Jroc99SS

iTrader: (2)

Thanks Patrick G

Specialized

iTrader: (15)

I just took time over the past two days and read this entire thread and I believe I am walking away with a lot more knowledge than I walked in with.

I appreciate all of the input from everyone, and I will be taking most (can't take all) of it into account when I order a cam in a month or so.

DuronClocker

iTrader: (25)

Just wanted to give an update on my noise issues. I finally measured for pushrods and ended up buying some 7.350" pushrods. They quieted things down considerably, and already it is much more enjoyable without all of the added engine noise. Weird, you would think excessive valvetrain noise would be caused by too short of pushrods not too long of them.

The heads are ported. I don't have a complete flowsheet, but when I bought them I was given a few of the numbers, and they were right around 310 and 250-260 at useable lifts with this cam. I will get them flowed next time I pull them off, which shouldn't be until next winter now.

Anyways, I did not check PtV clearance as I was told there would be no way I could have any troubles with these cam specs. Haven't had a single problem though. Only have a few thousand miles on the setup, but so far so good.

Patrick G

iTrader: (14)

I just added an idle clip to my signature for anyone interested. You can hear how smooth the idle is (at 850 rpm). Some people expect a 110LSA to have a really hard chop to it. Mine is nice. You will also hear the underhood valve music (for those wondering how loud LSK lobes are with stiff springs).

Idle clip here

camarokid94

iTrader: (2)

WOW that sounds good LSK not even that bad. lopes less than my 233-239 113

i hope ol pat can help me get a cam figured out that will should that good and make soem AWESOME TQ HP for my 402

hammertime

iTrader: (1)

Patrick - that sounds great! It more than enough to let people know what's up, yet plenty streetable.

Thanks for posting the vid

Hennytime

iTrader: (33)

that thing sounds great, btw im sorry if it was covered in the post prior, but how would the lsk lobes work with the stock 02 heads with the proper valvetrain of course

PREDATOR-Z

That is because your 233/239 has 10* overlap and Patrick's only 5* overlap.
Natural that it lopes less

Patrick G

iTrader: (14)

With the correct springs, the LSK lobes work very well on stock heads. The additional curtain area allows you to run less duration for the same power gains of larger cams.

LS1Formulation

iTrader: (13)

So in another thread I was looking to do an XE-R lobed cam, 226/230@.050, .585/.592 Lift w/ 108+1 LSA . After reading this entire thread, I've decided to switch specs to an LSK lobed cam, 220/224@.050, .632/.636 Lift w/ 108+2 LSA . Keeping in mind I want to shift under 6300 RPM and want great low end, will this cam work for me?

Patrick G

iTrader: (14)

It will be a torquey ****, that's for sure. Even with stock heads, your DCR is going to be very high. It should be a stump puller (if that's your goal).

LS1Formulation

iTrader: (13)

Yeah, I want a cam that makes a lot of power between 2500 and 4500 but still pulls like a **** up to redline. After reading how well your cam performed and the fact that it still pulled all the way to 6500 without having to use a lot of duration, I figured a slightly smaller grind would work great for what I wanted to do.

Ragtop 99

iTrader: (7)

You'll have a much earlier IVC (36*) on a narrower LSA cam. His cam pulls to 6500 but he has some key advantages:

*ported heads
*high compression
*90mm intake
*cam is installed straight up

It might work, or it might crater by 5800 let us know. I would vote for straight up.

LS1Formulation

iTrader: (13)

Hmmm, you may be right there. I'm wondering though, why does my stock cam seem to pull all the way to redline even though it's only 198@.050? Is it because of the incredibly wide LSA? Does anyone know what the DCR is for a stock cam? I'm hoping I can spec this cam to actually gain a little torque over the stock cam down low and just annihilate it above 3000 RPM.

1989GTA

You could always retard the cam a couple of degrees to delay the IVC closing to raise the peak power. Sounds like maybe a custom cam would be in order.

hammertime

iTrader: (1)

While I'm uncertain of the DCR given by the stock cam, you have found the answer. The wide LSA closes the intake valve fairly late, even though the duration is short. The IVC is determining where peak power occurs, while the overall intake duration dictates cylinder fill and how much power can be made.

N4cer

iTrader: (11)

That wouldn't raise the peak power. It would only shift the power curve to a higher RPM, and actually probably reduce the peak number as well.

LS1Formulation

iTrader: (13)

Well yeah, it's definitely going to be custom, lol. I don't think anyone has an off the shelf 108 LSA Comp grind with LSK lobes. I'm curious what the valve events are for a stock cam. Is there any place on the site I can look them up? I did a search but only found lift and duration figures.

hammertime

iTrader: (1)

I'm guessing you found these:
Good luck finding the advertised durations. Also, the ramps are so much slower than even Comp XE lobes, that the actual intake valve closing point is much, much later than that tiny duration @ .050" would suggest. Using XE rates from .006 to .050, 116 + 0, and the DCR calculator, I get a 8.53:1 DCR. But I'm sure that the rate is much slower than 53 degrees from .006 to .050. I'd guess there is 10 more ramp opening and closing to keep the noise down. That gives a rate of 73 degrees, and a DCR of 7.88:1

Patrick G

iTrader: (14)

Stock '98-00 F-body cam gives a 6.97:1 DCR based on these valve events from the Cam Doctor:

1998-2000 Stock F-Body Cam 0.006 0.050 0.200
Intake Duration - ID 284 199 113 stock cam
Exhaust Duration - ED 289 210 118 stock cam
Lobe Center Angle - LSA 119.5 119.5 119.5
Intake Centerline - ICL 119 119 119

Intake Valve opens - IVO 23 -19.5 -62.5 BTDC (- indicates ATDC)
Intake Valve closes - IVC 81 38.5 -4.5 ABDC
Exhaust Valve Opens - EVO 84.5 45 -1 BBDC
Exhaust Valve Closes - EVC 24.5 -15 -61 ATDC (- indicates BTDC)
Exhaust Centerline - ECL 120 120 120
Overlap 47.5 -34.5 -123.5 degrees