Building a 383 or 440 a small dome piston or flat

[moparjohnny]

High performance street eng i can not decide? I have both blocks for a 69 roadrunner,i want enough compression to equal about 10 and no more than 10?

 

[Cranky]

What's the combination going to be? Aluminum heads? What cam? You have to take into consideration the total package before picking your static CR. Personally, I like a bit more than 10-1....

 

[moparjohnny]

will be factory heads open chambers,comps thumper hydraulic flat tappet cam,10-1 to 10-5 compression will work as well.

 

[RustyRatRod]

Here's the 383 I'm fixin to sling together.

.030 over 383 block cut to acheive zero deck height
KB400 domed pistons
516 closed chamber heads, ported with 1.74 exhaust valves installed
Compression blueprinted at 10.4:1
This cam: http://www.lunatipower.com/Product.aspx?id=1573&gid=283
Isky 8005 springs

Dynamic compression at 7.767 so it will run all day on pump gas. That doesn't even take the .043" quench distance into consideration, which will help it even further. Contrary to popular belief, domed pistons WILL work with quench, just not quite as good as flat tops. But the way the KB400 is designed, the domes are shaped taking quench into consideration.

 

[Budnicks]

MoparJohnny is it going to be a street car, a street/strip car, a race car, or just a cruiser or daily driver ??, what is it's intended usage going to be ??, what fuel are you planning on using or that is readily available in your areas ??, there are many other variable you should also consider, when choosing pistons/rings &/or compression ratios & camshafts... what type ignition system ?? what heat range of spark plugs ?? what type/size/material of cooling system, what water pump & what fan ?? what rear end gear ?? what transmission will it be an auto or manual ?? what work is performed on the cylinder heads ?? will the heads be ported ?? what camshaft ?? do you have allot of power accessaries, pwr brakes, pwr steering, A/C etc. ?? what kind of vacuum do you need to pull ?? what induction system/carb/manifold ?? will it have headers or iron original HP Manifolds ?? what size exhaust ?? what size valves ?? what size combustion chambers ?? what thickness & bore size of of head head gasket ?? what stroke & bore size ??... all can effect the actual usability/drivability & some will directly effect the final or static compression ratios also, especially how far down in the hole the piston are ??, what type of top ring ??, bore size ??, camshaft duration/overlap ??, intake & exhaust valve & port shape or size ?? type/style intake manifold & carb size ?? combustion chamber size & shape ??... There's a great site with a ton of calculators, to figure out many combos & mathematical type equations... IMHFO if set up & tuned properly, you can run 11:1 compression ratio, in either dome or flat tops easily, even with iron heads... www.WallaceRacing.com/Calculators.html Good luck