351C

[Ford Blue blood]

Alrighty then, got the 351 broke in, all systems work as they should.  Ran it at 2000 RPM for 30 minutes, set the idle, noted the engine temp and oil pressure at idle, all was well, shut it off and moved on to other thing.  Went to move the Ranchero, started, idled for about a minute and hasn't hit a lick since.

Just got done trouble shooting with a friend who has raced 351C engines and built more then you can throw a stick at in two days.  We verified the timing, the firing order, the spark all the way to the plug, the valves are all moving, verified the valves are moving in proper timing sequence, everything says it should hit and run but nothing.  Shot a little ether in it and nothing.  Put a vacuum gauge on it and no vacuum.  The rocker arms will not compress, that is the lifters will not bleed down.  We feel they should.

All the systems look fine.  The oil is clean, the coolant is clear and clean, oil comes up to the rockers just fine, gas was puddled in the intake and the card squirts as it should.  So, I'm going to pull the intake and see what we can see.  Appreciate any thoughts you guys might have.

[thomasso]

You didn't mention the plugs or the timing chain.  Compression?  Distributor gear?  I'm sure you guys are as knowlegable as anyone, but sometimes its the smallest thing.  Good luck.

[Ford Blue blood]

New Cloyes double roller, verified valve timing, 125 on #1 cold with the remainder of the plugs still in, new distributor, turns as it should, times up correctly, both of us are well experienced and we both came up with the same conclusion.  No vacuum indicates valves not sealing and given the heads have a new valve job doubt that is the issue.  I will be pulling a lifter out and checking to see if they might be the problem.

After an afternoon of going over things we both feel the lifters are not bleeding down or the push rods are too long.

[terry_208]

...
After an afternoon of going over things we both feel the lifters are not bleeding down or the push rods are too long.

IDK, just a thought. Wouldn't the result be be the same, holding the valves open?

[Ford Blue blood]

Pulled two lifters out using my magnet.  Both were pumped up to the max.  Disassembled, cleaned them out, verified all the parts and pieces were as they should be, re-assembled, soaked in oil overnight, re-installed and determined the push rods are the correct length.  There is the correct play when the lifter is all the way down.  The other lifters are so tight against the rockers that I can't move the rocker the least little bit.  With #1 on TDC tightening the rocker stand until the rocker tightens up the valve actually moves for the last 1/2 turn  to seat the rocker stand.  Still hunting.....

[lalessi1]

Are you saying you have 125 psi compression on #1 cylinder? Just a little confused (as always).

[rmk57]

The rocker isn't interfering with the retainer is it ?

[Ford Blue blood]

All right.  Went into the thing hard.  Ran compression check on all 8, PSI was between 125 and 130 on seven with the carb open full, all eight plugs out, fresh battery, and a cold engine.  Found #3 had nothing, dead as a door nail.  Spinning the engine and listening through the carb I and my friend could hear a cylinder "puffing" back into the intake.  Pulled the head to see what the heck was going on.  Both valves were in great condition.  Put layout dye on the valves and the seats, applied a little lapping compound and had perfect seat indications on both the valve and seats.  I put the head back on the engine with the old head gasket (new one on order), torqued it down, put 145 PSI air on the cylinder, no leaking.  Leak down takes forever to show a drop on the gauge.  I'm going to conclude that the head, valves, piston, rings, and the combustion chamber are good.  Checked to see that all eight push rods from that bank are all the exact same length, they are.  Stopped working last evening to ponder the situation.

Today I'm going to pull the plugs, put the push rods and rocker back on and re-do the compression check on #3.  All we have left is faulty lifter or faulty cam with a miss ground lobe?  The cam was "degreed" in when assembled but I used #1 lodes to do the testing never looking at the rest of the lobes.  Timing mark (TDC) on the balancer was checked and good.  Ignition timing is correct, been checked by three people to this point.  The only conclusion I've come up with is/was something is holding the intake valve open and it has fallen out.  I'd buy that but I did the valve check on a clean, cloth covered table and there was no foreign object to be seen.....

[terry_208]

I would think the engine would run, even with a dead cyclinder. I'm wondering, yet don't even want to think it, if the cam survived initial run in.

[terry_208]

I would think the engine would run, even with a dead cyclinder. I'm wondering, yet don't even want to think it, if the cam survived initial run in.

After thinking about it, if the cam were flat the valves wouldn't have to close as they wouldn't open!

[Ford Blue blood]

I think I have this sorted out.  Turns out the line I used to put air on the cylinder in question would not let air into it!  It is a flex line that came with the compression tester, it lets air out but not in.  Thought about testing it but decided not to, wrong on so many levels!  Made a fixture (spark plug gutted welded to an old air hos fitting), put air into the cylinder, turns out the exhaust valve leaked like a sieve!  After careful lapping it turns out the valve seat was "out of whack".  Got out the stones and touched up the seat and all is well.  Waiting on gaskets to put it all together again.  See what happens after that....

[lalessi1]

If you have (1) valve seat "out of whack" maybe there are others? Has your head ever been milled? I am assuming you do not have adjustable rocker arms as well...

[Ford Blue blood]

Went through and tested all the remaining cylinders and they are good.  I think the no start and run issue started out as a loose wire in the distributor.  The issue with #3 was there but didn't keep it from running.  Got that fixed and by then the timing was so messed up it wouldn't hit.  Got it all put together and put a "junk yard tester" on it.  Fired up and ran but had a miss and back fired.  That lead to finding #3 bad and the rest is history....

The junk yard tester is a home made item that consist of a Chevy fan motor (mid 60s), a breaker plate assembly, two bumps welded on the fan shaft, and a hot coil.  The fan turns, the bumps open and close the points and the coil fires.  Put the tester coil wire in the center of the distributor, hook the test leads to the battery and crank the engine.  If timing, gas, cam timing are right it will run.  A good friend that ran a yard made this thing to test engines before pulling them for resale.

[lalessi1]

Glad you got it going. Never heard of a "junk yard tester"...pretty cool!

[Ford Blue blood]

I hadn't either but I can attest to the fact it exist and the fact that it works!  Made me happy, turns out I wasn't chasing ghosts.