Dan_the_C5_Man

I know this topic is probably tired, but I'll ask anyway..

Looking to put a Z06 cam in my 2000 LS1, bump the rev. limiter to no more than 6500 RPM (set at 6300 now).

What about the cost difference between buying a new aftermarket cam with identical specs (or close to it.. Does it exist? If so, who makes it?) re-using the stock pushrods vs. a slightly used Z06 cam and buying 7.4xx pushrods.

$$ are an issue. And I do all of my own work, so no outlay for labor, just parts..

I already have a set of used 04 Z06 springs on the way..

Thoughts?

TNormZ28

iTrader: (9)

You don't need pushrods. The stock ones are good. Bumping the rev limiter is good too. You cannot get a less expensive cam with the same specs than the 02 LS6 cam. I had one before and liked it in an F-body. A cam swap is an awful lot of work on a vette for just an LS6 cam though in my opinion.

Dan_the_C5_Man

Well, I know the base circle of the LS1 cam is different than the LS6, ad being the **** type I want to keep the valvetrain geometry as perfect as possible.

Good input, please keep it coming. TIA.

TNormZ28

iTrader: (9)

We ran a 99 WS6 M6 with the stock pushrods on an 02 LS6 cam, Vortech G-Trim with all supporting bolt ons to the tune of 639 rwhp. The stock pushrods will be just fine. I also ran the stock ones in my 01 SS right up until a soccer mom plowed into it totalling it with no problems putting 340rwhp with a 3500 stall being the only other mod to the car, (stock manifolds). Point is you don't need to spend the cash on the different length pushrods. **** or not.

C5XTASY

If you're interested, I have a 2003 LS6 cam for sale. Shoot me an email.
Ed

GTO_Scott

iTrader: (3)

I also have a 2002-2004 LS6 cam for sale (Brand new) less than dealer cost.

KSB

If I could jump in please. Will be getting some stock 02 - 04 GM LS6 heads for my 99SS. Had the same "geometry" concerns . I plan on running my Hotcam rather than the
matching LS 6 cam.

Because of the different base circles of the cams, or dif. valve lengths W/ new heads, would the stock pushrods, & geometry be ok ? Iv'e never seen anyone run ths combo. People usually will get the factory LS6 cam , or one of the many after market cams that work so well with the LS6 heads.





I'm trying to keep my build up as much "GM" as possble.
Didn't mean to hijack this thread, any response appreciated !

Dan_the_C5_Man

The reasoning behind needing new (longer) pushrods in an LS1 using an 02-04 Z06 cam is that the Z06 cam has smaller base circles.. The factory made up the difference by using longer valves.. You can make it up by using longer pushrods.

pdd

iTrader: (3)

all that work id at least put in a tr224

KSB

Dan, So you are saying if I run my Hotcam with the LS6 heads I'll need different pushrods ? If so what size ?


________________________
99SS1111 M6 NBM

Cal

iTrader: (1)

The beauty of hydrallic lifters is they will pump up to compensate for slight differences like that.

Cal

iTrader: (1)

Ditto!

Dan_the_C5_Man

I'm going to "bow out" of this one and refer you to the more experienced members of this forum.. I have learned that LS1 cams in F-bodies are not necessarily the same as those used in a Y-body (C5) LS1; I am much more familiar w/ the Y-body side of things.

From my CF thread:

Quote:
Originally Posted by Flareside
Contrary to what you'll read on the internet forums, pushrod length has absolutely no connection to valvetrain geometry in our cars. Pushrod length will change the preload, and that will only effect how low the lifter piston sits within the lifter body while the engine is running. If you really want to change/maintain the stock geometry, you have to change the valve stem length or rocker height. In a nutshell, you have to increase stem length as you increase valve lift.

Think about what happens when you install a longer pushrod. Has the position of the rocker and where it sits on the valve changed at all? It hasn't. The position of the rocker on the stem is controlled by the valve stem length (or you could also shim or mill the rockers to change it). The pushrod isn't part of the equation.



You are correct about the lifter position in the bore; that is exactly what was cited in the article; here is a snippet, directly from the GM engineer that designed our motors:

"The ’01 base circle reduction did not require a change in dimensions of any other valve train part, however, the 405-horse cam was a different story. "I wasn’t comfortable reducing base circle that much," Hicks told us, "without compensating for it somehow, because the position of the plunger within the hydraulic lifter is not optimal any more–you’re too high in the lifter.

"There’s different ways to correct the geometry. The one we selected to minimize the impact on our manufacturing operations was to increase the length of the valve. The valves in the 02 LS6 are 0.6-mm. longer than the valves in all other Gen III engines."

99% of the posts I've read indicate that running a slightly longer push rod is the solution to this "problem".

Is it your assertion that this really isn't an issue, or that running a longer push rod doesn't solve it?

If you think it through, they really don't seem to be concerned with the position of the rocker in relation to the top of the valve, since that changed when they went longer; they wanted the rocker to push the push rod down farther into its bore, forcing the lifter to ride in a different position. You can get the same result w/ a longer push rod. Basically they (GM) said, "we have a issue, and since we are going to make new valves anyway, it make sense (cheaper) to make them longer, instead of having different length push rods to manufacture and keep track of."

Dan_the_C5_Man

The only issue I'd have w/ running a TR224 (or similar) cam is it seems like it opens a Pandora's box of issues..

Need better springs, need better pushrods (although I'd want those anyway I guess, for geometry reasons), require a tune, potential reliability issues, on and on.

I guess my thought was I would take my time, replace the stock crappy balancer w/ an ATI unit, swap out the LS1 oil pump and timing chain w/ an LS6 model, buy a set of used springs (on the way) and a used Z06 cam, pop it in there and get a solid 30 HP increase (incl. the ATI pulley) without a tune, and call it good.

That would put me on par (or slightly ahead of) a stock 405HP LS6, and that would be perfectly fine w/ me. I have 3.90's and the car pulls pretty strong already.

Any more comments?

ssheets

iTrader: (1)

Sounds like you've pretty much got your mind made up.

As for the push rods, you can check the wipe once installed, if you're not happy you can buy an adjustable from Summit or ??? for about $12 and get an accurate measurement and then order what will work best. You may also need to look at shimming the rocker arms...I have a link to a thread on shimming, but it's on my other PC. If you want it PM me and I'll send you the link when I'm at my desk.

Kraest

iTrader: (3)

Need more cam

Dan_the_C5_Man

O.k. guys, what about something like this, w/ stock pushrods?

99-220/220-114 Thunder Racing Custom Camshaft - 220/220 .551/.551 114 LSA 1500-6500 RPM Power Band. Computer Tuning Required with automatic transmission cars. A very well balanced camshaft that makes excellent power across the entire RPM range. Due to the fast ramp rate of this camshaft, the use of 1.8 rockers is not recommended.

Kraest

iTrader: (3)

Check this place out

http://www.futralmotorsports.com

Mike