orangeapeel

iTrader: (18)

Wow, how did you manage to capitalize ever word?
And to answer the question....Just upgrade your stockers with new needle bearings and you will have a stout 1.7 for a cam in the long haul of things.

badmfkr

iTrader: (4)

I will evolve into this setup right now digesting the cost and amount of time involved in the cam swap, the swap I did myself.

Thanks

mrr23

iTrader: (3)

well here you go. been posted on here for some time. stock tune as well. vinci/crane 1.8 accelerated lift rockers and dual springs

dyno 9 before
dyno 11 500 miles later
dyno 14 10 months later

4mula

not to sound like a smartass, but no two dyno pulls are alike sameday neverless months apart.

also i called bullshit to the guy who said 18-25 rwhp for rockers
todays about 30 degrees cooler than the day my car put down 379. ill bet it dynos different today

mrr23

iTrader: (3)

so, i guess my 17 rwhp is fake then. along with the 5.3L truck that vinci did the 1.8 rocker swap on for CHP mag. again on stock tune. made 19.2 peak rwhp

JPH

iTrader: (2)

Thanks Mrr23, Finally A Couple Of People Agree With Me On The Rocker Set Up. Guys These Rockers Really Work, I'm Sorry They Cost So Much, But I Can't Help That. If You Are Building An All Out Deal, They Are The Way To Go Or Even Think About The Shaft Rockers As Well. I Am A Crane Cams Dealer And Have Used And Installed Plenty Of There Lsi Cams As Well As Rockers And There Products Are Not To Be Taken Lightly, I'm Sure R. Vinci Can Agree With Me On That. Bang For Your Buck, Rockers Are A Little Expensive, I'd Rather See You Put A Cam In Before Rockers But All In All The Rockers Do Work People! If You Wanna Know How Check Crane Cams Website As Well As Vinci's Website. Thanks

orangeapeel

iTrader: (18)

I am still thinking that there are more worthy mods out there than the hit or miss with the rockers. I look at this the same as if you were deciding to de-screen your MAF or leave it alone.

4mula

i stand corrected

mrr23

iTrader: (3)

well, i do agree, that cost wise, it's a big investment with small return when compared to some other items. it's just one of those do it or don't things.

orangeapeel

iTrader: (18)

agreed

kenp

iTrader: (9)

Well, you don't have to buy the Cranes new. There is a fairly constant flow of the 1.8's into the used parts for sale area. Used they sell for less than half the new price.

I put them in my car and I like them. No, it will not create any lope, but the exhaust note of my car did change a bit.

You can add a cam with the Crane 1.8 rockers. You can safely install a cam with up to .551 lift @ the 1.7 ratio in your car using the 1.8 ratio Cranes. That will give you about .584 total lift.

If you install a new cam you will need new springs just as you will need them if you put the 1.8 rockers in. The rockers work; and included in the kit is hardened pushrods. An additional benefit is that the rockers are adjustible. Read all of the posts where people can't get the pushrods right because they've milled heads, changed gasket thickness, and cam base circle. That ain't no problem with the Crane gold quick lift rockers because they're adjustible. If you have new needle bearings put in your old rockers that isn't cheap and you still don't have a rocker with roller tips, the guide plates, hardened pushrods, or the flexibility of an adjustible rocker.

This question comes up quite often and the thread starts with the bashing of the 1.8 rockers until mrr23 posts up the dyno results.

I can only say I have them installed in my car and I am satisfied with them. I can also say that I have a new cam I'll be installing with my Crane 1.8's this spring.

I would have had more flexibility in my cam choice if I had gotten the Crane 1.7 ratio quick lift rockers.

pla-tym

Don't the 1.8 rockers increase valve lift by only .015

4mula

not many people get those gains. thats why they 1.8 rockers get bashed.
my dyno graph was posted. my numbers are typical

vettenuts

iTrader: (4)

One thing to remember here, you are comparing different brands of rockers. The Harlands are not the same as the SLP's which aren't the same as the Cranes. All rockers vary in ratio during valve opening, in fact the most inefficient valve opening is a rocker design that "attempts" to keep a constant ratio. My point is there is more to this than just stating out of hand 1.8 rockers suck.

