98vtec

advertised lift vs. actual ???

lol

mgags7

Shawn did you check the p/n to be sure they're the right cams?

Rosko

iTrader: (1)

part numbers on the box match the numbers on their site and their catalog.

NirVTEC

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Rosko &raquo;</TD></TR><TR><TD CLASS="quote">part numbers on the box match the numbers on their site and their catalog.

</TD></TR></TABLE>

How do those measurements compare to the Pro1's? Are they maybe the wrong cams in the right box?
Just thinking out loud......
Is it possible Skunk exaggerates specs?
Try to find someone else that has them....measure.
Did you contact Skunk about it yet?

Rosko

iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by :=:NirVTEC:=: &raquo;</TD></TR><TR><TD CLASS="quote">

How do those measurements compare to the Pro1's? Are they maybe the wrong cams in the right box?
Just thinking out loud......
Is it possible Skunk exaggerates specs?
Try to find someone else that has them....measure.
Did you contact Skunk about it yet?
</TD></TR></TABLE>

I checked them against the other skunk cams and they didn't seem to look like those either. I contacted them and the response I got was to make sure that my indicators were paralell to the valve, but if the indicators were actually at an angle it would give a greater reading than what I am getting.

I measured the lobe lift and gave them those specs and I'm waiting to hear back from them as to wether or not they are correct.

mgags7

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Rosko &raquo;</TD></TR><TR><TD CLASS="quote">part numbers on the box match the numbers on their site and their catalog.

</TD></TR></TABLE>

I think they enscribe a pn into the dist side end of the cams.

Rosko

iTrader: (1)

^^I'll go look right now.

heres the specs of the pro series stuff..

Rosko

iTrader: (1)

theres a "10" engraved in the last lobe of the exhaust cam and a "9" in the last lobe of the intake cam, but no other numbers anyehere.

flyrod

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Rosko &raquo;</TD></TR><TR><TD CLASS="quote">I'm coming up with .487" lift on the intake when it should be .504" and .464" on the exhaust side when it should be .472" Maybe I'm just being ****, but something just doesn't seem right.</TD></TR></TABLE>

How do they get their lift numbers? Do they just take lobe height and multiply by a "rocker ratio" or something? That "rocker ratio" doesn't really take into account the rocker geometry, so if that's what they did it could explain the discrepancy.

mgags7

yeah, and furthermore, if they have some way of estimating it, its probably for b series stuff, and could be off from h stuff.

So Shawn, did you get the advertised 18-22lbs of torque?

Rosko

iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mgags7 &raquo;</TD></TR><TR><TD CLASS="quote">So Shawn, did you get the advertised 18-22lbs of torque?</TD></TR></TABLE>

lol, I dunno my engine stand doesn't tell me that

I just put my crower 3 in the intake side and I came up with .467" lift and iirc the spec on that was .468" (close enough), So it just about has to be an issue with the pro2 cam right?

Rosko

iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by flyrod &raquo;</TD></TR><TR><TD CLASS="quote">

How do they get their lift numbers? Do they just take lobe height and multiply by a "rocker ratio" or something? That "rocker ratio" doesn't really take into account the rocker geometry, so if that's what they did it could explain the discrepancy.

</TD></TR></TABLE>

I HOPE thats not how they do it. When I measure the pro2 lobe lift and multiply it by the ratio 1.5 it ends up at .504" which is what they advertise so I dunno.

mgags7

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Rosko &raquo;</TD></TR><TR><TD CLASS="quote">

lol, I dunno my engine stand doesn't tell me that

I just put my crower 3 in the intake side and I came up with .467" lift and iirc the spec on that was .468" (close enough), So it just about has to be an issue with the pro2 cam right?</TD></TR></TABLE>

yes it has to be, I measured my crower3s as well and got the exact same specs. Though mine were both .468, your intake cam must be slightly worn.

Rosko

iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mgags7 &raquo;</TD></TR><TR><TD CLASS="quote">

yes it has to be, I measured my crower3s as well and got the exact same specs. Though mine were both .468, your intake cam must be slightly worn.</TD></TR></TABLE>

Well that cam is the one that broke in half last year, so its got other issues as well

I took some lobe measurements on the crower and backfigured that it uses a 1.45 rocker ratio to get to the .468 lift whereas the math for the skunk figures out to a 1.50 ratio &lt;&lt; thats the math based on what the advertised lift is divided by the measured lobe lift. -edited

But like Flyrod mentioned the ratio is always changing due to the geometry of the rocker so maybe that doesn't mean anything.


Modified by Rosko at 5:49 PM 7/10/2007

Rosko

iTrader: (1)

hmmn one more thing... if I take the lobe lift of the pro2 and multiply it by the rocker ratio I back figured from the crower 3 (1.45) I come up with the exact lift I measured on the pro2 (.487")

117

It depends on the company. I know the Crane roller cams I have list the gross lift with a fixed rocker ratio. I need to check my cam card at home, but IIRC, the rocker ratio was somewhere around 1.5. The ratio changes as the cam turns, so I'm not sure if they actually measure the rocker ratio at max lift or not.

