SLP V6 1.8 rocker arm package

[Boehlke]

<blockquote>quote:</font><hr>Originally posted by 67-03 RIP:


Jam - I only mentioned possibly needing new pushrods to Boehlke because he already had new pushrods and wanted to just buy the rockers seperately. Different rocker ratios may throw off your geometry enough to need shorter/longer pushrods. The pushrods you get with the SLP rockers should be right for that application.

Ron<hr></blockquote>

Ah yes, geometery angles. I didn't think about that. As it turns out I can't use 1.8's anyways, but thanks for the advice, that's something I never thought about before.

[AllTheGoodNamesAreGone]

Ohh yeah.. and then there is the 3rd gen intense rockers due out this summer.. I dont have to much info on those.. but they sound like they acctualy might be worth the wait..

Too many Friggin' options.. and not enough good information..

~Billy

[AllTheGoodNamesAreGone]

Ok, been talking with the guys over at intense.. again this is opinion.. but i am definatly waiting for their 3rd gen rocker kit... It sounds like it will be pretty cool.. it will be a similar product to slp's (ie. roller aluminum rockers- not modified stock ones) and competative with slp's price.. I will post again in april (hopefully w/good news).. I am also planing to do dyno testing on this upgrade.. mainly for fun.. because i have never done it.. and i feal like giving a little back to our community..

later,
Bill

[BigG]

How can I get a copy of this article?

"GM High Tech Performance (5/03)"

[JAM]

will the Hypertech PP3 advance timing, and higher octane work with this 1.8:1 ratio rocker set up?

[BLUE]

Good question... I have a Jet Chip and I would like to know if 1.8 rockers will work on my car. 10 rwhp sounds really good for 530 bucks. ;)

[Blazzin Joe]

To those asking about whether or not this type of mod will work with computer reprogramming...


The answer is yes. Now before everyone freaks out lets look at why it will work. The hypertech and jet chips adjust fuel trim and timing. This is all based in part by the amount of incoming air and the temperature of that air. We are not modifying the amount of incoming air that is metered by the MAF. We are only opening up the the intake and exhaust valves slightly longer (or techinically HIGHER lift = longer overal duration compaired to stock) which allows more air to enter the combustion chamber.

The hypertech and jet chip have nothing to do with how much fuel is actually mixing with the air, this is all done by the O2's. So you should have no worries in using this kind of modification in conjunction with a reprogrammer.

[Magnus]

Just a note: For ~$450 you could install a cam instead and gain even more. The kicker is if you can get through the install which is a little more difficult than just a rocker arm swap.

[67-03 RIP]

<blockquote>quote:</font><hr>The answer is yes. Now before everyone freaks out lets look at why it will work. The hypertech and jet chips adjust fuel trim and timing. This is all based in part by the amount of incoming air and the temperature of that air. We are not modifying the amount of incoming air that is metered by the MAF. We are only opening up the the intake and exhaust valves slightly longer (or techinically HIGHER lift = longer overal duration compaired to stock) which allows more air to enter the combustion chamber.
<hr></blockquote>

Joe - Are you sure about the duration part? Lift and duration are two seperate things and making higher lift would not necessarily have any change to duration. The increased ratio only lifts the valve higher, so for any given valve event, the valve would lift higher, but wouldn't increase the duration that's ground into the cam.
Not diss-ing, just diss-cussing...
Ron

[HAZ-Matt]

<blockquote>quote:</font><hr>Originally posted by 67-03 RIP:


Joe - Are you sure about the duration part? Lift and duration are two seperate things and making higher lift would not necessarily have any change to duration. The increased ratio only lifts the valve higher, so for any given valve event, the valve would lift higher, but wouldn't increase the duration that's ground into the cam.
Not diss-ing, just diss-cussing...
Ron<hr></blockquote>

The duration at 0.05 will go up, since you will get to 0.05 lift a little faster [img]smile.gif[/img]

[Magnus]

Yea duration will change but not by any significant amount.

BEST way is a cam. ;)

[AZ3.8Camaro]

<blockquote>quote:</font><hr>Originally posted by Magnus:
Yea duration will change but not by any significant amount.

BEST way is a cam. ;) <hr></blockquote>

I sure hope so. I know I can make it through the install. I hope my car will make it through the cam.... :D

[67-03 RIP]

I stand corrected about duration...

Many people incorrectly assume that a change in rocker arm ratio has no effect on the duration the valves are open. In actuality there is some change to the duration at the valve depending on the lobe profile of the camshaft. Comp Cams explains that by lifting the valve an additional 7-8%, but beginning and ending the lift at the same point, the opening and closing rates become steeper. This increases duration, measured at the valve at 0.050" lift, by 1-2 degrees. You can measure the actual duration change by using a degree wheel and dial indicator set on the valve retainer. Coincidentally the principle of a steeper rate of opening and closing is what Comp Cams has engineered into their Extreme energy camshafts to enable more valve duration for a given lobe duration.

Ron

Got "valve duration" confused with "lobe duration"

[ February 25, 2003: Message edited by: 67-03 RIP ]</p>

[AllTheGoodNamesAreGone]

Hmm.. I was looking as my valve covers today.. and I was thinking that this install is not going to be that easy.. on my 2000 car.. you will need to move the coil packs.. and i dont really see how you remove the assembely brackey on the front of the driver side valve cover.. Not to mention there is anoter similar bracket on the back of the passenger side that makes me even more nervious (becuase I cannot see what it covers)..

Has any acctualy ever taken their covers off? was it difficult?

I dunno.. looks like alot more work then GMHT showed in their artical (possably becuase it was a earyler 3.8)..

~Billy

[Zooomer]

For the kind of money and work involved I think a cam is a better way to go if you have an F body. Having said that if you are going to buy a different rocker then why not do the best. The latest issues of GM HP showed a dyno gain of 9WHP after installing the SLP rockers. That sucks.

At ZZP we dyno tested 13 different rocker ratio setups on the L36 and I can tell you that 1.8/1.8 is far from optimal. In fact it's one of the worst combos you could pick.