good street roller cam selection

grumpyvette

Administrator
Staff member
" HEY GRUMPYVETTE?
I need some help on selecting a cam hyd roller.I have a std vortec block with the zz4 cam in it .it has elder. E-tec 200 heads air gap intake.holley 750 vac secondary . My cr is 9.4. I was looking at the lt4 hotcam with 1.6 or is there something better


rear gear ratio?
transmission used and stall converter speed?
headers?
max lift clearance on valve train?
intended use for car?
do you need to pass emission testing?

viewtopic.php?f=52&t=82

viewtopic.php?f=52&t=181

http://www.superchevy.com/how-to/67838- ... 355-build/


rockertrunion1.png





2400/2800 stall .700r4 trans .long tube headers 2x 2 1/2 tail pipes . 3.73 posi. no test yet ! It a 74 nova daily driver .and would like to make it to the track some times I was hoping for 400 HP + 575 or 600 lift





http://www.cranecams.com/product/cart.p ... il&p=24192
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heres what Id use (above)it may look a bit mild but it matches your goal well
it would have the .575 lift on the exhaust,I was just pointing out that the exhaust lift on the milder cam with the .539 listed lift using 1.6:1 ratio rockers has increased effective lift at the valve to .574 so you need to verify clearances but keep in mind durability is important and the milder cam puts less stress on the engine which can be important when your not into busted parts replacement
now if you want to go radical you could go with this cam (below)

but its going to be a bit much with the lower compression than ideal, in a car used mostly for transportation, I use this cam in my 383 and its not ideal in traffic, and certainly not with the lower compression, Id bet you would regret going with a cam that large


either cam easily at least potentially gets you over 400hp with that combo
119661c.jpg

(CRANE CAMS USED TO SUPPLY MANY G.M.PERFORMANCE CAMS,
Chevrolet Performance LT4 Hot Cam Hydraulic Roller Camshafts 24502586

this is no longer true and QUALITY has dropped off noticeably by who ever is currently supplying the cams)



http://www.cranecams.com/product/cart.p ... il&p=24188
 
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grumpyvette

Administrator
Staff member

HEY GRUMPYVETTE?
Now that I've sold my drag radials and officially retired the Impala from the strip I'm looking to do a cam swap to a more street friendly grind. My current Comp 288AR solid roller is a terror at 6500 rpm but I know the car would do much better stoplight to stoplight with a more conservative camshaft. Here's my specs:

454+.060
9.2:1 static CR
AFR 305 heads
Performer RPM
Holley 850
Hooker Competition headers
2.5 exhaust w/ x-pipe
4 speed
4.30 gears
4200 lbs

I've invested in a set of Crower solid roller lifters so the new cam has to be a solid roller. I've looked at both the Lunati 60230 and 60231. The intake valve closes much earlier on these than the Comp 288AR, which should increase dynamic compression and really help move the car at lower rpm.

Any suggestions?

Thanks,




youll want to find a solid roller cam on a tight 108-110 LSA with about 235-240 duration @.050

heres the crane roller ID be using, its about 10 degrees less duration than your current cam, enough to make a noticeable improvement in street driving, the problem your having is that they don,t make many MILD solid roller cams and your heads port size and design are designed for upper rpm power not cruising


138551crane.jpg



every choice is a compromise, heres your current cam below, notice the 8-10 degree less intake duration on the newer suggested cam, posted above
comp288ar.jpg
 

grumpyvette

Administrator
Staff member
viewtopic.php?f=44&t=10200&p=40438&hilit=hotcam#p40438

http://www.superchevy.com/how-to/67838- ... 355-build/

the crower steel units will have a longer fatigue life and the bearing trunions are replaceable so they can be rebuilt after 60K-80K

,Fatigue limit, endurance limit, and fatigue strength are all expressions used to describe a property of materials: the amplitude (or range) of cyclic stress that can be applied to the material without causing fatigue failure.[1] Ferrous alloys and titanium alloys[2] have a distinct limit, an amplitude below which there appears to be no number of cycles that will cause failure. Other structural metals such as aluminium and copper, do not have a distinct limit and will eventually fail even from small stress amplitudes. In these cases, a number of cycles (usually 107) is chosen to represent the fatigue life of the material.
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camsd1a.jpg