I am running the Crane 1.8's right now, and went to far as to pick up a set of their 1.7's for my head installation. I am no way associated with Crane, but a lot of responses in this thread are based on what people have read on the internet, and not facts or first hand experience. I also seen it stated how heavy the Cranes are, when in fact weight doesn't mean beans, its rotary mass moment of inertia that matters in a rocker and the Cranes are less than stock. Also important is the rocker stiffness, no one ever mentions this yet the Cranes are stiffer as well.

One thing I do agree with is that they are expensive and whoever is considering them needs to assess where they are trying to go with their car and what their goals are. The full adjustability is one of the things that I was after in my rocker arm selection, without machining my heads. The stock rockers are good units, but the limit in pushrod length variability also limits your capability to dial in the lifter preload.

To answer the original question, the valve event will change and the exhaust note might change slightly. If you are after a better exhaust note, a different exhaust system is probably a better choice.

mrr23

iTrader: (3)

on another note, you aren't severely limited on your cam choices just because you have 1.8 rockers (any brand). so long as you have proper spring control and piston to valve clearances, you can use them. yes, i know, TR says not to use them with their cams. haven't ever seen why they say that.

think about it. the current LS7 motor uses a 218/230 duration with 1.8 rockers direct from the factory.

mrr23

iTrader: (3)

depends on the amount of lobe lift to begin with. here's the math formula:
take valve lift and divide it by current rocker ratio. this gives you the lobe lift. then take that number and multiply it by the new rocker ratio.

example

.551/ 1.7 * 1.8 = .583 a change of .032"


now, a thing to remember about the vinci/crane rockers. the max lift point on these particular rockers are 1.82.

.551/ 1.7 * 1.82 = .589 change of .038"

4mula

a person is very limited with cam choices. small lift cams only.

ss1

iTrader: (32)

It all depends on the cam you are using. The bigger the cam, the more lift you will gain by going from a 1.7 to a 1.8.

Example 1: Your cam is .544" with 1.7 rockers. Take .544 and divide it by 1.7, you get .320" of lobe lift.

Now take your .320 and multiply it by 1.8, you end up with .576" of valve lift. A gain of .032" at the valve.



Example 2: Your cam is .581" with 1.7 rockers. Take .581 and divide it by 1.7, you get .342" of lobe lift.

Now take your .342 and mutiply it by 1.8, you end up with .616" of valve lift. A gain of .035" at the valve.

You can see it's only .003" difference. The ratio of the rocker is simply a multipier. So depending on the existing cam, the gain in lift will vary slightly.

ss1

iTrader: (32)

Wow! mrr23, you beat me to it!

So I'm going to hijack this post for a minute. I'm the guy who was asking you about the 1.80/1.89 rockers not long ago. I just figure it's not worth starting a new thread over, since we're already on the subject and have everybodys attention.

My cam in my car is the one I mentioned above. It's .544/.544" 230/222 114 lobe separation. #'s and mods in sig below.

Since my current cam works well, but is slightly on the small side. I don't want to get involved in changing the cam. Would it be worth my while to try out 1.80, 1.82, or 1.85 rockers and bump up the lift to .576, .582" or .592"? This would put me in the ballpark of most of the newer cams on the market.

Another dumb question, If I put on the new rockers, would something in the tune need to be changed? My current tune is decent and I don't want to mess anything up. There aren't any shops that I know of in my area that i'd want to mess around with my car.

mrr23

iTrader: (3)

only due to what reasons? even so, you have built the lift into the valve via the rockers. this aides in slowing the lifters, pushroods, and rockers. which in turn allows the springs to better maintain valve float because it isn't having to control the inertia of those parts i just mentioned as much as if you accelerated the entire valvetrain via building it into the cam. 1.8 rockers is nothing. you've got as much as 2:1 ratio rockers in major racing engines like NASCAR and NHRA style.