I am curious what is the difference between the two types. This is what I know:
- how each type works
- solid is louder
- solid must be adjusted regularly (every ~10,000 miles)

but this doesn't seem like its the whole picture. What is the advantage of solid lifters? I am in the super early stage of selecting an engine (350 with 3.750 crank), this is one of the things I need to decide on. Either way I will go with roller lifters.

It seems a lot of people recommend hydrolic ones, but solid ones must have some kind of advantage. Otherwise, they wouldn't be made.

Car I am building will be mostly for summer fun. Some street driving, few if any drag runs, hopefully a road course. Definitely not daily driver, so I wouldn't mind having to adjust the lash once a year (it is relatively easy, right?)

 

"Solid" simply means the "joint" between the cam lobe and pushrod is a solid piece of metal (in simplistic terms). The rocker arm is adjusted so there is a precise gap in the train (lobe/lifter/pushrod/rocker arm/valve stem) when the cam is on the "heel" of the lobe. This insures the valve closes completely. As the lobe starts to lift the lifter/follower again, the tapping noise is heard. AKA mechanical lifters.

Hydraulic lifter/followers have a hydraulic mechanism built into them to take up that gap and allow the valve to close completely without any noise (or at least, less noise). They tend to self-adjust, if they stay in good operating condition, so are more maintenance free. However, they also tend to be heavier, and can "pump up" at higher RPMs and not let the valves close completely - limiting their maximum RPM usefullness.

Solids are reported to not make knock sensors happy. Other than being noisy, they typically aren't needed for typical street car, but can offer a good performance improvement with the proper cam/induction/heads/exhaust package.

Hydraulic and solid cams are designed differently, and the parts can't be mixed.

 

related question....what do you need to buy to have a solid roller setup...just the cam and lifters? ...or do you need to buy some kind of special pushrods and rocker arms, etc...

I still have yet to select a cam and lifters for my engine..and haven't completely ruled out this possibiliy.

 

That would be a 383 stroker motor....
What RPM-s are You looking to turn the motor ? How much HP are You looking for ? These are all things that would have an influence on the cam/lifter selection for the given motor. If You are building a high RPM smallblock that sees 7000rpm and regularly goes over 6000 RPM, then a flat tappet mechanical may make a bit more power than a hydraulic, which will not want to turn much over 6500, but probably start to make less than the mechanical above 6000, IMO. For the "average" 400 HP 383 there is no need for a solid cam, IMO, unless You race a lot. Keep in mind that a 3.75 stroke smallblock would not like to rev much above 6000, and I would consider 6500 the upper limit for longetivity on the street, and that RPM range is just fine for a hydraulic cam if You have good quality lifters and springs and the preload properly set...

 

Will need to get the whole setup...pushrods and the springs as well as the cam and lifters...

 

Flat tappet follower cams, whether solid or hydraulic, have a slight angle to the face of the lobe which has the effect of turning the follower so it doesn't wear against the lobe in the same place all the time. That also has the effect of pushing the cam back in the block against the cam gear.

Roller lifter cams cannot have that angle - the lobe has to be square to the axis of the cam. But, the cam can't be allowed to move back and forth or the rollers will get worn out in the lifters. So, a means of positively holding the cam back must be used. The old hot rod trick has been to use a "button" which bumps up against the timing cover and keeps the cam in place. The factory used a plate bolted to the front of the block to keep it back.

Roller lifters cannot be allowed to turn in their bores, so the old hot rodder way of keeping them from doing that is to tie pairs together with a lever. This typically makes them taller than their non-roller counterparts, so the pushrods typically have to be a different length as well.

 

so basically, if I got this right, the only advantage of solid lifters is lower oscillating mass which makes them more friendly at higher RPM.

Usable RPM is another question I still have to decide. I would like it to go as high as possible, as long as under non-spirited driving I can keep it around 1600-2000. I would not mind if at that RPM, engine feels like its a 4-banger as long as it can still pull the car. Having said this, how high do you guys think I can make this thing.

Like I said, it is not a daily driver, but I'd like to take it out occasionally for some fun. My primary goal is to take this thing to watkin's glen (sp?) and kick my bro-in-law's 330ci's european a$$, so for road racing I'd like to get as much reliable HP as I can out of this thing.

