GIVE EM' THE BIRD

iTrader: (1)

To make this easy: current setup=

Stock bottom 99ls1 car.
Built A4 and 2.73 gears(going with 3.42's or .73's soon)
Full bolt on supporting mods for a H/C/I car... Headers, ls6 intake, yadda yadda yadda

Livernois 243 castings with .690 max lift dual springs.
comp 218 cam
1.82 comp rockers
Pushrod length unknown?

I'm planning on buying a cam in the 228-230 range with around .590 lift.

Should I have any issue with my PTV clearance??? I know I wouldn't without the 1.82 rockers, but I'd like to keep them if possible/practical. They're nice and all

I've never had an issue with PTV clearance or had to check it so I'm a newb in this respect.

My plan is to pretty much just swap the cam and then take it to the tuner immediately... Not trying to go flickering and all that jazz as my setup is pretty good right now, just wanting to slip in a bit bigger cam bc it's pretty cheap and labor is free

Was thinking a fast intake and new tune if I'm gonna have PTV clearance issues... But trying to save that for next spring/summer since rebuilding my rear is next.

Thanks for the help,

Derek

KevinR

Nope, you shouldn't have any PTV issues with what you are looking at.

GIVE EM' THE BIRD

iTrader: (1)

Boy I hope your right man! Bc if it all goes well with the install I'm gonna be like a kid on Christmas!

Those 1.82 rockers are just jacking with me making me think my valves are gonna be too close.

I called Livernois and they said they're heads are only a tiny amount shorter than a stock 243 casting, which is just due to resurfacing the cores I'm assuming, but it's still been bugging me. I like to make sure all my **** is in check so I can do the job quickly and be in and out. I'm hoping for a one day deal with this swap but we will see...

Anyone think I may need longer pushrods?

KevinR

Man, it NEVER hurts to measure if you are worried about it. And whatever cam choice you go with, you will have to measure for push rod length as well.

GIVE EM' THE BIRD

iTrader: (1)

Yeah I figured it wouldn't hurt to check regardless, im just wanting to keep it to a simple swap. Money isn't the issue, just don't wanna go fly cutting or back to stock rockers.

Curious tho, anyone done a swap with a cam this close in size and have the pushrod measurements?? Or lucky enough to not need new ones? Just wondering if I might have the "close enough" factor in that aspect. I'm gonna pull one of my pushrods out tomorrow probably just to measure it to get an idea of what the previous owner put in it...

GIVE EM' THE BIRD

iTrader: (1)

Have a Vengence Vrx4 cam heading this way...

Curious as to how much difference in length my pushrods will be. Cam isn't much larger but idk.

Anyone have any experience with a small swap like this?

GIVE EM' THE BIRD

iTrader: (1)

Nvm, talked to vengeance about the setup. Sounds like so long as my PTV clearance is ok my pushrods should be fine.

PREDATOR-Z

But that cam has too high of a lift to have spot on valve control with the 1.82s. You need to choose a softer lobe.

JPH

iTrader: (2)

If the heads have been milled or are going to milled any or .030+ and the intake centerline is in the 105-107* range, it can be fairly tight. Measure and find out I would suggest.

GIVE EM' THE BIRD

iTrader: (1)

Heads are milled down to 64cc.

LilJayV10

iTrader: (39)

I was going to ask a similar question but it wouldn't have sounded nearly as smart.

LS1-450

iTrader: (33)

Yah, why 1.82's? Why not just choose a cam that yields the same resulting lift as 1.82's would, but, get the lift through a 1.7 rocker. There are dozens of threads in here that demonstrate the valve float that will result from using 1.82 rockers on cams similar to yours.


IMO, best combo would be to get the lift you want through 1.7 rockers, .105" wall comp pushrods of length to be measured & dual springs designed to handle that cam @ max RPM.

Generally, 1.8 rockers are used by guys wanting more lift on stock or mild cams. The 1.8's would be done in leu' of a cam swap.

GIVE EM' THE BIRD

iTrader: (1)

It's not that I put the 1.82's on there, they're just already there on the 218 cam setup and I didn't know they were no bueno for anything with a bit more lift. My 218 setup hardly lopes at all on these so I didn't realize there would be that big of a difference by going with a bit larger cam. I don't have any stock rockers so I was just wanting to avoid buying a new set of 1.7's.

My springs are rated to .690" lift btw

PREDATOR-Z

It is not as much a matter of springs handling the lift, it is a matter of geometry and harmonics. The steepness of the lobes will make the valves bounce. That doesn't mean it hasn't been done, weight of valve-train has to come into play, it is more or less a less preferable way of doing things and usually leads to valve-train instability and premature wear.

GIVE EM' THE BIRD

iTrader: (1)

Gotcha! Thanks very much for the help.

I have stainless valves but as everyone has implied, I'm sure it's worth it to just get some 1.7's on.

LS1-450

iTrader: (33)

Often, stock 1.7's w/ cradles can be found in the "parts" section for $40-$50. Whether or not you choose to install the Comp rocker needle bearing upgrade kit is up to you. I just tack the stock covers in place & call 'em upgraded. The idea is to keep the needle bearings contained. Rare for a needle bearing cover/retainer to come off, but, it can happen.