Cj0KCQiA8t2eBhDeARIsAAVEga0o2tuX3uMY0yidWJxPSrjjNmfkTXz5eU0JywTKRadRYyr0MlVf6jQaAo6kEALw_wcB&gclsrc=aw.ds

could be welded to the head of the valve.  Place a socket wrench or pipe, (with a large enough I.D. for the valve to pass though), over the valve, and use a threaded rod or bolt to draw the valve into the tube.   A socket wrench will have a small enough hole in it that an ordinary flat washer or two will suffice.  if you use a pipe or tube you will need some sort of washer that's no less than 1/4" thick.  Hardware store threaded rod is made of cheese and not up to the task.  

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29 minutes ago, DB26 said:

Is this the donor car you’re using to repair the wrecked DB? 

That was the original intent but this car is very original. I’m going to drive it as is until the other one is up and running. I decided that I’m going to do an off frame restoration on the wrecked one and have this one as an original runner. I got the motor to run on one cylinder, but three valves were stuck open and now one valve is broken and very stuck.

48C69A44-8D32-45DB-A9C2-6D0F66044EDD.jpeg

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I spent many days on my block with a pressure hose and various tools to pry loose the build up of rust and scale in the water galleries. The important thing is to get clear passage between each cylinder from top to bottom. It takes much patience and persistence to achieve good results.

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The bottom of that valve looks mushroomed out. if it is, best get in there with a small file and clean it up before trying to push it up. I had to do this same thing with a Model T block, just kept working at it. Only took a chunk out of one valve guide boss. 

 

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7 minutes ago, Mark Gregush said:

The bottom of that valve looks mushroomed out. if it is, best get in there with a small file and clean it up before trying to push it up. I had to do this same thing with a Model T block, just kept working at it. Only took a chunk out of one valve guide boss. 

 

I tried to get it to turn with a pair of vice grips. I tried to cut above the marks. I’ll file it.  Is there a way to press the valve up. 

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Tap it up from the bottom, tap it down from the top, use plenty of penetrating oil then let it soak (not WD-40), tap it down from the top, tap it up from the bottom, rinse and repeat. Tap don't hammer and use a brass punch if you can. 

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I would clean the valve stem up at the top.

Obtain a thick piece steel to make a plate / block with a threaded hole for a high tensile bolt (perhaps larger than half inch and turn down the end to the diameter of the valve stem) I would clamp this plate to the block rather than use the head studs.

Use the bolt tightening to press out the damaged valve.

Trying to punch it out will not be successful as the block will flex and could break. If necessary you could take both the guide and the valve remains out together but this would require an hydraulic press.

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