Chevy High Performance has Crane Rocker Arms for an LS1 that has been newly released. Claimed to add 20rwhp. 1.8 setting also has valve springs built with two into one. And kit comes with hardened push rods. My WS6 has 50,000mi and so I was thinking springs need changing soon anyway. Also Arms will fit under my stock valve covers. My question is will the rocker arm change make cam into the perfect turbo or blower cam when I install a pro charger this fall. Stock cam is what I have now.

 

must be talking about the vinci/crane accelerated lift rockers. i have those along with the vinci/crane dual valve springs. had them on the wife's 99 formula for over a year now. here's the dyno results with the stock cam.

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

 

I recently switched from a set of SLP 1.85's to a set of Crane 1.80 Quick-Lift rockers and, even though my max valve lift decreased slightly because of the lower rocker arm ratio, I gained 10 rwhp and 8 rwhp with the Cranes vs the SLP's. Going from the stock, non-roller tip rockers to a set of the Crane Quick-Lift rollers, you should see even greater gains.

 

I should see some good hp out of this and also some other benefits thanks for your replies and I will be getting a set soon.

 

They will just add lift to your present cam. They also are a true 1.8 rocker after deflection. sorry but I don't know what would make a good blower cam.

 

Crane also has a brand new roller lifter design that hasn't been advertised anywhere. I think I've got the first set sold at retail on the way here now. Don't Know all the tech details. You'll have to call Crane to get that info.

 

I think you're talking about their new shaft-mount, polymer-matrix bearing roller rockers which also incorporate the Quick-Lift technology. These eliminate the need for needle bearings, allowing for less friction, less noise, and more power. These aren't going to be cheap, but the performance gains should be awesome. On a BBC motor they picked up ~20 hp over the other shaft-mounted rockers they tested and you'd expect even bigger gains going from a set of pedestal-mounts.

These rockers have already been released for some applications and the LS1 versions should be out soon.

You can read all about them here.

http://www.cranecams.com/?show=techarticle&id=5

 

Hey Guys, Thanks for all of the interest in the new products we are making for the LS1. Both of you are right about the products you have discussed. Gold Z is correcct in stating that we have recently released new "long travel" hydraulic roller and mechanical roller lifters for the LS1. (Part # 144510-16 for mechanical rollers and #144535-16 for the hydraulic rollers...both are in stock and ready for shipping). The bodies are made from "carburized" billet steel for strength and the oil band has been relocated and sized to allow up to .700 valve lift (when using 1.7 rockers, more with 1.8s or 1.9s). This relocation of the oiling band prevents the band from dropping out of the bottom of the lifter bore on (small basecircle) high lift camshafts which would result in loss of oil pressure. Of course, these lifters have premium quality wheels, axles and bearings. The hydraulic roller lifter is designed to work with .060"-.100" preload and we know it will be quiet. This lifter incorporates our 4th iteration of internal oiling in a hydraulic roller lifter. It's interesting to note that one of the hydraulic roller lifters that is highly acclaimed on this site is an exact copy of our 1st design. Oops! Maybe I've just given out too much info and they will look at the improvements in these new "long travel" lifters!!

As far as shaft mount rockers go, XTooper is right. Where did you hear that XTrooper? You must have an "in" at "rumor control"!!! We didn't pursue shaft-mounts for the LS1 for quite a while for two reasons:1) for the most part there is no advantage to shaft mounts until you get over 450# open pressure. We have had dozens of field tests showing that our LS1 Gold Race rockers produce more RWHP than what many consider the best shaft mounts. 2) our investigations have shown that there is no reasonable way to make a "bolt on" shaft mount that has proper rocker geometry to provide anything close to what we term "Quick-Lift"... that is why our stud mounts have made more power!! After several design exercises, we have developed a design of shaft mounts using our Polymer Matrix Composite bearings that we feel will be the ultimate in "Quiet, Quick-Lift" design. They will not be bolt ons, but will require removal of the heads, and some elementary machining. They will be available in 1.7, 1.75, 1.8, 1.85, and 1.9 advertised ratios (of course being Quick-Lift designs, they will start the valve off the seat at a ratio of at least .1 higher than advertised) We expect they will be used by people wanting the best and willing to do what is necessary to take advantage of the design. They might fit under stock valve covers, but that can't be promised yet. In all honesty, we are probably 4-6 months from production and I don't have any ballpark price, yet. I can guarantee they will make power and be quieter than stock!! Hope this info helps. I probably will start a thread in the next few days highlighting the new lifters . Again, Thanks for your interest in our products!

