2.7 won't turn clockwise

[racer_X]

So....I am on the slippery slope of fixing a few oil leaks and am in the process of installing RSR o rings on the rocker shaft, only trouble is I can no longer rotate the crank on the engine.



When I finished the third cylinder's rocker shaft (#6 on the other side) and began rotating the crank, it would stopped rotating around 60 degrees clockwise.



I have done a quick search and only found this thread Wayne, John Walker -- Help! It turns counter clockwise, but not clockwise..
Which doesn't seem to capture my situation.

The engine ran fine just leaked excessive oil out of the rocker shafts. It was rebuilt at 90k and now has 150k on it. The engine is on an engine stand with the exhaust and intake removed. I can't see any obstructions on the fly wheel side. I have not rotated the engine counter clockwise. I removed the distributor and loosened the valves that I just adjust as I installed the rocker seals. I have removed the timing chain covers, spark pluds and don't see any obstructions.




The intake valve appear to have no obstructions, and the exhaust valves, while covered in some carbon, have been upside down (such that any loose carbon would fall), so I don't see any obstructions. It turned freely before.

Any ideas? I am stumped and getting nervous that this will go beyond my abilities, budget and time!

Thanks in advance for any insights!

[Heinz911]

Are the spark-plugs out?

[crg53]

There are really only 2 things that will stop the engine from rotating freely in your situation. One is valve to piston contact, the other would be the chain jamming because the tensioners are slack. I would check those and then let us know.

[racer_X]

Originally Posted by Heinz911

Are the spark-plugs out?

Yes, the spark plugs are out, that was one of the first things I did.

Originally Posted by crg53

There are really only 2 things that will stop the engine from rotating freely in your situation. One is valve to piston contact, the other would be the chain jamming because the tensioners are slack. I would check those and then let us know.

I am not sure how to check for a chain obstruction other than the visual that I posted. Does anything look unusual from the pictures? The chains appear "tight" and I can't see into case where the intermediate shaft connects.

Any suggestions on making sure the valve retract if one is stuck? Should I spray oil in there? I looked quickly last night before I posted at the intake valves, I didn't see any carbon or any other obstructions.

Thanks for the quick responses, I will flip it over tonight to look at the exhaust valves.

[Luke M]

Did anything get dropped in the intake/exhaust ports? Reason I ask there was a guy not long ago that had the same problem. He believes one of his kids dropped a nut into the intake port when he wasn't looking. Are you sure those rags in the intakes aren't causing an issue ?

Where about in Roch are you ? You can pm that if you want. I'm 20 mins west of the city.

Luke

[BURN-BROS]

Make sure the starter gear is not making contact with the Engine Yoke.

[JJ 911SC]

Originally Posted by Luke M

Did anything get dropped in the intake/exhaust ports?...

+1. A wet/dry shop vac will take care of it.

[JFairman]

It looks like your chains are worn because the tensioners are extended out almost as far as they can go.
When I got my car it had around 118,000 miles and they were extended out a lot like yours.
Then I replaced the chains and sprockets and the same tensioners didn't extend out nearly as far.

Tensioners with worn chain:



Same tensioners with new chains and sprockets:



I have the paper towels stuffed in around the lower side of the chain in case I accidentally dropped something it wouldn't end up in the case. The chain didn't snag or tear on the towels when turning the crankshaft so there was no problem there.

[Flat6pac]

You're at the point you can't go forward, go backwards
Figure which 2 pistons are up close to TDC go backwards until it stops
That will tell you where to look for foreign stuff in the engine.
Bruce

[racer_X]

Well I am stumped. I went counter clockwise 5-10 degrees or so and it is free. Rotating back clockwise, and there is a sudden stop, every time.

Engine yoke seems to clear starter ring.

I removed one of the intake rockers thinking it was hitting but no difference.

I think I am going to purchase a bore scope and try to see into the case where the chains wrap around the intermediate gear. Maybe the chain is bunched? There is no slack either side.

Is it possible that rotating the engine upside down would drop anything anywhere that would bind a chain?

My plan is to scope it, then remove the rockers, as a start. Do you guys think the chains are too far stretched?

[Walt Fricke]

Most likely you have installed the right side cam 180 degrees from where it should be. Easy to do. You can rotate it just fine that way if only #1intake and #4 intake rockers are installed. But at some point as you add more rockers and rotate you will have a valve hitting the top of a piston.

Remove enough rockers so you can rotate the crank 720 degrees, loosen the right cam nut, pull the locating pin, and turn the cam 180 degrees, insert the pin, and retime it. Bet that solves it.

[racer_X]

Originally Posted by Walt Fricke

Most likely you have installed the right side cam 180 degrees from where it should be. Easy to do. You can rotate it just fine that way if only #1intake and #4 intake rockers are installed. But at some point as you add more rockers and rotate you will have a valve hitting the top of a piston.

