Mechanical vs Hydraulic cams

[Mrturner1]

So I know that roller cams make the most power because the opening and closing rates are much faster due to steep ramps, and they also rev higher and last longer and all that good stuff. But if a guy were to compare two flat tappet cams, one solid lifter and the other hydraulic lifter, with all other things being equal how much more would the solid make over the hydraulic? The ramp speeds of a mechanical aren't as fast as a roller, but they are faster than a hydraulic correct?

[GR8-68]

This puts all of it in a new perspective with the technology we have today

http://www.superchevy.com/how-to/eng...t-roller-cams/

[hamjet]

unless you're planning on alot of high rpm, and racing I'd stick with hydraulic. they perform very well these days, and you'll get tired of the constant adjusting of the solids.

[Mrturner1]

Originally Posted by hamjet

unless you're planning on alot of high rpm, and racing I'd stick with hydraulic. they perform very well these days, and you'll get tired of the constant adjusting of the solids.

Well, if I decided to change cams which isn't in the plans for a while, a mechanical would still be practical even with a periodic valve lab check/adjustment because I only drive the truck a few times a month if I'm lucky. Unless something is wrong the lash really shouldn't be out of adjustment more than 2-3 times a year. But I don't mind wrenching regardless. I'm wanting to know more about the power difference between the two, if it's a seat of the pants deal? Just a couple hp? Noticeable night and day?

[Mike C]

Engine masters has a video on you tube comparing a hydraulic roller with a solid roller in a 600 hp big block Chevy. They have done their best to make the cams the same "size". It's an interesting watch, but the conclusion is for a street motor go hydraulic. Spoiler, the mechanical roller is worth about 25 hp on a 600 hp big block but a good chunk of the gain at highest RPM.

There is always something else to work on with the truck so why add a complication with a mechanical cam unless it's just something you want?

Comp offers several grinds that "duplicate" muscle car mechanical cams, but if I were to run one on the street it would be the 282s. (My Camaro has a Comp mechanical street roller in it and lash not a big problem. But the 427 I'm building for my short step is getting a hydraulic roller. Money where mouth is!)

[jocko]

Go hydraulic or go roller. Solid lifters just not worth it anymore. Gives a little more rpm, or rather allows you to get there a little more quickly, but you'd be lying to yourself if you were telling yourself you felt a seat of the pants difference on a daily driver. I put a solid can in a 57 bel air with a tunnel ram. Never again - as stated above. There's always something else to fix and no matter how much you enjoy wrenching, it WILL become a chore. There's really no reason for solid lifters these days in my book.

[Mrturner1]

Originally Posted by Mike C

There is always something else to work on with the truck so why add a complication with a mechanical cam unless it's just something you want?

Comp offers several grinds that "duplicate" muscle car mechanical cams, but if I were to run one on the street it would be the 282s. (My Camaro has a Comp mechanical street roller in it and lash not a big problem. But the 427 I'm building for my short step is getting a hydraulic roller. Money where mouth is!)

Well from all the reading I've been doing, there really isn't as much lash adjusting as there used to be if any at all. This is due to the way Comp makes the new solid lifters so no complication added as far as I can tell. That's funny you mention the Comp 282S, that's exactly what I was looking at except a custom grind on a 106 LSA. Now THAT would make for a badda$$ cam!

I've been reading ALOT about rollers and it seems there really isn't anything that even comes close to a roller that is set up right. Its very interesting how it all works and what makes it so far superior.

[Mrturner1]

Originally Posted by jocko

Go hydraulic or go roller. Solid lifters just not worth it anymore. Gives a little more rpm, or rather allows you to get there a little more quickly, but you'd be lying to yourself if you were telling yourself you felt a seat of the pants difference on a daily driver. I put a solid can in a 57 bel air with a tunnel ram. Never again - as stated above. There's always something else to fix and no matter how much you enjoy wrenching, it WILL become a chore. There's really no reason for solid lifters these days in my book.

What was it about the solid cam in the Bel-Air that made it so terrible for you? I'm not sure sure how up to date you stay on cams and valvetrain technology (in fact I'm sure you know more than me) but mechanical cam and lifters don't have to be adjusted all the time contrary to popular belief. Also, the oiling system in the new Comp solid lifters is supposed to be great and much improved over the older design.

