Some compression problems in cylinders 6 & 8 and an intake swap

After (and during) cam break-in, I noticed that the sound from the right exhaust was different from the left one. I have two separate exhaust pipes, no X or H balancing. I noticed that the exhaust gasses from the right exhaust where less hot than the left one. With the infrared thermometer I measured a much lower temperature on the right exhaust manifold. And the engine shook, as if there where a couple of cylinders that didn't work.
So I did a compression test. Cylinders 6 and 8 did not have any compression at all! That meant I had to take off the cylinder heads.

 

By now I know the drill. All the coolant has to be drained. The intake, valve covers & valve train have to come off, again.

The right side cylinder head is off. The gasket is still on the block. And of course there came out a lot of coolant. Apparently it isn't possible to drain the coolant from the heads. So you see some coolant in the cylinders. The coolant poured out when the head came off.

The left cylinder head is off.

Headless

The first picture is from chamber 8, you can clearly see that the exhaust valve is too high into the head. On picture two, you see chamber 6, same as chamber 8.

Here you see that the left and right valves & springs are much higher than the two in the middle.
This can only mean one thing: severely burnt valve seats. So I took my two cylinder heads to the machineshop.

Two weeks later I had two fresh and almost new cylinder heads. Cleaned and with new valves, seats, guides, springs, spring retainers, locks & stem seals. The springs and retainers are from Edelbrock, they belong to the Performance camshaft.

One of the chambers.

The top side, the springs.

The machineshop noticed a little crack in one of the heads. (Just left from the head bolt hole on the right)

Luckily they could repair it.

Preparing the block. The remains of the old gasket had to come of.

The right cylinder head is back on the block again.

The left side as well.

The rockershaft & rockers and the pushrods are back again. The rockershaft is not yet thightend, as you maybe noticed.

Because I didn't want to install the old intake, just to see if everything was working. And after that, taking it off again for the new intake. I installed the new Edelbrock Perfomer intake right away.
Not visible in this picture, I used intake gaskets without heat crossover holes. I don't need heat below the plenum.

After installing this intake, I can only think; who's the idiot design engineer, who designed this particular intake? I don't think that person has ever tested if you can use a torque wrench and short socket on the two bolts, marked with a white arrow.

The water neck was completely corroded. So I cleaned and painted it. It's installed with a new 180°F thermostat.

A new problem presented itself. The Mopar Performance aluminium valve covers are touching the intake at two places at each side (see green circle). I've read about it. If the intake and valve covers making contact with each other, you can't install the valve covers properly. Unfortunately I have this problem too. The solution is simple, you have to mill or file some of the aluminium, from the valve covers, away.

The problem with the valve covers is resolved.
I filed a lot of valve cover aluminium away. And this is times four. I first filed the edge of the cover away, but this wasn't enough. I had to file some more away at an (approx.) 45° angle. Because the intake runner wasn't at the same angle as the cylinderhead.

As you can see, it fits nicely. Maybe a little too wide.

This is with a gasket. And I made the bare aluminium black again. This way you can hardly see there's missing some material.

I am not happy with the water bypass hose and fittings. I couldn't screw the blue fitting (see green circle) deeper into the intake. It was too long and I couldn't install the bypass hose. So I had to saw off a piece of the blue fitting, including the hose barb. I had to use some RTV silicone rubber to make it (hopefully) watertight.
Now I know what is best: the original Mopar Performance fitting P4876374 and a new bypass hose which fits the P4876374 fitting. I had to fabricate a tool to screw the hose fitting in, but that was well worth it. It fits like a glove :-).

I installed the exhaust manifolds and bolted the exhaust pipes to the manifolds. The exhaust on the passengers side had a heat riser control valve. When the manifold was off the head I removed this. But that left me with a hole in the side. So I tapped some threads in it and plugged it with a bolt and some sealant. This way the heat riser doesn't restrict the flow of the exhaust gasses.

With the new intake I also changed the place of the ignition coil. Original it's horizontal mounted on the intake near the distributor. Not a good place, too much heat. And I think an oil filled coil should be mounted vertical. So I found a good place for it. The mounting points where originally used to mount the receiver-drier of the air conditioning unit. I made a bracket for the coil. This way the coil is upright and not to far away from the distributor.

The alternator is back in the engine compartment and all wired up. I had to fab a little bracket, because I forgot to remove it, when my heads went to the machineshop. They had removed it, so I had to make my own. Nothing special, only a spacer between the head and alternator.

The plumbing for the oil pressure sensor and switch. They share an oil pressure outlet. We will see if this will work. This way you see immediately there is no oil pressure, because of a bright red light. If you only have a gauge, you don't notice it right away.

I did a compression test and all cylinders had good compression!
This means the compression loss from cylinders six & eight where due to burned valve seats.
Oh yes, the oil pressure gauge is working, although it was low, it was during cranking. So it looks like the plumbing, see photo above, has no restrictions for the oil.

The engine is running again. The engine fired up at the first try. I made a little movie (see below). This movie is shot with my phone, so you hear a lot of high tones. The fuel, oil temp and AFR gauges are not yet connected. The water temp gauge is working, but the engine was just started, so the water is not warm yet.

See also the propane page. Click to go there