Solid lifter cam VS Hydraulic lifter cam

[SCOTTGTK]

Good afternoon all, safe to say if you pull the solid lifter cam out of say a 1965 289 K code and install a hydraulic lifter cam.... you'll need to install compatible rods, lifters etc ? ... also, if the claim is made that the solid lifter cam was replaced with a matching spec hydraulic cam but the original K code rods, lifters etc were left in it... how would that effect the motor's operation?
Thank you!

[roddster]

In my experience cam and lifters should be replaced due to differing manufacturing specifications. And it's a no-no to mix different brands.
  When you say "rods" I believe you mean the pushrods. I'D advise the same. Things get messy if you mix these things.
 And as usual, somebody is going to reply that they do it call the time with no issues. Good for them.

[Road Reptile]

Hi Scott,
Just a few comments and I hope it will help with your questions. First and most important any cam replacement done should have matched lifters. Pushrod length will depend on type of lifter chosen. So simple:you can't swap a solid type with a hydraulic type of cam....same with lifters. Cam technology has changed and the main math you need to choose the best for your engine involves several factors like the rear tire size-gear ratio-type of trans.-and RPM range that is desired for the engine to operate within. Once this is factored you can think about available cam type. Many engine builders are now suggesting roller cams and they are available with solid or hydraulic lifters. It is very important to research this to choose properly. May also suggest you talk to a few cam tech lines to learn more. Expect a wide varience in price. Be patient it is worth it
Valve springs must also match with cam specs. The cam is like the Brain of the engine
And for the best in power/torque output you need everything in harmony.
R.R.

[SCOTTGTK]

Thanks RoadReptile and roddster.... these questions surround a K code coupe, 65 that isn't mine, but is for sale. Previous owner is said to have swapped the solid lifter for the hydraulic.... problem is no one can definitively say pushrods, lifters, springs etc were changed to accommodate the new cam. I have driven the car and runs well, but I'm not interested in purchase unless can verify what's in it. IMO if the K code solid lifter cam, rods, springs, lifters are gone, that's alot of K code not there!

Scott

[pbf777]

. . . . if you pull the solid lifter cam out of say a 1965 289 K code and install a hydraulic lifter cam.... you'll need to install compatible rods, lifters etc ? ...

    Note that the "mechanical" camshaft is engineered with what is known as a "take-up ramp" on the lobe in the grinding process; this intended to close the "lash" value established in the valvetrain gently, before proceeding to the more aggressive flank area intended to lift the valve from it's seating in the head.

    Hydraulic camshafts, since they don't possess a lash value don't require this take-up ramp, as the lifter is intended to always be in contact with the lobe surface.

    And it is this difference that would cause difficulties, even to the point of a the major problem if mixing.  If for example attempting to utilized a mechanical camshaft with hydraulic lifters the resultant "off-the-seat" duration would be exaggerated, this possibly to the point of creating drivability problems; and if trying to run the mechanical lifters on the hydraulic camshaft, this being without the take-up ramp, would cause excessive impact loading and possibly damage to the valvetrain componentry. 

    Pushrods are a mechanical connection in the valvetrain who's length is determined by that which is necessary to do such, and not being based on whether the camshaft might be mechanical or hydraulic in nature.   

    Scott.

[SCOTTGTK]

Pbf777, thank you so much! Either way you slice it, not a good idea!

[TA Coupe]

The only thing you can check without a whole lot of work is pushrod length and do that by checking the contact between the rocker arm and the valve tip to see if that is good or not. Lots of articles and videos on how to do that if you don't know how to. Other than that, if you like the way it drives, I wouldn't worry about it. Almost any cam, retainer, spring setup will allow you to rev the engine to 5000RPM but if you want to go beyond that, then you might start checking spring pressures, which is not too hard to do on the engine or just pull a spring and check it. Anything more will require quite a bit of disassembly.

      Roy

[SCOTTGTK]

Thanks Roy, very helpful! I do like the drive and seems I can always source correct K code cam, lifters etc and rebuild as original.... there's a member as we speak on SAAC under "parts for sale" with K code internals as well as block for sale. I asked for pics. Thanks again! Scott

[Royce Peterson]

I think a K code without mechanical lifters would be a non starter for me. There's something about a mechanical cam that changes everything.

[SCOTTGTK]

Yeah, I struggle with that thought as well Royce Peterson, then I think, this is numbers matching confirmed, I could get my hands on internals and make it whole again and it does get up and go now... torn..

[pbf777]

I think a K code without mechanical lifters would be a non starter for me. There's something about a mechanical cam that changes everything.

    Yeah, without the tickety-tick something would definitely be missing in the experience!

    But, being greedy, I probably would "cheat" on the profile, at least a little, for something a bit more aggressive than the original!

    Scott.

[SCOTTGTK]

pbf777, not sure what you mean... don't go back to original? Keep it the way it is?

[Bob Gaines]

pbf777, not sure what you mean... don't go back to original? Keep it the way it is?

I read it as him saying he would go back mechanical but maybe to a slightly different mechanical cam with a slightly more aggressive profile for better performance. One that would not be very noticeably different sounding at idle. Just how his post came across to me.

[SCOTTGTK]

Ahhh, I could see that also... thanks Bob. Do you have any thoughts on this Bob?

[FL SAAC]

heck I would go with a nice hydraulic torque cam for the street.

forget about the solid ticking and mystique

that's what the old folks call nostalgia

these new modern torque cams will have your car blasting out like a rocket a the street stoplight derby's

use one of these torque monsters

Crower Torque Beast Performance Level 3 camshafts are an excellent choice if you require more power and an extended rpm range. They exhibit good low to midrange torque for normal everyday driving conditions.

And as always enjoy your day !