Roller rocker question

[blown motor]

Is there much of a HP gain switching from flat tapper to roller rockers?

[Filthy Filbert]

Is there much of a HP gain switching from flat tapper to roller rockers?

Not exactly.    Just switching to roller rockers and changing nothing else, really won't increase HP.

However, roller rockers do reduce friction at the face of the tappet, and allows for much higher spring pressures.  This in turn allows for steeper lobe curves and longer durations than you can safely run with a flat tappet cam.  Think "rectangular shaped" lobes with very steep ramps and longer dwell times at maximum lift.

This in turn DOES increase Hp.

[Filthy Filbert]

DOH.   I answered about roller lifters, not rockers. 

[Scooter]

Is there much of a HP gain switching from flat tapper to roller rockers?

Don't think so unless your current rockers are really sloppy.

When I installed my aluminum heads I upgraded to 1.6 ratio rollers... because why not? I made a lot of changes at once so I cannot attest to what the rollers added aside from a much more stable valvetrain and added lift and ramp speed.

[blown motor]

So if I want to make more power then I should upgrade the cam also?

[usraptor]

Definitely.  You'd probably get better answers and suggestions if you'd let us know your current engine configuration.   

[Brads70]

Usually roller rockers are more accurate in their ratio compared to stamped rockers . So if you have a cam that is advertized as say .500" lift , with roller rockers you should get 500" lift if your measured it, stamped rockers are usually less lift and  consistant accuracy.  In addition to as mentioned the friction loss.

[blown motor]

Definitely.  You'd probably get better answers and suggestions if you'd let us know your current engine configuration.   

340 bored .060 over, stock intake, X heads, Lunati cam (specs unknown), TTI headers, 650 carb. The car is very responsive and runs strong. My idle mind is just playing around with the idea of reworking the heads to get more power, just for shits and giggles. Roller rockers, porting, valve job, etc. I know a lot of you are going to say that for what that would cost me I could get aluminum or other heads but that's not the route I want to go. I want to keep the block, heads and intake all together. Might be weird but that's just me. Im not an engine guy and I've never done this before so it would be a great learning experience for me.
If I go with roller rockers I think I'd have to get new lifters, push rods and springs wouldn't I?

[Scooter]

Definitely.  You'd probably get better answers and suggestions if you'd let us know your current engine configuration.   

340 bored .060 over, stock intake, X heads, Lunati cam (specs unknown), TTI headers, 650 carb. The car is very responsive and runs strong. My idle mind is just playing around with the idea of reworking the heads to get more power, just for shits and giggles. Roller rockers, porting, valve job, etc. I know a lot of you are going to say that for what that would cost me I could get aluminum or other heads but that's not the route I want to go. I want to keep the block, heads and intake all together. Might be weird but that's just me. Im not an engine guy and I've never done this before so it would be a great learning experience for me.
If I go with roller rockers I think I'd have to get new lifters, push rods and springs wouldn't I?

You should only need new push rods to accommodate the ball/cup ends. If you move up on the rocker ratio you will need to account for and additional .030 of valve lift per ratio increase. On my 360LA the slugs are a full .100 in the hole and the cam lift was only .450/.450, so I had no interference issues at all at .480/.480. If you are unsure what the cam specs are, best to test with clay to ensure no clearance issues valve to piston head. 

[usraptor]

"If I go with roller rockers I think I'd have to get new lifters, push rods and springs wouldn't I?"  No, not necessarily for just a rocker change.  However, if you change the cam then yes you'd need new lifters and possibly new valve springs depending on which cam you choose.  If you're looking for a HP gain but want to use the stock heads and intake, I'd choose a new Lunati cam and lifter set.  Call them and explain what you have and what you'd like to accomplish and they can give you a proper recommendation on cam choice.   If you're going to port the heads then I'd go ahead and upgrade the valve springs while the heads are apart.  You can also get the valve springs from Lunati.   However, you'd get the best bang for your buck if you'd install aluminum heads.  440 source has heads with OEM casting marks on the front of the head and once painted engine color nobody would be the wiser. 

[blown motor]

If you're looking for a HP gain but want to use the stock heads and intake, I'd choose a new Lunati cam and lifter set.  Call them and explain what you have and what you'd like to accomplish and they can give you a proper recommendation on cam choice.

Maybe I already have the cam that is the best choice for my application but I suppose we won't know without properly identifying it. Can I make a proper identification without removing it from the engine? I do like the way the car performs so I don't think I'm really looking for a cam swap, just a few more ponies to improve my gas smileage.   

What ratio are the flat tappet rockers? The rollers would need to be the same, not?

If I was to just go with rollers I could make the swap without removing the heads couldn't I?

[Brads70]

If you're looking for a HP gain but want to use the stock heads and intake, I'd choose a new Lunati cam and lifter set.  Call them and explain what you have and what you'd like to accomplish and they can give you a proper recommendation on cam choice.

Maybe I already have the cam that is the best choice for my application but I suppose we won't know without properly identifying it. Can I make a proper identification without removing it from the engine? I do like the way the car performs so I don't think I'm really looking for a cam swap, just a few more ponies to improve my gas smileage.   

What ratio are the flat tappet rockers? The rollers would need to be the same, not?

If I was to just go with rollers I could make the swap without removing the heads couldn't I?

You could get some tools and measure the lift, then compare that to their listing to possibly ID the cam?  And/or If your going to remove the timing cover to replace the timing chain ( always a good idea depending on mileage) it might have a part number stamped on the nose of the cam?
I don't think you will gain much just adding roller rocker though. It will be a lot of expence and labour for very little results in your case. As always it's the combo of parts that produce the results your after.

Another nice feature of roller rockers I forgot to mention was valve adjustability, stamped rocker are what they are and you need to mess with pushrods and machining valve heights to get pushrod preload right with stamped rockers.
I believe stock small bock roacker ratio is 1.5 ?

Beware of the dreaded " mission creep" this is where it starts... 

[usraptor]

I agree with Brads70.  To answer your question, no you don't need to remove the heads to install roller rockers, just the valve covers.  However, if you do install roller rockers you have to adjust the valve lash.  Nothing personal, but from your apparent lack of engine/mechanical knowledge, that is something you wouldn't be able to properly do.  Like Brads70 said, the gain in performance would be minute if any, and not worth the time, money and effort.  If you want to improve mileage and gain a few HP, that would come from tuning and adjusting your distributor, ignition timing, and carb. There's no need to install roller rockers unless you're going to install aftermarket aluminum heads and/or a hydraulic roller cam.

[blown motor]

Your right, I don't know how to set valve lash and would need help with that. So really it looks like either I pull the heads and go all the way or just leave it alone. Thanks for all your help, even this discussion has thought me things.

[anlauto]

Is it a number's matching motor ?
Why not spend your time/money building a completely new motor for the car...that way starting from scratch you can build (or have built) anything you want with as much horsepower as you want.....then one afternoon, just simply swap motors ?