426 Hemi engine questions

[dan juhasz]

I had started another thread on weak performance on this 426 Hemi. Started the tear down and have several questions .
So I want to detail and re paint the engine compartment regardless, so engine is out. This engine has not run in several weeks. There was all this liquid on every closed intake valve, to thin to be straight up oil, if it was gasoline from the last time it was shut of warm it would have evaporated right?
This is the first Hemi I have ever disassembled. Are the pistons supposed to top out below the blocks deck by a good 3/8 of an inch. As seen by the carbon line in the cylinder the top ring line is about 9/16 + from the deck, is this normal? Pistons appear to have Mopar part numbers. Bank one ends in 569 bank 2 ends in 568.
Also are these Milodon tube seals seated? All the tubes had marks as if these were misaligned.
The engine had great oil pressure but the cam bearing don’t look so good. Some seem like they were not centered in the bore, misalignment of oil hole. It is hard to capture in a photo but very odd wear pattern .
Would really appreciate some input from members familiar with these.
Thanks Dan

 

[AR67GTX]

I had my intake off last winter and I don’t remember anything exactly like that down in the ports although I did have a bit of oily soot in some of the intake ports. It does kind of look like my oil that had dye in it. I’ll be curious on what responses you get.

 

[pnora]

Oil on the intake valves is usually a sure indication of intake gaskets sucking in the oil.

 

[gkent]

Carbon line is where the top piston ring stops - not where the piston tops out !! And 3/8 sounds about right.

You sure that green stuff isn't antifreeze ???

 

[snakeoil24]

I had my intake off last winter and I don’t remember anything exactly like that down in the ports although I did have a bit of oily soot in some of the intake ports. It does kind of look like my oil that had dye in it. I’ll be curious on what responses you get.

View attachment 1568459

Any freeze in oil common with steel shim head gaskets

 

[R413]

Looks like you have 12.5:1 pistons with that tall dome on there.

the cam bearings are just fine. a machine shop will tell you that also. The number 4 bearing has 3 holes, and the holes in the bearing don’t line up perfectly with the holes in the block.

retrieve some of that green liquid on the valves. Mix it with water, does it mix or separate?

what color is your engine oil? Green or brown?

was the car losing coolant? What color is your coolant?

 

[dan juhasz]

Carbon line is where the top piston ring stops - not where the piston tops out !! And 3/8 sounds about right.

You sure that green stuff isn't antifreeze ???

Just to follow up, the picture I’m reposting here is with this piston at the top of its travel. This is a normal appearance? It’s looks so low in the bore.

 

[Fran Blacker]

That short is a mess,MO. Looks somebody used short rods 7.76? The pistons are so far down in the hole. Wonder if it had a blower on it? Hemis have left bank 1 3 5 7 right bank 2 4 6 8, piston pin offset.

 

[dan juhasz]

Looks like you have 12.5:1 pistons with that tall dome on there.

the cam bearings are just fine. a machine shop will tell you that also. The number 4 bearing has 3 holes, and the holes in the bearing don’t line up perfectly with the holes in the block.

retrieve some of that green liquid on the valves. Mix it with water, does it mix or separate?

what color is your engine oil? Green or brown?

was the car losing coolant? What color is your coolant?

I think the phone made the liquid appear green. It wasn’t. Before I dipped into it with a thin screwdriver I thought it was oil, but the viscosity was way too thin. The engine used would use a quart of oil every 300/400 miles. The coolant was old school Prestone I don’t recall consistently adding coolant. It did have single steel shim head gaskets.

 

[Fran Blacker]

Sorry for being tough in last post but you need to look every part over. Who ever owned did some hokey stuff.

 

[dan juhasz]

That short is a mess,MO. Looks somebody used short rods 7.76? The pistons are so far down in the hole. Wonder if it had a blower on it? Hemis have left bank 1 3 5 7 right bank 2 4 6 8, piston pin offset.

See that’s what I think. I believe it ran like a bit of a dog because those pistons are too low in the bores. Plus it has a tiny cam I measured approx .455 lift .

 

[dan juhasz]

Sorry for being tough in last post but you need to look every part over. Who ever owned did some hokey stuff.

No no I appreciate it . When I brought the pistons to tdc I said this can’t be correct.

 

[gkent]

Is it an 8-bolt crank ??? Do you see where I'm going with this ?!?!

 

[6PKRTSE]

Looks and sounds like the whole assembly may be a mess. Take it all apart mic/measure everything or have a reputable shop do it for you. Seems someone just slapped it together with whatever they could find.

 

[dan juhasz]

Is it an 8-bolt crank ??? Do you see where I'm going with this ?!?!

yup 8 bolt crank, one of the throws looks like it has a 2 holes filled with Mallory metal

 

[dan juhasz]

Looks and sounds like the whole assembly may be a mess. Take it all apart mic/measure everything or have a reputable shop do it for you. Seems someone just slapped it together with whatever they could find.

I need to look up the correct rod length for a 67 426, would there be any engineering numbers on the rods to ID them

 

[Runcharger]

Ugh: Put together with mismatched parts. Could be stroker pistons on a standard stroke crank. Those could be 12.5 pistons with the tops milled off, hard to say. Not likely short rods as the piston skirts would hit the crank in most instances.
Oil leaking in from the intake, could be gaskets not sealing or cylinder head studs leaking into intake ports.
Those Milodon tube seals will pull up with the sparkplug tubes when pulled. Just lodge them again using a block of wood before installing the plug tubes.
Might as well measure the stroke, you can do that using a measuring tape.
Good luck with the rest of it. Looks like it needs the heads rebuilt and a new set of pistons and a rebalance at the minimum.

 

[dan juhasz]

Ugh: Put together with mismatched parts. Could be stroker pistons on a standard stroke crank. Those could be 12.5 pistons with the tops milled off, hard to say. Not likely short rods as the piston skirts would hit the crank in most instances.
Oil leaking in from the intake, could be gaskets not sealing or cylinder head studs leaking into intake ports.
Those Milodon tube seals will pull up with the sparkplug tubes when pulled. Just lodge them again using a block of wood before installing the plug tubes.
Might as well measure the stroke, you can do that using a measuring tape.
Good luck with the rest of it. Looks like it needs the heads rebuilt and a new set of pistons and a rebalance at the minimum.

The pistons are Mopar pistons 3690858 and 859. When googling they may be 12.5 to one .020 slugs.
When I pop one out tomorrow will there be any part numbers on the beams that I can look up?

 

[dan juhasz]

Ugh: Put together with mismatched parts. Could be stroker pistons on a standard stroke crank. Those could be 12.5 pistons with the tops milled off, hard to say. Not likely short rods as the piston skirts would hit the crank in most instances.
Oil leaking in from the intake, could be gaskets not sealing or cylinder head studs leaking into intake ports.
Those Milodon tube seals will pull up with the sparkplug tubes when pulled. Just lodge them again using a block of wood before installing the plug tubes.
Might as well measure the stroke, you can do that using a measuring tape.
Good luck with the rest of it. Looks like it needs the heads rebuilt and a new set of pistons and a rebalance at the minimum.

What’s the easy way to quick measure the stroke?

 

[tonysrt]

The aluminum spark plug tubes should be flush with the valve cover top or recessed a bit if the blue tubes are seated properly in the head.