[davepl]

Hydraulic Roller > Solid
Solid Roller > Hydraulic Roller

That is, however, for "all out" engines. My brother has an 800+ hp Shafiroff big block that is solid roller, but if there's a hydraulic roller that meets your needs, I'd stay with that.

Remember too that because you have to leave lash you're always leaving lift and duration on the table with a solid cam, roller or otherwise. So you have to remember to back the lash out of the advertised lift number, and that in turn also reduces duration.

[A1971Blazer]

In 1974 I bought a brand new Z28 Camaro($4800.00)......the 350 was a little better than a "stock" 350 but at 5000 RPM it was out of breath.

My buddy's dad owned the local Chevy dealership and we would go in at night and add stuff we wanted to the parts orders....we got the good stuff at dealer cost....to give you an example...an LT1 short block with the forged crank and 11:1 pistons...in the crate was $325.00...!

I ordered a LT1 (old version) solid lift cam & lifters, aluminum Vette intake, and Holley carb, all GM factory stuff....also added a set of headers....that brought it alive.......it would pull strong on up to 6500 RPM......
I used the good, locking rocker nuts and never had any issues with the lash......the only thing I didn't like was the constant valve noise...but back then we ran loud mufflers so that really wasn't a big issue......and it sounded bad azz.

With the advent of the hydraulic roller cams.....they're really the best deal for a stout street engine.

[Mrturner1]

Originally Posted by Mike C

Engine masters has a video on you tube comparing a hydraulic roller with a solid roller in a 600 hp big block Chevy. They have done their best to make the cams the same "size". It's an interesting watch, but the conclusion is for a street motor go hydraulic. Spoiler, the mechanical roller is worth about 25 hp on a 600 hp big block but a good chunk of the gain at highest RPM.

There is always something else to work on with the truck so why add a complication with a mechanical cam unless it's just something you want?

Comp offers several grinds that "duplicate" muscle car mechanical cams, but if I were to run one on the street it would be the 282s. (My Camaro has a Comp mechanical street roller in it and lash not a big problem. But the 427 I'm building for my short step is getting a hydraulic roller. Money where mouth is!)

Also in that video about the 600hp cam shootout, both cams are rollers, so it's not really a good comparison as far as answering my question. Both those rollers will have faster ramp speeds and all the other benefits of a roller. What I'm wondering is, how much is there to gain going from hydraulic to solid in a Flat Tappet motor? The difference in ramp speed and lobe design should give a good power increase so I'm just wondering how much.

[Alex V.]

Solid lifter flat-tappet cam = noisy and higher maintenance. I think you'll go a long way with the rest of the engine before a solid lifter cam is justified.

[Mike C]

You were asking about solid vs hydraulic. Yes, both are rollers but it is a hydraulic versus solid test. I think it compares and shows the difference you might expect with the style of lifter.

Now with that said, the 280 street roller in my Camaro always has hit above it's weight class. The 236 @ .050 and .550 before lash lift (I lash at .020) runs a full second faster than the 292 hydraulic that was in there which was like 244/.525

But if max effort is NOT your goal, hydraulic is much easier and in a street vehicle you won't much notice the loss of power at the extreme top end.

[snj8198]

hey Matt! check this out dude.

https://www.youtube.com/watch?v=8UaXhfbAMF0

[PanelDeland]

There "might" be times when a solid lifter cam is practical on a street engine but I can't think of any. Even the guys running monster street motors with 800+ hp mostly use Hyd. If you need the extra 25 HP a solid will give you in 500 CI engine, go ahead and up the cubes. Keep in mind that a solid hammers things a lot more since here's no dampening from the hyd you will need upgraded pushrods and rockers etc. My personal opinion is that 25 HP can be found cheaper somewhere else.

[Mrturner1]

Originally Posted by Mike C

You were asking about solid vs hydraulic. Yes, both are rollers but it is a hydraulic versus solid test. I think it compares and shows the difference you might expect with the style of lifter

I agree. I was just thinking that the difference in performance between the solid and hydraulic both being flat tappets would be bigger than the difference between both as rollers. I suppose the difference might be the same, but on a higher level of performance?

