sothpaw2

Title says it all--Comp Cam guy says only 5800 rpm and valve float will result if you go much higher.

I thought lots of people here went a lot higher with no issues.

He recommended the Pro Magnum lifters 875-16 which I think are the Comp-R's. Lots of people have had problems with those, correct?

Opinions? Experiences?

Thanks!

TM-Z06

I think the LT1 and LT4's shared the same lifters. LT4's have a 6300rpm redline, and there are plenty of guys that spin them past 6500rpm

steve40th

6500 rpm's.I emailed 19 different shops/tuners that build LT1/4's and they said use OEM lifters, 918 springs (most of them) for my cam XE230/236 544/555 lift and said tehy dont recommend Comp Cams r's till you need higher rpms or you request them.

Z06_BluByU

The -R type lifters require frequent adjusmtnet settings (or swap out) as I've been told by comp cams... the recommend factory replacments for the cam I ordered from them... see sig

vettedave

stock hydraulic lifters are generally good to about 6500 imo. for reliability issues.

Valve float is usually a function of valve spring pressure.

Some hydraulic lifters go into what is called pump over a certain rpm where the valve could be held off the seat by hydraulic pump causing the plunger in the lifter to make it act like a solid lifter.

sothpaw2

Frequent swap out for the -R? Who on earth would want to do that? Maybe someone who wants to spin to 7000+rpm but maybe they should think solid roller at that point. I don't get it.

What factory replacements do they sell? Just curious.

Thanks everyone--after posting I remembered the LT4 probably has the same roller lifters and the general should have certified them up thru 6300 rpm minimum.

Anyway, 6500 rpm is more than I spin and 6500 is about what I thought the limit was. Thanks again for your responses.

SStrokerAce

Gone into the high 6000 range no problem... the problem you would have steve is the cam lobes and getting them to make power over 6000rpm.... those XE deals aren't the best things for going over 6000rpm even if you have beehives.

Bret

luvmy92

I've been using the Comp R's in my car for 5 years now, with lots of track miles during that timeframe. I have a 224/230 cam with .606"/.622" lift using the 977-16 springs. My shift light is set at 6100, and I am probably making my shifts between 6300 and 6400. No problems as of yet with the lifters...

Mike

rocco16

Lifters are not the issue. Springs are.

Larry
code5coupe

steve40th

Thanks Bret, I was doing what was recommended by Comp Cams. And the Dyno shows no issues, but I only go to 6300rpm for a short time too. My TTS datamaster doesnt show knock or anything to show float or problems to where the PCM takes control of timing or fuel.
The articles coming out on the streets are showing these springs to work very well up to 6500 rpm with similiar cams, not XE's which I know have aggresive ramps, but cams that are high lift cams. I am no expert, but the reviews and that fact that they are lighter, due to retainers, and have good spring pressures, they seem to be capable of the rpms I am making. There are a few guys with the High Lift XE cams here, and no one seems to be haveing problems so far.