Question About 440 Piston Choices

[RemCharger]

In my old trw catalog, the bbm pins were the heaviest in the book, and one version of the 440 piston was THE heaviest piston in the book! (NOT counting diesels).

I have a 440 and 302 pin on my desk. The ford one is basically nothing more than an alternator spacer in comparison lol.

 

[lewtot184]

I found this in some of my old paperwork. It's from an old Arias catalog where they listed a forged quench dome 440 piston. They refer to the quench dome as a deflector dome anyhow, maybe an option. Part number is E4296030.

 

[Rusty34]

Would the higher compression height of the flat top L2355F yield about the same compression ratio as the domed L2295F with lower CH?

 

[1968rt]

2355 will yield about 9.7 with an 88cc head and .020 gasket, The 2295 will yield about 10.8. keep in mind the 2295 is a race piston, needs more clearance and will be noisier.

 

[Rusty34]

I'm trying to straighten out a stock rebuild that the previous owner's local engine machine shop made a few mistakes on. I'm OK with a heavy piston heavy as stock. Not really looking for high performance, just want to get all the numbers and clearances right because it's the original engine in my 71 GTX and it's just a 4bbl with factory AC, Power Steering and automatic. Thanks for all the great replies!!

 

[33 IMP]

For a numbers matching stock rebuild (heavy car, no offense, with ps, ac, and a 727) I would probably chose a KB flattop, over a forging. You don't need the strength of a forging in your app, and the KB's won't require rebalance and can be run tighter/quieter. Just check to make sure .040s are available. I would shoot for an honest 9 to 1, probably run ok on mid grade junk gas.
Edit: remember... factory compression ratios were frequently optimistic, sometimes very optimistic.
For a lighter street/strip higher horsepower higher rpm application, lighter forgings would be a no-brainer.

 

[PRHeads]

Pump gas street build with iron open chamber heads…….
The KB184 gets my vote, with the quench area of the heads set/equalized for effective quench.

 

[Rusty34]

I have no idea why newer engines have open chamber heads and short compression height pistons way down in the hole at TDC. Talk about zero quench! What do you think is the greatest benefit from light pistons? A stock 440 is a fairly low RPM engine.

 

[lewtot184]

Pump gas street build with iron open chamber heads…….
The KB184 gets my vote, with the quench area of the heads set/equalized for effective quench.

This. Kb184 was designed for the open chamber iron head and pump gas. But, following the instructions that are provided with the pistons is a must but and isn't difficult.

 

[33 IMP]

I have no idea why newer engines have open chamber heads and short compression height pistons way down in the hole at TDC. Talk about zero quench! What do you think is the greatest benefit from light pistons? A stock 440 is a fairly low RPM engine.

Light pistons greatest benefit, imo, is less stress on the connecting rod, (essentially making the con rods stronger, ) and less stress on the bottom end of the block, especially in high rpm/high hp applications. I might add 500 rpm to my self-imposed redline with a light piston, compared to a heavy trw. With enought head flow to support the extra rpm, that can be a decent chunk of horsepower.

 

[lewtot184]

I had did some engine work for some folks using light pistons and always wanted to try them for myself. I ended up taking about 3/4 of a pound off each cylinder with a piston and rod change vs stock. I also got fairly **** about bearing and rod side clearances. I ended up with the smoothest running 440 I'd ever had. I didn't gain rpm and light componets by themselves don't make power increases, but they have to be much easier on the crummy factory two bolt caps. They can let the engine rev quicker and that's a plus at the track. I'd do it again.

 

[33 IMP]

I had did some engine work for some folks using light pistons and always wanted to try them for myself. I ended up taking about 3/4 of a pound off each cylinder with a piston and rod change vs stock. I also got fairly **** about bearing and rod side clearances. I ended up with the smoothest running 440 I'd ever had. I didn't gain rpm and light componets by themselves don't make power increases, but they have to be much easier on the crummy factory two bolt caps. They can let the engine rev quicker and that's a plus at the track. I'd do it again.

My stroker pistons (ross), bb Chevy rod and pin, is a full pound per cyl less than my old maxwedge pistons and rods. Of course, the max stuff I had was extra heavy. ( the crank had steel slabs welded to the couterweights for balance, before mallory was in common use.)

 

[lewtot184]

I've built a couple of big chevys. I was thinking stock pistons and rods were around 750grams each. Noticeably lighter than Mopar. I used icon 836 pistons and some light 440 source h-beam rods.

 

[33 IMP]

I've built a couple of big chevys. I was thinking stock pistons and rods were around 750grams each. Noticeably lighter than Mopar. I used icon 836 pistons and some light 440 source h-beam rods.

That's a nice piston. Has 440 source got a 440 length h-beam with a Mopar big end and a bbc pin? (BBC pin saves something like 75 grams alone.)

 

[lewtot184]

That's a nice piston. Has 440 source got a 440 length h-beam with a Mopar big end and a bbc pin? (BBC pin saves something like 75 grams alone.)

the 440 source rods i used were 734grms, .990 pins, and had a mopar big end. side clearance with these rods was about .020"-.025"; better than the .045" i had with the CAT rods i took out. i don't think those rods aren't available anymore; may have been too light for some extreme builds. pistons were 716grms, pins 141grms. i've had some mopar pins that weighed 235grms,...ouch!