Comparing Mech To Hyd Cam Adv/.050” Durations

[12many]

Solid Vs. Hydraulic Lifters - Mopar Muscle Magazine - Hot RodLooking for verification that when comparing a mechanical cams advertised and @.050” durations to that of a hydraulic “in general” an equivalent mechanical would have approx 10 degrees less advertised and approx 10 degrees more @.050” Example, my current 280 adv, [email protected]” hydraulic would be approx 270 adv, [email protected]” Seen one article stating as such, but not much else. Trying to determine how much bigger I’ll be going switching to a solid as best is possible considering how the advertised can be measured between companies.

 

[Wyrmrider]

easiest way is to compare cams from vendors who use SAE method
.006 at the valve
which eliminates valve lash and "intensity"
using .050 at the cam you have to adjust for lash which may be .030 or tight lash giving widely different results
takes experience with the different lobes involved
we have a cam doc to make these comparisons
ymmv
.050 is best used to degree in your cam
comparing with .050 is a snake pit for cam salespersons

 

[pishta]

I'd always consider a solid. Our cars ancillary parts are already loud (headers, air cleaners, etc) so the drum of a valve train is not a bother. Also, we are somewhat maintenance savvy and have no problem with popping a valve cover every 6 months to make any adjustments or just to oggle at the adjustable rockers! Nothing else a hydro setup offers with one exception: Rhoades high bleed lifters that work so bad at low RPM that they make a long and tall cam seem like a small one which can be a good thing (?) if you have that type of driver.

 

[AJ/FormS]

easiest way is to compare cams from vendors who use SAE method
.006 at the valve

That makes sense
but I haven't seen any commonly talked about cams spec'ed at .006 valve lift.
Why does this situation even exist?
I mean how hard would it be for a manufacturer to set up a test apparatus to give us an after-lashing spec?
Imagine how many converts to Solid FT there would be, once we knew what we were buying, compared to our current hydro.

 

[Wyrmrider]

right aj
you find SAE at Elgin, Sealed Power etc (TRW)
the aftermarket sharks do not want you to be able to easily compare
you could see that the same lobe just looks different with different rocker ratioswhat I was trying to say is that some aftermarket grinders use different lobe/master names for sbc and bbc when they are exactly the same lobe- the one size fits all which saves them money on setting up for different cam cores

 

[AJ/FormS]

yes, I understand that; but I think those days are long gone. I would think that the market for SFT performance cams has got to be dwindling; not burgeoning like in the 70s. So it seems to me that it would behoove the cam manufacturers to more forthcoming, so that those of us wanting to make the switch, had a decent jumping-off point, instead of guessing at "one size bigger";and when that doesn't work out the way we had hoped, then ; just "try another size bigger". So what happens? America's garages are full of take-out cams that didn't work out, and the manufacture's sales records prove that sales are booming. That ain't the way to do business.
So instead of jumping in, I for one, just keep the Hydro I got, cuz I know how it runs. Sure I know I'm giving up some performance; but how can I know what Solid to install, that will be any better? I mean the nuances can be subtle to killer, but at an average cost of say $350, how many Solids am I gonna go thru before I find the "right" one? The one that is "one size bigger at .050 and/or one size smaller at .006/.008, and/or faster in the midrange? I mean I can call up the manufacturer of my current HFT and instantly get the next size bigger HFT shipped. And I know exactly what to expect.
But as you know, there comes a point with an HFT, that bigger at .050, means I gotta start over with more compression.And that introduces it's own set of issues, especially for manual-trans streeters,like me. I've run the gamut from 223 to 248 @.050, HFT s,with it's associated required parameters. So I know what my 367 likes, what I like, and I got a pretty good idea of where I'd like to be; but I'm unwilling with a Solid, to play the stab-it-in-and-hope-for-the-best, routine.
So I don't buy the SFT at all.
And I bet there are many more like me, saying
Meh, my Hydro is close enough..........

 

[Wyrmrider]

well said AJ
most do not have the equipt and computer to adjust for lash and print/ graph comparisons

 

[K.O. SWINGER]

even though that article is going on 20 years old it's still is one of the better ones for explaining the differences between Hydraulics and mechanical camshafts. But hydraulic camshaft have changed quite a bit in the last 10 years and give up very little to a solid lift profile to sixty-seven thousandRPM in my opinion. And with zero Lash make them faster in the beginning of the events more than most solids but after about 66,000 RPM a solid lifter takes over

 

[K.O. SWINGER]

so AJ what stick are you running these days?

