3rdCoastPowerSports

iTrader: (5)

didn't you degree the cam, check installed spring height, shim to .060" or so from coil bind, check ptv clearance, measure for proper push rod length? no disrespect but I think its time to call in a professional. also im sure your motor is fucked, those needle bearings can cause some carnage.

stangkiller2005

iTrader: (15)

Im not wondering why im having issues. Im trying to resolve the problem i got myself into. The springs were rated above the cam lift so.i figured they would be fine; that way they didnt run out of spring. The spring recommended is 650 lift spring but for 644 lift i wanted more cusion. Guess thats a problem. I have pac seat locators. Like i said it was a kit. the seals.that im using came with my felpro head gasket kit. They are the bulky metal.kind. I put.them over the pac seat. And i eould lovr to get ahold of the person that specd the cam nut thunder racing has the worst customer service.ive ever experienced.

Gray86hatch

iTrader: (83)

There is more to valve springs than max lift.

Professional help is what you need. Pay someone to figure this out for you before you damage more stuff.

I don't do my own stuff I pay FTI to spec all my valvetrain.

Tim

stangkiller2005

iTrader: (15)

well yes now im going to pay to have springs pulled. cant i remove shims and be fine? you guys make it seem like nobody has done this before. this cam is been used by many people with same heads and pushrods. whats so different from mine? i feel like the springs are coil binding because of shims that i put. maybe the installed hight is different from 1.8 that pac says they should be. yes i know i should have measured but instead of bashing on me can we try and figure it out? ive done multiple cam installs and never had this happen before. went with what was recommended and had no issue. i could see if this was some crazy *** heads and an enormous cam, but it is not. many have run this without issue. if i need new springs ill buy new springs, if i need to remove shims than thats what ill do. but saying oh u shoulda done this and that will not help me. i hope my motor is not shot. if it is than maybe i can salvage the top end and get a bigger short block. my setup is far from crazy. its pretty much a stock ls1 with ls6 top end. should not be much different from installing a cam into a 03 z06. i beleive my **** up is in the shimming. are none of you guys familiar with PatrickG and all the work he does? he knows his stuff. i agree now i need professional help. thats why im turning to you guys. good local help is not easy to come by around here. wish i lived back in texas. i would have no issues.

Tainted

iTrader: (9)

Are they shimmed to install height of 1.800 or 1.740 (within .060 of coilbind)?

Gray86hatch

iTrader: (83)

I don't know anything about the lobe on that cam but the specs on it are not that agressive. I don't run that agressive of a spring on my engine and it is 250 250 .660 .660

You need a spring for that cam. Taking shims away is not your answer. Then measure the pr and go from there.

Again paying someone who does this every day is going to be your best bet.

Tim

Brian Tooley Racing

iTrader: (13)

If you installed the "hat" style seals over the locators then there's your problem.

Simply throwing tons of spring pressure at a cam isn't very smart. Increased spring pressure over 400 lbs when using 5/16" pushrods makes the valvetrain less stable due to squashing the lifters and pole vaulting the pushrods.

These are the proper seals: http://www.briantooleyracing.com/ls-valve-seal-kit.html

These are the incorrect "hat" style that are only to be used with single beehive springs: http://www.briantooleyracing.com/ls-...hat-style.html

outkast6991

iTrader: (34)

What is the actual installed height?

Ferocity02

iTrader: (60)

What Tooley said! The one piece valve seal/seat are for stock springs or stock replacement beehive springs. They don't require another spring seat because the seat is built into the piece. If you used these on top of the PAC seats, you basically are running two seats and may have coil bind issues.

Ferocity02

iTrader: (60)

And also you should check your pushrod length. If that cam has a stock base circle and you're running LS7 lifters, you should be using shorter than stock pushrods, not longer.

stangkiller2005

iTrader: (15)

They are hat style. So i will be swapping for the smaller version. I used 1.8 for installe height.measurement. The lifters are not ls7s from what summit said. I beleive they are stock replacements for an ls2 6.0. The whole spring kit is from pac. Retainer, seat, and spring. Thats how i cam up with.measurements for shims used.