[Mrturner1]

Originally Posted by snj8198

hey Matt! check this out dude.

https://www.youtube.com/watch?v=8UaXhfbAMF0

That was a cool video! The solid cam is good for hp and tq through the entire power band. I'm thinking that the difference in power between the two flat tappets would be even greater, but I don't have any proof, YET. I just so happen to have a Comp 280H installed in my 355 right now, and that's headed to the dyno next weekend to see how I did on my first ever top end rebuild I also just so happen to have a Comp 282s cam sittin on the shelf with .495" lift and 236/236 duration @.050 which after lash should be close the the 280H magnum cam. That one is .480" lift and 230/230 duration @.050

Someone who knows more about solid cams and lash please correct me if I'm wrong about those being close to the same even though the solid cams numbers say it's bigger.

Matt

[Mike C]

They are both close. Once you take the lash out of the solid cam it knocks a little lift off both duration and lift. At about 8 min point of the Engine Masters video where they show #'s on the two cams the solid is also about 6 degrees more duration at .050.

One thing about comparing your two cams is that the solid will have about same lift as hydraulic once you take the lash into account, but the two cams they test in the video, the solid has a LOT more lift than the hydraulic.

I would guess the #'s on the two flat tappet cams are close to the same. The reason you would run solid is if you want to make more power above the 6000 rpm mark than the hydraulic plunger would allow once again based on valvetrain weight.

For a 99% street driven vehicle I have the same conclusion they did, run the hydraulic.

[Mrturner1]

Originally Posted by Mike C

They are both close. Once you take the lash out of the solid cam it knocks a little lift off both duration and lift. At about 8 min point of the Engine Masters video where they show #'s on the two cams the solid is also about 6 degrees more duration at .050.

One thing about comparing your two cams is that the solid will have about same lift as hydraulic once you take the lash into account, but the two cams they test in the video, the solid has a LOT more lift than the hydraulic.

I would guess the #'s on the two flat tappet cams are close to the same. The reason you would run solid is if you want to make more power above the 6000 rpm mark than the hydraulic plunger would allow once again based on valvetrain weight.

For a 99% street driven vehicle I have the same conclusion they did, run the hydraulic.

So here's the curve ball and I'm glad I have you here to reference my junk lol the 280H is a shelf cam, on a 110 LSA. The 282s however, I had ground on a 106 LSA. So how do you think it will act/sound, and how will that compare to the almost identical 280H cam?

After researching and reading a TON, my expectations for the 282s on a 106 LSA is it will make gobs more torque in the low-mid range, have a much harder "hit" when the power comes on, but will top out around 6k compared to the 6500 rpm 280H. Also I'm thinking it won't even be in the same ballpark as far as sound goes. The 282s should have a wicked nasty idle right?

[1fast10]

Hyd vs mech all depends on application. In roller applications both the cam. Lobes habe a larger footprint. This allows more low rpm durstion and in return allows more tq and hp and a broader range. Solid rollers can maintian a higher rpm due to the lifter not being able to collapse. Now flat tappet cams are another beast the cam lobe rides on a flat lifter. The lifter design internally is the same hyd vs solid. Hydraulic has a small cushion of oil onder the pushrod cup. Solid dont. This small cushion can br sqeezed out of the lifter during high rpm. Allowing the lifter to collapse or valve float. Flat tappets cams have a peekier lobe and usally make power in a peekier fashion over a hydor mech roller. Cam. Profile. Imo all street cars would benefit from a hyd roller. Not jsut becuase of the power gains but oil(evene with additives) have less zinc in it and zinc along with other properties are what prevents flatt tappets from wearing out from. Metal to metal. Contact

[Mike C]

The only cam I ever ran on a 106 degree centerline was a Comp drag race solid lifter cam. It was advertised 300/300 265 @ .050 and .540 lift before lash.

It had a wicked lope to the idle.... at 1500 rpm! It didn't make enough torque to pull taffy below 3500 rpm, but from that point to 7500 you didn't have time to blink before time to shift.

That's the motor still in my Camaro and I will say the 280AR street roller has been the better solution. Car runs 12.7's at 110 mph with a 1.97 short time. And has since the early 90's when it was actually fast relative to new stuff.

