I need someone to calculate DCR for two cams. I don't have excel so I can't use the spread sheet.

Motor Specs
Forged 346 12/1 comp ratio
ET 215cc milled to 59cc cambers
Custom diamond nitrous pistion(not sure on specs but has slight dome)
.045 cometic gasket

Cams are the same but with different intake closing points and ICL

Both cams are comp grinds. LSK intake and XER exhaust
First cam would not run on 93 octane/Getting knock in hot weather.
dur @.050 235/240
lift .6xx/.6xx
lobe sep 111
ICL 109.5
IVC of 47 degrees
15 degrees of overlap

next cam
dur @.050 235/240
lift .6xx/.6xx
lobe sep 111
ICL 111
IVC of 48.5 degrees
15 degrees of overlap.

I know I need to be in the 8.9 or lower to run on 93 octane.

 

Please add the .006" and .200" durations also. I checked on comp's website, but they only list the XER and smaller stuff that I could find. Need the piston info also.

 

need piston height and dish/dome cc's..

 

From what I remember the engine builder set up pistions .007 out of hole. The dome on piston is 1cc-1.5cc from what I remember. Put compression at 12/1 static.

 

LSK lobe 235 dur @.050/ XER lobe 240 @.050

dur @.006 285/ dur @.006 289
dur @.200 160/ dur @.200 161

First cam mentioned is my old cam but at IVC of 47 it would get knock on 93 octane when hot outside. I had a new cam specd and installed It has a IVC of 53 degrees. It runs great on pump gas but lost alot of hp/tq under 5500 rpm. I lost 15 rwtq at peak and 15-20 rwtq under the curve. I also lost 15-20 rwhp under 5500 rpm. I think on a stock cube motor the IVC of 53 degrees is to late. Just trying to get some power back and run on 93 octane.

Current cam in car.
LSK lobe 240 dur at .050/ LSK lobe 244 dur at @.050
dur @ .006 289/ dur @ .006 293
dur @ .200 164/ dur @ .200 168

LSK/LSK
dur @ .050 240/244
lift .649/.653
lobe sep 113.5
icl 113.0
IVC 53
15 degress overlap.


There is one other cam I spec'd using XER lobes to be easier on valve train.
XER lobe @.050 238/ XER lobe @.050 242
dur at .006 287/ dur at .006 291
dur at .200 159/ dur at .200 163

dur @ .050 238/242
lift .6xx/.6xx
lobe sep 112
icl 110
IVC 49
16 degrees overlap.

So I need to know the DCR for these cams. Thanks for everyones help.

 

235/240 w/109.5 ICL = DCR 8.97
235/240 w/111 ICL = DCR 8.84
240/244 = DCR 8.50
238/242 = DCR 8.84

 

Very cool, Thanks for the help. I can see why the first cam did not work on 93 octane. Looks like the cam straight up 111 ICL should work or the 238/242 cam. Thanks again.

 

You would probably have very good results advancing your current cam 4 degrees to a 109ICL. This would put the DCR at the same 8.84.

 

 

On your cam selections, your actual degree of overlap are 15.5.

 

I was using a cam spec calculator and it said 15.1. So I just rounded. I'm just not a big fan of cams with LSA in the 113/114 area. I think that advancing it 4 degrees is a band aid. That would mean that it would have +4.5 advanced. I'd rather spec a proper cam for my app. I've always used cams in the 111-112 lsa. I'm not saying that it is wrong just my opinion. The tighter LSA seems to give better low to mid power. That is where races are won usually on 60ft and 1/8 mile. For instance my previous cam would 60ft 1.57-1.59 all day on 17 inch ss wheels. The current cam I can't get to 60ft better that high 1.7 dead hooking(acutually bogs of line). Let me see if I can post a pic of my old cam on the 275/40/17 ET streets. Thanks again with all the advice/help.
.

 

Car used to leave hard on motor. Now it is a pig down low.