Old school 440 build

[Montclaire]

It's simple math and not worth dissecting every single word a guy says.

Put in the 1.99" piston and fine tune the desired compression ratio with the head gasket. That's what I'd do - cheap but no quench. For those that believe that all motors live and die based on quench, buy a 2.06" piston with a 13 cc dish. But then you're looking at balancing, and bushing the rods for the likely 0.990" pin.

Once the motor is apart and the measurements are done, its 2 minutes with a calculator, and 30 minutes in some piston catalogs to figure it out.

Yep. I’ll report back when I have some hard numbers.

 

[PRHeads]

A combo I’m certain has been built countless times over the last 40-50 years......
Std deck block, 2355’s, skim cut heads, fel-pro std head gaskets.
With 88cc heads(open chamber), you get about 9.2:1.
With 78cc heads(915’s), you’re at about 10:1.

To get to 10.5:1cr(or more) with a 440...... you generally have to build/plan for it.
Especially with open chamber heads.

 

[IQ52]

I think Montclair is trying to figure how the 2355 sixpack pistons got to 8.9-1. I was kinda wondering the same thing. I calculate flat tops at .021 down at 11plus with 915s, and mid tens with 906s. I would like to know what I'm doing wrong.

When toying with Pop's engine my combustion chambers were 93.5cc and I had 8.89:1 compression. You must measure your own components to know what you have. "If I have"..........won't cut it.

 

[wyrmrider]

what prh said earlier about quench
on one of my 6 pack piston builds they ended out + .015
due to amount block had to be decked to square it up
I used marine gaskets with 915 heads
easy to get 0 deck with 2355
impossible with 2" ch piston- forget thoes
lots of 73 have forged cranks and 6 pack heavy rods
if so loose them and use LY rods

they will help offset te weight of the 2355s
now since you have to ballance just find a nice modern light piston- with quench
makes a whole different eperience

 

[PRHeads]

When toying with Pop's engine my combustion chambers were 93.5cc and I had 8.89:1 compression. You must measure your own components to know what you have. "If I have"..........won't cut it.

I was using 88cc to come up with my 9.2:1 guesstimate.
If I added the 5.5cc of your heads to the total volume, it changes to 8.85:1.

“Most” of these builds aren’t built around 100% virgin castings.
Many have been through the shop at least once....... especially the heads.
There really is only one way to know what you have.

The farthest off from spec I’ve seen from a set of BB Mopar heads were some original Stage 6’s.
Catalog said(well...... some of them) 78cc.
Buret said 92cc.

 

[33 IMP]

When toying with Pop's engine my combustion chambers were 93.5cc and I had 8.89:1 compression. You must measure your own components to know what you have. "If I have"..........won't cut it.

Thanks, you explained what we missed, the 93.5 cc heads. That will definately skew calculations.

 

[BSB67]

Getting to 10.5:1 with 2355's and 915's is pretty easy. Zero deck, 78 cc, and a 0.040" gasket and you're there. Not sure I'd go there for a pump gas motor.

 

[qkcuda]

Great info in this thread, especially the links to the older dyno tests. This will help me a lot on my current 361 refresh.