just want some reassurance on combo choices

brian, your calcs are WRONG!,
if isky suggested a cam with LESS duration that will produce MORE compression
will work ,how can a similar cam with marginally longer duration produce higher compression in the same engine? (it won,t it will result in marginally lower effective dynamic compression)
Ive used that cam in similar engines with zero issues,
if a slightly milder cam in ricks T-bucket in a similar engine,works rather well,
and the crane cam has a slightly longer valve timing holding the valves open slightly longer,
that effectively results in even lower dynamic compression, will tend to reduce marginally the effective compression, but remember were talking only a couple degrees different, probably less than .2 in compression, (8.2 vs 8.1)

that issky cam has a .050 intake valve close at 42 abdc
that crower cam has a .050 intake valve close at 44 abdc
that crane cam has a .050 intake valve close at 45 abdc
look heres several cam manufacturers numbers why not call each, and average the suggested cams duration and lca
read this thread
http://garage.grumpysperformance.com/index.php?threads/semi-fool-proof-cam-sellection.82/

crane (386)310-4875

crower 619.661.6477
https://www.crower.com/camshafts.html?cat=854

erson 800-641-7920
http://www.pbm-erson.com/UserFiles/Documents/Catalogs/2013 erson catalog.pdf

lunati..662-892-1500
http://www.lunatipower.com/Performance-Cams.aspx

ISKY 323.770.0930

clay smith 714-523-0530

herbert cams 714-491 -2267
 
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Grumpy said:
brian, your calcs are WRONG!,
if isky suggested a cam with LESS duration that will produce MORE compression
will work ,how can a similar cam with marginally longer duration produce higher compression in the same engine?
Ive used that cam in similar engines with zero issues,
if a slightly milder cam in ricks T-bucket in a similar engine,
and the crane cam has a slightly longer valve timing holding the valves open slightly longer,
that effectively results in even lower dynamic compression

look heres several cam manufacturers numbers why not call each, and average the suggested cams duration and lca
read this thread
http://garage.grumpysperformance.com/index.php?threads/semi-fool-proof-cam-sellection.82/

crane (386)310-4875

crower 619.661.6477
https://www.crower.com/camshafts.html?cat=854

erson 800-641-7920
http://www.pbm-erson.com/UserFiles/Documents/Catalogs/2013 erson catalog.pdf

lunati..662-892-1500
http://www.lunatipower.com/Performance-Cams.aspx

ISKY 323.770.0930

clay smith 714-523-0530

herbert cams 714-491 -2267
Click to expand...


Your Letting Your Emotions get in the Way Grumpy of Laid out Facts.

This is what You Taught us here.
John & Me.
John is following.
He is cross checking.
 
7.891 on the above grumpy camshaft on grind 119651 as posted will run some ea simulations tonight need read info on combo. Too many open variable. Need real header size and exaust if running. Intake air gap and single plane will run then will excel info on graph. Let number speak including a whole curve to compare. Will make good discussion.
 
crane119651.jpg



HR306 Grumpy.PNG

SHOW ME MY ERROR GRUMPY.

YOUR HR306 CRANE CAM IN KEITH BLACK DYNAMIC COMPRESSION CALCULATOR.
DYNAMIC IS 8.8 TO 1.

WAY TO HIGH FOR PUMP GAS 93 OCTANE.
 
I'm not letting emotions get into the discussion just FACTS and EXPERIENCE

thank you

Strictly Attitude

thats almost exactly what my dynamic compression calcs show
 
Allot thrown around in here but need to group info in one post make easy to pick through pump gas only combos 8.3 and under dynamic aim 8.2 range using advance will be used at my discretion. Dyno sim will run 2000-7000rpm. Need Carb info also. Christopher, Brian, and Grumpy post cam cards you want to see. I will do the rest tonight.
 
Grumpy said:
I'm not letting emotions get into the discussion just FACTS and EXPERIENCE

thank you

Strictly Attitude

thats almost exactly what my dynamic compression calcs show
Click to expand...
Then the entire premise of your Keith Black Dynamic compression ratio teachings has been Futile.

so what happens when VE Cylinder fill rate is 105-140 % ?

What I have know for some time .....Dynamic only for low revving street engines.
 
Without Pipe Max used its going to be difficult to predict true VE.
Dynomotion shows what it can.

Real World VE is measured on an engine dyno with the Air Bell Flow Meter calculated from there.
 
Screenshot_20180831-091354_Samsung Internet.jpg
But besides that let's just group the cams over lay them see what happens then let Chris decide I like Isky so does Brian Grumpy has his crane and crower favorites and Chris likes ? I like custom ground also.
 
brian, this is NOT PERSONAL I really would prefer the guy select the correct matching cam ,
and if its the isky roller thats just fine, as long as his engine runs well, thats the goal,
I don,t have a damn thing to gain here if he selects a CRANE,ISKY,HERBERT,LUNATI OR CROWER ETC
and in fact if I were to advise something that won,t work Id look foolish.
I don,t pick components out of thin air, I base the selection on my past engine builds
 
Like I said early on in this thread your better off looking at cranking compression ratio.
Best factual proven to run on pump gas 87, 89, 91, 93 octane RM/2.
 
Id point out that the forged 400 pistons generally have valve clearance eyebrows closer to 7cc- 8cc in depth/volume
WIC758.jpg

and if the blocks never been decked its at least .024 taller from zero deck calcs.
youll want a .040- .042 ideal quench
Id also state I suggested you start with split over lap cam timing that retarded the cams valve timing 4 degrees.
Id also point out the .004 valve seat timing
crane119651a.jpg


remember the piston compresses zip until the valves seat
crane119651a.jpg

crane119651a.jpg

on the 119651 crane roller, the kb calculator assumes the valves seat at 15 degrees past the .050 valve timing, the cam specs show the intake valve seat time near 82 abdc not 60 as listed in the calc
that calculator used only a very rough guess , on valve seat timing, based on flat tappet cams, roller cams have different ramp designs
roller cams can not last if the lifter lose contact with cam lobes and bounce,
thus the closing ramps last or lower edge trys to prevent valves bouncing,
and theres a longer and slower last bit on the rams closing velocity
remember that at lower rpms that seat timing allows air compressing over the piston to bleed out but as rpms increase the time is reduced,
this is also the case for the cylinder burn and detonation timing,
at lower and mid range, rpms detonation can become far more damaging than at higher rpms,
simply because theres far less time for detonation to occur between the ignition spark initiating the burn, and detonation potentially occurring
and the piston already dropping rapidly away from TDC.
if the ignition flame front has already washed over the whole piston dome due to rapidly increased turbulence and squish,at higher rpms the potential for detonation is greatly reduced
at 2000 rpm theres only roughly 17 power strokes per second
at 6000 your up to 50 per second, thats significantly less time to bleed of compression through a small valve seat gap.
vgd5.jpg

porting+valve_area.jpg
 
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The best way to make it sound like a Race car with a mild cam is to run No exhaust at all.
Just Loud.

But no 5 cycle lumpy lump guys in the know.
Engine also Twitches dances around with a Race Cam at idle.
Solid mounts entire car shakes race cam in it.
 
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