Roller Rockers - I need some schooling

I work in the Health Care Sector, probably as far away from the automotive scene as is possible, so I gather all my automotive information from what I can read.

I was asked by a good friend of mine to try to find a source for roller rockers for our Chev 261" blue flames, which I'm researching, using the internet.

I'm doing all this without knowing the benefits of roller rockers vs. Standard rockers, so I'm asking anyone ..."What are the benefits???" And for that matter, what about roller lifters.

Whilst we're on the subject of rollers - Does anyone know of a company that makes roller rockers (and roller lifters) on a limited order basis??

Thanks for your help.

Mark

 

the benefits of a roller rocker are:

1. Reduced friction (increased power and longevity)
2. Increased strength
3. more accurate ratios (possibly more power)

As far as roller lifters, they require a special roller cam as well (made out of heat treated billet steel), but again the benefits are:

1. you get the reduced friction (and subsequent increase in power and longevity)
2. a roller (cam) lifter will allow you to run much more aggressive lobe profiles than are possible on a flat tappet cam (also leading to more power).

 

Thanks for the speady reply.

Looks like we'll be up for a new cam too if we go this route.

 

I have a few questions.....

Lifters can never be re-used right, Because they bed-in with the cam lobe their put with? Does the same thing apply to roller lifters/rockers, basically can you buy and use second-hand ones?

Can you only run roller lifters with a roller cam and if so why? Why can't you run roller lifters on a normal cam grind to get the benefits of a fairly friction free method of lifting the valves. I know that the roller cams have really a really aggressive cam profile, which is the reason for using the roller in the first place.

 

What are these rocker thingees that you speak of?

 

Rockers? What rockers?

Sorry 4ever4, Flatdog and I don't run no rockers
(flatheads don't come with them!)

Now if your talking SBC, I have roller tipped rockers on mine. (roller is in contact with the tip of the valve)

 

Packard flatheads come with roller rockers.

 

I run the comp cams Pro magnum roller rockers...these have the roller tip and have the roller fulcrum,basically has ball bearings. SBF...check out summit racing or something.

 

needle bearings...

 

Yea.

The rockers don't care if you change cams or not. The are actuated by the pushrods and don't wear into the cam.

Call about any of the cam/rocker companies and you can probably order a set of roller rockers for your blue flame. I wouldn't think you be so lucky with a cam for the same, but ya just never know. If you don't find roller rockers anywhere else for your little mill you might try Harland Sharp.

You don't gain HP with roller rockers (actually torque is what we're really concerned with) but with less friction it takes less torque to make 'em move. Less torque used means you have freed it up for something else, ideally turning the tires.

I guess in theory if you change rocker ratio you can possibly pick up a little HP boost. Example SBC stock is 1.5/1 and you can buy 1.6/1 rockers. Thsi increases you lift at the valve which in turn causes you valve to open farther. There actually is more to building zot than gross lift, but that's way over my head.

 

I'm no cam expert, but the way I understand it, is regular cams(both solid and hyd) have a slight angle to the lobe that causes the lifter turn in its bore. Roller cams don't need or have this angle.

 

thanks...that's what i meant.

 

Id check if the rocker arms you have are the same size as the small block chevy, you might have to buy 8 to use 6 of them but it might not be that different. They make all different ratio sizes. Take one of your rocker arms down to a speed shop or try to match it up. You might even call one of the manufactures so see if they have specs on your engine. It will be worth it , I like the roller stuff, I mean it might not sound as good as a solid lifter cam but it will make a difference in HP.

 

And if you havea 8 you got two extra. I carry around two extra regular rockers just in case one of my roller tips breaks...good insurance. Haven't broken one yet, only a rocker stud...

 

With a faster rocker ratio (1.6 vs 1.5, 1.7 vs 1.6, etc), you get a small bit of extra lift, but the big advantage is that a larger ratio (faster ratio) opens the valves faster. This makes your cam behave light a slightly larger cam, without some of the other headaches like overlap, duration, etc.
You can run into valve spring bind issues, as well as piston interference with the increased duration, but you're usually fine--especially if you're starting with a stock cam. (You can get screwed fast if you're using a big cam already!)
-brad

 

OK, OK, Doc. One for you! Wasn't thinking about Packard.
Flatdog and I are blinded by FORD's flatheads!!

 

SBC rockers are completely different to these 6 cylinder rockers - unfortunately.

I've emailed Harland Sharp asking if they'd make some, and await their reply. If you go to their web site, what we need is something like the "Spitfire" rockers, as thet are offset like the Blue Flame rockers.

Thanks for all the input guys.