wow

Need help understanding the difference between lifter and cam terminology...

What is a tappet, same as a lifter...

What is flat tappet, is there a non flat tappet...

Can flat tappet be hydraulic or solid lifter...

Are rolller rocker and roller cam a unit, i.e. you need one for the other...

Can you have flat tappet and roller rocker...

Can you have solid lifters and roller cam and/or rockers...

Can I ever understand all this...

Thanks, Nick

amtronic1

What is a tappet, same as a lifter...
Yes exactly the same thing.


What is flat tappet, is there a non flat tappet...
A roller lifter/tappet.


Can flat tappet be hydraulic or solid lifter...
Yes.


Are rolller rocker and roller cam a unit, i.e. you need one for the other...
No, you can put roller rockers on flat or roller cam.


Can you have flat tappet and roller rocker...
Yes. Roller rockers are useable on flat, roller, hydraulic or solid.


Can you have solid lifters and roller cam and/or rockers...
No, wear and valve float issues if you mix flat tappet and roller cam. The lifter rides in direct contact against the cam so this is a critical area. Roller rockers are not critical, they are up under the valve cover so you can use them anywhere you want.

The only thing you should be aware of with roller rockers is the ratio. SB are 1.5 ratio, BB are 1.6 ratio. You can sometimes put BB rollers on a SB and get away with it, but the pushrods may contact the heads where they pass thru and this contact can cause pushrod failure, metal shavings, or other problems.

LDB C5

OK: Here goes:

Tappet = Lifter For all intents and purposes they are each produced as either "Flat" or "Roller". Which one you need is a function of the cam. Cams are available either Flat Tappet, OR Roller; solid or hydraulic.

To further complicate the matter both are available as either "solid" or "hydraulic"; again a function of the cam you have chosen.

"Roller" rockers can be used with either solid or hydraulic lifters; and with flat or roller cams.

The lifters ride against the lobes of the cam as it rotates; lifting the push rods which in turn act on the rockers. The rockers then pivot and open the valves.

Most (all ?) newer cars have "roller" type valve trains with hydraulic roller lifters. All C2's cam from the factory with flat tappet cams. Lower performance options were hydraulic, while high performance engines used solid lifters.

Hope this helped.

JohnZ

Tappet = lifter; same thing.

Two kinds of lifters - flat and roller; both are available as "solid" (require running clearance and adjustment) or "hydraulic" (no adjustment required after installation, and no running clearance - oil pressure in the lifter maintains zero clearance).

Cams are ground differently for flat tappets and roller tappets - you can't use flat tappets on a roller cam or vice versa. Cams are also ground differently for solid lifters and hydraulic lifters - you can't use solid lifters on a hydraulic cam or vice versa.

Roller rocker arms can be used with any kind of cam and lifters; rocker arms are independent of cam and lifter type.

65hihp

You know that with Google you can find the answer to anything, well almost anything. Here is a pretty basic primer on cams and lifters that a Google search revealed. There are some excellent pictures at the bottom of the article.
http://www.chevyhiperformance.com/te...ics/index.html

wow

You guys are the reason this forum exists...and you're better than Google...thanks for your help...I'm starting to uderstand...

So, if you can use roller rockers arms with a solid lifter cam and lifters, why would you...what would and could you gain? And on a big block, would you use 1:6 or 1:7 ratio...I've seen both...thanks

knight37128

That is not exactly true.

You can run flat tappets on a roller, they just won't live long.

There are a few truck pullers that use them that way because the class says you must use flat tappet lifters.

JohnZ

What you gain with roller rocker arms is a slight reduction in friction, picking up maybe 3-5hp (not the 10-20 some of them claim). Big-blocks came stock with 1.7:1 rockers, and small-blocks came with 1.5:1.

Tampa Jerry

As long as we are on the topic of cams, is anyone using solid roller cams? I remember a friend putting one in a Pontiac in the early 70s. The cam was a high lift and not at all streetable. The engine was a beast. Jerry

LDB C5

You should decide what you want the engine to do; street, street strip, road racing etc. Speak to an engine builder and get his input. Making an engine perform well is NOT like ordering from a Chinese restaurant; 1 from column A, 1 from column B etc. Everything HAS TO WORK TOGETHER. There is a lot more to consider besides cam, lifters and rocker arm ratio.