Rob,

I am sure you will get more replies from people who know more about this than I do but I have recently had to make the same decision. The advantage of a flat tappet cam is $ and simplicity. They are significantly cheaper to buy and easier to install.

The main advantage of a roller cam is that the cam lobes can be ground steeper causing the valve to open faster meaning they are open longer than a flat tappet for the same duration. This allows the engine to get more air and fuel into the combustion chamber and making more power.

It really comes down to your goals for your engine and what other parts you are using for the build. A build really needs to be thought out and planned to meet your goals. If you can tell us what other parts you are using and what your goals are for the engine that would help with making a recommendation.

Good luck

 

I just had my engine rebuilt less than a year ago, in my 1969 Camaro with a 350. I used Vortec heads and used a Lunati Bracket Master flat tappet cam and lifter set, part number 00017LK. Runs great, and has that great sound. Only thing with a flat tappet cam is that you will need to add a zinc additive with the oil. Thanks, Jerod

 

The roller is probably a better choice although as was already mentioned they cost more money.

One of the nice things about a roller set up is you can change cams and re use the lifters...you can't do that with flat tappets (well you can with certain race lifters, but not good for 99.99% of application$).

If you decide to use a flat tappet instead of adding minerals and compounds to make your oil adequate I would recommend finding a source for Brad Penn Racing oil....it is already formulated for flat tappets, compatible with ethanol fuels, and can be found for about 65 bucks for a case of 12, or $700 for a 50 gallon barrel.

 

Cure for insomnia? Roller cam. More expensive but you'll make a few more ponies and limit your worries about oil recipes. Install is bit more involved (setting up end play) but it's not difficult.

Good luck!

 

Rob here,s my 2 cents. I would use a flat tappet cam from a good place and either G/M Johnson or Morel LIfter,s , I think Howard,s lifters are Morel not shure though. I would stay away from the Quick Ramp cams AND there are two companies that have had thier share of lobe failure,s.Use the right oil BReak it in with G/M EOS and a cam core made in the USA. Call the MANUFACTURER and ask if you need a P55 core. Howard,s , Elgin ,Isky ,Lunati,Crower and Bullet all make good quality stuff. There are also other ,s That will grind you a cam like Chris Straub who has an excellent reputation. For off the shelf stuff you cant go wrong with the above. Rollers are great but expensive and for a car thats only driven a couple of miles a year its a lot of expense. I only drive mine on weekends weather permiting and only a couple of hours at a time . Hope this helps . Good Luck ! Alex

 

Hea Rob,If you have the $$$ go with the roller cam well worth the $$.Installed a Comp roller cam in my 1966-396-375hp and what a difference and does she rock.Mike

 

I would go with a roller regardless of horsepower if you have the extra $1,200 or so to do the retro roller.
Rollers not only make significantly more power when compared to a flat tappet cam with similar specs, but they last heads and shoulders longer than a flat tappet cam.
Nothing wrong with a good flat tappet cam, never had one fail, never added ANY zinc additive, and most of mine were comp which people give that company a bad rep, all because they had a "bad batch" of cores, which is more than likely a bunch of people breaking in cams wrong, Comp is a good company.

 

I would figure about 50 hp more for a comparable roller cam, for about $1000 more in cost everything included. No worries about oil additives for high lift cams and much less worries about the initial break in period, but the trade off is you do need to set the end play on the cam. Those are the basics on a roller cam vs flat tappet decision.

 

Both cams the same but one is roller and one is flat tappet...the roller makes more power across the board :yes:

Rollers do go bad, but not very often....you read a lot more about HFT cams going bad.

I swapped to a roller and will not run a HFT cam again....I just like them better.

 

The roller I went with was only $350 more than a flat tappet.

Howard's has street roller cams for $520 - cam and lifters.

http://www.summitracing.com/parts/HRS-CL120245-12/

I think the HP advantage is about 20 HP compared to a flat tappet with identical specs.
And you will get a little bit of payback in gas mileage.

 

Anyone that tells you anything negative about a roller cam OTHER than cost is flat crazy. Why do all the HP rigs today come with them. Let me just say and then back up with a couple of videos.

