My Dauntless Ate A Valve.

It still runs. Loss of power. Smokes a lot. Contestant ticking.

I thought maybe somehow the rod fell off the lifter but when I pulled the rocker assembly this is what I saw.

 

Yea and we’re boondock camping in Leadville.

 

OH MY, do have a plan yet?

 

No.
Do y’all think the valve is thru the piston and into the oil pan? Is there anyplace else for it to go?

 

See if you can run a light/scope down the valve guide for a looksee.
Or take that spark plug out and have a look while rotating or bumping the engine.
Man, that's a big bummer....

 

Hard to say. Do you think the valve stem could still be in the guide, or is it completely not visible.

 

How far away is your truck and trailer? Are you stranded?

 

I would not run it. Pull the head replace the valve and gasket before you need a new piston.

We can get it fixed to at least run a few days if the piston and bore doesn't get messed up.

 

Sometimes the valve gets stuck in the port:


But it usually punches a hole in the top of the piston in the process:


Those are from money shifting my old 5.0L Mustang at the track. It didn't like 7000 rpm.

You "might" be able to salvage the bottom end, but the piston and connecting rod are suspect. It can also damage the bore. You can see where it cracked my cylinder when the piston got cocked sideways.

The head probably has damage in the combustion chamber and probably needs a new seat at the very least if not some welding. Finding another running dauntless is your best bet to get it running quickly.

 

We’re fine. The jeep was in the trailer when we pulled up to camp. I drove it out/off. I think a piston is going to be my biggest challenge.

Can a piston be changed with the engine in the jeep with regular hand tools?

 

Thanks James. I’ll let you know.Boston Bob may have parts I would need.

 

Yes, getting it out should be no problem. Be careful not to scratch the cylinder bore with the connecting rod when removing. Taping the rod bolts or using protective sleeves on them helps with this.

You will need a ring compressor and a torque wrench for reinstalling. The rod cap needs to be put back on the rod in the proper direction (with the bearing notches on the rod and cap on the same side). The new piston/rings need to match any overbore your engine has. If the pistons aren't stamped you need a way to measure this. If using new rod bearings, they need to match any undersizing the crank may have. If you're using new rings, you'll need to hone the cylinder so they break-in properly. The pistons are usually directional and will need to be install on the rod in the correct orientation and installed in the block facing the right direction. Your best bet is to find a piston and use your current rod, bearings, and rings.

Be sure to carefully inspect the lifter, pushrod, and valve spring for that valve too. On of them may have caused the issue in first place.

 

I have an uncle in Montrose that might have some engine tools still. There's a reputable machine shop in Gill if it goes that way.

If I'm not mistaken you'll need a press and a rod heater to get that old wrist pin and piston off/on. I don't know a good way to install a new one in the bush but it's critical you get it in there right and you don't gall the rod eye, pin boss, or wrist pin.

Go ahead and pull the other valve cover and rap on the tip of the valves to make sure the keepers are in the keeper grooves. Cheap insurance.

 

Yes, a machine shop should do the rod swap.

 

These guys do things the right way and should be able to help you out, Scott.

JAMSI Online - Automotive Engine Parts

 

load it back into trailer . when ready to leave for home
deal with it then