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the DV Live Now post

Moderator: David Vizard

skinny z
HotPass
HotPass
Posts: 1625
Joined: Tue Mar 11, 2008 8:42 am
Location: Alberta Canada

Re: the DV Live Now post

Post by skinny z »

Interestingly, DV makes several references to Mike Jones...This brings to mind our earlier discussions (I'm referring to you Jon). Seems that between the two of you, this is a solid endorsement.
Thanks again.
Kevin
SchmidtMotorWorks
Vendor
Posts: 10660
Joined: Mon Apr 11, 2005 2:30 am
Location: CA

Re: the DV Live Now post

Post by SchmidtMotorWorks »

skinny z wrote: Thu Nov 17, 2022 10:07 pm Interestingly, DV makes several references to Mike Jones...This brings to mind our earlier discussions (I'm referring to you Jon). Seems that between the two of you, this is a solid endorsement.
Thanks again.
Yes of course, a cam picker has so much less information to draw from than a cam designer.
Helping to Deliver the Promise of Flying Cars
SchmidtMotorWorks
Vendor
Posts: 10660
Joined: Mon Apr 11, 2005 2:30 am
Location: CA

Re: the DV Live Now post

Post by SchmidtMotorWorks »

skinny z wrote: Thu Nov 17, 2022 10:03 pm It appears we may have been responding simultaneously.
I've attached my text regardless although the closing line is only emphasized by your reply.
Thanks.

Found the reference to the .7 CoD.

From this we can say that the LCA = 128 - (CID/# of Cylinders/In Valve dia. in inches x 0.91). Putting some numbers into that we have for say a 355 inch SB Chevy that the required LCA =128- (355/8/2.02 X .91) which equals 108 degrees. So how accurate does that work out to be? Compare it to the graph a couple of posts ago – 108 is virtually spot on and so it will be for any parallel valve pushrod motor such as the SBC or similar (i.e. SB Ford & Chrysler) that has a CR around 10/1 and valve CD in the region of 0.7 (which most 3 angle valve jobs do).

If the intake valve has better than 0.7 CD average over the first 0.100 to 0.200 valve lift that 128 figure will increase and could go as high as 131 but only if the seats are really trick. If of course they are not and the CD is worse - then the key number could drop as low as 125.

Anyway, I'm genuinely hoping that DV steps in here.
Mr Schmidt has some very valid points to cover.
Chamber design is only one of many considerations for cam events.
The extraordinary focus on that is bizarre.
Helping to Deliver the Promise of Flying Cars
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