Roller versus Flat-Tappet Cams!
Do you want to spend big bucks on a hydraulic roller cam setup or low bucks on the old-school flat-tappet cam? The answer depends on your desire for power and durability
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00:00 Bam!
00:00 Watch this video and you might save a buck
00:03 because you can decide if you can live with the power
00:05 of the budget flat-tap it camshaft
00:08 versus the bucks up roller cam.
00:10 (dramatic music)
00:13 (engine revving)
00:18 (dramatic music)
00:26 (dramatic music)
00:28 This is Engine Masters presented by AMSOIL
00:34 and supported by Mr. Gasket and Earl's Vapor Guard.
00:37 Today, we're gonna show you the difference
00:40 between a flat-tap it camshaft and a roller camshaft.
00:44 And we're talking like a $100 to $250 investment
00:48 versus the roller cam, which can get up over a thousand bucks.
00:52 So we're gonna show you the difference in power
00:54 and you can decide if it's worth it to you.
00:55 What we're gonna use for this test is that motor,
00:58 which is an old favorite here at Engine Masters.
01:00 You'd probably recognize it more
01:01 if it still had its dual quads
01:03 and its big, fat, hairy tunnel ram,
01:05 but we've reconfigured it a little bit for here.
01:07 Here's what we got going on.
01:08 The long block is a crate engine from Blueprint Engines.
01:12 It's a 400 cubic inch small block Chevrolet
01:15 using an aftermarket block from Blueprint.
01:18 It's also got Blueprint heads on it,
01:20 which are 220 as-cast head.
01:22 This thing has 10.3 to one compression.
01:25 Up top, we've added our 850 Holley XP,
01:28 my favorite carburetor on Engine Masters.
01:30 And the intake manifold is a big, hankin' Super Victor
01:34 Edelbrock single plane.
01:36 The camshaft we're starting out with
01:37 is the hydraulic flat-tap it.
01:39 And what we've got here is an Iskey 292 MegaCam.
01:43 So you know that's gotta be good.
01:45 The specs on it are 244 degrees of duration
01:49 at 50,000's tap it lift on both the intake and exhaust lobes.
01:52 And it's a 108 degree lobe separation angle.
01:55 And we've got 505,000's inches of lift
01:59 on both the intake and exhaust as well.
02:01 So now we're gonna go hang this on the dyno,
02:03 sauce it up with some AMSOIL,
02:04 fire it up and find out what power we can make
02:06 with a low buck flat-tap it cam.
02:09 Oil's gonna be more important than usual on this thing
02:11 because we have to break in a flat-tap it cam.
02:14 And so AMSOIL hooked us up with some info.
02:16 This is like gonna be more baffling
02:18 than you can actually handle.
02:19 But they want 2,000 parts per million of zinc
02:24 in a break-in oil for a flat-tap it cam.
02:26 And then they want to use something like the Z-Rod
02:30 that has zinc in it for running that flat-tap it cam
02:32 forever on the street.
02:34 And that needs to have 1,000 parts per million of zinc.
02:37 So if you wanna follow that advice,
02:38 you're gonna have to call your oil company
02:40 and ask 'em about the chemical breakdown of the actual oil.
02:43 But what's really important is using
02:45 one of these break-in oils with a lot of zinc in it
02:47 for a flat-tap it cam shaft.
02:49 [upbeat music]
02:52 Okay, our 400 is hung on the dyno.
02:58 Are you ready?
02:59 - I am.
03:00 - Flat-tap it cam power?
03:02 - Yes.
03:03 [laughing]
03:05 - I'm trying to say it with a straight face.
03:06 - Come on.
03:07 - They're good, they're good.
03:08 A lot of guys still use flat-tap.
03:09 - They're cheap.
03:10 - And they're inexpensive.
03:11 [dramatic music]
03:13 [engine revving]
03:16 - It's not bad.
03:39 - Looks good.
03:40 - Yeah, yeah.
03:40 - Yeah, very good.
03:41 - Man, that thing's a buzzsaw.
03:42 Seven grand.
03:43 - Yeah, you like RPM.
03:44 - Oh man, I love it.
03:45 - Don't you love it when guys say they like the 327s
03:48 because they rev higher?
03:49 - Yeah, I know.
03:50 - I only have 400 inches here that just went
03:51 and go 7,000 RPM.
03:53 - With the hydraulic flat-tap that of all things.
03:55 - So here's our baseline with the flat-tap it cam shaft.
03:58 It made 486.5 pound feet of torque.
04:00 And up here in the horsepower,
04:02 it's really flat through here.
04:03 It's making a range of 494 to 496 horsepower.
04:07 The peak being 496 at 6,200.
04:09 But we're all stoked this thing actually ran cleanly
04:12 to 7,000 RPM.
