Mocked up the engine for Bobby's Checker today.

40 over, stroke verified at 4.125.
0.186 down the hole. .039 for the composite gasket, 5.94 cc's there. Flat tops.
Average chamber at 61 cc. Need .050 off the deck for 9:1 Static, or cut the head down for 45cc.
We'll be putting my Erson RV15M RDP in this engine for regular pump gas. Intake closing at 59 deg, overlap at lash 40 deg.

Can I get a math check?

7.45:1 Dynamic by the Wallace calculator, but no place to input the overlap. Maybe someone can help?

CJ

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Part of Tyrde-Browne Racing

The cochise downloadable calculator has a few more variables including the LSA and cam centerline it also displays the events and overlap and your numbers on the cam look correct per the standard cam card...If so then:

At your regular measurements (no cuts yet) and the cam is put at 106 intake centerline, SCR 7.58:1, DCR 6.36:1

Only Cut of .050 off the deck = 8.15 SCR and 6.82 DCR...
Only Cut the head for 45cc/ no decking = 8.90 SCR and 7.43 DCR...

.050 off the deck and 45 cc head = 9.74 SCR and an 8.12 DCR

45 cc head, deck for .020, and intake centerline for 103 =9.21 SCR and 7.84 DCR...

I'll have to install WINE on the machine to see if that calculator will work in Linux.

Found the error, and corrected the number in the Wallace calculator. Came out closer. Still not the same as your resultant.

Can you email the data set and results you pulled for the 7.84 DCR combination DI?

I'll send you a PM for email info if you don't have it.

Thanks for running those numbers! Something didn't look right. Haven't run a set since building the Hooptie. That's been a while.

CJ

_________________
Part of Tyrde-Browne Racing