NEW "correct" C.R. Pistons coming

[Challenger340]

stay Tuned....
2 product offerings may be coming for 440 mopars.

Seems to be a HOLE in the marketplace for actual factory "Correct" pistons for 440 Mopars, especially when it comes to a quiet running, inexpensive, cast replacement Pistons for the '68 to '70 440 Magnum and 440-6 pack engines.

So if I get my way..... coming soon....
1.) '68-'70 Cast Pistons, Flat Tops, on the factory correct 2.025" Compression Distance
and
2.) '68 to '70 Cast Pistons, Flat Tops W/4 Valve Reliefs, on the factory correct 2.055" to 2.062" Compression Distance.

Both will be quiet running as able to fit without a Torque Plate(another issue for many) at .0025" to .0030" piston to wall
Both can use the factory Cast or Moly 5/64"  rings(inexpensive).
Both will be offered in .030" .040" or .060" just like the factory did.

NO "special" fitting requirements as with Hypereutectic or Forged....
No " special' ring end gap requirements as with Hypereutectic or Forged.....

I will keep you posted.

[66FBCharger]

Why cast versus forged? Weren't the original pistons forged?
Can you please explain what you mean by "compression distance"?
I always learn new things on this site.
Thanks,
John

[don duick]

Can cast pistons handle 10 to 1 compression ?

[b5blue]

I get ya....and although to late for me, I hope it happens! 

[Challenger340]

Can cast pistons handle 10 to 1 compression ?

Yes, absolutely even if they were 10:1.
The factory pistons were cast, and many ran hundreds of thousands of miles.
Nonetheless,
they won't actually be 10:1 anyways, but neither were the original 1968 to 1970 Pistons, that were merely advertised as 10:1 ?

To explain better,
The original factory '68-'70 440 Pistons were approximately .055" to .060" down from the deck @ TDC, depending upon Block Machining tolerances. The original "Compression Distance", which is where the "Pins" are in relation to the Flat Top was a dimension of 2.025" to 2.030".
The original factory '68 to-'70 440 open chamber Cylinder Heads casting #2843906, "as cast" in production ranged between 84-86 CC's
And,
a Steel Shim Head gasket was used of .022" Compressed Thickness

Doing the Math as it relates to factory original Compression Ratio, as delivered in the "real world", these are approximate but close
84 CC Head + 5 CC Head Gasket + ~14.5 CC Piston Downfill Volume = 103.5 CC Clearance Volume
on,
a std Bore 440 Swept Volume of ~901 Cc's.

Making the actual "as delivered" 440 Magnum 375 hp Compression Ratio was closer to 9.6 to 9.7:1 as pretty much a best case scenario.

When rebuilding these Engines nowadays,
99% of the time a "composition" style Head Gasket is used at 10 CC's
which,
in conjunction with pretty much any open Chamber Head measuring upwards of 86 CC's even after rebuild a surfacing(lots are 88-90 CC's), very quickly ups the clearance volumes more in the 110-111 CC range and higher as a minimum, which even on a .030" overbore 440 very quickly yields an even lower 9.2:1.

At around 9.0 to 9.2:1, lowered still by the actual Dynamic Cylinder pressure from the "magnums" hotter Cam Intake Valve Closing point, and lacking much if any quench characteristic, the target is about right for todays fuel on ~140-145 psi cylinder pressure.
It won't win any races, but at least it will show up, which is far better than any of the current rebuilder Piston offerings are doing.

[BSB67]

Great Bob.

At least a guy will have a fighting chance to get back to factory original performance if he really wants.  Quality head work (no porting), newer cam designs, real 9:1 CR and a good tune will put them back to where they should be power wise. 

It is sickening to go to Mopar events at a track, like the Nationals,  and watch car after car after car run incredibly embarrassing high 14s and 15s at 90 mph, i.e. minivan territory.

[glhs0426]

Has the manufacturer made any headway on this?  A friend of mine will be be needing a set soon as well as myself. 

I'm finding the same poor "correct" piston availability with the 383 we are building for his daughters '71 Charger 500.

[BSB67]

Has the manufacturer made any headway on this?  A friend of mine will be be needing a set soon as well as myself.  

I'm finding the same poor "correct" piston availability with the 383 we are building for his daughters '71 Charger 500.

There is one, and only one, factory like piston for the 383 that is close to the factory compression height.  It is 1.920" verses the factory 1.932", if my memory serves me right.  However, 383 were well below their factory advertised CR, and if the heads have had a couple of valve grinds, and you use a 0.040" head gasket, your CR will still be in the toilet.  You really need to watch the details on the 383.  They were really not great performers to begin with.

[Canadian1968]

Great Bob.

At least a guy will have a fighting chance to get back to factory original performance if he really wants.  Quality head work (no porting), newer cam designs, real 9:1 CR and a good tune will put them back to where they should be power wise. 

It is sickening to go to Mopar events at a track, like the Nationals,  and watch car after car after car run incredibly embarrassing high 14s and 15s at 90 mph, i.e. minivan territory.

Curious, so in your opinion. Off the show room floor, with modern day radials ( for current day comparison ). What do you think a  68/ 69 R/T 440 AT, would run?

[BSB67]

13.8 to 14.0 @ 98 to 100 mph.  Decent tune, decent driver, decent air.