04:14 - And didn't fall over.
04:15 It rolled over pretty reasonably.
04:15 - Let me ask you this, Ryberger.
04:16 If you were drag racing that,
04:18 I mean, you wouldn't shift it at the power peak at 62.
04:21 I mean, look at the way it carries all the way to seven.
04:23 Where would you shift that thing?
04:24 - At seven, definitely.
04:26 And then let it fall back down into here.
04:29 And then you're using all that meat.
04:31 And this thing's pretty cool
04:32 'cause you're launching the thing
04:33 with like a 3,500 stall converter.
04:35 You're just getting into the torque curve.
04:36 - Or even a clutch.
04:37 - 4,000.
04:38 - Yeah, it's good torque right in there.
04:39 - That's pretty good.
04:40 - I like it.
04:41 - I'm more enthused than I thought I might be.
04:43 - Yeah, me too.
04:44 We're gonna be more enthusiastic
04:45 when we put the roller in it right now.
04:46 - That's a really pretty curve though.
04:48 There's no funny stuff with valve control issues
04:51 or any dips or anything.
04:52 That's a really good looking curve.
04:53 - So that's a happy thing.
04:54 A roller cam's happier.
04:56 - So are we done?
04:56 - Yeah, let's go install it.
04:58 - Oh, I thought it was like beer time.
05:01 - I'm happy with it.
05:02 We have to change it.
05:03 - So Steve and I are changing the cam?
05:04 (laughing)
05:05 - Actually, I was thinking,
05:06 let me know when you guys square it away.
05:07 I'm just gonna be right here.
05:09 - Okay, I guess I'll go handle it.
05:09 - Oh boy, I thought we loved this so much
05:11 we didn't have to change the cam.
05:12 - Oh no. - We have to know.
05:13 - We love more power, more.
05:14 - Okay.
05:15 - Yeah.
05:16 - Hydraulic roller. - Go.
05:17 - That was the power that we made
05:18 with the ISKEY 292 MegaCam
05:21 with the hydraulic flat tappet lifter.
05:24 And now we're gonna move on to a camshaft
05:26 that uses a hydraulic roller lifter.
05:28 So what are we talking about?
05:30 These right here are what are called tappets or lifters
05:33 or sometimes followers even.
05:35 They're what ride on the camshaft
05:37 and move up and down to open and close your valves.
05:41 Now the difference in design is pretty clear.
05:43 The flat tappet has a flat surface
05:45 that rides on the cam lobe
05:47 and the roller has a little roller
05:49 that rides on the cam lobe.
05:51 Now, what we're doing here is not a scientific analysis
05:55 of just the difference in performance of these two lifters,
05:58 but instead, it's about the difference in performance
06:01 that we can get based on the way
06:03 that a camshaft can be ground
06:05 depending on what type of lifter it uses.
06:08 See, we can have the same duration on both camshafts,
06:13 but the roller allows you to have
06:15 a more aggressive ramp rate on the lobe
06:18 and more total lift per degree of duration
06:23 than the flat tappet cam.
06:24 To put that in hard numbers,
06:26 the two camshafts that we're testing today
06:28 both have the same degrees of duration
06:32 at 50,000th tap at lift.
06:33 It's 244 degrees.
06:36 However, they have completely different lift.
06:39 The flat tappet cam is 505,000th of an inch lift.
06:44 The roller tappet cam is 558,000th of an inch lift.
06:49 Not only do we have that 53,000th extra lift
06:53 with the roller tappet,
06:55 but the more aggressive shape of the camshaft lobe
06:59 is gonna open and close the valves
07:02 more quickly and more aggressively
07:03 than you can with a flat tappet,
07:05 which sort of gives you more effective duration.
07:09 Now we're gonna go install this hydraulic roller camshaft
07:12 and give you even more little tips and tricks along the way.
07:16 So now we're gonna swap the camshaft,
07:17 which means taking a lot of stuff apart.
07:19 We're gonna have the whole front end apart,
07:21 valve covers off, rocker arms off,
07:24 push rods out 'cause a lot of that stuff has to get changed.
07:27 The intake manifold will come off
07:28 so that we can get at the lifters.
07:30 - And I'm bringing the block.
07:32 - Yeah.
07:32 If you ever take flat tappet lifters
07:37 off of a flat tappet cam,
07:39 you wanna keep them in order
07:41 'cause if you put the cam back in later,
07:43 you do not wanna take a lifter off one lobe
07:46 and put it back on another
07:47 because they sort of mate to each other as they break in
07:51 and they will wreck themselves
07:53 if you put them on the wrong lobe,
07:54 even though Dulcich has done that probably many times.
07:56 - Yeah, I know.
07:58 We won't talk about that.
