ponyboy88

Trying to work out the details for my build, and a few questions regarding compression ratio's.

Is there any reason why lowering the compression ratio via larger CC heads would be less efficient then using dome pistons. Just trying to decide between 58cc heads or the larger ones from afr/tfs.

wildcobrar

Need more info. What cubes? What Head gaskets? Pump Gas? Race Gas? Powere adder? If so what choice of power adder?

Joe

Venomantidote95

Compression ratio will limit and reduce or make power depending on your application! you have to know five things to figure it!

gasket thickness
cylinder volume
cc of chamber
piston to deck clearance
piston dome, dish, relief cc`s

the overall idea is total volume at tdc related to total volume at bdc gives C/R you have to know these five things to accuratly get your numbers! fuels and such will be bi-products of the ratio!

Higher the better fuel grade has to be used and less nitrous or boost you can run, higher C/R engines run better n/a and need less added power
lower you can use more nitrous or boost, poorer grades of fuel, engine will produce gererally less power without addition of a power adder!

uedlose

you can run all the compression you want with Nitrous if the tune is on you will be fine. low compression is for boost. What are you gone to do with it. Like said more info on the build is needed.

ponyboy88

car will be a stroked windsor, somewhere between 380 and 427 cubes, it will be boosted by a centrifugal blower, it will be a street car, so it will have to run 91-93 octane, dont want to mess with meth or Nitrous, probably with a tfs R intake and 90 tb.

will have the motor build by woody at fordstrokers, unless i find a good deal on a shortblock off craigslist,

debating between 58cc heads and 72cc heads.

wildcobrar

Let your engine builder figure it out.

Joe

Venomantidote95

Well he`s gonna mention probably what i have stated, and ask what exactly u want, but anyhow good luck.

There is only 1 way to figure compression ratios and i gave it to you!

combustion chamber size will affect more than c/r it will affect how the air and fuel mix in the chamber also both intake and exaust! you can use a big chamber with a big dome and get similar results as a flat top with a small cc the cylinder with operate a little different though. meaning the burn rate will be different in a dome application.

A flame will burn faster and more complete on a flat surface rather than a hill, hell the next time california is on fire watch how fast it burns on flat ground vs`s a hilly area!

no offence to the cali group on here!

brentsSVT

def stay away from nitrous, but meth will be your friend for sure!! and its cheap! i agree with what everyone has said. when i build my motor im shooting for 9:1 compression. that will still be safe and offer solid response on top of being good on pump gas. then add alittle meth and watch the boost climb and power soar!!