Remove enough rockers so you can rotate the crank 720 degrees, loosen the right cam nut, pull the locating pin, and turn the cam 180 degrees, insert the pin, and retime it. Bet that solves it.

Thanks for the suggestions, but this is not a rebuild (though I am worried it is turning into one). The car ran great when I pulled the engine out. The reason for the pull was to fix the oil leaks the car was having. After thoroughly de-greasing the engine, I determined that the leaks were from the rocker arms, and possibly from the top of the engine in the rear.

I will take your suggestion of removing the rockers though to see if this is a valve to piston issue.

This engine was rebuilt at 90K and it now has 150k on it. The engine was align bored and has all of the updates. There is one cylinder that looks like the valve guide is leaking oil, other than that it appear solid including the head studs.

The intake valves look okay I think, I would be interested in second opinions.

[racer_X]

I am limited to ten images per post, here are the exhausts valves.

The exhaust aren't perfect, you can see one has a leaky valve seal.








I don't think the obstruction is in the heads (valves piston) but I can figure this out by removing the rockers and seeing if that works

I plan on purchasing a USB bore scope to see into the case where the chains meet up.

Any other suggestions?

Or comments on condition of the engine from here?

Thanks,
John

[Flat6pac]

The chain isn't bunched on the intermediate because you have the tensioner in place
And they are correct.
Turn backwards 360 degrees, which piston is nearing the top of the throw, there will be 2 to check because if you can't get by it clockwise you won't get by CCW.
If you can go more than 360, the answer is in the valve train.
Bruce

[racer_X]

Originally Posted by Flat6pac

The chain isn't bunched on the intermediate because you have the tensioner in place
And they are correct.
Turn backwards 360 degrees, which piston is nearing the top of the throw, there will be 2 to check because if you can't get by it clockwise you won't get by CCW.
If you can go more than 360, the answer is in the valve train.
Bruce

So the danger to the timing chains by turning counter clockwise is only if you don't have enough tension?

Before I turn it backwards, is there any thing should I be aware of?

[Dpmulvan]

Think maybe it's time to tear her down and do a full rebuild?

[356RS]

Did you get a bore scope yet? Luke may be right in thinking something fell into a cylinder.

[boyt911sc]

Originally Posted by racer_X

So the danger to the timing chains by turning counter clockwise is only if you don't have enough tension?

Before I turn it backwards, is there any thing should I be aware of?

If you have sufficient tension on both timing chains, turning it manually (slow and gradual) either directions without due force is OK. I've been there last month and the problem was due to losing the chain tension for the right side while removing the sprocket. There is a possibility of stray object inside the engine. Consider it too. One thing I learned from that scary experience was to tilt the engine to the right side if you are working on the right side sprocket and vise versa. With the engine tilted to the side you are working, the timing chain sits correctly on the intermediate shaft gear even without tension. The weight of the timing chain keeps it in place.

Tony

[Speed Buggy]

This might be a dumb question, but when you back it off, can you rotate the engine on the stand and listen for something rattling or something I the engine?

[racer_X]

Originally Posted by Speed Buggy

This might be a dumb question, but when you back it off, can you rotate the engine on the stand and listen for something rattling or something I the engine?

This is not a dumb question.

Like I had said, I ordered a bore scope from amazon:

Supereyes N015 2M/6.5FT Waterproof 10X USB 7mm Endoscope Borescope Inspection Camera with LED

And some screw on accessories that I thought would come in handy, like a 45 degree mirror, a hook end and a magnetic end.

Supereyes Hook Magnet Side View Mirror Set for Borescope Endoscope N005 N013J
Sold by: Magicon LLC

I overnighted them and got them when I arrived home from work. I searched around with the camera. I was convinced that I needed the mirror to see the bunched up chain. Well, I couldn't see anything that looked wrong. So I gently rotated the pulley back 15 then forward 15 and thought to look in the cylinders that were in the compression stroke as was suggested.

Now the last think I could imagine is that something had fallen in even the cylinders as Luke suggested.... my kids are in college and the dog mostly stays away from this end of the garage. I never see the cat on top of the motor.... the only way I could have dropped something was when I was removing the intake manifold and I was missing one nut.....

What is interesting here is that when I finally found the nut inside the combustion chamber using the bore scope with the magnet, I also found out that the nut was only slightly larger than the spark plug bore.

Crap.

Long story short, I was able to rotate the crankshaft so that the #2 intake valve was wide open and adjust the intake valve as far open as I could. This allowed me to use the bore scope and retrieve the nut from the path it took into the cylinder.



The motor turns freely!

Thanks for the help and moral support.

I am sure I will have more questions later.