I was in the same situation. I have a bone stock 454 with stock 781 heads. A good intake and exhaust setup. Had a 272H crane came with .515 lift. Thing ran pretty darn good. Decided I would switch over to a roller and as stated, knew I could reuse the lifters on a bigger came down the road. Because the motor has almost no compression (not even 8:1) I was told by many not to waste my time. Decided to go with a comp 270HR (270*/276* and .510 with a 110 lsa). Bought the cam mint used with lifters and correct length pushrods for $275. Below are a couple of quick runs on the ole country road. Let's just say I cannot believe the difference. It flat rips and I have the proof below. If you got the cash the "roller" with it!!!

I think the HP differences are much higher than 20HP. I was told by come that you can realize anywhere from 50 to 75 hp gains. That might be a tad bit of hype but I think 20 hp is a bit low.

P.S. Sorry for the dirty windshield.....it just came out of the shop.

http://youtu.be/uUtAvw0tEws


http://youtu.be/Q56GHXjgGgM

 

I think the HP differences are much higher than 20HP. I was told by come that you can realize anywhere from 50 to 75 hp gains. That might be a tad bit of hype but I think 20 hp is a bit low.

Dubs,

We totally agree that the roller has less friction and opens and closes the valves much quicker.

But when you compare cams they must have identical specs. And the 20 horsepower advantage I give to roller cams is at the high end of the rpm range - 6000 rpm. Of course racing engines wouldn't even consider running a flat-tappet.

To argue a roller gives more than that (20 hp) is a stretch IMHO.

But the fact is Chevy hasn't built a flat-tappet engine in over 15 years! Now I'm thinking someone will prove me wrong.....

 

Actually a roller can give you the best of both worlds due to the improved opening/closing rates. You can gain more top end HP with the same .050" duration while also getting more idle vacuum & low end torque as the seat timing will be reduced over a flat tapped cam. For most street applications, you will not beat a hydraulic roller cam.

Once you start using roller cams, you will never want to go back to flat tappet.

The factories would never have went exclusively with more expensive roller cams if there was no benefit.

 

My guess at 50hp was based on using cam quest program comparing cams with same lift and duration specs from comp cams in the range of cams I was looking at. Obviously not a perfect prediction of the differences, lots of other variables would come in to play that could increase or decrease what a person would see and it's only an estimate to start with.

I think the difference between hydraulic and solid rollers was an easy 20hp alone and more in the cams that rev higher obviously.

 

I certainly cannot argue either. Since I don't build motors for a living or own a dyno, I can only go on what I have read and been told by cam manufacturers.

I can tell you that I would use a flat tappet again on a turd but never again on anything remotely in a "hot rod" catagory. I am amazed at how my stocker 454 rips. It's also funny the look when I tell people I run a little 650 HP on it. Built by me (HP Carburetors on eBay), it's all it needs.

 

Thanks for the info. I think I will go with the roller cam

 

I would also HIGHLY recomment the cloyes quick button timing cover. I went with the cloyes billet timing chain gear set. It came with a nice torrington cam bearing which acts as a thrust washing. Setting the cam end play, which you will have to do, is SUPER easy with that quick button setup. I'm sure I will be using that cover from here on out unless I run into the need for a 3 piece someday. Just make sure you get the valve train geometry right. That will be controlled by the length of your pushrod (this is asuuming you will not be running huge springs that might make the retainer come into contact with the bottom of the rocker. Below is what you are shooing for.....to have the pressure of the rocker tip as centered on the valve stem as possible. You will need different, shorter pushrods since the retro-fit roller lifters are taller.

http://www.cloyes.com/HighPerforman...rmance/Products/QuickButton2pcTimingCover/tabid/182/language/en-US/Default.aspx

 

I have a flat tappet in both my race car and my daily driver hot rod. In my race car I run a .060 over 427 with 10.8:1 compression,stock GM rectangular port heads,and a stock GM L-88 cam taken out of an L-88 crate motor in 1969(262 duration at .050" and .560 lift),454R intake and 1150 dominator. It makes a tick over 600 hp at 6800 rpm on pump gas and gets spun to 7200 rpm. In my daily driver I run a .040 over 400 with 10.2:1,stock GM camel hump heads with a bowl blend job and 2.02/1.60 valves,Torker2 intake ported to the heads,650 double pumper,cheapie 1 5/8" headers,and a Crane Powermax 278 flat tappet cam with 1.6 rockers(222/232 at.050,.500/.530" lift). That combo makes a little over 400 hp at 5100 rpm. So you can make plenty of power even with a flat tappet cam.

