diagnosing a collapsed lifter

Ok, the Y-block in one of our 54 Mercs has been determined to be a 292 out of a 58 Ford. The guy we got it from said it made some strange poppy-tapping sound every so often. Upon pulling the rocker cover and running it, you can watch the pushrod go almost all the way into the head and stay that way for several revolutions and then it will pop up.

Is it possible that this is a collapsed (or collapsing) lifter or maybe a flat spot on the cam? We have not driven the car at all, only let it idle, and it doesn't smoke or seem to burn any oil.

We have a 256 with a rebuilt top-end that we could swap in, and that seems like it would almost be easier than pulling the heads.

Thanks in advance!

 

Be a really good bet that lifter is messed up the way you are describing it.

 

Agree with the bum lifter diagnosis above. When a cam goes, it does the same thing all the time... or doesn't.

Bob

 

What you describe sounds very odd! First I'll say a flat cam would not be intermittent as you describe. Now, you say the pushrod goes down into the head? This sounds like the valve closing (lifter is now on the base circle of the cam). And it pops up only after a few revolutions? This really makes no sense to me. It's telling me the lobe of the cam only pushes the pushrod up ocassionally, and not regularly like the others that you observe? That does sound like a radically sticky lifter. Does the motor sound noticeably better when the pushrod does move? I'd say put a qt of ATF in the crankcase and run for a while. The high detergent content might free the lifter. Problem is it may take a while, and you may bend a pushrod in the process

 

Sounds like it to me. If the cam was bad it would never pop up.

 

The lifters in a Y block may break, but they are solid, so they dont collapse like on other engines. Adjust that rocker down and slide it over to pull the push rod. If its stock, the push rod is solid. They like to bend. Hammer it straight on a flat board, put it back in and adjust it to .018 This happens from to many RPM's, or an engine that sat for so long it gets rusty in places. Oil it up and take it out for a forty mile trip with fresh oil in it.

 

True this can be a fast and easy way to find the problem. But you need to look at the possible long term problem of doing this. The last thing anyone wants to do is free up junk thats in an engine. It can result in much more work down the road as compared to pulling the lifter out and cleaning it. At the same time you will be able to see how clean or dirty the engine is inside.

 

That's what I was thinking at first also, maybe a sticky valve but those usually break stuff when they stick closed. hopefully the push rod snaps, and it doesn't take out the lifter before it takes out the cam. Sticky valve might have been what screwed up the lifter.
The crank will make 2 revolutions to the cams 1 , and with a sick lifter who knows what up with it. For example - Might have a whole in the bottom and when it rotates that hole gets closed enough for pressure to build, rinse repeat. Might have a bad seal inside, anything could be wrong. But if it doesn't move on the cam every time, its a lifter. Biggest problem shows up first.

 

Oil filter

 

So much for collapsed lifters theary. This why I love the HAMB.

Valve

• The valves of the 292 have an operating clearance of .019 for intake and exhaust in hot or cold weather. The clearance refers to the gap between the valve's stem and the lifter that makes sure the valve closes completely. The valve has a seat angle of 45 degrees, meaning it sits at a 45 degree angle against the surface it rests on when it is closed, and its spring pressure is 161 pounds at 1.39 inches, meaning the spring exerts 161 pounds of pressure when it is installed at height of 1.39.
  
  

Read more: Ford 292 Specs | eHow.com http://www.ehow.com/list_7345489_ford-292-specs.html#ixzz1tMoyNRIq

 

So in other words, it's the next guy's problem

 

No, it's the oil filter's problem/job

 

If the Y block's lifters are solids.....now I'm really confused with the OP's observations. If the pushrod came out/up, and intermittently dropped...THAT would make more sense to me. Could it be he's watching something other than the pushrod?

 

Fuck, I'm lost now, just going to watch.

 

X-2

 

161 Lbs on the seat (valve closed) sounds like a LOT for a stock motor. That's almost race-roller territory

 

Lifter may break......

 

I tell you what happened to me.

I had a 350 that every once in a while would start to miss so I started changing plugs,wires, vacuum hoses and even the distributor thinking it might be shorting out.

Well long story short it would miss every once in a while and I was stumped trying to figure out what was going on.

I could friend of mine who is 80 years old and has been building engines for years told me to get a quart of Marvel Mystery Oil and pour in the crankcase and when I asked what that would do he explained the problem was a lifter that every once in a while got stuck.

I followed his advice and never had any problems again.

It seemed to me to be an electrical miss and that is why I changed all those parts but in the end if was a lifter.

Jimbo

 

54 Mercruiser, How does this engine run? does it have a miss?, pop thru the carb? is it an intake or exhaust valve?

 

This comes to mind. Engine got over rev'd and floated the valve's. Bend push rod as suggested and a bent valve. You may be seeing things in the reverse. The valve is hang'n up and the the push rod being bent may hold it up as well and the tap tap is the top of the lifter lobe hitting the lifter from possible mushrooming of the lifter base.

 

have you guys ever worked on a y block?? they have a solid T lifter with the top part of the T on the cam and they can break and gouge out the cam i have seen that on my first 3/4 race engine!!!




or you could have a sticky valve which could be loosened up by some skunk pee of sorts

you will ever make the lifter do anythinjg with additive as its a solid piece of metal

 

I'm an idiot. Y Blocks don't have hydraulic Lifters. I'd say Johnny Gee is probably right.

 

Ole don's is the one how said they was solid not me (see reply #6). I quoted him and posted what I found on line about your exact Y Block.

 

If it was my car.. it would be apart. It's never what you THINK it is.

Bob

 

Y block spring installed height was between 1 3/4 to 1 13/16 depending on year. I'd pull the push rod I'd bet it's bent also take a bar and push that valve open see if its extra hard to open or sticks.

 

Wow, this is a lot of information to take in..lol I'm not sure wether it's the intake or exhaust, and it idles ok, haven't taken it above about 1500 yet, watching that pushrod pop around is disconcerting.

The old man and I are debating over just swapping in the 256 that we know is good and get this car on the road, or maybe pull the heads...I am leaning towards the swap. I want to keep the 292, but since it is an "unknown origins" engine, the swap seems to be the route to follow.

Anyone in D/FW looking for a 292?

 

Ok, Im a Y block virgin. So I googled y block lifters and such. There's some pretty good info out there, few scary pictures of broken lifters.

 

Pretty hard to collapse a solid lifter. I am not absolutely sure but I don't think that they made a hydraulic Y block. Maybe into the '60s they did just to keep up with GM but '58s were still solids as I recall.

 

All of the Ford Y-blocks were solid lifter engines ,lifter was a "mushroom" design that the cam end was much larger the the shank/stem. Another case where the O/P could be well served by buying a old "MOTOR"S" manual.

 

Will you at least being opening up the Y block to see what exactly what the problem is?