Dissect this CR calculation sheet..please

[nicpaige]

Scan.jpg

I plugged in a comp cams 231 profile(really planning on a custom late model profile cam for retaining plate so these numbers might change), and dished BullTear pistons @26cc, also plan on the Edelbrock head which I believe is 55cc chamber.

[Cheromaniac]

Looks correct to me but try adding 0 feet as the altitude and see what SCR and DCR you get.

[nicpaige]

Why would I want zero altitude, I'm not at sea level?

[nicpaige]

At zero altitude it goes to SCR 9.5:1 and 8.30 DCR. Will this live on 89-91 octane with .045" quench.

[Cheromaniac]

At zero altitude it goes to SCR 9.5:1 and 8.30 DCR. Will this live on 89-91 octane with .045" quench.

Should run on 91 octane no sweat.

Why would I want zero altitude, I'm not at sea level?

I know but you need to enter 0 feet altitude to get the correct SCR.

[nicpaige]

How do the numbers look for a street driven XJ that I tow a 10x12' trailer with on occasion? I hope Bulltear can do the 26cc dish with their blanks.

[Muad'Dib]

At zero altitude it goes to SCR 9.5:1 and 8.30 DCR. Will this live on 89-91 octane with .045" quench.

Should run on 91 octane no sweat.

Why would I want zero altitude, I'm not at sea level?

I know but you need to enter 0 feet altitude to get the correct SCR.

Keep in mind that altitude does effect SCR, so entering 0 or nothing in the altitude fields will give you the results based on your engine running at sea level both DCR and SCR. If your at a higher or lower altitude and you want to build specifically for those conditions, then make sure you enter the altitude you are running the engine at.

[jeepxj3]

Use a different cam choice closer to what you will be using with the cam retainer plate cam.