The 454 will make the 525+HP mark with ease.
With that cam it will probably make peak hp at 5600.
A 427 version would very likely make exactly the same HP, with the same parts, but would make peak HP at 6300, but the TQ would be way less.
I ran a very similar cam in my 454 when I dyno'd it.
https://www.corvetteforum.com/forums...ls6-build.html
It made 490HP at 5300-5600 rpm and 550ft lbs of TQ at a very low 3500.

Here's how my experienced engine builder did it:

• I had an aluminum 074 L88/LS6 cylinder head requirement. Held it back roughly 30-40HP over AFRs. My rectangular port heads are probably worth no HP at this RPM range over good ovals, and may cost TQ.
• I had a 569 OEM lo-rise intake manifold requirement to fit easily under the stock BB hood. Held me back another 30HP above 5000. I was guaranteed I could get that back by intake porting, but was $1400.
• OEM 4803 780 Holley
• 850 might gain 5HP, I only had 1.5" vac at 6000.
• So add those up and you have 560HP.
• 10.5 CR, .015" decked block, .001" piston deck height, .040" quench
• Custom Erson Solid Roller cam. 270/278* adv duration, 230/238* @ .050", .012 lash. This was the real secret sauce for the TQ. The very fast roller ramps (40* intensity) kept the adv duration short, and overlap short, and built the impressive low end rpm TQ. Since this is a solid cam, you have to subtract the lash to get the true valve duration. 230/238* turns into 224/232* after the .012 " lash. Much like the cam you were talking. Except .620" lift. We're guessing the custom cam made 40# TQ more than a normal one, and at 600rpm less, with virtually no impact on HP. It probably makes close to 450-500# TQ at idle. That you can't get except with cubic inches.
• 110LC, 4* adv, 106* ILC
• 16".5 vac at 850rpm idle
• 1-3/4" headers
• Just a little lope to it at idle. Milder than I thought. Sounded like a 350HP SBC, with bass.
• My dyno run is online.
• BTW I have since changed the cam to a slightly larger one (LOL) and that 230/238 one is available if desired. Only 10 dyno runs on it.

Here I backed my real dyno run of my custom cam into the simulation software. And compared it to the TQ curves of a normal LS6 cam, a 427 L72, and a L78 396. Factory but identical cams on those three. The numbers above will not be exact, but the trends are real.
Low end TQ comes from cubic inches!
Lorenzo has dyno'd many of these, and going from 396 to 427 to 454 adds 30-40# TQ for each size increase.
But only the simulation software can show what it looks like off idle to 3000. They don't like to start dyno runs below 3000.
But where are you actually going to drive it? 90% of the time? 1000-2500 right?

 

When talking big blocks....or even healthy small blocks.....lift should usually be in the mid 500's on small blocks and low .600's at least with any decent head.

I did a nice 388" with 525 HP for a buddy. Basic 11.0 compression, old unported Dart 215 cc as cast heads and a custom high 240'ish solid roller cam. It honestly drives incredible and has been running for over 10 years with regular flogging into the 7000+ RPM range.

I love 427's....ran mine in many combinations over the years and was never scared to jump on 454's.....but I shifted it at 6500 or so with oval ports and closer to 7500 with rectangular port. The ovals are a much better combo on the average street motor with a little work on them.

Doesn't sound like you need to go crazy with heads....but if for whatever reason you end up buying a crank...go straight to a 489-496 combo and have lot of easy HP and drivability.

zjim

 

Thanks again for the real world information. I think I've settled on the 383 for a few reasons. I already have a 350 to start with so the foundation is there. I'll put the $2k savings into the chassis and coilovers for increased civility and handling. I'm not afraid of 11:1 compression with aluminum heads as 93 octane is everywhere here in FL. it seems like I might be able to increase the duration and lift a little on my cam without moving the power curve too high. I'll look into a the comp cam 08-432-8 which has 230/236 duration, .510/.520 lift (.543/.553 with 1.6 rockers). As long as that doesn't move the peaks too high killing low end torque, idle quality, and vacuum I'll be good to go. I guess it's time to move from theory to actually consulting with my local machine/speed shop. Here we go...!