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http://garage.grumpysperformance.com/index.php?threads/semi-fool-proof-cam-sellection.82/

http://garage.grumpysperformance.co...-street-roller-cam-selection.5709/#post-46850

http://garage.grumpysperformance.co...a-better-cam-to-a-zz3-350-sbc.182/#post-26013
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[color:red]READ THE LINKS[/color]

http://garage.grumpysperformance.co...train-clearances-and-problems.528/#post-57678

http://garage.grumpysperformance.co...train-clearances-and-problems.528/#post-66870

http://garage.grumpysperformance.co...e-springs-and-setting-up-the-valve-train.181/

http://garage.grumpysperformance.co...fit-under-stock-valve-covers.6641/#post-21035

http://garage.grumpysperformance.com/index.php?threads/rocker-push-rod-wear-issues.9815/#post-54232

http://garage.grumpysperformance.co...g-block-pushrod-guide-plates.4596/#post-52034
lots of guys install the HOTCAM kits to the LT1 and TPI engines as a dependable upgrade

a fairly simple G.M. HOT cam upgrade can easily produce gains of 35-40 hp, over the average stock OEM cam, the G.M. hot cam is DESIGNED to be about pushing too the limit on what can be used with stock components and still function, and yes it really requires upgraded valve train components and its best used with a manual transmission or a 2600 rpm stall converter and a 3.54:1-3.73:1 rear gear.
stock valve springs limit you to about .480 lift the hot cam lift is .525 so the springs ,retainers and rockers are required upgrades

(CRANE CAMS USED TO SUPPLY MANY G.M.PERFORMANCE CAMS,
Chevrolet Performance LT4 Hot Cam Hydraulic Roller Camshafts 24502586


this is no longer true and QUALITY has dropped off noticeably by who ever is currently supplying the cams)

http://www.summitracing.com/parts/NAL-1 ... /?rtype=10
GM Performance 12480002 - Chevrolet Performance LT4 Hot Cam Hydraulic Roller Cam Kits

hotc4.jpg

The cam is listed as NAL-24502586 (summit number) http://store.summitracing.com/partde...6&autoview=sku
It is a hydraulic roller with 1,500 - 5,800 operating range, 218/228 at .050, .492 lift with 1.5 rockers and a 112 lsa.

YOU MIGHT FIND THESE LINKS WORTH READING ALSO[/color]

I found this LUNATI advertizement and I think its VERY MIS-LEADING, while theres little doubt the cam can produce the increased power the fact that they don,t tell you it will require other upgrades to get there is being ignored[/B]
http://www.hotrod.com/features/1411-wha ... -camshaft/
vechart.gif

Id also point out that the small 180cc ports used in the lunati dyno test are being very restrictive , and the low compression ratio hurts almost as much,and both factors are causing the power curve to drop off rather early in the potential rpm range , especially if you selected the longer duration cam options

bootlegl.png


http://www.bootleggercams.com/#cam-specs
bootl1.png

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lt4 hotcam comes here inexpensively in a kit with springs and rockers , and whats not being stated, in that bit of LUNATI ADVERTIZING,posted above is the fact,
the fact that you can install the hot cam in the stock engine with just the valve spring and added 1.6:1 ratio rockers and expect it to run fairly well with the stock TPI or LT1 fuel injection system without changing the computer controls injectors ,and have it work with the cars torque converter speed or rear gear ratio,is a huge selling point. and AND thats NOT likely to be the case with the more radical and longer duration and higher lift LUNATI CAMS, thus the result you see is a rather apples to oranges comparison, and ID also point out that if your willing to change the cylinder heads,rear gear ratio, compression ratio, converter stall speed, ETC. theres dozens of cams made by CRANE, CROWER LUNATI,ISKY ERSON that will provide similar or better results

http://www.jegs.com/i/GM+Performance/80 ... 7Aod6RUAsw
THE G.M. HOT CAM has 218/228 duration at .050 lift, and maximum lift with 1.6 rocker ratio (intake/exhaust) is 525/525. Valve lash is zero/zero and lobe centerline is 112 degrees. it was designed to be about the max compatible upgrade that would not require rather extensive supporting upgrades to allow it to function.
 
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