Smooothie119

I undertsnad that the best thing to do is change a cam with heads too, but is it at all possible to put a slightly more aggressive cam into a LB9 motor w/o having to change the complete head assembly. I'm not lookin for anything crazy, just wanna add a little more oomf to my car. I wanted to try changing to 1.6 roller rockers but seeing that the motor has 100k on the clock, I'd prolly have to change the springs also. What do u guys think??

Perry93TransAm

I would recomend changing the springs ,but the stock cam is so weak the springs might not even notice the little extra lift...lol, seriously, I just added 1.6s to my 86 LB9 car and left the springs alone, They are far from coilbind even with the 1.6s. But if you have the cash now I would go ahead and get the cam and springs done.
Perry

Smooothie119

what exactly will happen if the springs are too weak and I put 1.6s on?

aklim

Valve float? Coil Bind?

Perry93TransAm

Which would result in a few things such as bent pushrods and maybe a bent valve (because it hit the piston).
Perry

Smooothie119

How would I know if my springs could take the extra push w/o finding out the hard way?

Perry93TransAm

The best way is to set it up and then get a rocker to full lift. then measure the distance between the retainer and the guide (the guide will have the seal on it so you have to allow room for it too)the best way is to allow a paperclip in between the guide and bottom of the retainer. also the springs must be able to have a .030 or so feeler gauge fit between the coils (yes even the bottom and top windings). Make sure the engine is warm when you do this so the lifters will be full of oil. But to tell you the truth the stock cam has less than 420 lift and the stock springs are good for 450 lift.
Perry

[This message has been edited by Perry93TransAm (edited August 07, 2002).]

Kevin91Z

100,000 miles? Definitely change the springs when you do the cam. With stock heads, you need to stay under .470" lift or so. The Compucam line from Crane has some good cams, like the 2032. Its about the biggest cam you can use with stock heads.

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1991 Camaro Z28
350 L98 w/ T56 (originally 305 LB9 w/ T5)
318 RWHP, 419 RWTQ
12.803 @ 108.50 MPH (1.932 60')
Member: SoCal F-Bodies
ThirdGen 4-Life!

Smooothie119

What about an LT1 cam...Can I install that w/o changin heads and get worthwhile hp increase?

Kevin91Z

What year is your LB9? The LT1 cam is only slightly better, probably less than 10 HP gain if you swap it.

Smooothie119

My LB9 is an '87 w/ 100k on the clock

Perry93TransAm

The LT1 camis head and shoulders above the stock LB9 cam, 450/460 lift ,203/208 .050 duration and depending onthe year 116 to 117 lobe sep. If its free or real cheap its a good choice but if you have to pay full price for it I would look elsewhere.
Perry