Mark Campbell
VP, R&D
Crane Cams, Inc.

 

great job Mark, keep the good parts coming

 

Is there any advantage to switching the stock rockers with the 1.7's that Crane makes? Just wondering if there is any HP with a stock cam to be had without getting into changing springs.

 

Sorry, guy. I had roller rockers on the brain!

Mark: Thanks for your great update and the clarification!

 

Absolutely. First off, you're going from an actual standard ratio of 1.69 (stock) to 1.72 (Crane). The 1.70 is the rounded off marketing number.

Next (this is where the Quick-Lift technology kicks in), the stockers ratio when the valve leaves its seat is 1.52 while the Crane's is 1.82 all the way up to ~.300" of valve lift! Then as the valve starts to close, at ~.300" the Crane ratio again increases to 1.82 while the stocker decreases to 1.52.

Lastly, the Cranes, being true roller rockers, have a roller tip which makes for less friction, less valvetrain wear, less noise, and more power!

Combine all these advantages and it's no surprise when you see the power gains guys get when they switch to these rockers even when they stay with the same rocker arm ratio (though as you see above, it really isn't quite the same).

One other comment: The stock LS1 valve springs are in a word, weak. Some cars leave the factory experiencing valve float in the upper rpm range. If you have some miles on the springs, they could probably stand to be replaced. In any case, my point is, your motor would be better off and you'd undoubtedly see more power from this or any valvetrain mod if you got a proper set of valve springs.

 

Here is my question.... can I buy just the rockers in a 1.7 ratio? I have seen packages that include the springs and retainers, but I have 918s with Titanium retainers, so I don't need everything else. I'm currently running a TR 224/224 cam but my heads are milled a fair bit, so I don't want to much extra lift, but I do want a quieter top end which I hope these would help solve.

A link would be great.

THanks Steve...

 

The rockers are not sold as a kit with springs and retainers. They are sold as rockers only (#144750A-16 for 1.7, #144759A-16 for 1.8) and as rocker kits that include: screw-in studs, pushrod guide plates, hardened 7.250 heavy wall pushrods for correct geometry...144750-16 for 1.7, and 144759-16 for 1.8). Some people think the kit is a little expensive, but when you compare the total cost of the parts it really isn't. Other people say that for the price of the complete kit you are close to the price of a set of competitors shaft mounts; but those people have not tested our rockers back to back against the most respected shaft mounts. We have and we know our rockers deliver more RWHP. It is all geometry. There is no way(on an LSx head) that a "bolt-on" (no machining) shaft mount can put the rocker in proper geometry to make the most HP with the way the factory LSx head is configured. It can happen on other heads, I won't debate that, but there are definite geometry issues on the LSx head that limit bolt-on shaft mount performance. It is interesting that the new LS7 head has corrected much of this error (it isn't perfect, but it is a lot better than the LS1/6. For more info, go to www.cranecams.com, click on "products" at the top of the page and then "rocker arms"\ "gold race LS1/LS6. Hope this helps!

Mark Campbell

 

Thanks XTrooper; I was verifying 144759-16 was the new quick lift design.

What happened was on the new motor build, we determined the stock rockers were toast, so my builder insisted on 1.8 Crane. He ordered it , but I was concerned it was a standard 1.8 not the new design.

So, my new motor will have the new 1.8 quick lift design on my custom FTI 227/231 112 571/579 lift caM ( TAKING IT TO 603/612 ).

Good deal!

 

Yep, that's the right number and the same kit I have in my motor.

That sounds like one sweet setup!

Be sure to post results when you get it in and running.

 

Thanks, it should be a ton better than the JPR setup from 2002 back when we used to converse on LS1.com. Glad to hear you moved up to the vette BTW!! My motor should be in by 6-1-05.

 

I've got a JPR setup and love it... but I want to take care of the top end before it becomes an issue.

 

Yea, you should.

My top end let go last fall from him. Got 12K out of the motor. You know all the folks who got hosed by him ( verbs, 21Bravo, VINCE, Bear etc. ).

Anyway, new shortblock is from LPE, looking forward to a good combo this time around.

 

Thanks!

I bet you can't wait!