07:59 (upbeat music)
08:02 - Now's when we get into some of the stuff
08:08 that you need to know when you have a roller cam
08:09 that can make it more expensive.
08:11 The roller camshaft, you need to control end play,
08:14 meaning fore and aft movement,
08:16 whereas that's sort of handled on its own
08:18 with a flat tappet cam.
08:19 So you need some way of retaining the camshaft
08:22 at the front of the engine and establishing that end play.
08:25 On a factory GM block
08:27 or on this aftermarket blueprint block,
08:29 you can use a plate like this.
08:30 On others, you need to get what's called a cam button
08:33 that presses against the inside of the timing cover
08:35 and sets that.
08:36 It can be kind of a pain.
08:37 It's just something you need to know.
08:38 The other thing that's gonna cost you
08:40 when you're changing to a roller
08:42 is if you're taking out a flat tappet lifter
08:45 and putting in a roller lifter,
08:47 the roller is almost certainly taller than the flat tappet,
08:52 which means you need a shorter push rod.
08:56 Sometimes, of course, you're gonna need a different push rod
08:58 for the flat tappet anyway.
08:59 I mean, you always need to check valvetrain geometry
09:02 when you're putting a cam in,
09:03 but when you're doing the roller,
09:04 guaranteed you're gonna need a new push rod.
09:06 When you're working on a small block Chevy,
09:08 if you've got a block that can accommodate it,
09:10 you can use a factory roller lifter,
09:12 which is what these are.
09:14 If you don't have that,
09:15 or if you're dealing with, let's say, a big block Mopar
09:17 or something that never came from the factory
09:19 with a roller cam,
09:20 you need what's called a link bar
09:22 that attaches the two lifters together.
09:25 Now, the factory handled that with this,
09:28 which is called a dog bone or a bow tie,
09:30 which slides over the lifters like this
09:34 and holds them together
09:36 to keep them from rotating in the block.
09:38 'Cause here's the thing,
09:39 if this lifter were to spin sideways,
09:42 the roller wheel would get sideways on the cam like that
09:45 and it wipes itself out immediately.
09:48 And so all of that little hardware and stuff
09:50 is sort of what adds up and makes the roller cam deal
09:52 closer to a thousand bucks instead of the flat tappet,
09:55 which is closer to 250 bucks.
09:58 (upbeat music)
10:01 So once we get this intake on there,
10:05 we have to slam on the valve covers
10:07 and then I think we're ready to fire it up.
10:10 - Can I do one of the valve covers?
10:12 - Are you allowed?
10:12 - I don't know.
10:13 - Are you gonna grease the gasket?
10:15 - No, you don't have to with those kinds of gaskets.
10:17 (upbeat music)
10:20 - So we have the roller cam all installed now
10:25 and ready to fire it up.
10:26 It's gonna make more power,
10:27 but there's no reason to assume
10:29 that it would take different ignition timing, right?
10:33 - No, I don't believe it.
10:34 - And the jetting will probably solve itself?
10:36 - Yeah, I mean, we'll take one good look at it,
10:38 but I think the timing is going to be pretty much determined
10:41 by combustion chamber and dome and cylinder head.
10:45 (engine rumbling)
10:53 (engine revving)
10:56 - Oh yeah.
11:12 - That's stout. - Way better.
11:13 Let's look at the overlay of that versus the flat tapping.
11:16 Our official run with the roller cam,
11:18 492.9 pound feet of torque, 517.5 horsepower.
11:24 Let's overlay the flat tap
11:25 and see how much better it is everywhere in the curve.
11:28 Oh, not as much better down here below 4,300
11:31 as I thought that it might be.
11:32 - That's what I was saying, I thought it would diverge.
11:33 - It did, but up here when you start picking up engine speed
11:36 above 4,500, look at that, the roller is way better.
11:39 - Way, way the additional airflow.
11:41 - The question is for most people,
11:42 I think we agreed roughly $800 difference in price,
11:46 somewhere in there, 700 to a thousand.
11:50 Is that worth it to have that much more power?
11:52 - That's a lot, it's definitely worth it to me.
11:54 Right there, that's quite a bit.
11:56 - It's worth it also to me because the fears
11:58 of grinding a lobe flat with a flat tap at lifter
12:01 are sort of gone.
12:02 - And this is still, in my opinion, a mid-level motor.
12:05 You know, when you look at the guys who are doing 572s,
12:08 they've even got some packages now for super gas
12:10 and super comp with hydraulic roller camshafts in them.
12:14 And those things are like in the 270s
12:15 and you're not gonna be able to make that kind of power
12:18 that's required with a flat tap.
12:20 I think that this duration at 50 is about as big
12:22 as you wanna go with a hydraulic flat tap.
12:25 You can run a little bit bigger with a solid flat.
12:28 - Yeah.
