426 Hemi engine questions

[Runcharger]

Just rotate one to TDC, measure how high the top of the dome is above the deck, then rotate it 180 degrees and measure how far down it is below the deck. Add that last measurement plus the first measurement and hopefully you'll end up with 3.75 (within a tenth of an inch allowing for the crude measurement). I would do it with #1 and hopefully the balancer is correct at TDC.

 

[snakeoil24]

Measure the rods and go from their

 

[snakeoil24]

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

All years 66 to 71 r the same assume nothing

 

[snakeoil24]

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.
View attachment 1568512

These pistons don't look to be milled

 

[snakeoil24]

Remember the studs on valley lots of guys didn't have correct wish bone extension for valley studs wound up warping heads from over tightening we have a vg machine shop in South River who can help you and knows hemis 99 percent of machine shops have never seen a hemi

 

[dan juhasz]

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.

They must be good then, I’ve heard from others that some machining may be required as they are clearance challenged on one side which may keep them from lining up perfectly when trying to insert the tubes.

 

[dan juhasz]

Remember the studs on valley lots of guys didn't have correct wish bone extension for valley studs wound up warping heads from over tightening we have a vg machine shop in South River who can help you and knows hemis 99 percent of machine shops have never seen a hemi

Steve what is the shops name?

 

[snakeoil24]

2 different companies second one is charlie weston does lots of mopars

 

[dan juhasz]

2 different companies second one is charlie weston does lots of mopars

I’ll reach out to them tomorrow, you prefer one over the other?

 

[snakeoil24]

Nick is a old guy who has been around english town 40 plus years. Charlie Weston runs a modern operation with tons of hi tech equipment both are good.

 

[Fran Blacker]

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.

Was about to correct the rod length, would check anyway, to stroker pistons.

 

[tubalcain]

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

I would almost bet my sister-in-law's reputation that they are stock 426 Hemi length of 6.860.

 

[Bird 426]

You can get new o'rings for those spark plug tube cups, and it may even need new tubes, mine did. I just tore down the Hemi in a Road Runner I just bought. Engine was thrown together, sort of. It's going to cost alot before I get it straightened out. Similar problems here.
Chevy shop did the last work.
Good luck sir

 

[dan juhasz]

You can get new o'rings for those spark plug tube cups, and it may even need new tubes, mine did. I just tore down the Hemi in a Road Runner I just bought. Engine was thrown together, sort of. It's going to cost alot before I get it straightened out. Similar problems here.
Chevy shop did the last work.
Good luck sir

Were your pistons also recessed in the bores at top dead center?

 

[Bird 426]

I would say no. Could take a picture of a cylinder top, haven't progressed further, on light duty from open hernia surgery!
Here's a picture of a cylinder top, my pistons are out, but ring land seems pretty close to yours. Didn't measure it.

 

[dan juhasz]

just a quick update, pistons were direct connection forged 12.5:1 pistons. They were milled to reduce the ratio. The rods are factory hemi rods 6.860. Stroke is standard 3.75. So apparently this is where these pistons were supposed to be in the bore at tdc. I'm having a cylinder head chamber cc'd and also a piston dome cc'd to get me the as built compression ratio. I'll go from there. Cam will be replaced as it measured after the ratio at only .450, really would like to go back to a solid lifter cam.

 

[snakeoil24]

just a quick update, pistons were direct connection forged 12.5:1 pistons. They were milled to reduce the ratio. The rods are factory hemi rods 6.860. Stroke is standard 3.75. So apparently this is where these pistons were supposed to be in the bore at tdc. I'm having a cylinder head chamber cc'd and also a piston dome cc'd to get me the as built compression ratio. I'll go from there. Cam will be replaced as it measured after the ratio at only .450, really would like to go back to a solid lifter cam.

So will they do the machine work for you??

 

[dan juhasz]

So will they do the machine work for you??

Weston? No, all they do is block and crankshaft work. No more complete engines, no more cylinder head work.

 

[snakeoil24]

then who

 

[dan juhasz]

then who

Really not sure yet.