Does this DCR sound right to you?

[Guest iskone]

At first I was going to use 210cc but they made alot of torque down low.

So I've decided to go with the 230cc, that is unless some one tell me why not to use 230's.

The only thing I can think of is thortle response but with 360lbs+ of torque I think I should be a ok.

[Kevin Shasteen]

Sorry iskone-but I have no knowledge or experience to pass along on the 230cc heads.

 

I will say this though, you are getting in the "Dedicated Race Engine" cylinder head territory with the 230cc sized ports.

 

Port Sizing for a Typical Small Block

upto 165cc = Mild Sized Ports also for Smaller Cubic Inch Displacements

165 - 195 = Moderate Sized Ports; H/O Street for mid Displacements

195 on up = Maxed out Sized Ports: H/O Street and Dedicated Racing for Larger Displacements

 

Usually the 230cc heads will be found on 406 cu inch engines & up. Where is the line drawn between the point of "Delaying The Airflow Velocity" at early rpm, such as in a light Z car, -vs- suffocating your engine at low rpm due to too little CFM caused by cylinder head/carb/cam combo that is mismatched?

 

Without looking at someone else's documentation all we can do is guess. Keep in mind the only real way to know if your 230cc heads are too big for a 383 V8 is if we had the Airflow CFM at lower rpm's and then factor them into our DCR process.

 

Remember-when you work out your DCR to match your SCR: all you have done is made a "Mechanical Connection"...and this is a great start yet it is not the only item you have to nail down when building a performance engine: as you have not factored in the Volumetric Efficiencies of that engine.

 

This is what I elluded to in an earlier post about DD2000. That engine sim "ASSUMES" your port pressures, ergo-Cylinder Pressures, are always optimum. Yet, in the real world, once your parts combinations begin to creep upon and cross the line of streetability-the reality is that your Port Pressures, ergo-Cylinder Pressures, will not be optimum at lower rpms.

 

When building an engine for maximum performance, whatever your level of performance is, its also good to realize that your actual VE% can fall, at idle, to 20% or 30% its actual displacement: this would put your engine's DCR in the 3.0:1 DCR range. This means that your 383 is breathing like an 81 cu in V8. So be careful about using DD2000 when looking at 230cc heads for a street engine.

 

As I said earlier I have no hands on experience with these heads nor have I read up on them when being utilized in an engine build. Surely someone here has used those heads before and will have some input for clearification.

 

Perhaps you might want to start a new thread and title it "210 or 230cc Heads?" then you will get a better response.

 

Kevin,

(Yea,Still an Inliner)