Was your solid a custom grind? Comp shows 110 as the off-the-shelf LSA.

[Mrturner1]

Originally Posted by Mike C

The only cam I ever ran on a 106 degree centerline was a Comp drag race solid lifter cam. It was advertised 300/300 265 @ .050 and .540 lift before lash.

It had a wicked lope to the idle.... at 1500 rpm! It didn't make enough torque to pull taffy below 3500 rpm, but from that point to 7500 you didn't have time to blink before time to shift.

That's the motor still in my Camaro and I will say the 280AR street roller has been the better solution. Car runs 12.7's at 110 mph with a 1.97 short time. And has since the early 90's when it was actually fast relative to new stuff.

Was your solid a custom grind? Comp shows 110 as the off-the-shelf LSA.

The 280H is a shelf cam, but yes the 282s is a custom grind and on a 106LSA. I'm hoping with the 236 duration my power will be a little lower than yours in the Camaro. Should be a pretty sweet cam though

[Mrturner1]

Originally Posted by 1fast10

Hyd vs mech all depends on application. In roller applications both the cam. Lobes habe a larger footprint. This allows more low rpm durstion and in return allows more tq and hp and a broader range. Solid rollers can maintian a higher rpm due to the lifter not being able to collapse. Now flat tappet cams are another beast the cam lobe rides on a flat lifter. The lifter design internally is the same hyd vs solid. Hydraulic has a small cushion of oil onder the pushrod cup. Solid dont. This small cushion can br sqeezed out of the lifter during high rpm. Allowing the lifter to collapse or valve float. Flat tappets cams have a peekier lobe and usally make power in a peekier fashion over a hydor mech roller. Cam. Profile. Imo all street cars would benefit from a hyd roller. Not jsut becuase of the power gains but oil(evene with additives) have less zinc in it and zinc along with other properties are what prevents flatt tappets from wearing out from. Metal to metal. Contact

Rollers are certainly the way to go, but budget doesn't allow this time.

[Mike C]

I had this discussion in my head for a long time before finally buying a cam for my 427 that I am putting together for my '69 stepper.

On a small block that I was building I would be tempted to start with a pick-n-pull Vortec donor motor that is equpped with the factory hydraulic roller. That would allow a roller cam for a lot less than the aftermarket conversion.

For the 427 I decided to go hydraulic roller. Big Chevy's seem to have such a high failure rate with performance cams in street applications anymore I decided the extra $ was "cheap" insurance to avoid the dreaded flat cam.

Just to continue talk about cam strategy, I went with the smallest hydraulic roller that Comp makes for the BBC. It's 224/236 at .050 on 113 degree lobe center. My goal is to have the motor look/sound like a 390 hp 427 and am going to try and run it through the big block 'vette manifolds so the extra exhaust duration a crutch to scavenge the cylinders better.

Goal is 350hp at the wheels. Induction is a GM performance parts intake and a Holley 750 double pumper, one of the new electric choke ones. (Finally!) Air cleaner is a '70 Z/28 dual snorkel repro.

[Mrturner1]

Originally Posted by Mike C

I had this discussion in my head for a long time before finally buying a cam for my 427 that I am putting together for my '69 stepper.

On a small block that I was building I would be tempted to start with a pick-n-pull Vortec donor motor that is equpped with the factory hydraulic roller. That would allow a roller cam for a lot less than the aftermarket conversion.

For the 427 I decided to go hydraulic roller. Big Chevy's seem to have such a high failure rate with performance cams in street applications anymore I decided the extra $ was "cheap" insurance to avoid the dreaded flat cam.

Just to continue talk about cam strategy, I went with the smallest hydraulic roller that Comp makes for the BBC. It's 224/236 at .050 on 113 degree lobe center. My goal is to have the motor look/sound like a 390 hp 427 and am going to try and run it through the big block 'vette manifolds so the extra exhaust duration a crutch to scavenge the cylinders better.

Goal is 350hp at the wheels. Induction is a GM performance parts intake and a Holley 750 double pumper, one of the new electric choke ones. (Finally!) Air cleaner is a '70 Z/28 dual snorkel repro.

That'll be a really cool setup!

The vortec roller block is a great idea I hadn't even thought of that.