12:28 - So there you have it.
12:29 That's your difference between the flat tap at cam
12:31 down here in red and the roller in black.
12:33 That's a lot of meat in the power curve.
12:35 You just have to decide if it's worth it for you.
12:38 How about you?
12:40 - Definitely worth it for me, yeah.
12:41 - Totally.
12:42 - So what, did we deliver the bam?
12:49 - Bam.
12:50 - Really?
12:51 - Hydraulic roller.
12:52 I wanted to be a hydraulic flat tapping guy,
12:54 but I'm convinced now.
12:55 - Oh, I don't know.
12:56 I'm gonna go the other way.
12:56 I was really impressed with that 292 mega cam.
13:00 I was surprised it went to 7,000 RPM
13:02 and it made pretty good power.
13:04 And it confirmed, I think, my suspicion that like,
13:07 when I was 17 years old and throwing a PAW camshaft
13:11 in my 3.3 motor, it might not have been that bad.
13:14 But the takeaway, I always think of it
13:16 from like the average muscle car guys perspective,
13:19 which is, we keep saying this, a flat tap of cam,
13:21 this setup's about 250 bucks for the cam and lifters.
13:25 If you're gonna go with a roller conversion
13:27 and the roller lifters and cam
13:30 and the distributor gear that you might need
13:32 and the cam button and push rods, closer to 1,000 bucks.
13:35 So you gotta decide if that extra 750 to 800 bucks
13:40 is really worth it for the project
13:42 that the average viewer is putting together.
13:44 And I think most people building an engine
13:46 to this level, 500 horsepower,
13:48 probably are not even considering a hydraulic flat tap
13:51 but to begin with, and some of them might now go,
13:53 that wasn't that bad.
13:54 - It depends on who you are.
13:56 You might be that guy who wants to get the hydraulic roller,
13:59 spend the money, it might not mean that much to you.
14:00 Or you might be the bucks down guy
14:02 who can make pretty close, you know, same RPM,
14:05 pretty close to pretty good power and save a bundle.
14:08 - Yeah.
14:09 - So I'm usually that guy.
14:10 - I know.
14:11 - Yeah.
14:12 - Now you like the hydraulic roller better than ever
14:13 and I like the hydraulic flat tap it better than ever.
14:15 Not that I would pick it every time,
14:17 but I was just more impressed with it
14:18 than I expected to be.
14:19 - Yeah, so they were both actually pretty good.
14:21 - Yeah.
14:22 - Yeah.
14:23 - And that's the type of testing that you're gonna get
14:24 every time when you tune into Engine Masters
14:27 presented by AMSOIL,
14:28 supported by Mr. Gasket and Earl's Vapor Guard.
14:31 We'll see you next time on YouTube,
14:33 on Motor Trend On Demand.
14:35 And now, did you know that you can even subscribe
14:37 to Motor Trend On Demand through Amazon?
14:40 - Wow, that's cool.
14:41 - We're big time, Dolcek.
14:42 - Oh man.
14:43 - Yeah, see you next time.
14:44 (upbeat music)
14:46 - So you're saying this valve spring
14:48 was probably a little bit heavy for the flat tap it,
14:51 but probably right for this one?
14:53 - Yeah.
14:54 - So it's not gonna float, you're guaranteeing it?
14:55 - I'm not guaranteeing 7,000.
14:57 I think it'll make it to 64 or 500 without any issues.
14:59 - I will guarantee 7,000.
15:01 - Yeah?
15:02 - Yeah.
15:03 - Is this your clairvoyance?
15:04 - Well no, because--
15:05 - Channeling through again?
15:06 - Just watch.
15:07 - Don't fail me, Raleigh.
15:08 - Just sit there, operate the dyno and observe.
15:11 - Oh shut up.
15:12 (laughing)
15:13 - Observe.
15:13 (engine revving)
15:16 - Clean as a whistle.
15:19 - You don't really know that 'til you look at it.
15:21 - Oh no, you can hear it.
15:22 (laughing)
15:23 - Do you ever win?
15:24 - I thought you were dyno brain Boullee.
15:28 - I am, but I try to talk sensible stuff
15:30 and he just pulls his stuff out of the air like this
15:32 and all of a sudden it happens.
15:33 I can go show you five other small block Chevrolet's
15:36 that struggle at 7,000 with a hydraulic roller.
15:38 - Oh I know.
15:39 - He picks the one that'll do it with 350 or 60,000.
15:41 - Yeah, I guess it must just be dumb luck, huh guys?
15:44 - It's the magic ISKI grind.
15:45 - Yeah. - That's it.
15:46 - Look at that, it carried perfectly smoothly.
15:48 - Oh yeah, that's just like picture perfect, guys.
15:52 - Wow.
15:53 [BLANK_AUDIO]