Pistons/CR

[dukeboy_318]

Recently picked up a nice 440 on the cheap, block was fresh from the machine shop and it came with a new set of pistons. Keith Black Silvolites.

http://www.summitracing.com/parts/uem-s1263-030/overview/make/dodge

Block is bored over .030, stock rods, stock crank, 1973 block. Stock rebuild on 452 heads.  Assuming little or no decking done to it, what compression ratios will I be seeing if I chose to use these pistons?

[John_Kunkel]

Assuming stock block height, a .020" gasket and 90 cc heads the pistons will sit .113" down for a CR of about 8.5-1.

[BSB67]

Assuming stock block height, a .020" gasket and 90 cc heads the pistons will sit .113" down for a CR of about 8.5-1.

This pretty much nails it.

[dukeboy_318]

Sweet. Thanks a lot. So if one wanted to get up to say 10:1 or close to it, sell these pistons, which piston would you all recommend? Goal here is 459-500 flywheel HP. Will be going with aluminum heads, probably RPMs, will be using a M1 intake and 509 Mopar cam. Car is going to be a 4 speed.

[BSB67]

Sweet. Thanks a lot. So if one wanted to get up to say 10:1 or close to it, sell these pistons, which piston would you all recommend? Goal here is 459-500 flywheel HP. Will be going with aluminum heads, probably RPMs, will be using a M1 intake and 509 Mopar cam. Car is going to be a 4 speed.

Any flat top piston of your choice with a 2.06" ish compression height (with valve reliefs), zero decked block, 0.040" gasket and 80 to 84 cc Eddy RPM heads.  Head cc should be adjusted depending on the cam and how close you want to get to the edge with the fuel you will be using.

Icon, Diamond, Probe, Ross, Weisco, Speed Pro (my last choice) all probably make a piston as described.

Check out Challanger340's post in Engine Combos, "....lowly 440....":  

http://www.dodgecharger.com/forum/index.php/topic,106687.0.html

[dfarr67]

Leave it 8.5 and put a blower on it

[Cooter]

Leave it 8.5 and put a blower on it

Assuming your referring to the roots style (vin diesel) blower, but why?
Roots blowers are only about 50% efficient and no intercooler.

[SRT-440]

Leave it 8.5 and put a blower on it

Assuming your referring to the roots style (vin diesel) blower, but why?
Roots blowers are onky about 50% efficient and no intercooler.

They are like fake boobs, they don't produce more milk or serve any real purpose other than giving us guys something big to look at!! LMAO!

[Cooter]

Agreed, roots blowers are like huge "pro street" tires. Just makes it that much harder to prove the car has the performance to back up the look.
for my 4grand, I'd just invest in a stroker and keep it under the hhen old with reasonable compression.

[c00nhunterjoe]

Agreed, roots blowers are like huge "pro street" tires. Just makes it that much harder to prove the car has the performance to back up the look.
for my 4grand, I'd just invest in a stroker and keep it under the hhen old with reasonable compression.

Big tire cars are easy to back up the look..... drag the rear bumper when you launch and i will beleive the power is there.... lol.

[Cooter]

Agreed, roots blowers are like huge "pro street" tires. Just makes it that much harder to prove the car has the performance to back up the look.
for my 4grand, I'd just invest in a stroker and keep it under the hhen old with reasonable compression.

Big tire cars are easy to back up the look..... drag the rear bumper when you launch and i will beleive the power is there.... lol.

Seen plenty of what's considered 'small engine' cars do this with only a few incorrect settings on the 3-4 link.
dragging the bumper is losing time.

A Fox body we set up for a customer one time hooked the best I've seen since. Sure, everybody loves wheelies, but just like big Mickey (yes, the bias ones for the street, hence the term "pro street. NOT slicks), they do nothing for performance.
this fox left with only about 1" under front tires, but was lethal quick.

[SRT-440]

What's impressive to me is...big turbo cars NOT pulling the wheels off the line, but pulling them at the 60 foot mark when the boost comes on...they usually end up running 7's or faster.

[69rtsetracpac]

Assuming stock block height, a .020" gasket and 90 cc heads the pistons will sit .113" down for a CR of about 8.5-1.

Would this cr hold true for a 72' stock build?

[69rtsetracpac]

Sweet. Thanks a lot. So if one wanted to get up to say 10:1 or close to it, sell these pistons, which piston would you all recommend? Goal here is 459-500 flywheel HP. Will be going with aluminum heads, probably RPMs, will be using a M1 intake and 509 Mopar cam. Car is going to be a 4 speed.

Wouldn't just going to a good aluminum head with a smaller(better) cumbustion chamber get your CR up where you needed to be without changing pistons?

[Cooter]

Sweet. Thanks a lot. So if one wanted to get up to say 10:1 or close to it, sell these pistons, which piston would you all recommend? Goal here is 459-500 flywheel HP. Will be going with aluminum heads, probably RPMs, will be using a M1 intake and 509 Mopar cam. Car is going to be a 4 speed.

Wouldn't just going to a good aluminum head with a smaller(better) cumbustion chamber get your CR up where you needed to be without changing pistons?

Yes, but that will only get you about a half to a little better. You want like full points of compression jumps, your gonna haveb to get it through pistons/machine work. Plus, aluminum heads allow more heat to escape the chamber. While normally not a bad thing, when dealing with 9:1 compression it can have adverse effects.