Dyno Sim

Lmus10

Member
Would like some to run a Dyno Simulatation on a motor that I am looking to build.
Not sure what info you will need.
355 sbc, .025 deck height, flat top 4V pistons, Dart 200cc Iron Eagle heads 64cc cambers, 2.02/1.60 valves,
solid flat tappet Bullet cam Duration @ .050=255/263, Lift .540/.556 (1.6/1.5 rockers)
Lobe separation=106, Intake centerline=102, Holley Single plane intake, Holley 750 mech.
Please let me know if any other info is needed.
Thanks for your time and help.
 
What intake manifold?
Flow numbers at each lift number for your heads.
Cam card OR all the opening / closing angles, both Seat-to-Seat and at .050 lift.
Valve lash if not on the cam card.
Head gasket thickness.
Headers, what primary tube size?
 
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Holley Single plane intake, info on the cam stated above is all that Bullet gave me.
Have not purchased cam as of now.
Not sure where to find flow numbers for these heads.
1-5/8" primary tubes.
I know not enough to go on.
 
If you would like it, give me your email in a PM and I will send you Desktop Dyno 2000, 2003 and CamQuest..
 
Holley Single plane intake, info on the cam stated above is all that Bullet gave me.
Have not purchased cam as of now.
Not sure where to find flow numbers for these heads.
1-5/8" primary tubes.
I know not enough to go on.
I can make some assumptions, but of course the numbers won't be as accurate. Might have
something later today, around 5:30 pm CST.
 
Looking at those numbers you posted for your camshaft seem pretty radical for a first
engine build. I assume this is your first. Therefore I picked something more streetable in
an Hydraulic Flat Tappet camshaft. That Single Plane manifold is typically for higher
RPM than this camshaft is designed for, but I left that as is for now.
http://www.proracingsim.com/desktopdyno.htm
My program DynoSim5 had some flow numbers from 1999, so have no idea how accurate they will be.

DynoSim5_Parameter_Flow01.jpg
CompCamsXE274_01.JPG
 
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Rick just for giggles please try these two cams, as I have used them both several times
(usually with 1.6:1 ratio roller rockers on the intake sides)
and on engines with at least 10:1 compression.
and long 1&3/4" tube headers and a high rise single plane intake design
like a

Holley Keith Dorton Series


hly-300-110_xl.jpg

https://www.summitracing.com/parts/hly-300-110


Holley Strip Dominator

hly-300-25_xl.jpg

https://www.summitracing.com/parts/hly-300-25


edelbrock 2925
EDL2925.jpg

with a 750-850 holley cfm 4 barrel carb
and brodix 200 cc IK heads which I,ve found work rather well on 350-406 sbc combos
Certainly not the only effective combo but well proven over decades


bro-1021001_w_xl.jpg


https://www.summitracing.com/parts/...MIjbzDwsq51gIVDG5-Ch3lowyLEAQYAiABEgLTVPD_BwE

IMG_2071.jpg

0204vet_rockers_05.jpg


crane110921.jpg

crane110981.jpg
 
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Grumpy,

I'm working on your request. I guess I've never done a flat tappet cam and the
program was not making any sense with it's calculations concerning valve lash,
lift at the valve and gross lobe lift. It also reduces the duration because of the
valve lash of 0.026 inches.

Another words, it's calculates the valve lift with three numbers ..... lobe lift,
rocker ratio and valve lash. Now I can put together a couple of different calcs
with those three numbers. I just can't get it to agree with my manual calcs.
DynoSim5 was NOT entirely clear about how to handle it either. I spent a few
hours and a couple of beers before it made sense.

Since the wife informed me of a prior commitment today that I didn't know
I had tomorrow morning, it looks like it might be Sunday before I can finish
those simulations.
.
 
no rush, looking forward to your calculated results
 
Since I trust my numbers for the Brodix IK200 more than the Dart Iron Eagle from the
DynoSim5 program I changed that. I did go back and do the same for the simulation
above and difference was about 15 HP higher, so I'm not re-posting that Dyno graph again
unless asked.

Below is the Crane 110921 camshaft installed Dot-to-Dot or 4° advanced.

DynoSim5_Parameter_Flow02.jpg

Crane_110921_02.JPG

Crane_110921_CamManager.JPG

The Dynamic Compression Ratio (DCR) could be a little higher, especially if you retard the
camshaft at all. Engine #2 is retarded 4°.

Crane_110921_DCR_02.JPG
 
question, on that dyno sim,
(btw thank you for taking the time and effort to do that)
how can the valve lift with a cam designed to have a .518 valve lift on the intake with a 1.5:1 rocker's
still have the same .518 valve lift with the higher 1.6:1 ratio rocker?
especially when its a solid lifter valve train and all that .0026 valve lash is absorbed on the cam lobes feed ramps?
and yeah! I've always installed cams strait up or split overlap
while thats not going too provide an earth shaking improvement itthe two changes will tend to carry the power curve through too 7000 rpm a bit better.
if you compare the two graphs notice the predicted power is 100 hp higher at 9000 rpm, with that crane 110921, now no one in his right mind will spin a 350-383 to near that rpm level ,
but the fact remains that at 6500 rpm-7200 rpm the difference youll feel will be real. enough
 
how can the valve lift with a cam designed to have a .518 valve lift on the intake with a 1.5:1 rocker's
still have the same .518 valve lift with the higher 1.6:1 ratio rocker? especially when its a solid lifter valve train and all that .0026 valve lash is absorbed on the cam lobes feed ramps?
You welcome, I always learn something when I do these things.

You wondering how you .518 lift with a 1.6 rocker. It after you take into account the valve lash.

