Very well put Xtrooper, I could not have said it better myself.

 

wow, kickass! I just got the issue in the mail. Well that would be great to have this with the TR cam I wanted to get!

 

Interesting results, but you are not running a stock cam, correct? I have been thinking about a rocker swap (Crane 1.8) and new springs. However, I was hoping to get by with the LS6 springs on the stock cam. Would I need to go to the Crane dual springs as well with this kind of setup?

Not interested in doing a cam. Huge amount of work and some folks have been having problems with their dampers after removing them so I would rather not crack the motor open at this point.

 

I would use either LS6 or CompCams 915 springs with the stock LS1 cam and Crane 1.8 rockers.

 

Damper problems, please elaborate? I'm in the middle of my forth cam swap, this time the heads are off again to replace the lifters and notch the pistons. Believe me there is nothing wrong with "cracking the engine open". I also get to scrape the carbon off the pistons and clean them up with brake cleaner. By the way my engine has 77,000 miles and the cross hatch marks are still on the cylinder walls. Mobil 1 and Mobil 1 filter since 5,000 miles.

 

it is not required to use the crane springs with the rockers. so long as the springs can handle the added lift. when i had vinci add the 1.8 to the wife's car, i had them install the vinci/crane springs as well. here's the dyno results of using the rockers with a 99 stock ls1 cam.

dyno9 before
dyno 11 500 miles later
dyno 14 10 months later

 

Correct. I have an aftermarket cam in the motor. I really can't give you a definitive answer to your question. I think the likelihood of you having a problem is minimized with the stock cam, but I couldn't promise you that you wouldn't have one using the stock valve springs. I do think the benefits are worth giving it a try and, if worse came to worse, you could then go to the Crane springs.

BTW, I'm on my third cam and second set of aftermarket heads. There are no problems inherent in "cracking open" a motor. They aren't Humpty Dumpty after all. If care is taken in your work, you won't have any issues.

 

I'm running the Crane Gold Race 1.7 accelerated lift rockers with the G5X3, and the motor felt stronger after the install of these vs. the stock 1.7 rockers...I actually installed them just to get rid of the tap, tap, tap sounds that were driving me crazy after the cam install...Now, it is has a nice mechanical sound that isn't embarrassing to hear at a stop light...

Peace...Gman

 

hmm, if the crane rockers dont need the crane springs, marketing ploy on their part to make u use their springs, then i assume the 918 comps would be fine?

 

Why not use the Crane springs? After all they must have eliminated a problem for XTrooper and on the Vinci/AFR head test they seem to have eliminated a power dip as well. The harmonics must be very good!

 

What are you talking about "marketing ploy?" First, Crane doesn't say "you must use our valve springs with our rocker arms." Second, did you read my initial post? I had a problem using another brand of valve springs with the Crane rockers and a switch to their springs cured it. That's not a marketing ploy, that's a fact.

You can't "assume" that the 918's will work though they may very well work just fine. The fact is, I had a wicked power dip (over 20 rwhp) that started at 5900 rpm which partly recovered at about 6100 rpm. This was with a brand-new set of PRC Gold valve springs. When we swapped in the Crane springs, the dip was eliminated. Additionally, I recently saw an article in Corvette Fever magazine where they installed a set of Comp roller rockers in an LS1 motor and they got nearly the identical dip in power that I experienced. They then swapped in a set of the Comp springs, the dip disappeared, and, in their case, they picked up 16 additional horses at the rear wheels through elimination of the power dip (I picked up 13). My experience and the one related above makes me believe that roller tip rockers are very sensitive to valvetrain harmonics and I personally don't think you should "mix and match" them with different brand valve springs. My advice would be if you're going to use Crane rockers, use Crane springs and if you're going to use Comp rollers, use Comp springs with them. I think this is your safest bet to avoid encountering problems.

On top of all this, I see no advantage to using one valve spring over another as long the ones you are using are working and you're not having any issues with them. Valve springs either do the job or they don't. The Cranes are working great for me so switching to Comp 918's (or any other springs) would gain me nothing and might create new issues so I'm sticking with what works.

 

Cost mostly. He can use his stock retainers and save some money by using behive type springs. I am sure the Crane springs and retainers are verygood but more expensive and overkill for what he is doing.

