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Why the engine wont run

Seems to me the fuel line zip tied is the least of the problems.
I would say it's likely the pistons hit the valves, bent the stem and then the pushrods followed.
Either too big of a cam for the piston selection or the cam was timed improperly.
Could be a big mess...
 
I do not see how that engine could have possibly run, except for the first time....and not for long. Something had to be wrong from the get go.
 
I got the engine running after replacing the eight bent push rods. Ran smooth and quiet. Next day, started it up, engine making a racket, running rough and getting worse till it finally died. Pulled the valve covers to find 3 more bent push rods, all on the intake valves.

Discussed it with the machinist who built the engine, who is on this forum. He said to tap on each of the valve tips with a light hammer and brass drift. If any sound solid they are seized in the guide. Found three intake valves that were seized, all the ones that bent the push rods again.

The theory on why this is happening goes back to the sour fuel the engine must have been started up on. After replacing the bent push rods the first time, I cranked the engine over slowly with the starter. The lifters were probably not pumped up yet, and the valves freed up slowly. After that heat cycle, the engine cooled and 3 of the intake valves seized back up in the guides again. Starting the engine the next day and having it fire up like normal bent the pushrods again before the valves freed up in the guides. Viable theory?

The car has been sitting all week. I wont have time to pull the heads till next week.
 
How long did you run it each time? Oil pressure.
I really don't think old gas will make valves stick shut the guides are on the top.
It's something else not enough clearance on the guides perhaps.
I'd remove a couple springs and check the clearance.
Buy a boroscope for a phone and look inside for piston to valve interference.
 
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I'd like a explanation of how "sour gas" would seize valves. Bad gas screws up combustion, but seems like the guides didn't have the proper clearance. Careful further examination is required.
 
Old/stale gas does not burn completely and leaves a gummy mess. When an engine has stale gas introduced, it will still run, but once it is shut off, the mess will wick down (more than it already had) between the intake valves and guides. After the engine cools down, the intake valves are stuck solid, and upon restart, the part that gives are the pushrods. I advised to lightly tap on the intake valves to gauge how solid they sounded which confirms that they were stuck. With the continued attempts to start the motor, the guides were flushed with clean gas which helped free them, in my opinion, and allowed Paul to start and run the motor with the new pushrods. Once the motor came to temp and then cooled, residual gum was allowed to stick 3 valves again, bending 3 more pushrods. This is what stale gas does to a motor, and the reason why you should never run stale gas thru an engine.

The valve guide clearance is fine, the cam is tame, the timing is set correctly, and the deck height is more than enough to prevent any piston/valve contact. The culprit is the stale gas.
 
I guess you can always learn something.
Perhaps a new engine is more prone to have this problem?
I've never seen or heard of this and I've run all kinds of stuff (probably more worn engines) with various aged fuels.
So I just dismissed it as a possibility.
But I guess not so much in recent history with the alcohol in the gas.
 
69Bee said:
Old/stale gas does not burn completely and leaves a gummy mess. When an engine has stale gas introduced, it will still run, but once it is shut off, the mess will wick down (more than it already had) between the intake valves and guides. After the engine cools down, the intake valves are stuck solid, and upon restart, the part that gives are the pushrods. I advised to lightly tap on the intake valves to gauge how solid they sounded which confirms that they were stuck. With the continued attempts to start the motor, the guides were flushed with clean gas which helped free them, in my opinion, and allowed Paul to start and run the motor with the new pushrods. Once the motor came to temp and then cooled, residual gum was allowed to stick 3 valves again, bending 3 more pushrods. This is what stale gas does to a motor, and the reason why you should never run stale gas thru an engine.

The valve guide clearance is fine, the cam is tame, the timing is set correctly, and the deck height is more than enough to prevent any piston/valve contact. The culprit is the stale gas.
Click to expand...

Interesting explanation. Another question, how was "clean gas" introduced into the guides to free up the valves? Just wondering.
 
With the constant attempts to start the engine, it will eventually flood and the raw gas sill seep into the guides kind of like using carb cleaner. One big thing I worry about is washing out the rings when they have not completely seated yet. Washing out the rings and wiping them out means washing the oil off of the cylinder walls and affecting ring break in.
 
Well the cylinders with stuck valves shouldn't be loaded with raw fuel
 
@Paul_G I'm in north Glendale ... so if you need another pair of eye's I can swing by and take a look.
 
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I would pull the heads off and take them to a different machine shop, probably reem the guides to the correct size or replace them,
 
Don Frelier said:
You never said you had valves stuck open?
Click to expand...
When the engine stops turning do all the valves close? No they dont.
Nevada dan said:
I would pull the heads off and take them to a different machine shop, probably reem the guides to the correct size or replace them,
Click to expand...

The machinist who did the heads wants them back. The offer to repair them at no cost to me was given. I dont think there was any error in machine work. The engine ran like a swiss watch. Especially since this time only 3 intake push rods were bent, where as the first time all 8 were bent.
It is conceivable that if I work the valves and get them moving, like I did after I replaced the bent push rods, start it up with a heavy dose of techron in the fuel, then road trip it, it might be fine on it's own. 69Bee, what do you think of that idea?
 
Paul_G said:
When the engine stops turning do all the valves close? No they dont.


The machinist who did the heads wants them back. The offer to repair them at no cost to me was given. I dont think there was any error in machine work. The engine ran like a swiss watch. Especially since this time only 3 intake push rods were bent, where as the first time all 8 were bent.
It is conceivable that if I work the valves and get them moving, like I did after I replaced the bent push rods, start it up with a heavy dose of techron in the fuel, then road trip it, it might be fine on it's own. 69Bee, what do you think of that idea?
Click to expand...

You could give it a shot, so far, all it is killing is push rods. From 8 to 3 to ? good odds. Some snake-oil fuel cleaner might help. You just basically want to get the gum out of the guides. I believe you said that you cleaned out the tank, lines, carb, etc.. so it might work on the third try. I wouldn't say any valve stems bent because you say the motor sounded good when you replaced the original pushrods. The weak link are the long *** pushrods.
 
put some star tron enzyme fuel additive in with the new fuel, it will eat everything in the lines and places you cant get to, it works I've used it on a truck that sat for over 10 years, do you think he had bad gas in it when he did it the first time?
 
Berrymans will clean better than anything else. Don't use too much.
 
Nevada dan said:
, do you think he had bad gas in it when he did it the first time?
Click to expand...

Without a doubt. It had that horrid smell of old fuel. It is a brand new tank. might be a few years old now, but yes the tank was drained, fuel lines blown out, carb cleaned, new filter, and 3 gallons of 91 octane.
 
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