 

[12many]

I can call up the manufacturer of my current HFT and instantly get the next size bigger

Exactly my intentions with the Isky I have now. Tell them exactly what I have, what my plans are, see what they say and then I’ll know exactly how much more/bigger I’m gonna go from the current cam if I go with them, or have a better understanding of what others may recommend. Or when picking my own. I had what I would consider about a two sizes bigger hyd cam I was going to slide in my current setup, but with bigger overall changes “I gots to know”

 

[AJ/FormS]

so AJ what stick are you running these days?

Since 2004,
I've been running a Hughes hydraulic HE3038AL, which I have installed at 108, so it's
276/286/110+2/61 overlap(60Effective)/114 compression/105power. /lifts of .549/0.571 @1.6rockers/and .050s of 230/236;
Installed with Hughes anti-pump-ups, at what started out as .020 preload, but some of them are now, after 50,000 miles, ticking.
My Scr is 10.95, and cylinder pressure is about 177psi with OOTB aluminum Eddies.
It's a clutch-car, so it's sensitive to to pressure loss at low rpm.
That is to say I hate slipping out the clutch like a 302Mustang . It's a Mopar. It's supposed to be a dump it and go deal. Now, with a 3.09 low and 3.55s the starter gear is 10.97.Together with the heavy factory flywheel,this makes it so. Blip the throttle just a lil, slip it out hard and fast, letting the flywheel do the work, and drive away like it was an automatic.

I miss the top-end rush of the DC 292/292/108, ([email protected]), and
I miss the stout off-idle torque of the 270/276/110 Hughes, (223/230@050), so
I put up with the 276/286/110,(230/[email protected]) having made the changes to run it.
And I have become used to it.
I set the engine up to run the 292 cam with a thin gasket and adjusted the Scr on each of these cams, in various ways, that most guys would never take the time to do, to achieve about the same 180ish psi. So I believe I have a good idea of what to expect at that pressure, and I am unwilling to run any less. I can't go back.
But I would be excited to go forward with more pressure and more duration @.050. How is that possible? Without more machining ,and staying with a hydro, it's not.
But since this current combo has gone 93 in the Eighth, I just leave it. Certainly, as a streeter, that is fast enough.

 

[Wyrmrider]

from the old article
"For instance, in the Competition Cams line, hydraulics are rated for duration at .008-inch lifter rise, while solids are typically rated at .020 inch."



Crane .004 Comp, Lunati and most other .006, Engle, Racer Brown are .008 and MP is close to .008 Comp has never been at .008
as for .020 figure a tight lash tighter than .020 vs a .030 looser .020- what difference does it make.
I have found similar with the rest of the article
(too bad they did not show a XE275 non HL or a H275 older grind)
OP
Problem with ISKY is they use a different height for each of their lines an their "Mega Cam" line is even a higher checking height than .008- Meaning their seat durations are longer than any other vendor than you think they would be.
Essentially the longest and the laziest. (Which is why they wear well and rev well- Old School- down on torque and not what you want in a low compression motor )
You can get more area under the curve from almost any other vendor (except say Erson or Elgin)
you can get the same area with much less seat duration from almost any other vendor
you can get much more area at the same seat duration
you can get less seat duration AND more area from vendors with modern masters
would more seat duration hurt your low end and 60 ft times?
do you like the rev range/ power band you have now? and just want more power in your current power band?
too bad comp does not have any mopar hyd less than the tested XE275HL

 

[AJ/FormS]

Reading between the lines, Nice write up.

 

[12many]

Only lobes by Isky I’m interested in are a couple of the solid Magnum XL .842” lifter lobes, got my eyes on what I think may work good, maybe maybe not, but they will know better than I. I’m all for filling out cam requests and calling and viola I got a cam. What did I learn about what it takes to spec one? Nothing. I’m trying to absorb and fill in the blanks on some finer aspects of lobes, learn all I can and see what I come up with at the same time. I’m already in the high 11’s @110+ on a good day, and spec’d everything myself to date, considered others advice, done a bit of reading, etc. My combo is what it is, not the best of everything, latest up to date parts or perfectly ideally matched components. I know I did pretty damn good for putting something together though. So I’m shooting for mid 11’s or better @115+ on any day, and for some radical street enjoyment. With a new converter, bump in compression, TF heads it’s not gonna take much more cam. Just not definite on how big I want to go. I need more top end more than anything though, to overcome the aero handicap this van has. I’m looking at a variety of solids, but avoiding very aggressive lobes for .904” and very slow .842” lifters.

