cam specs 222/222 .564 112, I was thinking about geting 1.8 rocker arm, I dont know if my cam has to much lift to use the 1.8 rockers. Can anyone help me out?

 

.551 max lift is what Crane cams designed for 1.8 rockers have.
For the cost of 1.8 rockers you can get a larger cam and still have cash left over.
Crane LS1 grinds look a lot like old Lunati LS1 grinds to me.

Your cam specs sounds like the C1, aka "hammer" cam or the LPE GT2-5. You're most likely looking at XE lobes. Not 1.8 friendly.

 

There's always Comp Cam's pro Magnum 1.75s. I'm using them on a cam a LOT bigger than what he has listed above.

 

How much lift can I go with and not have to worry about the valves smacking the pistons?

 

Depends on other factors besides just lift, but cams with over .6" lift is becoming more common. .590's is common.

 

Stock rockers will work fine.

That's what I'm using and making more NA stock cube rwhp than anyone else on this board.

 

Up into the .620s I'd imagine, but it depends greatly on valve timing events and increased duration and lift.

Mike

 

With Crane 1.82's you would be slightly over .600 lift. As already stated, lift is only one factor, so checking p/v clearance is a good idea. I think actually, Vinci says all of its .551 lift cams will work with the 1.82's but they don't say that's the max lift that will work.

I have the Cranes and they are costly new, but they can be had for half or less used. $300 isn't bad for a set of fully adjustible roller tip rockers with guide plates, poly locks, and hardened pushrods.

And I know I've seen posts where Vinci says the Cranes will work with any cam lobe profile. They use them with their quick lift cams and they claim those are as aggressive as any cams on the market.

I'm no expert, but I expect they might qualify as experts.

 

I ran the numbers. w/ .551 lift I get ~.590 w/ the 1.82 rockers. According to their wedsite it nets to about .583" lift.

Sorry, a cam like the VHP Beast w/a duration of 228/232 and a minute lift of .551 will not have agressive lobes. After you install their $600 rocker set it will, but you can get a cam from them with the same duration that comes with .6" lift ground in it for $200 less. Or their 220/224 .551 compared to the Comp ground 220/220 w/.581" lift. Now those are more agressive lobes. So, why pay an extra $600 or even $300 for used parts when you could have bought a cam that comes with more lift already ground in it?
Since you want to get into used prices, I've seen many small duration cams with more agressive specs going for $150. I even picked up my GTP420 (226/226 .590 112*) for $80. So again, where does getting longer rockers become better?

And no, Vinci may not say to not use thier rockers with more agressive lobes, but read on other sites and they will. Even TR has this disclaimer "Due to the fast ramp rate of this camshaft, the use of 1.8 rockers is not recommended." in their cams with 220/220 .551. Makes you wonder how agressive Crane lobe profiles are. Wouldn't Thunder Racing (one of the largest names in the LS1 cam market) be considered an expert on LS1 cams???

Are full roller adjustable rockers neccessary? NO. Look at Kraest. He is making more power than any Vinci car that Vinci shows on their website all with stock rockers. I don't know of any of the fastest LS1 cars that run Crane rockers. Most still run stock. Why? Because thats $ better spent elsewhere when the stock rockers do the job just as well. The way the market is now, $300 is about 1/3 of the cost of some ported heads. Actually I've seen some used ported LS6 heads around here for $575. Now THAT will make you some more power.

 

including this car??

http://www.vincihighperformance.com/...%20WHEELIE.jpg
JOHN REESE 2000 C5 AUTO
SUPERCHARGED PUNISHER PACKAGE
9.80 @136mph
WAY TO GO JOHN!

JOHN WAS CHOSEN TO PARTICIPATE IN THE ANNUAL HOT ROD PUMP GAS NATIONALS. A RARE AND HONORABLE PRIVILEGE. CONGRADULATIONS!s

 

why?? what is the concern??? is it because the valve springs they use???? lifters can't handle it????? piston to valve clearance??????

 

Once again:

Don't waste your money on aftermarket rockers (unless you're going with a shaft setup).

I wouldn't have chosen that cam, either.

Mike

 

to say it's a waste would be incorrect. depends on what the person is doing. for someone that doesn't have the desire to change the cam, it's a good way to increase your power without all the tuning, idle, and driveability characteristics that come with a cam swap.

even for a person that is looking to extract as much as they can out of what they have, it's still a good choice. not everyone is looking be be the fastest/quickest person out there. even still, tony mamo from AFR used the vinci/crane accelerated lift rockers in his last motor. in his current 383, he's using the crane shaft mount rockers.

 

your new total lift would be around .597-.613 depending on what 1.8 rocker you go with. it's a matter of if your valve springs can handle the increased speed and lift with the higher ratio rockers and whether or not you'll have enough piston to valve clearance.

 

Actually, a stock car can benefit 10-15 rwhp with a dynotune and the Futral line of cams drive near-stock, which would give you MUCH more than a rocker change.

Mike