the404man

So the smaller the number the more aggressive? Also, gm ls hotcam, what if the cam card number for advertised duration is taken at .006 ?

kinglt-1

iTrader: (26)

yes smaller the number, the more aggressive the lobe. Just subtract advertised duration from .050 duration.

the404man

So gmpp ls hotcam is 53 and howards version is 48.. wow thats a big difference huh?

Also iv looked all over for the gmpp ASA cam advertised duration but can't find, im thinking its the same as the hot cam, because the howards version is will yeah 48 too

Totally man thanks you just taught me something haha too cool

dave04da

iTrader: (2)

I just purchased a Howard's hot cam and am going to install it with morel 5315 lifters and blue ls6 springs in my 99 hawk. What are the pros and cons to the more aggressive ramp rates? I want a reliable valve train that I don't have to change springs on, with a nice idle. I have a stock lifter that is making noise so I figured I would put a small cam and decent lifters in. Would I have been better if to buy the gmpp version of this cam?

the404man

Me and thats not saying much as i no nothing really about ramp rates and what not, but im not going to be buying a howards asa cam now do to the aggressive ramp rates and as for as the ls6 springs with the aggressive ramp rate howards hotcam or asa cam for that matter, i really dont think it would go good together or at lest for very long..

But yeah im really disappointed in the howards aggressive ramp rates Edit: on their LS hotcam and ASA cam versions :end Edit.. ill stick with the gmpp hotcam and yellow ls6 springs for longevity.. and when i do decide to buy a ASA im going gmpp even though its more money LOTs more

I might though look for a howards cam that doesn't have such an aggressive ramp rate.. neways yeah sorry didn't really answer your question, but i had to say something, since im kinda upset about the ramp rates, also from what iv been studying, the howards hotcam version might make a small bit more power.. but yeah peace

mgood613

iTrader: (1)

Fwiw I had pac 1218 springs with1.7 rockers and went to 1211x pacs with the 1.85 slp rockers.

the404man

Fwiw i found these to be a good read https://ls1tech.com/forums/generatio...cam-lobes.html

And here is the sticky link https://ls1tech.com/forums/generatio...cam-guide.html

HCI2000SS

iTrader: (2)

I have a Howards cam as well. You guys have me wondering if mine has aggressive ramp rates now too

kinglt-1

iTrader: (26)

aggressive ramp rates are hard on springs and lifters...anything lower then 49 is a aggressive, anything above 51 is considered mild or soft. I would be running a better spring then a blue LS6. PSI 1511 if you want a quality beehive.

CTK30

Why not get a custom cam made for your 1.8 rockers?

I just had one made from Jones Cams, it's not that much more expensive

My ramp rate is 44 and 46, solid roller and PAC 1905 springs though

Matt Mayberry

So, even though the lift is .525, having the lobe that aggressive, at 48 is still going stress the valve springs say more than one with .600 and a ramp of 52?..... Just curious.

Darth_V8r

iTrader: (4)

Yes. The ramp rate is measuring from .006 to .050 lift. The total lobe lift does not come into the ramp rate discussion unless you are also looking at 0.200 lift durations as well.

There is velocity. Then there is acceleration, which is the rate of change in velocity. Then, there is "jerking", for lack of a better word, for the rate of change in acceleration. faster ramp rates mean higher "jerk" rates, which are very hard on springs and valve train hardware.

Also, there has been more recent findings that cams with milder ramp rates are actually making more power. That's why you see cams by cam motion, EPS, etc using softer ramp rates in their profiles and still making 0.600+ lift. better valvetrain stability and life AND they make more power.

kinglt-1

iTrader: (26)

I would think you need a PAC 120x series spring for that cam...jmo.

CTK30

Those springs look to be the same as the smaller 120x springs

I guess an inverse radius cam like mine isn't harder on the valve train? It's a pretty big cam for road racing, I trust his judgement though

Here's a link with some info

http://speedtalk.com/forum/viewtopic.php?t=8711

Sorry for the hi-jack

dave04da

iTrader: (2)

Well thanks again guys. I was able to cancel the order and already received my refund from the seller all within about 15 minutes. The seller was fast-times-warehouse on ebay, obviously they have great customer service. I guess I will bite the bullet on the gmpp version of this cam. I will just have an extra set of springs because I upgraded to the blue ls6 ones last year due to higher rpm valve float.

speedtigger

iTrader: (16)

The best way to assure that your camshaft will get the most out of 1.8 rockers while maintaining good valve train stability is to have a cam ground with lobes designed for 1.8 rockers.

Cam Motion will grind you a camshaft specifically for use with 1.8 rockers at no extra charge. How can you beat that?

kinglt-1

iTrader: (26)

Comp also made a series of cams designed for higher ratio rockers. XFI Xtreme rpm based on XE lobes. However I would go with Cam motion, especially being all the bad cams comp sent out that were not polished correctly.

Martin Smallwood

iTrader: (2)

Most definitely it will. 48 degrees of duration from .006 to .050 with .525 lobe lift is a train wreck waiting to happen IMHO. This is one of the main reasons that XER lobes were so hard on valve train components. Fast, short seating durations (49* from .006-.050) and short lobe lifts.

SRD uses only Cam Motion camshafts with SRD's proprietary lobe designs. SRD's lobe designs are designed for maximum stability and power output at high engine speeds and designed for quiet valve train operation.

Darth V8R is dead on with his description as well. Choosing the right amount of acceleration and velocity for a given lobe design is paramount. Keeping as much jerk out of the lobe as possible will lead to a happy long life for your valve train components and normally will make more power. Unless you have extremely stiff valve springs, shaft mounted rocker arms, large OD diameter push rods and high dollar short travel lifters, you'll never see the added power from a very aggressive lobe design. Most will in fact see less power, especially the more common street set-ups seen in this section.

dave04da

iTrader: (2)

Wow, good thing I read this thread. I guess timing is everything! That Howard's cam would have been exactly what I didn't want. My main goal is valve train longevity. Do you have any other cam recommendations similar to the gmpp hot cam?

SarGntoperez

How much rwhp where u making when u where usimg stock rockers? Where u using the prc stage 1 ls6 heads?