Blue smoke. Now wtf?

[Mark1972]

Have done the compression test 4 times, and it never goes above 20, which is the lowest number. Also did it again on other cylinders and it have the same original number. So the gauge is good. I borrowed a bore scope off a friend but it's older and the quality to poor to see anything. Well that's it for today. I'll speak with engine builder tomorrow and go from there. Thanks all. Not a good day.

 

[threewood]

Check the rear corners of the valve covers near the firewall. They can and will leak with the tin covers and it will drip right on the exhaust. Looks as if it us coming from the pipes while driving. Just a thought.

Edit - just saw the low compression on #2. If you have a broken ring or other stull going on it would definately pressurize the oil in the crankcase. Was the car running rough?

 

[1 Wild R/T]

I'd remove rockers as the last test before pulling head. Don't know if you'll get a good reading without intake valve opening maybe back off adjuster if you have adjustable rockers.

With the rockers removed you would want to do a cylinder leakage test, I'm sure the O/P doesn't have the tool but by simply applying compressed air you can learn allot, you won't have a percentage number but you'll see if air comes out the exhaust, intake or crankcase breather.....

The 10 PSI number is so bad it has to be a valve or a hole in a piston...

Years ago I had a truck in my stall, less than 2K miles runs rough.. It had 50 PSI in #5... When I tore the engine down there were no rings on that piston..... So bad rings aren't gonna get you 10 PSI

 

[Ernie ingling]

Pull right vc rotate engine so #2 is off lobe apply forced air to cyl not much press. Listen for air out carb int. valve. Ex pipe ex valve
Oil stick piston.

 

[PRHeads]

In light of what’s already been done, I’d pull the valve cover and watch the valve motion for the cylinder with low compression.

Actually, if you have a leak down tester...... leak that cylinder down first.

If it leak tests acceptable, then I’d pull the vc and watch the valve motion.
An intake lobe that’s MIA will give low cranking compression numbers.

If the leak down test is as bad as the compression test, where ever the air is going...... that’s the problem.

 

[kiwigtx]

Just another 2 cents worth here....

Did you manage to cross over plug leads 5 & 7 during the break-in period at all?
If so, and you had a massive back-fire, you probably split the turkey pan (intake gasket) - check for oil sitting on the pan, as it will run out the back and onto the headers or exhaust manifold while driving. I know this...done it myself once.

 

[Mark1972]

Regarding break in and crossing 5+7, I couldn't tell you. The engine builder dyno'd the engine for break in, and said there were no issues at all. I've never heard this engine backfire once since I've had it in my car. Hell even with 7 cylinders it still ran pretty smooth yesterday. I don't have the tool for a leak down test. It's really up to the engine builder to decide how to proceed now. If he wants me to pull the valve cover and look for valve issues, that's fine. If he wants to come here and see what's happening first hand, by all means come over. I just want to get it figured out and fixed. It was supposed to go to storage next weekend to make room for another project. I'll post tomorrow after I speak with the shop. This shop is very reputable, and has been excellent to deal with. I foresee no issues in getting this problem sorted out.

 

[Fran Blacker]

Wonder if you have broken valve spring on that cylinder leaving a valve open?

 

[Mark1972]

The intake rocker of number 2 cylinder was punched out. The indent where the pushrod sits broke, and was laying on the head. The rocker and the shaft under the rocker was blue from excessive heat. Obviously wasn't getting any oil. Picture below. I grabbed a leak down tester and set at 90psi, and the loss was 5%. The shop is replacing the rocker shaft, rocker and pushrod, and I'll pick them up tomorrow, and then do another compression test. I'll post again when I know more.

 

[1 Wild R/T]

Excellent.. Love an easy fix...

 

[Mark1972]

But why did it not get oil? How long would it have taken to turn blue from the heat? My concern is that it happens again.

 

[1 Wild R/T]

Those look like used shafts/rockers... Were the plugs removed from the ends of the shafts & a bottle brush used to clean the inside of the shaft?

 

[Mark1972]

Those look like used shafts/rockers... Were the plugs removed from the ends of the shafts & a bottle brush used to clean the inside of the shaft?

The shafts were used, but the stamped rockers along with everything else on the valve train is new. The shop assembled and tested the engine, so I'll assume they did what was required to prep the shafts. The shaft this rocker is on will need to be replaced, as like the rocker, it turned blue from heat and is now weakened.

 

[PRND21]

Hole plugged in rocker shaft or hole plugged in rocker would be the first place to look. Glad there’s not too much damage, still sucks when you have to take something back apart.

 

[Fran Blacker]

This may not apply to BB but I put one of my rocker shafts in wrong on a 318, did the same thing. Think I put it upside down.

 

[BSB67]

Hole plugged in rocker shaft or hole plugged in rocker would be the first place to look.

Agreed. If I was a betting man, I would guess the new rocker as the cause over the used shaft.

 

[Fran Blacker]

Wonder if Mark1972 should bump engine so cam oil hole line up to make sure he has a flow of oil? If I was building a BB wedge I'd have the small groove cut in cam journal 4. Hemi's have it why not wedges? Anybody have an answer why not.

 

[1 Wild R/T]

Agreed. If I was a betting man, I would guess the new rocker as the cause over the used shaft.

I don't agree, The hole on the rocker just allows oil to get to the pushrod... That whole rocker turned blue, no oil was getting out of the shaft....

 

[BSB67]

I don't agree, The hole on the rocker just allows oil to get to the pushrod... That whole rocker turned blue, no oil was getting out of the shaft....

Good point. Is the rocker stuck to the shaft, or are they galled?

 

[PRHeads]

A fast rate hyd cam, higher valve spring loads, and aftermarket stock replacement rocker arms.
That’s a combo that doesn’t make me feel warm all over........ although I think in this particular case, the oil feed hole to that rocker was probably blocked.

If the plugs on the ends of the shafts don’t look new(from being replaced)....... there was/is likely some debris inside(and they should be cleaned out).

I put a pushrod thru a rocker on my heap about 35 years ago....... nothing was discolored though...... it just fatigued and failed.