does any one know if you can swap out HYD roller lifters for solid rollers on the same originally for hydraulic roller camshaft. I know that hyd rollers are heavy and add to valve float. This is a daily driven street car so take that into consideration. How often do they need adjusting?

 

no there's more to it than just differant lifters ,and the solids aren't any lighter andvalve float is more a function of the springs than lifters

 

actually solids are quite a bit lighter. i understand thet increased spring pressure would cure valve float but you are limited to about 350 lbs open seat pressure with HYD lifters, solids don't have this problem. Do you know of any specific problems with using the HYD cam with solid lifters? I understand that you may not be able to do the opposite, because solids can be more aggessive. I also understand that i will lose a bit of duration due to lash.

 

Don't do it. The lobe designs for solid roller cams are designed specifically for a valvetrain with a wee bit of lash in it...hydraulic roller cams' initial ramp will slam the valvetrain together and make noise. The solid roller lobe has a more gradual initial ramp to bring the lifter/pushrod/rocker/valve together before moving the valve.

Call CompCams tech line for more info.

 

See, that makes sense to me!. I'm not really going to do it, i was just wondering to myself if a hyd cam was a mistake. I hear so much a bout valve float at 6000 rpm and collapsed lifters i got to thinking that it might be posible if adjustment intervals were long enough. Thanks for the input. I would like to here more if anybody has something to add.

 

some thing else to think about with solid lifter?the knock sensor will pick up the lifter noise and retard your timming.you would need some PROM tunning.

 

That one did not occour to me, at the moment i am running an 84 LG4 ecm ( stock cept for the old hypertech ) without a knock sensor, ar leats i didn't find one when i swapped enguines, my brothers HO has one though.

 

You can't do it. The lobes on solid cams are different with a much more gradual lash ramp. Running solids on the wrong cam will break things.

Then there is the whole knock sensor problem.

 

my 84 LG4 didnt have a knock sensor either. can someone please explain valve float alittle better for me?

 

sure, its pretty simple. When you open and close valves really fast, as in a roller cam setup, you need a very strong spring to keep the valves and associated gear ( rockers, pushrods, lifters ) in contact with the camlobes. if there isn't enough spring pressure the valve gear will not follow the cam lobe, and will lose contact with it. this results in the valves bouncing off there seats atr high ( and sometimes not so high ) RPM. This may not sound too severe but it is because you will lose power, damadge lifters, throw or bend push rods, maybe drop a valve. It also causes the springs to fatigue and lose there pressure at a greately elevated rate. It is most severe in roller setups because the valve is accellerated much more quickly than a flat tappet can, that is after all one of the reasons roller cams work so well, by opening a valve quickly you can get more flow in a shorter duration, and roller lifters are heavier than flat tappets, this is also a reason that overhead cam motors can rev so high they do away with a lot of valve train weight.

 

ahh thank you very much for explaining that to me.