Hi, I have a 396 - .030 with KB 9.4 hypereutectic pistons,"215" oval port heads - stock valves , no porting ,felpro no retorque gaskets , and a Comp nostalgic LS6+ camshaft,installed straight up.What is my DCR? Thanks.

Any idea of the cc's on those pistons? And I don;t know what to use for the 215 chamber size. Thinking 101 or so. Bear in mind that without actually measuring this, its an approximation. Also, what exactly do you mean by "installed straight up" on that cam?

The Effective Head volume : -17cc , the piston dome : .180 (hollow dome) , the head cc : 96.4. the camshaft isn't advanced or retarded 4 degrees,the timing chain marks are zeroed(straight up).The cam card valve timing at .006 - INT 30 btdc(open) 66 abdc(closed), EXT 78 bbdc(open),26 atdc(closed)the cam was installed at 108 intake centerline,the lobe separation : 112. I hope this helps.

Mark, why don't you download the calculator and run the numbers yourself. It's linked in my sig. If you have any questions after that feel free to ask.

I tried to load the DCR calculator, but with no luck, I'm just curious about what my set up is.

9.96 static assuming .015" deck, dcr = 7.8911 assuming the cam is +4 which is what straight up means here.

Could one of you gurus run a comparison for me? I've been using the DCR calculator on the Keith Black home page ( http://www.kb-silvolite.com/calc.php?action=comp&PHPSESSID=1f97db2885cba4dedccfd2c8c243a25e )and it seems to be fairly accurate. Please pick any combo and run it there against Mr. Kelley's and see how they compare. Note that the KB calculator requires you to use the .050 duration and ADD 15 degrees. Thanks!

427L88 - the deck was never milled, it was flat within .002 , and thank you for your help. Is a 7.8911 DCR good for the street, this is relatively new for me.

If the deck was never milled then I believe the ratios will show high as the the real deck height is likely closer to .020".

Yeah, 7.89 is fine and it might be more like 7.85. Likely run on 91 octane, maybe even 89.

I tried that KB site and couldn't get my static right.

Try this site..

http://www.rbracing-rsr.com/comprAdvBMW.htm

And I like the ROSS Racing Pistons site's static compression ratio calculator..

But do read Pat's site's info... And I too have trouble loading Pat's program but it's b/c I'm almost computer illiterate(Sp?), and it's not Pat's program at all is all...

pdq67

I've ran a comparision with the KB calculator. My recommendation of using advertised duration comes from David Vizard in his book on SB cams and valvetrains. Using advertised duration gives the same answer for both calculators. I recommend using .050 + 15º for low intensity cams like the Performer Plus cam (277/288, 204/214 @ .050). For more agressive cams using advertised duration gives a more accurate answer.

Thank's Pat for that tip.

Did you catch my Melling solid cam info over at "Little Brother"??

pdq67

Little Brother???

Little Brother??? code for camaros.net (I think)

Pat,

Chevelles are like bigger cars, you know, "Big Brother's" and Camaros are smaller cars, like "Little Brother's"!!

Dueces are like Cousins...

pdq67

It's all perfectly clear now smile.gif . I haven't been over there in a long time.