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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
Both of those cams are WWWWWWWWWWAAAAAAAAAAAAAAAYYYYYYYYYYYY too much for LG4. They need more compression. The 1103 suffers from the inadequate compression problem in the LG4 as well; its EXTREMELY LAZY ramps cause considerable bleed-off of cylinder pressure at low RPMs, and consequently will give very soggy results with the gears you have.
For the early ones like yours, with just over 8:1, the Comp XE256 is a very good option. For the L69 and later LG4 with the 9.x compression, the XE262 works well.
I'd strongly recommend the XE256 or something in that same range from another mfr; the Lunati Voodoo series would be a good place to look, if they have one. If they do, its advertised duration will be acoupla degrees lower than the Comp, like maybe 253 or 254.
For that matter, even the cheeeeeeeeeep Summit 1102 works reasonably well in the LG4, if all you want is "improvement" and you're not looking for the absolute optimum.
mind if I hop on and ask what cam would be good for 1990 LB9? Been thinking of replacing lifters and while in there maybe even having the heads ported along with an Edlebrock intake and SLP runners. just a dream for now, really wanting to get back on changing rear drums to disks and putting in some better gears.
mind if I hop on and ask what cam would be good for 1990 LB9? Been thinking of replacing lifters and while in there maybe even having the heads ported along with an Edlebrock intake and SLP runners. just a dream for now, really wanting to get back on changing rear drums to disks and putting in some better gears.
are you able to tune? If yes then 08-501-8 is another 212-218 cam but roller. I'm running it in my current 350. Good cam. But if you're changing intake and cam that speed density ecm needs to be tuned. I ran on a stock 350 prom for a short while so it can be done but not recommended. Given you'd be opening up the intake and heads, it'll need tuning even more.
LB9 needs a roller cam specifically and carefully targeted to the unique requirements of TPI.
I agree w/ the 501 recommendation. That's what that series was made for. Another somewhat similar one is the 302 grind. Both will "work" with stock tunes but will benefit GREATLY from tuning. The 500 or 301 grinds will deliver less improvement but can probably get by without tuning. Needless to say, either will require springs; the LS6 ones mentioned above will work for these as well. Lifter replacement not really required unless they're bad or wore out in some way, but always a good idea in high mileage motors of course.
thanks guys. have the EBL P4 setup, so I have the ability to "learn" to tune. just looking for more street pep, not a 1/4 mile runner. lifters sat in one position for 25 years while in storage, so I'm thinking replacing them could be an improvement, even if subtle. can change the shift point with the EBL P4. not sure if the rest of the motor can handle higher RPMS but will to do what it takes to get there, including springs/rockers. 65K on motor
thanks guys. have the EBL P4 setup, so I have the ability to "learn" to tune. just looking for more street pep, not a 1/4 mile runner. lifters sat in one position for 25 years while in storage, so I'm thinking replacing them could be an improvement, even if subtle. can change the shift point with the EBL P4. not sure if the rest of the motor can handle higher RPMS but will to do what it takes to get there, including springs/rockers. 65K on motor
the rollers are probably fine. I doubt sitting harmed them. You can disassemble and clean them too. Springs are all you'd really need. Factory rockers would be fine though full rollers are an improvement. Changing the intake is the only thing that'll greatly increase rpm range. The tpi long runner is going to force it pretty close to stock no matter what.
the rollers are probably fine. I doubt sitting harmed them. You can disassemble and clean them too. Springs are all you'd really need. Factory rockers would be fine though full rollers are an improvement. Changing the intake is the only thing that'll greatly increase rpm range. The tpi long runner is going to force it pretty close to stock no matter what.
I had the top of the motor off to do valve seals and cleaned up everything during that process. when torquing the rockers, I noticed torque would not old on some of them, as if the lifter was weak and bleeding down. Are you saying a ported SLP runner wont help increase upper rpm range?
I had the top of the motor off to do valve seals and cleaned up everything during that process. when torquing the rockers, I noticed torque would not old on some of them, as if the lifter was weak and bleeding down. Are you saying a ported SLP runner wont help increase upper rpm range?
adjusting lifters with the engine off will have the oil bleed out of the lifter...the oil pump isn't filling them back up. Unless I'm not understanding you.
A siamesed runner will move the rpm band though not nearly as much as switching to a super ram or hsr for example. What I was trying to say was without changing intake length the rpm won't move much, even if the cam is made for a higher range.
adjusting lifters with the engine off will have the oil bleed out of the lifter...the oil pump isn't filling them back up. Unless I'm not understanding you.
you understand. not all of them did that too me. man, it sure makes it hard to get proper torque.
Originally Posted by aliceempire
A siamesed runner will move the rpm band though not nearly as much as switching to a super ram or hsr for example. What I was trying to say was without changing intake length the rpm won't move much, even if the cam is made for a higher range.
but your still thinking the 501 cam will offer some benefit over the factory "hot" cam? If I port runners and heads, and get more airflow, won't that allow a little higher RPM range? If not, what does it do?
you understand. not all of them did that too me. man, it sure makes it hard to get proper torque.
but your still thinking the 501 cam will offer some benefit over the factory "hot" cam? If I port runners and heads, and get more airflow, won't that allow a little higher RPM range? If not, what does it do?
what do you mean by 'torque' on the rocker arm adjustment? You don't torque them down in the traditional fashion. You don't use a torque measurement at all. Are you just referring to adjusting them?
The larger cam will fill the cylinders more, more air and fuel equals more bang. Ported runners, base and heads will give more air. The runner length will be a bigger decider of rpm range.
In other words, the cam may be able to make more power and work well in a higher rpm range but the intake runner length will be what determines the actual range the engine works at.
Last edited by aliceempire; Dec 7, 2020 at 11:36 AM.
what do you mean by 'torque' on the rocker arm adjustment? You don't torque them down in the traditional fashion. You don't use a torque measurement at all. Are you just referring to adjusting them?
If I recall, the factory manual specified a procedure for tightening the rocker arms that involved torque. but I may not be recalling correctly. its been a while. maybe after I got them adjusted, they came out of adjustment due to bleed down and that is what I am recalling.
If I recall, the factory manual specified a procedure for tightening the rocker arms that involved torque. but I may not be recalling correctly. its been a while. maybe after I got them adjusted, they came out of adjustment due to bleed down and that is what I am recalling.
No torque spec for the rocker arm nuts. The stock rocker arm nut is a jam nut that uses friction to stay in whatever position on the threads you turn it down to. When adjusting the rocker arms, you make sure the lifter is on the base circle of the cam and not on the lobe, tighten the nut until you take up the slack in the pushrod (zero lash) and then turn the nut tighter by how much preload the lifter spec calls for(typically somewhere between 1/2 and 1 turn of the nut). If you adjust all of the lifters this way, and then rotate the engine over, you will find that all of the pushrods appear to be loose. That's normal because the valvesprings compress the lifter and push the oil out of them. Once you start it up and there is oil pressure, the lifters will pump back up.
