I'm looking into getting a cam for my 350 and I needed to know How much lift can you run on a stock hydrualic roller lifter?

 

I believe they are good upwards of .550" lift. You have a factory 4 bolt main roller block?
If these are actually retrofit lifters, then it's a totally different ballgame.

The only limit on a factory roller lifter would jumping above the spider right? Can you measure that yourself? Clearance the block if neeeded?


PS - Did you rig up an 8.5" to suit your 3rd gen yourself? I was going to do that one day, curious how you did it?

 

I'm not sure if the block is a factory 4 bolt they aren't a splayed bolt pattern. but the blot is a factory roller and I have a set of factory rollers for it, so I figured why not!

I just got the car and I made an assumtion, which I found out earlier was a wrong one, so I need to change that about the diff!

 

I don't know the exact number, but it's falling below the anti-rotation dog-bones that limits lift. Remember how you get more lift out of a cam and still get the cam through the cam bearings.

There are aftermarket lifters that are taller so they don't fall out of the dog-bones.

 

would .36" lift at the lobe(.540" at the valve w/ 1.5 rocker) be too much for the stockers?

 

.600" is the lift at the valve with 1.5:1 rockers that stuck in my mind.

 

so I should be fine with the 540 lift cam?

 

anyone know beyond a shadow of a doubt? I really can't afford to spend $260 on a cam just to ruin it!

the cam pecs are as follows

Basic Operating RPM Range:2,500-6,000Intake Duration at 050 inch Lift:236Exhaust Duration at 050 inch Lift:242Duration at 050 inch Lift:236 int./242 exh.Advertised Intake Duration:288Advertised Exhaust Duration:294Advertised Duration:288 int./294 exh.Intake Valve Lift with 1.5 Rocker Arm Ratio:0.520 in.Exhaust Valve Lift with 1.5 Rocker Arm Ratio:0.540 in.Lobe Separation (degrees):110



thanks-
Eric

 

My ZZ4 cam has .510" exhaust lift, and it wasn't even close to a problem. I didn't measure how much the lifter stuck over the dogbone, but at the very least you could install the cam and check it yourself.

 

For absolute fact, anything over 0.530" advertised lift, with 1.5:1 rockers, is risky. If you want more, either spend a little for 1.6:1 rockers or spend huge for Crane's long-travel lifters.

 

I have faced this same dilemma. I have a crane cam with .538"/.558" lift and have also seen where people say no more than .530" lift unless you use cranes lifters that cost like $520. Instead of doing that, I called comp cams and they told me they know guys who routinely use cams with close to .600" lift with their pro magnum lifters. These lifters have a different type of retention device that holds the lifters internals in, in order to allow you to turn over 6000 rpm and avoid lifter pump up and valve floating. I used to use the stock lifters in my engine for a while (but I wasnt really beating on it either) but I got a set of the pro magnums to put in but have not had the time to perform the swap. If you look on the comp cams website you will see that even with their largest cams for our oe roller blocks (in the area of .580" lift), the premium lifters are the pro magnums, with no mention of any other special valvetrain components. By the way, the pro magnum lifters are like $230.

 

well, I'm ordering the cam monday morning, I was able to get a hold of tech support @ comp cams and they said anything under .400" at the lobe (.600" at the valve) was good, so I should be fine, the way I heard it was that as long as the lifter dosn't contact the dog bone I should be fine..

we'll know soon enough!

thanks for all of the help-

Eric

 

As long as it doesn't lose contact with the dog bone, you'll be fine.

 

what I meant was lift the dogbone (because it would break or at least thats what I was told)

Thanks again!

 

I'm running .582" lift with 1.65 rockers with factory GM roller lifters.

 

I had a customer with a Mini-rammed 355 and a .530 cam turning 6500 rpm.
This was a road-course car. One day, he brings the engine in. One lifter had gotten free of the anti-rotator, and had killed the entire short-block. Big circular groove in the cam lobe, too! If you're gonna risk it, keep your revs down.

 

Rev kit!

 

oh yeah, ericjon, make sure the spider is still putting ample tension on the dogbones...you may need a new one to make sure it will hold them down correctly. When i first put the cam in mine i noticed that the spider wasn't putting much tension on the dogbones...this could also be the reason for people experiencing failures with only moderately sized cams...who knows.

 

how hard is the spider supposed to push on the dogbone? is the spider supposed to be rigid, or more springlike?

I've decided to go with the comp cams lifters instead of the stockers, the warrenty on the cam is voided if you don't (and knowing my luck...). has anyone used the comp cams magnum roller lifters? I heard they tick, is it annoying? are the more expensive high energy roller lifters any better?

thanks for all of the help, if you couldn't guess, this is my first roller cam motor!

 

I have the AFR Hydra-Rev kit on my engine.

http://www.airflowresearch.com/hydra_rev.php

 

I'm running over .600 on mine with with Oem lifters
But, using the AFR Hydra Rev kit.
Pushed past 6600 few times and still pulling.
Few times, getting to old for that stuff.

HTH

Later

 

Pic on AFR Rev Kit.
Engine out after Dyno run
Later

 

WOW!

I always thought a rev kit was new valvespings!

how hard is that to install/is there any machine work required?

thats just awesome!

Thanks for showing me that!

 

ericjon, a new spider will almost be spring like. as far as the choice between the high energy and pro magnums, the high energy are basically a performance replacement lifter, and the pro magnums are the more expensive, higher performance version. I also see where comp is now offering a "short travel" race lifter, but for $475 i dunno. I'm going to stick with my pro mag's for now. I would also consider the use of the hydra-rev kit, especially if you plan on running upwards of 6500 rpm frequently.

 

is afr the only company to make a hydraulic roller rev kit? also how fast can you turn a motor with a rev kit installed, are you limited to 6500, or can you go higher?

also, the pro mags are cheaper than the high energy at summit.

http://store.summitracing.com/egnsea...115+4294900391

thanks again for all of the help!

 

As far as rpm limit with the rev kit, as I said I've pulled
thru 6600 ocassionaly and was still pulling pretty hard.

(But), Rev kit not all thats contributes to this.
Running lightwieght valve train. Titanium retainers
lightwieght valves ect. ect.
The hyd rollers are heavy.

HTH

Later

 

very true. I think I'm going to get one eventully, but I don't know how well my bottem end would hold up to 6500+

Maybe when I get a forged bottom end and some better heads