NIC cam + rockers

[BoostedPontiac]

Im currently running a NIC cam on the stock 1.6 ratio rockers. Im planning on upgrading to 1.7 because that will take my lift up without maxing out the stock heads. My question is, is it worth it? Or would I lose too much boost?

[darkhorizon]

You would lose power and lift going to 1.7 rollers.

[coolone]

NIC cam... .317 lift.317x1.6=.507
.317x1.7=.539


Ummmmmmm, how is that losing lift? I'm just curious...


OP, I wouldn't do that on stock valve springs and retainers either, it wouldn't be such a good idea.

[Iceman6669]

Because there is some debate that with stock rockers on aftermarket cams the contact point changes and the ratio actually increases beyond 1.66

[NebTurboST5]

You would lose power and lift going to 1.7 rollers.

have you actually set up a test to measure the lift at the valve with stock rockers to confirm your theory? and then with 1.7's to measure the "loss" that you speak of?

[darkhorizon]

have you actually set up a test to measure the lift at the valve with stock rockers to confirm your theory? and then with 1.7's to measure the "loss" that you speak of?

yes, ive posted it before.

[Overkill]

I can tell you that switching from stock rockers to CompCams 1.73 roller rockers on our SBC cam test car picked up just over 1mph in the 1/4 with no other changes. SBC uses the same CompCam lobes and lift as the ZZP NIC cam

[NebTurboST5]

yes, ive posted it before.

link? id like to read it.

[darkhorizon]

I can tell you that switching from stock rockers to CompCams 1.73 roller rockers on our SBC cam test car picked up just over 1mph in the 1/4 with no other changes. SBC uses the same CompCam lobes and lift as the ZZP NIC cam

ive gained over 1 mph trap speed just because it was a little bit colder out or on closed loop cars, afr changes all the time... Super random and biased information.

[Reptile]

Here...since he doesn't wanna post his claims, here's just a few examples of his testing........

http://www.grandprixforums.net/threa...ley-size/page3

http://www.grandprixforums.net/threa...-use-one/page2

http://www.grandprixforums.net/threa...for-an-S1X-cam

[NebTurboST5]

wow...i will submit to the fact that the rocker ratio changes using the stock rockers and that you do get more peak lift. however, im not going to jump on the bandwagon that you are somehow going to loose power going to a roller rocker. more then just peak lift in the equation here. i love gerenic claims with no real data to prove them.

[16MustangVet]

well after reading all 3 of the above i have to derail this thread a little more. i cant help but wonder if i should put some heavier springs in my s1x e85 car thats on stock rockers right now.

reason i bring this up is ill admit i dont drive the car nice and once in a while the rpm seems to hang between shifts if im hard on it, like rolling off ramp to 85 mph interstate speeds or from a dead stop and smash it.

im certain i have 105s in it now and ti retainers from when greg had the car. i havnt taken the vc off. now if i do switch the springs to 130s which i happen to have in the basement still use the same retainers and keeping stock rockers?

also might as well do new seals and i hope i can leave the heads on the car. reason i bring this all up is the rpms acting goofy once in a while or "rev hang" make me leery about ever spraying the car either. which of course the zex kit is also just chillin in the basement too.

[Reptile]

My two cents here...and I know how Nick hates LS6 springs...but....
I've ran them in every build I have, and I don't have any problems with them. No hangups, no valve float, nothing. I also keep my shift points at 6200 because I don't really see the need to raise them. There, I've said it.

[16MustangVet]

no idea on mileage on them springs but could be cheap insurance down the road should the bottle ever happen. as for now i could just be nicer to my car....... lol

[coolone]

Because there is some debate that with stock rockers on aftermarket cams the contact point changes and the ratio actually increases beyond 1.66

I remember reading a great debate on this, is why I asked... But geometry is... Well geometry! A ratio of 1.6 stock or roller, is still 1.6 based upon the pivot point. Unless the PIVOT point changes, the ratio remains the same, hence then why 1.7 or even higher "ratios". Based on the fulcrum and angular momentum. The valve isn't moving or changing its height or contact point, nor is the cam midstream.

Now if in fact the rollers are somehow losing contact with the valve and creating float? I'd have to see it to believe it. Maybe at 7k rpm... Yes, I am a sceptic! If the rollers offer no benefit, then why roller/hydraulic lifters too? I have 1.8's set up on this engine build with Overkill's BBC cam I have going in and maybe, just maybe, if I ever have the time, I'd love to screw around and dyno it and swap out the rockers same day and dyno it again! : )

[CrazyGuy03]

This is exactly where Dark lost me. I was going to run my s1x with 1.8RRs and he insists i would lose power. I never figured out how or why (something about the roller tip having a variable contact point?) but scrapped the idea all together later on for a larger cam and stock rockers.
The way Dark likes to give advice is like telling jokes and leaving out the punchlines ... Lmao!

[GTPpower]

The way Dark likes to give advice is like telling jokes and leaving out the punchlines ... Lmao!

Most solid info in this thread!!!!

[GTPpower]

As far as I'm concerned, the only reason that anyone should switch to roller rockers, is to maintain correct valvetrain geometry. And, with that, you need adjustables. There is very little actual testing out there on this. I believe ZZP did some testing way back in the day, but documentation is limited.

I was looking at running an ST5 cam, but I was wanting to switch to T&D shaft mount roller rockers. I was told they were 1.7 ratio, but when I recieved the rockers, they are only stamped with 1.6. So, as of now, ZZP is creating a custom cam with more lift to make up for it, but with the same duration. I may measure the difference in lift between stock rockers and roller 1.6's to see what the actual difference is, if it's not too difficult. I need to look at my heads first to see if it's possible anymore.

I care very little about peak lift numbers, or peak power numbers for that matter. Your engine spends very little time in this area during a 1/4 mile pass. You are way better off working to increase airflow at lower lifts where your engine spends much more time. (And power across the band, instead of peak.)

[NebTurboST5]

look who thinks hes a badass with fancy roller rockers....

[16MustangVet]

I care very little about peak lift numbers, or peak power numbers for that matter. Your engine spends very little time in this area during a 1/4 mile pass. You are way better off working to increase airflow at lower lifts where your engine spends much more time. (And power across the band, instead of peak.)

This makes wayyy to much sense for a forum like this....... Better stop before you confuse people LOL!