 

Get a roller. There shouldn't be any going back. When did Chevy or anybody else produce a V8 pushrod engine without a roller? 22 years isn't it?

 

You tell 'em Rich, the flat tappet cams certainly aren't dead just yet.

I don't disagree with much that is written here-sure, there are things a roller cam can do that most reasonable flat tappet sticks won't. But in the effort of full disclosure I think it's noteworthy to mention that roller lifters tend to be heavier than a solid flat tappet....and the needle bearings in the lifters do come apart occasionally. And if you have a serious knot in that cam tunnel you will really need to use the new Isky EZ roll lifters and they are damn near a grand, and need to be rebuilt occasionally.

Granted they only need to be used with really aggressive cam profiles that require some serious valve spring tensions, but I mention this just so everyone doesn't think roller lifters are the best thing since electricity.

The hydraulic rollers are heavy, and rpm limited that may not bode well for a serious street/strip application. Probably not a big deal in a pump gas stroker that isn't going to turn 7500 rpm....but I have an old school gene that flairs up from time to time and when I jump on the loud pedal I like to let the thing sing to 7500 rpm or more if I'm feeling lucky.

I've used many solid and hydraulic flat tappet cams, still do actually. I've never had a problem with any of them and in fact my 600 hp 434 pump gas sbc is in the shop now soon to be fitted with a brand new Bullet solid lifter flat tappet bumpstick. And it is going to rock, if it doesn't shake the fenders off the car I'm going to send it back and get another one.

Rollers are the best option, yes, but I just wanted to make people aware that they do have some problems from time to time (and those errant needles can wipe out the engine) and that flat tappets still have usefulness. Matter of fact, NASCAR CUP and Nationwide cars still use them (I think the trucks use rollers).

And, one last thing....if you have a healthy roller set up you really need to check the valve lash somewhat often...if you find the adjustment is off consistently on one or more lifters you really need to pull the lifter(s) in question and take a look at them.

 

Flat tappet will probably never die period. Bottom line is I bet if we asked all the big cam makers, they are still selling WAY MORE flat tappet than roller. Also no getting around the old skool kool solid flat tappet.

 

I won't build a flat tappet engine unless I'm forced to.
That said, Jim (540 Hotrod) has shown that the newer solid flat tappet cams can make incredible power - they give up very little to the rollers.
Rollers were designed to allow more aggressive ramps. With a flat tappet, you're limited by the fact that if you get too aggressive, the edge of the lifter will hit the lobe before the face...but they're lighter and love to rev. The roller wheel on big solid rollers allows much more aggressive cam profiles. We're talking race engines, not street stuff.
I use rollers to eliminate the problems many have had since the EPA made oil manufacturers significantly reduce zinc and phosphorous in their blends.
Plus you don't have to break a roller cam in like you do with flats.

 

with a more agressive ramp you can get more power in a street car without giving up vac needed to run accessories too.

 

All I know is I went with almost the exact same roller specs as I had in my flat tappet, giving up .005 lift and there is a NOTICEABLE difference.

You talk about lifter weight. Seems to me that the trade-off of far less valve train friction (roller lifter, fulcrum and tip) outweighs the slightly heavier lifter. It's like the lisfter would act heavier due to the lack of a fluid movement up and down as compared to the roller (if that makes sense).

 

You don't need a cam thrust button on a Gen IV big block.

All you need is this. It comes with a thrust plate. Make sure the front of the block has 2 tapped holes behind the cam gear.

http://www.crateenginedepot.com/store/Timing-Chain-Kit-502-Engine-12371053-P244C28.aspx

 

You don't need a cam thrust button on a Gen IV big block.

HUH? Do you mean you don't need the trust in the back? You have to have a button in the front to keep the cam from walking forward on a roller.

 

Oh then you must have put IV when you meant VI.

 

No the MkIV block (1965-89?) can use the Gen VI timing set. The retainer plate is included.