Alright, so I'm trying to figure this out. I understand how flat tappet and roller cams work, and that's not the issue.. the issue is when we start making comparisons with different cams.

So my question is this: which would be the best POWER-wise for a street/strip application, and how quickly it makes that power (meaning driving the car 2-3 times a week 40 miles a day). I'm using a flat tappet now, but I want the most power for my dollar. That and I'm getting a new converter, so now seems like the perfect time to match to a new cam. Should I invest in a solid flat tappet because of cost and RPM flexibility? Hydraulic rollers are great, but I don't see the point when the cost is close to a solid roller. Can a solid live on the street if we keep the cam reasonable/not all out? This would cause less stress on the other components, but HOW MUCH might be negligable. That's something I don't have an answer to. It seems like the general consensus is that solid roller cams won't live on the street very long because idling kills the lifters.. the only way around it is to get the expensive lifters, and even then - nobody really knows the life expectancy from what I've read (like Morel's or ISKY's redesigned lifters to increase oil flow).

Based on my understanding, the breakdown of which offers the most power is: Solid Roller > Solid Flat Tappet > Hydraulic Roller > Hydraulic Flat Tappet

.. and the solid flat tappet being "better" simply because of the lifter characteristics offering a wider RPM range potential, as well as aggressive ramp rates with a different lifter type (even though we're still bound to a flat tappet style camshaft).

Which should I go with? Maintenance and cost is not a concern, but failure rate is. Opinions appreciated.

 

There's nothing wrong with a flat tappet camshaft. They're cheap, simple, have been used for decades and are still being used today. Roller camshafts, because of the roller design, allow more area under the curve that a flat tappet can not provide. This area under the curve is where power is made.

All things being equal, a roller cam will make more power than a flat tappet but a roller cam has more potential while using less.

Hydraulic and solid lifters each have their own place. For simplicity and no maintenance, the hydraulic lifter is the way to go. For a production car, that's what the consumer wants. For more performance, a solid cam is a better choice. Doesn't matter if it's flat tappet or roller. The only way "idling will kill lifters" is if you have a poor oiling system and the lifter runs dry. Flat tappet cams can fail. Roller cams can fail. Roller cams just don't wear out as easily because the friction on them is so much less than a flat tappet cam but have a roller lifter fail and turn in the lifter bore and the cam lobe gets wiped out very quickly.

 

So would a solid roller provide any real gains over the flat tappet xe274 that I've got in there now? You figure the cam is $320 and the lifters are also $500 from Crower.. plus pushrods. More or less $1,000. That's $1,000 I could apply a lot of different ways.. Obviously, I am interested in the HP gains, but HP is only a minor fraction to the whole equation as I am also interested in overall performance.

This is the cam I'm looking at:

Specs:

Solid roller, fair idle. Good high performance street cam with reasonable vacuum. Needs 2500 RPM stall converter, headers, 10:1 or better compression ratio, and 3.55 or better gearing.
•Advertised Duration (Int/Exh): 278/285
•Duration @ .050 (Int/Exh): 242/249
•Gross Valve Lift (Int/Exh): .556/.556
•LSA/ICL: 112/106
•Valve Lash (Int/Exh): .022/.022
•RPM Range: 2500-6600
•Includes: Cam Only


Part Number: 501B1LUN

 

Pick up some dyno software such as Desktop Dyno etc and input numbers to see what kind of changes they do. Many cams with similar grinds will perform almost the same and only a real engine dyno pull will see any differences. If you're really concerned about the numbers, call places such as Bullet Cams and get a custom grind.

 

I'll call them tomorrow and see what they say about things. I'm curious to see their opinion on the matter.

 

Something else to keep in mind, with solid lifters, you will be under your valve covers on a fairly regular basis to re-adjust your valves..... that's another advantage of the hydraulic fellers, set it and forget it.

 

Right, this I'm definitely aware of. That's actually why I went went the flat tappet two years ago. Adjusting valves doesn't bother me. It's more time consuming than it is difficult. That's why it has me thinking about it, haha. I saw another thread that I'll post a link to talking about solid roller lifters (a question I'd been looking into ALL weekend) and why they fail "prematurely" compared to their hydraulic counterparts. Interesting read, really.

 

I don't see any worthwhile advantage to running solid lifters on the street, unless you're going to run a more aggressive cam than hydraulic lifters will support. That would be a cam that a pump gas engine would have a hard time supporting. The key advantage of solid lifters is weight. They are considerably lighter than hydraulics, which keeps valve train mass down, allowing for higher rpm potential with less valve spring. The engine speeds at which this advantage is going to be useful is beyond what most any street driven engine will ever use.

 

I went ahead and called Bullet today and discussed things with them in thorough detail. They agreed that solid rollers offer awesome gains, but to expect any serious street life in them is farfetched... which matches what I had saw in another individuals research/comparison... most of which contributes to the size/diameter and amount of pressure that the lifters have to endure in a solid roller.

I compromised and went with a custom solid flat tappet. They said I should see a noticable power and RPM increase. Ended up being $255 shipped (with lifters); which is a lot cheaper than what we were looking at initially with the roller setups (retrofit roller setup being ~ $800 and the solid rollers being nearly double that).

I guess we'll see when I finally get it in. I'll run the XE274 for a little while, though.. at least until I get my new cylinder heads to replace my DARTS that I have now.