NirVTEC

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Rosko &raquo;</TD></TR><TR><TD CLASS="quote">

Well that cam is the one that broke in half last year, so its got other issues as well
Modified by Rosko at 5:49 PM 7/10/2007</TD></TR></TABLE>

WOW, another Luder with a broken C3.....how many does that make now? And people wonder why I won't use their cams.

PirateMcFred

Shawn, did you get any flow numbers off that Alaniz head?

Any news from Skunk? As for rocker ratio in H-series engines, it's a very dynamic valvetrain system. If you look at the way the lobe runs against the rocker you'll see that the RR is different at nearly any degree of cam angle. The cam's base circle changes the RR, the ramp angle and angle of peak lift affects the ratio too. It's much different than a shim under bucket system.


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by :=:NirVTEC:=: &raquo;</TD></TR><TR><TD CLASS="quote">WOW, another Luder with a broken C3.....how many does that make now? And people wonder why I won't use their cams.</TD></TR></TABLE>

There've been a couple threads about busted JUN cams recently. You ran those didn't you?

I am running Crowers and a friend is running Crower 2s in his H22 for the last 4.5 years at 45,000 miles and a couple thousand roadracing miles too.

If you want 99% reliability run OEMs or don't whine about it.

Pirate

Rosko

iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by :=:NirVTEC:=: &raquo;</TD></TR><TR><TD CLASS="quote">

WOW, another Luder with a broken C3.....how many does that make now? And people wonder why I won't use their cams.
</TD></TR></TABLE>

The crower 3 didn't just break on its own, the motor dropped a valve and that caused alot of stuff to break. head was destroyed, intake cam broke,keyeay tore up in cam gear, piston shattered, bent the rod, bent crank... Not that it was a great cam in the first place, but I can't blame the cam for what happened.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PirateMcFred &raquo;</TD></TR><TR><TD CLASS="quote">Shawn, did you get any flow numbers off that Alaniz head?

Any news from Skunk? As for rocker ratio in H-series engines, it's a very dynamic valvetrain system. If you look at the way the lobe runs against the rocker you'll see that the RR is different at nearly any degree of cam angle. The cam's base circle changes the RR, the ramp angle and angle of peak lift affects the ratio too. It's much different than a shim under bucket system.

There've been a couple threads about busted JUN cams recently. You ran those didn't you?

I am running Crowers and a friend is running Crower 2s in his H22 for the last 4.5 years at 45,000 miles and a couple thousand roadracing miles too.

If you want 99% reliability run OEMs or don't whine about it.

Pirate
</TD></TR></TABLE>

No I never asked about the flow numbers, I believe they are listed on the Alaniz zite though. I figure if they didn't come with my head then the chances were pretty slim of me getting the actual numbers from MY head after the fact. As long as it makes good power I'm ok with it.

I haven't heard from skunk2 yet today, but I figured out that the rocker ratio is actually 1.45 All the numbers I'm getting work out to that on the pro2's and the crower. It seems as skunk2 just took the lobe lift of the cam and multiplied it by the wrong rocker ratio (1.5) and came up with the higher numbers.

I realize its constantly changing, I'm just backfiguring from actual valve lift vs lobe lift and the numbers I'm measuring are dead on a 1.45 ratio whereas the numbers skunk advertises are dead on for a 1.5 ratio

If these cams have actually been tested and make the power they say they do it shouldn't be a problem... It just seems like the lift is advertised wrong and kinda makes me wonder if its the same scenario with their other cams.

alterdcreations

i was thinking about the pro 3's
please keep us informed

alterdcreations

did you measure at the lobe centers?
at +1 and +1.5
or +2 and +3 depending on which cam gears you have

Rosko

iTrader: (1)

Mine ended up being +1 on the exhaust cam and -2 on the intake. I have both aem and skunk gears but I'll be using the aem ones. My headgasket is also .03" thicker than stock so thats altering the numbers a little in the retarded direction as well.

I used the technique of measuring from .003 below max lift on each side of the cam lobe to find centerlines. Doing it this way takes the dwell of the cam out of play at max lift.

I didn't hear anythng today from the skunk2 rep that was helping me, but Tony Shagday answered my PM this afternoon and I gave him a few more specs and hopefully he will be getting back to me asap.

117

0.03" thicker than stock!!! That's like having two OEM headgaskets!!

Rosko

iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 117 &raquo;</TD></TR><TR><TD CLASS="quote">0.03" thicker than stock!!! That's like having two OEM headgaskets!!</TD></TR></TABLE>

LOL it is a pretty chunky gasket haha... still gonna have 12:1 compression yikes!

Bense

lookin good