Lash ramps for solid cams

[digger]

Mike what kind of tool steel do you use?

[bob460]

What type of lash ramps do the "HARDKORE Cam Series" have Mike?

Our HARDKOREcam series, is a series of Tool Steel cams. The profiles we grind on them, can be any of our profiles.
Most of our profiles use either Constant Velocity ramps, or a Constant Velocity/Jerk hybrid I developed.

What's the price for a BBF solid roller cam and BBF solid flat tappet cam.

[CamKing]

Mike what kind of tool steel do you use?

Mostly S7

[pdq67]

Back from the dead.

I have to ask why did GM make the -097 Duntov cam at .012"/.018" lash??

And the -346, (aka, 30-30), cam at .030"/.030" lash??

This one reason why I keep bringing up the -097 cam because it really is an old, "tight lash", cam...

-097 in the 360hp/327fi engine vs the 30-30 in the 375hp/327fi engine...

And if not mistaken the 375hp engine had big valve heads on it and 360hp engine only had medium valve heads on it so go figure if I am right???

Lets put the big valve heads on the 360hp engine and see what hp it produces? And vica versa, put the medium valve heads on the 375hp engine... NO other changes here EXCEPT to keep the CR's stock for both engines!!! I say this because I think the 360hp engine has like an 11.25/11.5(??) or so CR and the 375hp engine only has an 11 to 1 CR???

pdq67

[Stan Weiss]

Back from the dead.

I have to ask why did GM make the -097 Duntov cam at .012"/.018" lash??

And the -346, (aka, 30-30), cam at .030"/.030" lash??

This one reason why I keep bringing up the -097 cam because it really is an old, "tight lash", cam...

-097 in the 360hp/327fi engine vs the 30-30 in the 375hp/327fi engine...

And if not mistaken the 375hp engine had big valve heads on it and 360hp engine only had medium valve heads on it so go figure if I am right???

Lets put the big valve heads on the 360hp engine and see what hp it produces? And vica versa, put the medium valve heads on the 375hp engine... NO other changes here EXCEPT to keep the CR's stock for both engines!!! I say this because I think the 360hp engine has like an 11.25/11.5(??) or so CR and the 375hp engine only has an 11 to 1 CR???

pdq67

What is the seat-to-seat duration of each cam at said valve lash? What is the net valve lift of each cam at said valve lash?

Stan

[pdq67]

GM in their fu*king wisdom, didn't list advertised durations!

Personally, I want a cam that has the min. advertised duration, maximum duration at .050", as well as the highest lift up to the point of creating an unstable valve train.

On the needed centers for the intended application.

Imho, Camking is right to only list advertised durations for solid cams at lash!!! Hy-cams anywhere from .002" to .006" or so??

pdq67

[pdq67]

Unbelievable!!

Here ------- "loose lash solid cams", thread......

viewtopic.php?f=1&t=11597

Last of page 1 and then on to page 2..........

I have been looking for information like this for years!!

pdq67

[Stan Weiss]

In the earlier '70s I toke measurements ever 10 crank degrees with a dial indicator and degree wheel (not one of those large ones). These are the Valve theoretical duration with 1.5:1 rocker and 0.030" lash and duration at lifter raise. This is set at 115 ICL

Code: Select all

VALVE_____Lift______Opens___Closes__Duration
_________________Deg_BTDC__Deg_ABDC_____________Area
_________0.00000_____5.00_|_128.75_|_313.75_|__38.70
_________0.00600____-6.43_|_124.00_|_297.57_|__38.56
_________0.01000___-10.24_|_121.33_|_291.10_|__38.56
_________0.02000___-18.33_|_114.76_|_276.43_|__38.26
_________0.04000___-28.70_|_105.24_|_256.53_|__38.15
_________0.05000___-32.41_|_101.48_|_249.07_|__37.74
_________0.07000___-38.47_|__94.33_|_235.87_|__36.90
_________0.10000___-46.26_|__86.33_|_220.07_|__36.53
_________0.15000___-57.54_|__75.00_|_197.46_|__35.08
_________0.20000___-68.12_|__64.90_|_176.78_|__31.77
_________0.25000___-78.89_|__55.10_|_156.21_|__30.73
_________0.30000___-90.17_|__43.00_|_132.83_|__26.14
_________0.35000__-102.44_|__29.20_|_106.77_|__22.74
_________0.40000__-119.44_|__10.56_|__71.11_|__15.03
_________0.42500__-134.26_|__-3.33_|__42.41_|__10.85
CAM
_________0.00600____78.33_|_191.67_|_450.00_|__29.86
_________0.01000____55.00_|_170.00_|_405.00_|__29.68
_________0.02000_____5.00_|_128.75_|_313.75_|__29.00
_________0.04000___-25.00_|_110.00_|_265.00_|__28.21
_________0.05000___-30.56_|_103.33_|_252.78_|__27.66
_________0.07000___-39.80_|__93.00_|_233.20_|__26.90
_________0.10000___-50.86_|__81.67_|_210.80_|__25.88
_________0.15000___-67.06_|__65.91_|_178.85_|__23.90
_________0.20000___-83.33_|__50.36_|_147.02_|__20.94
_________0.25000__-101.15_|__30.65_|_109.50_|__16.26
_________0.30000__-130.56_|___0.00_|__49.44_|___7.73

