I have a 350 TPI accel 6 programable computer, stock 88 base,edelbrock runners,rpm heads milled .030
heads are now 64cc
head gasket .015
flaltop
bore 4.00
stroke 3.48
rod 3.700
CCA-12-256-4 COMP Cams Xtreme Energy Camshafts
Camshaft, Hydraulic Flat Tappet, Advertised Duration 256/ 268, Lift .449/ .456Intake close at 56 deg.
cr is 10.23
dcr is 8.95 using Pat Kelly's cal.
What cam do you recommend to bring DCR down to below 8.5?
I know it is a screwball setup but Thanks for any help you can give me.

Me2

 

The cam most likely comes with 4 degrees advanced built in. Try retarding the cam a degree at a time on Pat Kelly's calculator and see what happens. You might wind up with 4 degrees retard which in reality would be "straight up" with no advance.

It's the intake valve closing point which determines DCR. So if you want to change cams go to the next largest cam and that alone might do it for you depending on the IVC. Again you can play with the advance or retard some to get the DCR you want.

 

Thanks, 1989G TA TransAm.
Checked and you are correct.The cam has a 4 deg advance builted in.
Can it be retared 8 deg ,that will put it 4 deg retard from "straight up"
This will put my DCR at 8.2 Just what i want.
Will this cause me any other problems that you can think of?

Thanks again .
Me2

 

4 degrees retard will take all the advance out of it. That's as far as I would go. I believe any more than that and your valve events will get out of control. The cam you have selected is not all that big. Might go to a bigger cam or a thicker head gasket. Was the block decked at all? Did you have a chance to measure how far down the hole the piston was? Just trying to figure out why you are using a .015 head gasket.

 

Flattop pistons .022 in the hole.
Wanted quench at 37
I will check out a larger cam

Thanks
Me2

 

Quench at .040 is not bad at all. If you can find a .018 head gasket see what that does for your DCR.

 

Are they really flat top pistons? Most have some sort of relief for the valves, that will help lower both the CR and DCR.

 

Using .018 instead of .015 will lower the dcr by only .06. It came out 8.67 using .015 and 8.61 with .018.
Yes the pistons have valve releaf.I used 6cc to calculate the dcr.
Thanks again for your posts. I think my best bet is to find a cam with 64deg
intake valve closing witch will give a 8.2 DCR.

Me2

 

....and more power.