Don Terrill’s Speed-Talk

Larry, What are you using for Cd and FA? I long time ago I found somewhere on the internet. 70 Chevelle .42 Cd 25.52 FA Stan i did a very quick Simulation for Mark's 650 HP ... i didn't fine-tune it or nit-pick it however, i came out pretty close to reality :) VortecPro_DragCoefficient_FrontalArea....

maxracesoftware wrote: ↑Mon Apr 15, 2024 12:57 pm .... this would be an "Ideal Run" that would show 650 Peak HP with a very flat TQ and HP Curve
something to shoot for !

VortecPro_Ideal_Run_650HP.png

 

Larry,
What are you using for Cd and FA? I long time ago I found somewhere on the internet. 70 Chevelle .42 Cd 25.52 FA

Stan

I used 3500 and guessed at a few things. 60 Foot ET = 1.3451 330 Foot ET = 4.0295 1/8 Mile ET = 6.3696 1/8 Mile MPH = 104.4593 1000 Foot ET = 8.4108 1/4 Mile ET = 10.1480 1/4 Mile MPH = 129.8599 In better air close to DA = 0 60 Foot ET = 1.3132 330 Foot ET = 3.9323 1/8 Mile ET = 6.2165 1/8 Mile MPH...

I used 3500 and guessed at a few things. 60 Foot ET = 1.3451 330 Foot ET = 4.0295 1/8 Mile ET = 6.3696 1/8 Mile MPH = 104.4593 1000 Foot ET = 8.4108 1/4 Mile ET = 10.1480 1/4 Mile MPH = 129.8599 In better air close to DA = 0 60 Foot ET = 1.3132 330 Foot ET = 3.9323 1/8 Mile ET = 6.2165 1/8 Mile MPH ...

als427 wrote: ↑Sun Apr 14, 2024 5:23 pm ok fair enough , does a 155-170 gove an indication of engine health either way and suitability for the street? or is it all %^$£

That tells you nothing by itself about engine health. What is your CR and IVC (seat-to-seat @ the valve).

Stan

The car: My 1968 Chevelle, T350 4.56 gear, (not optimum) 30x9 radial slick. Exact weight will be posted when I run across the scales Sunday. The results from the first lackluster test were: 10.50 @ 124.5 140 60 foot, 6.61 660 @ 102 MPH #-o Same engine this time drag tested in different conditions. ...

vortecpro wrote: ↑Sun Apr 14, 2024 11:16 am I should mention the 496 in my test makes 650 STP corrected HP @ 6200 RPM.

Do you have a dyno sheet you can post? I was going to do a few simulations, this is what I have for your 496 from a few years ago.

Stan

Topsp33d wrote: ↑Thu Apr 11, 2024 10:41 am What about the ivc? Is it of no consequence? I have smaller cams, one I like is 66* (seat ivc). What if I retard that 4 degrees?

66* ivc retard that 4 degrees is 70 ivc, which should raise your DCR about .3 of a point.

Stan

HQM383 wrote: ↑Wed Apr 10, 2024 1:01 am Is the an IVC of 74* at .050"?

Could be at the seat-to-seat

Stan

PS - An example - 292 intake @ 108 ICL 38/74

This would be a good test engine to examine DV's 128 cam LSA formula. Couple cam swaps. Also interesting to see what a high rise dual plane (rpm air gap) does on this one. Question is: Does a calculated 105 deg LSA cam work better than this 108 LSA cam? Can you get most of the way there by adjustin...

Here is the latest FREE 14 Day Trial of our IOP / FLOW Program.

Stan

The other 14 Day has expired and will no run. This is the install package for a new 14 Day version of TMC. Note at this time TMC only does SBC.

Stan

There are current production engines, in street cars running 13:1 on 87, at WOT ...so a lot has changed. Those same engines do pick up power on 93. But if you are expecting old stuff to run more compression on 93 than we did 25 years ago, your setup won't be the same as it was 25 years ago. But not...

Actually RPM has no bearing. Trapped mass / VE% does.

Stan

Bore = 4"
Stroke = 3.48'
Rod = 5.7"
CR = 11.5:1
Cranking Compression = 230 psi
Temp = 60F
BP = 29.92 Inches Hg

DCR = 8.8539:1
IVC = 68.878

Stan