[F-BIRD'88]

Pd67: Why don't you measure and analyze the solid lifter sbc cam you got there? The .500" lift one with .030" hot lash.. You can analyze the effective change in seat to seat lash point durations by changing the valve lash each side +/- of the .030" spec.. And see what the practical +/- limits are going to allow on that cams lash ramp.
There are practical mechanical limits to how fast you can seat a valve at higher rpm and jow fast u can lift same valve off seat at higher rpm.
You can send that cam out to someone with a cam DR (tell them to manually setup the printout check points to show the lash ramp area in detail VS the programs default setting.
Or install the cam in a short block and measure it your self with a degree wheel and dial indicator .

On some cams the opening side lash ramp and flank is not the same as the closing side is. so look at both.
note: If you don't manually reset the lobe lift checking points to a range crowding the lash point on the lobe you won't get a detailed view of the lash ramp area.. The default setting does not show this in detail on the Cam DR software. Its adjustable ..and easily re-set back to the default .

[autogear]

As a 40y/o guy; I'd be curious to see if the guys REALLY in the know "back-in-the-day" really lashed the 'thurty thurty' as advertised? I'd be willing to bet that GM published that as a means to have a "rev limiter" in the system. It would keep a lot of chowderheads from knocking on their door.
I suspect some of you guys were lashing them .025 or even tighter.

Am I off-base?

[F-BIRD'88]

As a 40y/o guy; I'd be curious to see if the guys REALLY in the know "back-in-the-day" really lashed the 'thurty thurty' as advertised? I'd be willing to bet that GM published that as a means to have a "rev limiter" in the system. It would keep a lot of chowderheads from knocking on their door.
I suspect some of you guys were lashing them .025 or even tighter.

Am I off-base?

I believe the origional hot lash spec was .025" but gm changed it to .030" to reduce running overlap and duration to help idle quality and increase daily "drivability" in the 67-68 Z/28 camaros and the 70 LT-1 vette (350 cid)

[pdq67]

Imho, the old 30-30 cam in a 302 Z-28 engine will go above 8,000 rpms fine except for the wimpy -929 cam's valve springs they used back then. The -140 cam used better -142 valve springs.

As for the 370hp/350 engine, only the mule engine that GM tested used the 30-30 cam to get that 370 hp number.

GM later went to the -178 cam, probably because the 30-30 cam was not really usable with P/B's and A/C.

Please tell me how far off I am here??

pdq67

[F-BIRD'88]

on a 30-30 cam if the lash is set at .030" the duration is 327 deg. If the lash is set at .025" the duration is 359 deg.
If the lash is set at .035" the duration is 305 deg
Seat to seat .
The valvetrain deflection is not known.

[Geoff2]

These #s for the 30-30 cam come from a veeeeery old Crane cams catalog that compared durations of various brand cams during the duration wars, & 25 cams were tested.

Lobe lifts measured 008, 010, 012, 014, 016, 018, 020, 050 . Duration for the 30-30 cam: 440, 418, 396, 375, 354, 331, 314, 254. Factory adv duration was 354. The highest factory adv dur out of the 25 cams was...400*.

[Stan Weiss]

These #s for the 30-30 cam come from a veeeeery old Crane cams catalog that compared durations of various brand cams during the duration wars, & 25 cams were tested.

Lobe lifts measured 008, 010, 012, 014, 016, 018, 020, 050 . Duration for the 30-30 cam: 440, 418, 396, 375, 354, 331, 314, 254. Factory adv duration was 354. The highest factory adv dur out of the 25 cams was...400*.

Geoff,
Is it possible for you to post a copy of that chart / pages?

Stan