 

[K.O. SWINGER]

Since 2004,
I've been running a Hughes hydraulic HE3038AL, which I have installed at 108, so it's
276/286/110+2/61 overlap(60Effective)/114 compression/105power. /lifts of .549/0.571 @1.6rockers/and .050s of 230/236;
Installed with Hughes anti-pump-ups, at what started out as .020 preload, but some of them are now, after 50,000 miles, ticking.
My Scr is 10.95, and cylinder pressure is about 177psi with OOTB aluminum Eddies.
It's a clutch-car, so it's sensitive to to pressure loss at low rpm.
That is to say I hate slipping out the clutch like a 302Mustang . It's a Mopar. It's supposed to be a dump it and go deal. Now, with a 3.09 low and 3.55s the starter gear is 10.97.Together with the heavy factory flywheel,this makes it so. Blip the throttle just a lil, slip it out hard and fast, letting the flywheel do the work, and drive away like it was an automatic.

I miss the top-end rush of the DC 292/292/108, ([email protected]), and
I miss the stout off-idle torque of the 270/276/110 Hughes, (223/230@050), so
I put up with the 276/286/110,(230/[email protected]) having made the changes to run it.
And I have become used to it.
I set the engine up to run the 292 cam with a thin gasket and adjusted the Scr on each of these cams, in various ways, that most guys would never take the time to do, to achieve about the same 180ish psi. So I believe I have a good idea of what to expect at that pressure, and I am unwilling to run any less. I can't go back.
But I would be excited to go forward with more pressure and more duration @.050. How is that possible? Without more machining ,and staying with a hydro, it's not.
But since this current combo has gone 93 in the Eighth, I just leave it. Certainly, as a streeter, that is fast enough.

sounds like a great set-up AJ thanks for the response. I'm thinking about a stick change myself but moving in a little different direction oval track with 240 at 50 and 497 lift it's a bit old school and would like to move to a more modern grind

 

[12many]

oval track with 240 at 50 and 497 lift it's a bit old school and would like to move to a more modern grind

I’m old school as much as possible for the most part. I never really had it when it was new so it’s new to me. Give me a Max Wedge setup with “all” the old school you can.....but I digress

 

[Wyrmrider]

Isky had a great cam for our max wedge
It was the only .904 cam he had
I do not know if it's in the catalog anymore
but it would make a great bracket cam as it's super consistent
we used it to dial in chassis for years
why did Ed have to go to a .904?
Because he could not get any improvement over the factory cam (Cam Craft?) with his universal masters.
This was in the day of hardface overlay for the Fuel builds
IDK if the hardface masters were .904
Isky had some great new masters for solid lifters about the time we closed up
Call and ask for Ron

 

[12many]

Isky had some great new masters for solid lifters about the time we closed up
Call and ask for Ron

. Isky must be on extended holiday as phone unanswered, so for sake of discussion, these two lobes are from their Magnum XL lobe list. Just based on the numbers they look interesting to me for my setup. Running calculators and playing with different timing, ICL’s etc. Not sure if these lobes are among the new masters (at that time) you referred to? The first: LOBE S-632: 282 adv/ [email protected]/ [email protected]/ [email protected]/ [email protected] .370” lobe/ .555” 1.5rr/ .592” 1.6rr The second: LOBE S-645: 286 adv/ [email protected]/ [email protected]/ [email protected]/ [email protected] .376” lobe/ .564” 1.5rr/ .602” 1.6rr

 

[yellow rose]

even though that article is going on 20 years old it's still is one of the better ones for explaining the differences between Hydraulics and mechanical camshafts. But hydraulic camshaft have changed quite a bit in the last 10 years and give up very little to a solid lift profile to sixty-seven thousandRPM in my opinion. And with zero Lash make them faster in the beginning of the events more than most solids but after about 66,000 RPM a solid lifter takes over

That's just not true. A tight lash solid will blow the doors off a squishy hydraulic all day long and twice on Sunday.

