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1947 Mack EE stuck valves


Plainsman
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Hi,

I have a 1947 Mack EE with a Continental L head gas six - model EN 271. It did run good but has been sitting for a while. It seems to have several stuck valves and I hope the camshaft is OK. The distributor does turn. It has compression on cylinders 3 and 4 and some compression on 5 but has a funny popping noise on that cylindar. Cylinders 1, 2, and 6 don't have compression.

I have poured or sprayed Marvel Mystery Oil and penetrating oil, but have not yet been able to free the valves with tapping or prying through the spark plug holes.

I have been told the head can be hard to get off as the studs can rust to the head.

Any advice on how to free the valves or on removing the head would be appreciated.

Thanks

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i would try removing the exhaust pipe at the manifold, then plug the exhaust manifold remove all spark plugs and fill cylinders with solvent / diesel mix and let maranate for a few days. then if needed remove head i would sugest a air hammer / air chisel with flat bit and drum on heads of bolts this should free them from the rust with out breaking !

PS heavely oil the dist. shaft as it is most likely dry and rusty as well.

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I took the advise of an Antique engine rebuilder called Flat Head Jack pulling my 1929 AC Mack Engine appart.. Clean the rust and crap off the head nuts and the studs. Heat until a very dull orange and stick a pariffin candle on the stud and nut for 30 or more seconds. When the nut cools the paraffin gets pulled in. You may need to do it twice. Work the nut back and forth to work it off.

His advise for getting the heads off the studs was to clean the rust and crap off the studs and head. Than liberally soak the studs with PB Blaster and PB them and tap around them over a few weeks, I did that over a 3 week period and used a pair of wide flat putty knife style gasket scrapers (the blades done flex like a putty knife) to work around the heads to get movement. To about eek to get each head off, but the engine did sit exposed to the weather for 40 or more years it came apart pretty easy.

He used Milk of Magnesia (The suggestion for that is in the Ford model T and A service manuals) on the stud shoulders only, for re assembly to prevent problems if the head has to be removed again.

"OPERTUNITY IS MISSED BY MOST PEOPLE BECAUSE IT IS DRESSED IN OVERALLS AND LOOKS LIKE WORK"  Thomas Edison

 “Life’s journey is not to arrive at the grave safely, in a well preserved body, but rather to skid in sideways, totally worn out, shouting ‘Holy shit, what a ride!’

P.T.CHESHIRE

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Hi All,

Thanks for the replies and good ideas.

I think I will try plugging the exhaust pipe and doping it again first to see If I can free the valves before removing the head or the manifolds and valve covers.

I did start removing the head and the nuts came off pretty easily. What worries me is getting the head broken loose from the head studs. I think I now have some good ideas on how to break the studs loose from the head.

Is there any trick on removing the distributor besides oiling the shaft well?

I don't know how much access I would have to the valves if the valve covers are removed. I haven't done it yet the valve covers aren't very accessible without removing the manifolds, which also could result other problems. I am not sure which would be harder to remove, the head of the manifolds.

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Patience, heat, PB blaster and add some patience. I like the ideas from 41chevy for sure. I've used heat with PB blaster like the candle concept and it appeared to work although was stinky and smokey...ventilation is a must. Don't breath that stuff particularly when it is 1/2 on fire...

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if you have a thread in compression tester, adapt the sparkplug adaptor over to a shop air fitting then reinstall the nuts back on the studs leave about 1/8 in.of thread showing then use a regulated air source at about 20 psi then fill cylinder and tap around head with soft hammer or mallet, change cylinders as needed to lift head you may have to rotate the crank to get valves closed on other cylinders. CAUTION DO NOT GET NEAR ROTATING PARTS WHEN YOU ATTACH AIR TO THE CYLINDERS AS THE CRANK CAN SPIN!

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With the side covers removed you'll have access to the top of the lifter most of the valve springs and keepers.

Pull the head (intake and exhaust if you feel the need) and PB Blaster into the open stuck valve and the lifter galley . use a leather mallet to carefully work on the stuck valves. Just be sure the high point on the cam lobe isn't pushing on the lifter, it'll drop some unloaded so you can tell. Paul

"OPERTUNITY IS MISSED BY MOST PEOPLE BECAUSE IT IS DRESSED IN OVERALLS AND LOOKS LIKE WORK"  Thomas Edison

 “Life’s journey is not to arrive at the grave safely, in a well preserved body, but rather to skid in sideways, totally worn out, shouting ‘Holy shit, what a ride!’

P.T.CHESHIRE

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