Right now I am looking at this short block, but it may be a little of overkill if I choose to go with lower RPM range

 

There is also lifter pump-up... It sounds to me that You will be happy with a hydraulic cam...but, if You really want all the power You can get, the solid will have an advantage. A solid flat tappet will have a better idle than a hydraulic, for a given RPM range...because solids usually have less seat duration for a given duration at .050" lift...The downside is setting the lash periodically, but I would check it often, just to make sure its all OK, even though they may not require adjusting. If You are going carbed, You might consider a solid...or solid roller...(flat tappet would be more reliable, IMO) At the same time, keep in mind that 6500RPM is pretty good RPM-s, I wouldnt like to go much over that if You want the motor to last some time.
Since You are buying a block and internals...Have You considered a SBC 400 ?
With a healthy 406 You could be flying, even with a hydraulic flat tappet cam...450 HP easy, with proper heads...

 

No... a solid lifter will rev higher because it does not "pump up" at high rpm where a hydraulic lifter will.
The actual weight difference is minor.

A solid lifter camshaft can be made with a more intense lobe.
(It lifts the valve faster and higher) than a hydraulic lifter camshaft. Therefore it has a moderate torque and horsepower advantage over a hydraulic cam when properly selected.

A solid roller lifter cam has the potential of making the most power but requires specific high performance valvetrain parts
and a few mods to work in that engine.

 

well, to be honest, until 2 months ago I was thinking of a 350 when I saw that for $100 more bucks you can by 383. From what everything I've read, 350 is the most common SBC and cheapest to get parts for, so original plan was to stick with that block.

400 uses the same stroke crank (different journal diameters), right? I was thinking of making RPM peak around 6,500, but I was also hoping to maybe get it to around 7,000, or is that just not going to happen?

tommy, now I have more questions:

1) how is EFI/carb decision effect whether I should go with solid or hydrolic?

2) I couldn't help but detect a bias that personally you prefer flat tappet better than rollers. I was under the impression that rollers are always better because they allow for steaper lift curves therefore allowing larger volume of air enter the cylinder. I guess that's not a question, but I am curious if you can elaborate your take on this.

The reason I am considering all this is because I do want to build this thing to race, so it would be nice to sqeeze out as much HP out of this thing as I can without sacrificing reliability too much (what was that formula: ( reliability, HP, $$$ ) <== pick two

.. and it is interesting you guys did say with right parts, potentially solid will give higher numbers.

F-bird, what high performance valvetrain parts and mods are you talking about?

 

Need new springs? I already have real nice spring and such on my afr heads that were originally on a roller car. So solid roller would require solid-roller specific springs?

And what is considered too high of an rpm for regualr hyd lifters?

Set up is going into a 406 block...

 

If You want roller, go with the hydraulic. Will make great power (more than the flat tappet) and a bunch less trouble than a solid roller... I still advise the 400 tho... (now, that is a bias...)

 

Depends on what the specs for the cam are...solid rollers run a lot more spring pressure than hydraulic roller, since they don't have to worry about collapsing the lifter...so, again , depends on what cam those springs are for, and what You are getting...

 

so basically you are saying that rollers will generally make more power than tappet, but solid rollers are more trouble, so that leaves hydrolic ones as best candidates.

Are solid rollers less reliable that other type of lifters? or require a lot of maintenance or a lot of other special parts. What do you mean by "trouble"

 

By trouble, I mean maintenance. The weak link in the solid roller valvetrain is the roller lifter. With the high spring pressures the solid rollers run, the rollers take a beating. To this, add the lack of proper lubrication under idle and low RPM conditions and will have an explanation on why they often fail after only a few thousand miles. They have some better solid roller lifters on the market now with fancy names like Crower HIPPO, Isky RedZone, Comp Endure-X , that are a bit better because they feed pressurized oil to the needle bearing rollers to the roller part of the lifter, and this does increase their lifespan significantly. The solid roller guys are happy to have a set of lifters last 5-6000miles, even with these new lifters. Some even reach 10 000 before lifter replacement/rebuild. To me, that is still not a streetable setup. So, if You want a motor that You put together and not touch for a couple of years, the solid roller setup is not for You. If You are ok with checking lash often, and once a year pull the intake and rebuild/replace lifters for around $400/set , then go for it. To me, for a street motor that does not spin over 6500, its just more trouble then what its worth...

 

Well you just finally convinced me not to go solid roller. I wouldn't mind the valve lash stuff....but I would absolutely hate replacing the lifters that often. Especially when I consider that when my car was running it was seeing 1,300 miles or more a month,..