.060 and .030 shims on intakes

.015 and .030 shims on exhaust

stangkiller2005

iTrader: (15)

I had to learn the hard way, but it all starts to make more sense.

Brian Tooley Racing

iTrader: (13)

I just put a 1208X on the spring tester and checked it at 1.710" installed height (.060" &.030" shims) and it checked right at 200 lbs and at .650" lift it checked right at 500 lbs. That's way too much pressure if you're using stock rockers on something that will be driven a lot. As that much open pressure can damage valve tips long term. If it's a track only car then you'll be ok.

Honestly almost .650" lift is too much lift if using stock rockers, as the scrub increases dramatically at those lifts. All in all, I would put some roller rockers on it. Also carefully inspect your inner springs since you were running them into bind.

Tainted

iTrader: (9)

so brian this is off topic from the OP's post somewhat:

When running the roller rockers, whats the best way to make sure they arent gonna be snapping in half like the YT's etc? I jsut got some roller rockers, but I have no idea what brand they are or anything, and when I put this 408 together I wanna be sure I wont have any problems. What do you recommend?

Ferocity02

iTrader: (60)

What part number are they? "Stock replacement" tells me they are what everyone is calling "LS7 lifters", which require a shorter pushrod.

Brian Tooley Racing

iTrader: (13)

There's no way to ensure they won't snap in half, which is why I don't use them if I don't absolutely have to. I know YT redesigned their rockers and the new ones are much less likely to break. So maybe sell your rockers and buy the new YT.

When I spec cams for use with stock rockers I use conservative lift of .624" or less and gentle ramp rate lobes. Then I use springs with less than 400 lbs open pressure, oil with zinc additives and don't have any problems. I just had a turbo car run very low 8's with .621" lift, my Platinum springs that are about 390 lbs at that lift, 5/16" pushrods and stock rockers. He was turning it 7300 rpm through the traps. If people would realize that super high lift cams aren't the magic path to making power they would be better off.

It seems that everyone who is eating up valve tips with high lift cams, stock rockers and too much open spring pressure end up calling me, rather than the shops they bought the stuff from, I'm not sure why that is.

stangkiller2005

iTrader: (15)

.050 is the number using for coil bind sorry.

stangkiller2005

iTrader: (15)

So with that installed height that
You came up with, that changes the shims i should use? Its.going to be a daily driver. Is there a way to make these springs and cam work? If not i may have to sale everything and start over. But i reallly dont wanna do that. And need my car for work. I was thinking of doing truion upgrade. Those Comp cam bearings to reinforce rockers. How do so many get away with ms4? And that lift is even higher.
Is that installed height using PAC locator aswell?
Nal- 12499225 is the part number for the lifters summit.sent me.

Tainted

iTrader: (9)

if you use stock rockers over .630 lift we are all telling you sooner or later thats gonna catch up. trunion upgrade or not, its the geometry that counts.

Brian Tooley Racing

iTrader: (13)

The installed height I came up with was based on IF the PAC retainers setup at 1.800" and you used .090" worth of shim to get to 1.710". In all reality the PAC retainer is probably more like 1.820" installed height so you might be at 1.730" installed height. However the hat seal is .030" thick so you were probably at 1.700" on the outer spring, and about 1.400" on the inner spring since it would be sitting on top of the step built into the seal.

The only way I see to make the cam and springs work is to buy roller rockers, like the new Yella Terra.

I'm not sure why these guys who have had problems with high lift cams and stock rockers don't post on these forums, unless they do and the thread disappears. I think many don't feel like they have a problem until the rocker eats the valve tip all the way down to the locks. The guys who are observant who end up hearing valve train noise generally ask questions and then inspect their valve tips. Then they see them look like the surface of a golf ball or have trenches cut in them, and then they do something about it. The valve tip should be flat and smooth, not pitted or trenched out. Just because someones car is still running, doesn't mean it doesn't have issues. Too many guys think as long as it continues to run, then everything is fine. If it's eating itself up, then it's not fine in my book.