 

I've posted this a few times over the years,,,,but it's one I built for a magazine project. 400", Dart as cast 200CC heads, custom solid roller cam (very streetable). Test with dual plane, single plane and a heavily ported 283/270 2x4 intake with old WCFB carbs. The whole point was to disguise it as a 283/270 and make 500 HP. Still running today in a '61 Vette with a 5 speed, 3.36's and hubcaps. Always loved to surprise unsuspecting Viper, Vette, Mustang and Camaro owners.

JIM

 

Very impressive to put up those kinds of numbers on a "very streetable" cam. I thought power like that required lumpy, lopey, race cams. Nicely done!

 

Talked to a builder today about my specs. He liked my 427 idea to be different and recommended a set-up to get me to get me right at 10.5 compression (93 octane here). Still a very street/idle/vacuum friendly mix. Comp Cams 224/230 hydro roller, .51/.51 lift; 110 LSA; 1.7 rockers; Brodix Race Rite partial CNC 290 heads with 119 cc chambers. Icon forged pistons with -38 domes. .041 gasket. Life feels good today.

 

That cam is leaving a lot on the table.

Jim.

 

Like someone said before, if you are buying a BB crank, you may as well buy a stroker crank, and go 496.
It's almost zero cost difference, and you get 70 more cubes of TQ.

 

the builder agreed but for some reason was hesitant to recommend something bigger. If it was your engine what spec would you recommend keeping in mind some semblance of civil idle and vacuum?

I don’t have to have a cam from comp cams but I think I’d be fine with going up to 230/236 or even one more step up to 236/242 if it had a wider LSA around 114. Still too small? What say you?

 

It all depends on what you want the idle like, vs how much higher rpm HP you want.
A cam really is the critical selection that determines the personality of your engine, Driveability, HP, etc.
I'll give you a couple examples to help you decide.

I ran a 224 dur in my 454 BB on the dyno and it gave back 16.5" vac. @ 850 rpm. Had a mild noticeable lope but idled pretty tame. Made peak TQ at a very low 3500 rpm. Very tame cam in a BB. 110 LC. It was like a step bigger than an LS5. Peak HP at 5400. What a torquey every day driver that would have been tho.

So tame that I changed the cam already and went to a 232, 112LC. I do not expect too much difference, but a little. Vac should drop a couple. 2-3?
I am hoping for 13 vac and that it sounds a little bit more like an LS6 / L72 cam at idle. Noticeable but still drives very well. I have driven several of those, and that's my target. Just enough pop to really make it feel lively and responsive, at any speed, from idle to redline.

You can go a little bigger as you suggest. 236 on a 112-114 is about as far as you can go and still retain close to that almost stock idle & driveability. But it will have a stronger stacatto at idle, and vac will drop some more, say 11-12" at idle. On cams this size you can vary the idle up or down a 100 rpm and get more or less idle sound pretty easily. Tuning it to be smooth will require a little more effort. And at this idle vac level using a Q-Jet becomes very difficult, they do not really like idle vac below 13". If you are a good tuner it can still drive very well, with a Holley. It will be slightly weaker below 2000, but you may not even notice that on a BB. It will come on crisp and strong from 2000 up. With a BB you are going to be traction limited at WOT in 1st, and maybe 2nd, when it comes on the pipe.

I ran an even bigger 239* dur in my SB 350, and that was a very cammy engine for the street, 10.5" vac at 950 idle, barely worked PS even then without stalling. Very weak TQ below 2500 until it kicked in very strong, then it pulled hard to 6800. Felt like a race engine. A little difficult to drive in traffic, very touchy on the throttle, a couple hundred rpm felt like it doubled the power in traffic. But that was exactly what was fun about it. It forced you to concentrate to drive it. It lived to rev. But it was too much work for easy cruising. It would take a couple extra degrees past 239* to make a larger cube BB feel like that.

Mid 240s and you are basically talking L88 cam size, and you probably know what those are like. Full-on race engines. (I am quoting all Hydraulic duration #s BTW)

That racy SB engine of mine probably had down near 250# TQ at dead idle. The power literally doubled by 4000. A cammy SB keeps making more power the more you rev it up. