Time for a new engine

[ScottS]

Great. Nothing like being at the mercy of someone else. Tuned my SS with a laptop and LT1Edit without being "forced" to buy a tune. Oh well, all in good time.

 

[ScottS]

Finally got it worked out and ordered the tune. Just staring at email now.

 

[ScottS]

Got it running, but....
Setting codes P0016, P0172, P0175. Crank/cam correlation, left and right banks too rich. "Hunts" for idle sometimes and is down on power. Almost stalls coming to a stop. New VVT solenoid/valve, new crank position sensor, new 02's, pretty much new everything. Checked connectors. Can't see the VVT though. Any ideas?

 

[ScottS]

After hearing a rattling sound right after startup, like a loose flexplate, I pulled the crank sensor just to check it out. Stuck my finger in the hole and I can actually wiggle the sensor ring slightly. I would not think that thing should move at all.

 

[ScottS]

FINALLY figured it out. I was on the right track, just didn't follow my gut in time. The reluctor ring wasn't loose. My flexing finger was making me think so. Pulled flexplate cover. Convertor bolts are still tight. Replaced crank sensor. Same problem. Replaced cam sensor. Same problem. Still hunting for idle and sluggish. Couldn't talk myself into pulling the timing cover and check timing because a reputable machine shop assembled the long block, so I started researching other things. The mysterious rattle that I had heard a few times when starting the engine actually went away. However, the engine would not start any more. I could get it to run if I held the throttle. Checked fuel pressure. All good. After thinking on it for a few days, I finally broke down and pulled the timing cover. Everything looked good, but I couldn't see the crank sprocket to verify that the mark was at 0600 while the cam sprocket was at 1200. So I looked at several pictures of the proper alignment and noticed that when properly timed, the crank key-way is in the 2 0'clock position. Hmmmm. Mine seems to be closer to 2 thirty and favoring 3 o'clock. My gut is really telling me that the timing is off now. But, I put the cover back on and slept on it...sort of.

Next, I ran a compression test. 180-210 across the board except for #3 which was zero. Fearing a dropped valve seat, I stuck a scope camera in there and couldn't see anything. Top of piston looked good. Pulled the head and found a bent exhaust valve holding open. The pistons have a very slight valve relief for the exhaust valve and the #3 piston now has a very slightly larger relief than the others. Now that the head is off, I can put #1 to absolute TDC and see that the cam sprocket is a tooth off.

So, I reckon this is what happened. The timing was off from the get-go OR it jumped at initial startup. The rattling I heard was the #3 exhaust valve and its piston not adhering to the proper social distancing protocol. The rattling stopped because the valve finally stuck about a quarter way open. That's when it lost compression and the engine wouldn't run any longer.

Here's my concern now. I noticed that the timing chain tensioner moves back and forth at times even when rotating the crank in the normal way of rotation. I don't think it's enough to allow enough room for it to "jump", but I'm not familiar with this setup. I would rather have the old school shorter chain and solid guides. So, unless someone changes my mind, I'll get the valve replaced and get it timed properly and see what happens.

Anyway, any words of wisdom and/or sarcasm are welcome. Wisdom for obvious reasons. Sarcasm helps cheer me up.

 

[ScottS]

Here's something interesting concerning head installation. The service manual says:
Using the sequence shown in illustration, tighten the cylinder head bolts 1 through 10 to 34 N.m (25 ft.lbs.).
Using the sequence shown in illustration, tighten the cylinder head bolts 11 through 15 to 20 N.m (15 ft.lbs.).
Using the sequence shown in illustration, tighten the cylinder head bolts 1 through 10 to 54 N.m (40 ft.lbs.).
Using the sequence shown in illustration, tighten the cylinder head bolts 11 through 15 to 20 N.m (15 ft.lbs.).
Using the sequence shown in illustration, rotate the cylinder head bolts 1 through 10 90°.
Using the sequence shown in illustration, tighten the cylinder head bolts 11 through 15 to 34 N.m (25 ft.lbs.).

The machine shop guy told me this:
Tighten head bolts 1-10 to 30ft.lbs.
Put a permanent marker line on each bolt facing the same direction parallel to the length of the head.
Then turn each bolt in the proper sequence 90°.
Wait at least five minutes for the bolts to settle.
Then tighten each bolt in sequence another 90°.
When done, all of the previously marked lines on each bolt should line up. The idea of the permanent marker lines is to give a visual reference for having torqued that particular bolt in case you lose track.

That's an extra 90° over what the service manual calls for. I'm inclined to do it his way since that's what he obviously did to the other head that I have not removed and he has been doing it this way all along.

Any ideas?

 

[ScottS]

FINALLY! On the road again.

 

[cheffrank_357]

Did the machine shop tell you to use a wrench and crank the engine over a few time prior buttoning up?
I did on my 4 banger
I got a good few turns over so i could make sure the chain didnt jump
It took me a few but i was able to see it and eventually correct it

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[cheffrank_357]

Not bad at all. What sort of warranty did you get?

Its leaking oil
The pandemic has made me wait till
Now
But im taking it back tomorow
Its leaking oil onto the crank sensor
Ive burned 4 of them in the last month

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