(.340 x 1.6) -.026 = .518
..... (.544) - .026 = .518

Looks like to me, it would have to reduce the total lift by the amount of the valve lash.
 
cam install info
I think most experienced guys have two or three degree wheels for that very reason,
(that the larger size is tough to fit in an engine compartment on an installed engine)
I bought these
http://www.summitracing.com/parts/mor-62191/overview/
62191_ATA.jpg

http://www.summitracing.com/parts/pro-66791/overview/
pro-66791.jpg


http://www.summitracing.com/parts/pro-66830/overview/
pro-66830_cp.jpg

http://www.summitracing.com/parts/cca-4927/overview/
CCA-4926.jpg

JUST TRYING TO FIND TDC??

you FIRST disconnect the battery and use a ratchet to spin the engine slowly by hand , useing the damper bolt and a 5/8 socket after removing the spark plugs, chalking the wheels and putting the cars trans in neutral

ways to turn over the engine WITHOUT the starter

theres large bolts for your ballancer
0702352501.jpg


theres crank sockets

69727010.jpg


Crankshaft Socket Tool For turning AND MOUNTING Degree Wheels
61755_part.jpg

CRANK NUTS

8928625.jpg


crank rotaters
77866782.jpg


flywheel turning tools
55580530.jpg


http://www.jegs.com/i/JEGS/555/80743/10002/-1

finding TDC

youll need a piston stop and degree wheel to be exact
but thats not 100% required unless you want it to work correctly???

http://store.summitracing.com/partdetail.asp?autofilter=1&part=CRN-99412-1&N=700+115&autoview=sku
use of a camshaft install handle generally reduces the chances of damaged cam bearings
CCA-4919_xla.jpg

cca-4919_w.jpg

read

http://www.2quicknovas.com/happyTDC.html

btw you might want to verify this next time you degree in a cam, so that next time you use dyno simulation software you enter the data correctly,

worn10.gif

race-engine-cams.jpg

craneq2.gif

SBCOilingnew.png


theres a hugely popular myth that simply is wrong, if your using a dyno simulation software program, ...,

no you don,t reduce or subtract the lift of the cam lobe by the lash, clearance,
when calculating the valve lift of a solid lifter cam,
and you don,t subtract the lifter seat movement on a hydraulic cam,
as that change in lift rate is ALL absorbed or removed on the cam lobes feed ramp
the lifter still lift,s the valve to the full lift
.
measure the difference the edge of the lifter moves from the time the lifter is on the cams base circle to peak lift than set the lifter back on the base circle again and set the dial indicator to zero with a .0024 feeler gauge between the lifter and dial indicator, and re- measure total lift.
nothing changes on that peak lift , its change is absorbed by the cam lobes feed ramp, the rate of lift per degree of rotation is very slightly delayed , not reduced.

http://www.summitracing.com/parts/mor-62191/overview/
62191_ATA.jpg

http://www.summitracing.com/parts/pro-66791/overview/
pro-66791.jpg


http://www.summitracing.com/parts/pro-66830/overview/
pro-66830_cp.jpg

http://www.summitracing.com/parts/cca-4927/overview/
CCA-4926.jpg
 
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theres a hugely popular myth that simply is wrong, if your using a dyno simulation software program, ...,
no you don,t reduce or subtract the lift of the cam lobe by the lash, clearance,
when calculating the valve lift of a solid lifter cam,
and you don,t subtract the lifter seat movement on a hydraulic cam,
as that change in lift rate is ALL absorbed or removed on the cam lobes feed ramp
the lifter still lift,s the valve to the full lift
.
measure the difference the edge of the lifter moves from the time the lifter is on the cams base circle to peak lift than set the lifter back on the base circle again and set the dial indicator to zero with a .0024 feeler gauge between the lifter and dial indicator, and re- measure total lift.
nothing changes on that peak lift , its change is absorbed by the cam lobes feed ramp, the rate of lift per degree of rotation is very slightly delayed , not reduced.
If I set the lash to zero and a solid lifter cam, then the total lift would be rated lift + valve lash. Say
the lash is .025 and the camshaft is rated at .500 lift, then if you set the lash at zero you will measure
a total lift of .525. Would those statement be true?

You could say the cam manufactures are rating their lift already minus the lash?
 
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I set the lash to zero on the intake to overcome the discrepancy in the way DynoSim5 determines
total valve lift on a cam with other than standard rocker ratio.

DynoSim5_Parameter_02_Corrected.JPG

Crane_110921_02_Corrected.JPG
 
If I set the lash to zero and a solid lifter cam, then the total lift would be rated lift + valve lash. Say
the lash is .025 and the camshaft is rated at .500 lift, then if you set the lash at zero you will measure
a total lift of .525. Would those statement be true?

You could say the cam manufactures are rating their lift already minus the lash?

no , the valve lash is clearance it does NOT add or subtract from the lift , if you have a solid lift cam rated at lets say .520 lift with a 1.5 :1 ratio rocker, changing the lash clearance,will effect how it runs and when the valve comes off the valve seat by a degree or two ,but unless you add a good deal more than the .024 specified lash clearance or so thats listed, on the spec card, for lash clearance, it has ALMOST ZERO EFFECT on total lift, and a change to a 1.6:1 ratio will effectively increase the lift to .554

the lifter starts on the base circle, the lobe passing under the lifter causes the lifter and pushrod to move up away from the base circle too peak lobe lift, the rocker ratio increases that lift at the valve through the leverage it provides working through the pivot point on the ball or axle inside the rocker centered on the rocker stud,
rockersu1.JPG

lobeliftyu2.jpg
lobeliftyu1.gif
 
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