A published dyno comparison between CompCams 918 vs. Crane springs would be interesting to see using the Crane gold 1.8 rockers and a more radical cam like Xtroopers or mine in sig below....with AFR 205 heads bolted to a 347 LS1 motor.

 

This is a valid point, but keep in mind that the heavier stock valve spring retainers can cause issues of their own. I don't think it's wise to spend the money on a cam and/or roller rockers, then go cheap on retainers.

If you have a decent-sized cam in your car, as we both do, you'll want to raise your shift points and your rev limiter to take full advantage of it. Lightweight, titanium retainers make it easier for you to do this by raising that point where your motor begins to encounter valve float by 200-300 rpm.

I agree it would be interesting to see if the Crane rockers work with the Comp springs and vice versa.

 

Sounds like a plan!

I have a 2001 Chevy Tracker for running around. It is the definition of underpowered, but I can go forever on a tankful of gas.

 

Hey Steve, it's Brien Laswell... how the heck are you these days? How's the misses and your daughter doing?

It's interesting to read about your valvetrain experience. I have a TR224 cam with the typical clickety clacking of most aftermarket, high ramp rate cams and was curious about your experiences with the new roller rockers. I'm running Comp 918's but went with the Comp Titanium retainers as well. Maybe a switch in rocker arms might be in my future... who knows.

Take care and I hope to run into you sometime so we can catch up.

Brien

 

Hey, Brien! It's been a long time, amigo! Good to hear from you!

My wife had some recent medical problems (heart-related), but that's been mostly resolved and my daughter had her car wrecked by some frigging old geezer that ran a redlight, but she's ok and we just got her a "new" 2001 VW Jetta w/28,000 miles on its clock for her yesterday..............so if you'd asked me how things were a couple of weeks ago, I'd have said they SUCKED!

Now I have to say things are back on track and going very well. Thanks for asking and I hope all is well with you also.

 

so what youre saying is dont assume because it makes u an *** and 2 the way they designed the "kit" actually makes their springs the best choice for it. now if we could hve someone play with these rocker and diff spring sets to see which is best. i unno, i might jus be really confused

 

I agree with trooper when I first built my motor I had 918's in it. On the dyno it had a 15 hp dip from 4500 to 6000. When I changed the springs to comp duals the dip went away. I have been told that crane has tested everybody's valve springs and it is something to do with the spring harmonics setting off our knock sensors. They have also discovered problems with other rocker arms that do the same thing.

 

I had a problem with harmonics and I cured it with the Crane springs. If that makes me an ***, then I'm guilty as charged. If you or anyone else wants to buy a set of Crane rockers and experiment with some other brand of valve springs, have at it. It's your motor and your money.

For the record, I'm not trying to convince anyone to do anything, I'm simply sharing the experience I had, period.

 

Hey guys...On my '00 FRC, with the stock valvetrain, I was seeing the 20 rwhp dip at 5600 rpms and at 5800 rpms it instantly came back...I tried everything from intake parts to reprogramming, to exhaust...Finally came across a technical article, on the internet, from a valve spring manufacturer that dealt with "SPRING SURGE"...Basically what this is, is this...At a certain rpm, the valve springs would begin to oscillate and loose their ability to control the valve...It would only happen for a short period of rpms, then the frequency of vibration would change and the springs resonant frequency would pass...

I switched the LS1 springs for a set of LS6 springs...And the dip instantly dissappeared...

So, I guess my point is this...Spring surge isn't just something that the roller rockers are causing...In my case, there was one spring of the sixteen that for whatever reason, began to harmonically vibrate at 5600 rpms, thus causing one cylinder to dump power for a couple hundred rpms, until it once again began to work properly...

As for the Crane Roller Rockers and 918's...That is what I am running on the Z06...I also have titanium retainers, for the lighter weight...I've put 3000+ miles on since the install of the cam, Crane rockers and the 918's...And I have no issues running to 6800 rpm redline...Of course, the Z06 valves are quite a bit lighter than the standard LS valves, so that may be in my favor...But, so far, no issues...

The 918's should work for the 1.8 rockers also, as long as you stay within the limits of the springs design...

Peace...Gman