Mac 2002 SS

iTrader: (6)

Hey Guys,
I was wondering if anyone seen any difference in thier performance by installing a set of these ? I plan on keeping my stock cam for awhile and I'm content with the 12 second performance I'm getting now. I just want a little extra performance without changing cams right now. I just installed a set of SLP LT's a week ago. Haven't had a chance to hit the track yet ,but I will soon. Thanks in advance

LS1derfull

I havent run 1.85 rockers but i will say they will realistically only work with stock cam or very smooth action/low lift cams. 1.85 rocker will add like 5 degrees of effective duration at .050" lifter lift and will boost a .500" lift cam to .544" lift. This will realistaclly gain like 10 maybe 15 hp, but cam change down the road may render these rockers useless to you.Cam change is best way to boost power IMHO.

Mac 2002 SS

iTrader: (6)

Thanks for your input ,LS1derful. Anyonoe else ? I am planning on keeping my internals pretty much stock for a long time. I have my ol 93' to play with . But I do want my 02' to be pretty mean street machine ,too. So I am still considering the rockers. I would like to know if anyone seen any results from the rockers alone at the track (1/4 mile ) ?

MT POKT

iTrader: (10)

A couple of us in our club were debating the same thing. One of our members put one in his car, '99 Z28. This car has Hotcam, FLP LTs, dual cut outs, no emmissions, or EGR equipment, stock program, and 410 rear. He went from 12.6X to 12.3X consistently! I don't remember the magazine but they tested the SLP 1.85s on a 97 C5 and picked up 19.6hp at the wheels. My better half just got me a Comp kit for my birthday. I've got Hooker LTs, 220/224 530/534 112 cam, Port matched Weiland intake, all emmissions, all EGR, factory program and a couple other odds and ends NA running 12.5's Give me a couple of weeks and I'll more numbers for you...

Mac 2002 SS

iTrader: (6)

Thanks Greg. I'll be on the look out for those numbers from you. By the way ,I just seen that article about the rockers in the latest issue of CAMARO. I was pretty impressed with it. But I'm waiting to see some track results Thanks again.

Scott Turvey

Yup, I've put them on a few engines. Everything from a destroked 302 LS1 to a 427 LS6. The comment about them only being of use on a smaller cam has some merit. You have to watch going over .600 lift without changing pistons. Then again, if you do go over, you'll be changing them anyway.

With the GM Hot Cam (12480033) it makes the lift .603, gives it a nasty sound, and adds good torque. This is a result of the .015 increase in the ratio really not showing itself until the it gets well up on the ramp, and the fact this increase is predominately influential on the lift, not the duration. The result effectively is that of the old high-lift short-duration cams, more BMEP.

2001CamaroGuy

iTrader: (6)

It shouldn't make that much of a change is duration should it?

1.85 is only 9% more ratio so....

- 0.050" valve lift happens at 0.029" lobe lift on a 1.7 rocker

- 0.050" valve lift happens at 0.027" lobe lift on a 1.85 rocker

that can't be more than 1 or 2 degrees right.....or am I missing something?


I plan on running 1.8 rockers with my TR224/224.....I have 0.100+ P-to-V clearance so the extra .033" lift I get up top (new max lift of 0.595 vs. current 0.562) should really let the engine breath up top while keeping the shorter duration’s good low end....

LS1derfull

My estimate s hould be close, i will say that dynamics of cam will change and with out increased spring pressure your project should be attempted with caution. Faster action or valve velocity is key to great power but cam grinder should be consulted about your mods to confirm valve control at your intended rpm peak.

tbyrne

iTrader: (15)

This mod is good for about 15hp. I believe either GM High Tech or Popular Hot Rodding saw 19 or 20 on a C5 that they tested them on. SLP recommends upgrading the springs with these rockers. I'd say the kit with SLP springs, titanium retainers and keepers is the most popular one that we carry. This is like doing a small cam swap without actually touching the cam.

Ragtop 99

iTrader: (7)

by the time you add the sprngs, it is a pretty expensive change compared with the gain from a cam.

The best part of using the rockers may be that idle probably doesn't change much and if you have an A4 and are trying to do this w/o tuning you can still gain some power.

99 Black Bird T/A

iTrader: (4)

For most of us the cam change is probably the way to go.

My friends at SRP have done a custom cam designed for a heads and cam package to work with ~1.85 rockers using a cam with less lift, to make life easier on the valve springs and too stay away from having to cut the heads for duals. I think not cutting the heads for duals can allow a little more flexability in how to port the heads. The heads were hand ported and tailored to work with the 1.85's and cam selected. I think it takes a very custom set up to make the 1.85's worth it...like the SRP one. The benefit is getting XE-R like results much milder stress on the valve train and allowing more flexibility in porting the heads.

In other words as part of a custom package 1.85's can make good sense, as a stand alone...I'd just get a TR224 cam or 224 XE-R or something similar.

LS1derfull

I totally agree with single springs allowing more port work to be performed.That is critical area that is pretty thin to begin with, hopefully AFR castings will adress this.
I worship the 918 spring FWIW, say what you want but COMp did a great job on that baby!