 

[yellow rose]

Only lobes by Isky I’m interested in are a couple of the solid Magnum XL .842” lifter lobes, got my eyes on what I think may work good, maybe maybe not, but they will know better than I. I’m all for filling out cam requests and calling and viola I got a cam. What did I learn about what it takes to spec one? Nothing. I’m trying to absorb and fill in the blanks on some finer aspects of lobes, learn all I can and see what I come up with at the same time. I’m already in the high 11’s @110+ on a good day, and spec’d everything myself to date, considered others advice, done a bit of reading, etc. My combo is what it is, not the best of everything, latest up to date parts or perfectly ideally matched components. I know I did pretty damn good for putting something together though. So I’m shooting for mid 11’s or better @115+ on any day, and for some radical street enjoyment. With a new converter, bump in compression, TF heads it’s not gonna take much more cam. Just not definite on how big I want to go. I need more top end more than anything though, to overcome the aero handicap this van has. I’m looking at a variety of solids, but avoiding very aggressive lobes for .904” and very slow .842” lifters.

Im thinking (IMO) you should be heading to the .875 lobes at least. I'd probably want a .904 lobe for myself but at least an .875 lobe.

If you do that, you can shorten up the seat timing, maybe (most likely) gain several degrees at .050 and a few more at .200 and not give up any bottom end torque and have a much better idle

 

[Wyrmrider]

What yr says

.875 solids had a lot of development for NASCAR and other class racing
reliability at high rpm went up
However most all the isky lobes were for chevies
I'd find a camgrinder that has a list of Mopar lobes and work with them
Isky AFIK is not one of them, or Erson AFIK Exception makes the rule, prove me wrong)
Comp, Crane, Engle, Crower, ChetHerbert, Ultradine, Bullett, Howards, Lunati, Jones, Racer Brown
MP --all have solid ,904 lobe series- some more modern than others
good luck finding what you really need in a catalog

some are street, some are race only, some for heavy valve train, some for light, some take heavy springs, some require frequent maintenance- springs
BVVC
looking for Mopar circle track I'dPM Krooser and find others using MOPARS- they are not chevies

 

[12many]

What yr says

.875 solids had a lot of development for NASCAR and other class racing
reliability at high rpm went up
However most all the isky lobes were for chevies
I'd find a camgrinder that has a list of Mopar lobes and work with them
Isky AFIK is not one of them, or Erson AFIK Exception makes the rule, prove me wrong)
Comp, Crane, Engle, Crower, ChetHerbert, Ultradine, Bullett, Howards, Lunati, Jones, Racer Brown
MP --all have solid ,904 lobe series- some more modern than others
good luck finding what you really need in a catalog

some are street, some are race only, some for heavy valve train, some for light, some take heavy springs, some require frequent maintenance- springs
BVVC
looking for Mopar circle track I'dPM Krooser and find others using MOPARS- they are not chevies

Isky has a small list of .875 Nascar, all too much lift. But yup, that’s it.

 

[yellow rose]

Isky has a small list of .875 Nascar, all too much lift. But yup, that’s it.

How much is too much lift?

You need to understand what most of us already see...the needle is in, you're hooked and the aftermarket is your dope dealer!!!

BTDT LOL.
That's the nice thing about the quicker lobes. You can get the same area under the curve, or even more area with less seat to seat timing. The long seat to seat timing is what makes them dirty at idle and lazy down low.

Your heads will take more lift than normal because TF corrected the shaft location and worse case you'd need a small correction kit from Mike at B3.

I'd jam as much lift in there as I could. Let the heads do the work.

I run 280/280 255/255 on a 105 and I can set my idle at 750. I don't let it idle that slow, but it will do it without struggling.

And as good as you are at getting your carb in shape, correcting the fuel curve for a new, more agressive cam won't be an issue.

 

[12many]

On the lift I’m mistaken, their 875 lobes are big on both adv and @050 most are 290+ adv region/266@050 and up. The smallest with good lift is a 286adv/258@050/173@200/.388” lobe lift. Yes the needle is in. I like your analogy!

 

[K.O. SWINGER]

That's just not true. A tight lash solid will blow the doors off a squishy hydraulic all day long and twice on Sunday.

I don't claim to have your experience in this area but from what I read you're looking at 3 to 4% power Improvement on top with a solid flat tappet with a good hydraulic almost equal in torque in a moderate built engine