DSRE

iTrader: (7)

Erik-Do you think we are at the limits of a Hyd roller lifter or is this as it seems Poor Materials/Methods being used to mass produce a one size fits all part? I mean i hardly ever have any issues with Sollid roller tappets the last 5 years, We keep going with more aggressive cam profiles and springs and i guess at some point something has to fail, and Normally the Spring is the Weak link but now the Lifters are having a hard time, probably because the lifter has the most moving parts IDK

vettenuts

iTrader: (4)

Or other flexibility in the system are beating the lifters (pushrod flex for example).

printmanjackson

iTrader: (1)

are these lifters going down under just normal engine operating range or under high RPM's?

I find it hard to believe that Comp Cams has designed cam lobes and not have a lifter to handle it.

racer7088

No you can always do more but the problem is that a valvetrain is a system and not many of us have a spintron or dyno to really play with every setup to make sure it's stable. We have some .700+ lift stuff that turns very high rpm and is fine but it is much more expensive and uses lighter parts. People always want the moon but will not pay for the parts necessary to make it happen and basically there it is. With regular stuff I think we are close to the edge wit ha lot of the LS1 stuff.

People think a cam is like a super charger and it isn't. Once you have a cam that's close as far as valve events you can change characteristsics more than all out power really. Besides power adders you can only turn engines more rpm and / or make them larger bascially. We can always improve a little bit though even at teh same rpm and engine size but not that much more than where we are at. Maybe variable valve timing is the next level I guess.

whiteseven

iTrader: (8)

At what point is a Cam/valve spring setup just too aggressive for an LS7 Lifter? A 224R with double valve springs? 230ish? I am seeing the failures but they are on extremely radical cams. I believe the last one I read was 247/254?

The reason I ask is I'm using LS7 Lifters on a 233/239 cam, street car, don't take it to the track or anything but now with all this talk I'm SERIOUSLY considering tearing the heads off and sticking morels in it because I really REALLY don't want any wheels falling off in my engine. When I built it last year I really hadn't heard of any major issues with the LS7 Lifters. Now I'm somewhat freaking out.

Devils Mentor

iTrader: (20)

+1 but I am running the MS4 with the LSA @111


DM

chrs1313

iTrader: (24)

that intake lobe is pretty extreme being 239 with .649 lift...i just ordered up some morels, since i dont want to chance it with the same size cam...

DSRE

iTrader: (7)

Thanks Eric, VVT would be neat on a Gen 3, I wonder if some of this can also be contributed to using 5/16 .060-.080 wall push rods at 7000rpm, I'm using 3/8 .065 wall in my 383 as i believe Push rod harmonics and flex is NO good!, also Going to look for a set of Morels that go in the lifter trays, maybe someone has a slightly used set they wanna sell? LOL

Devils Mentor

iTrader: (20)

Well I guess I will play follow the leader

Thanks man!


DM

racer7088

3/8ths is usualy better than 5/16 yes if you can fit them.

Paint_It_Black

iTrader: (1)

That's just advertised lift.. I had my 227 LSK lobe doctored and it can out to 228.7 it was also supposed to be .639, came in at .644

chrs1313

iTrader: (24)

so it is even worse more agressive...even more reason...when I degrees my xfi/xer cam it was way closer to the specs than yours...we will see what the lsl cam is at when it comes in...

WKMCD

iTrader: (2)

FWIW: I pulled a set of Caddy Racing lifters after about 8k miles and replaced them with Morel tie-bar lifters.

99LSS1

iTrader: (12)

I am in the middle of my build and had ordered up some LS-7 lifters. After seeing this and other posts, I will be going with Morels instead. Not cheap insurance at 500 bucks, But seems like the best way to go if I don't want to replace lifters as well as other things if one or more fails... Can't remember ever seeing a post about Morels going bad!!!!

racer7088

I think Comp's numbers may come from .700 wheel so with a .750 it will show a wee bit more duration but they are are always a tiny bit different although we usually get the appropriate lobe lift that Comp says. Now the lift at the valve the rocker and geometry can affect it a lot even with same lobe lift.