flat tappet vs roller cam

SS Shaun · #1 10-16-2012, 12:12 PM

Ok guys and gals i was at a cruise the other night and a lot of guys got into a convo about cams. and they started to argue about roller cams how mechanical is better then hydro and so on. So it got me thinking about my cam in my car. I currently have a flat tappet cam and i know you have to do the whole break in process and all that. but i wanted to see what you guys think about this topic. since i have my intake off right now should i think about converting over to a roller cam setup? besides cam and lifters anything else i will need? like change my push rods? my rockers? and so on

carpoor · #2 10-16-2012, 01:00 PM

Honestly, there isn't much performance difference below 6500 RPM. An LS1 converted to flat tappet placed 2nd at the engine masters challenge a few years ago. The break in process isn't as big of a deal as some people make it out to be.

Hank70SS · #3 10-16-2012, 01:48 PM

If you have a good running flat tappet cam setup I don't think it's worth changing over to a roller cam. Now if you were building an engine you might want to consider it but it is a lot more expensive.

If you bought a roller cam and lifter setup they'll tell you what push rods you need, not sure if you need new or not.

The real advantage is not having to worry as much about what oil you use, don't need the ZDDP levels a flat tappet performance cam does. But how often do you change oil in your Chevelle? Is it a daily driver?

SS Shaun · #4 10-16-2012, 02:47 PM

no it will not be driven daily it will be a weekend warrior kind of a car get home from work friday afternoon and drive that for the rest of the weekend. hell even drive it to work on fridays. I am not planning on ripping the motor out yet but if i have to do it again i will do roller. but it was just funny about the fight. but i can tell you they do have worried about the cam. they told me o you will wipe it out it will go bad on you. you will have to tear your whole motor apart to fix it and so on. i thought once you get a good break in for 15 mins at about 2000 rpms it can last a long time. correct?

Hank70SS · #5 10-16-2012, 06:18 PM

Quote:

Originally Posted by SS Shaun

no it will not be driven daily it will be a weekend warrior kind of a car get home from work friday afternoon and drive that for the rest of the weekend. hell even drive it to work on fridays. I am not planning on ripping the motor out yet but if i have to do it again i will do roller. but it was just funny about the fight. but i can tell you they do have worried about the cam. they told me o you will wipe it out it will go bad on you. you will have to tear your whole motor apart to fix it and so on. i thought once you get a good break in for 15 mins at about 2000 rpms it can last a long time. correct?

You can wipe a cam after break in. But if you use a good oil, something with a high level of ZDDP it should be fine. Some of these engines have been running since they left the factory with flat tappet cams. I sure wouldn't tear down an engine to install a roller if the flat tappet is working good.

ZDDP has zinc in it. It's a softer metal and provides a cushion between the steel cam and steel lifters. ZDDP will also plug up a catalytic converter used on all newer cars. So the oil manufacturers had to reduce the level of ZDDP in motor oil to protect the catalytic converters. Car manufacturers had to do something to protect the camshafts and started using roller lifters.

You can spend a little more at each oil change to get a good quality oil with a higher ZDDP level, I believe 1,300 ppm is minimum for a flat tappet cam. If it's an aggressive cam even more would be good. Or you spend a lot to replace your flat tappet cam with a roller setup. There are a number of oils out there with sufficient ZDDP for a flat tappet cam. Some diesel engine oils and quite a few 'racing' oils.

carpoor · #6 10-16-2012, 07:21 PM

My father's 72' SS 454 has around 7K miles on the engine. (Flat tappet cam) I put Rotella in it, just cheap oil that has zinc in it. The cam in it is still doing just fine. My oil change routine for that car is 3K miles or 6 months - whatever comes first. I swear some people own stock in roller cans the way they try to pump them.

One of the other advantages of a flat tappet is lower seat pressure on the valve springs. They last longer, and are easier on the rest of the valvetrain.

shadowgray396 · #7 10-16-2012, 11:22 PM

I went with a roller cam because because my engine was not going to be fired up all that much and I didn't want to wipe out a cam after sitting all winter in the garage. I agree with what was said above. The price of a roller cam was at least double then a flat tappet cam. I know of a few friends cars who went with flat tappet cams and have had no problems and a couple of others that have. I'm hopping for no problems.

SS Shaun · #8 10-17-2012, 09:20 AM

ok that brings up another question then! my car will never see the road during the winter. so you are telling me that with my flat tappet cam i have to go out there and start the car every few days?

Hank70SS · #9 10-17-2012, 05:23 PM

Quote:

Originally Posted by SS Shaun

ok that brings up another question then! my car will never see the road during the winter. so you are telling me that with my flat tappet cam i have to go out there and start the car every few days?

Absolutely not! Flat tappet, roller, whatever, if you're not going to drive it then leave it alone. You've seen the white exhaust clouds in the winter, that's moisture. It's a by product of combustion. It takes a long time to heat up the engine and exhaust enough to dry that moisture. You can't do it just letting the car idle, you need to drive it and put a load on it to heat up the block, oil and exhaust.

I had a 396 with a comp 280H cam, fairly aggressive. Never touched the car over the winter and never had a problem. Use a good oil, maybe throw a battery maintainer on it and cover it up. It'll be fine until spring. Even the battery will be fine with no maintainer if it's fully charged. No computers on these cars so nothing to drain the battery. A lead/acid battery will hold it's charge for months, like 5 -6 months, in cold weather. It takes more amps to start in cold weather but heat kills batteries, not cold and heat will cause it to lose it's charge a lot faster than cold.

shadowgray396 · #10 10-17-2012, 06:54 PM

Quote:

Originally Posted by Hank70SS

Absolutely not! Flat tappet, roller, whatever, if you're not going to drive it then leave it alone. You've seen the white exhaust clouds in the winter, that's moisture. It's a by product of combustion. It takes a long time to heat up the engine and exhaust enough to dry that moisture. You can't do it just letting the car idle, you need to drive it and put a load on it to heat up the block, oil and exhaust.

I had a 396 with a comp 280H cam, fairly aggressive. Never touched the car over the winter and never had a problem. Use a good oil, maybe throw a battery maintainer on it and cover it up. It'll be fine until spring. Even the battery will be fine with no maintainer if it's fully charged. No computers on these cars so nothing to drain the battery. A lead/acid battery will hold it's charge for months, like 5 -6 months, in cold weather. It takes more amps to start in cold weather but heat kills batteries, not cold and heat will cause it to lose it's charge a lot faster than cold.

Agree with you Hank, the worst thing you can do is start your car up so your buddies can hear is roar. If you not going to drive it don't start it up.