Schwindj

Has anyone installed Crane Cams LS1 Gold Race Rocker Arms w/ quick lift technology? Their webiste says that they are good for 20 horsepower, I just wanted some outside verification. Thanks

jrp

iTrader: (16)

search VHP or mr223.

XTrooper

I recently swapped in a set of the Crane "Quick Lift" 1.80 roller rockers replacing the SLP 1.85 rockers I'd been using. Even though I lost a little on my max valve lift by going with the slightly lower rocker arm ratio (1.80 vs 1.85), I still gained 10 rwhp and 8 rwtq with the Cranes.

With the above in mind, if you replaced a set of the stock 1.70 rockers (actually 1.69) with a set of the Crane 1.70 rockers (actually 1.72), I think you could reasonably expect to see a gain of 15-20 rwhp.

vettenuts

iTrader: (4)

Wondering if the Crane 1.7's would also require a spring change?

1BadMoFo

iTrader: (1)

any thoughts on piston to valve clearance, when using in combinatioin with MTI's Stage 2E heads and their G1 cam?

JimMueller

iTrader: (9)

So what if you switched from stock to the 1.8[9]'s?

XTrooper

Well, the added valve lift of the 1.80 rockers will certainly give you bigger gains over what you'd get with the 1.70's, but I wouldn't want to guess what the difference might be. Personally, if you can safely use the 1.80's, I'd use them as they don't cost any more than the 1.70's.

lsx24

iTrader: (45)

Nice numbers

ls1mojo

Those are unique gains. I'd be interested to see if lobe profile has an effect on the top end numbers, and where the numbers are effected, since there are no results other than one or two, however positive so far. Are there any independent graphs?

mrr23

iTrader: (3)

well, i don't work for vinci or crane. so i guess i'm independant?? here's the dyno from the wife's car when swapping from stock rockers to vinci/crane 1.8 accelerated lift rockers on stock cam. also added the vinci/crane dual springs at the same time.
dyno 9 before
dyno 11 500 miles
dyno 14 10 months later

02SOMWS6

iTrader: (6)

I'm running stock rockers with a split duration cam .(lift is 581/588) I have double valve springs already. Is my lift gonna be to high with the crane rockers? I've been thinking about the jessel set up but the crane is looking like the cheaper way togo so there's more money for other things

mrr23

iTrader: (3)

you'll be at .622/.629 with the 1.8 accelerated lift rockers. you need to check the max lift for your springs.

02SOMWS6

iTrader: (6)

springs are not an issue, but I think it might be too much. maybe I should just go with the 1.7 I don't see many cams running as high of a lift for what I would be at with the 1.8

ls1mojo

You are dangerously close to too steep lift with 1.8s. I would run 1.7s with that cam 581 lift is already quite bit on a hydraulic valvetrain.

JakeFusion

iTrader: (7)

.581/.588 sounds like 224/228 XE-R? If it's XE-R, I wouldn't touch a 1.8 rocker, because the ramp rate is insane on that lobe. That = bad combination.

mrr23

iTrader: (3)

why's that?? we've been discussing this very same theory here: https://ls1tech.com/forums/showthrea...ghlight=rocker

is it because of piston to valve clearance issue? valve springs recommended for that cam not be able to withstand the increased speed of the valve now?

AsianIce25

iTrader: (2)

one of the guys at vinci is running the 049 cam with .600/.600 lift witht he 1.8 accell rcokers, so his max lift is ~.643/.643. this is a head cam stroker car, but the cam is one of cranes accellerated lift models, but i hear this is a less agressive lobe compared to an xer lobe. the motor/pistons will clear the lift, but the pretty aggressive cam works with the 1.8 (1.82max) rockers...

02SOMWS6

iTrader: (6)

I'm going with the 1.7

lsx24

iTrader: (45)

You are apparently missing the point and on your own little tangent. These rockers were designed to accelerate the valve faster than stock, that's why they are ground breaking.

Only time will tell, ok, the fact of whether a spring can hold onto that themselves is another issue all together. The fact remains, the original numbers would be increased because the extra rate increases the aggressiveness of the lobe thereby increasing the apparent size of the cam because of these rockers.

XTrooper

This myth is parroted "urban legend" BS. There are a number of guys running XE-R cams in combination with Crane "Quick-Lift" rockers and to good effect.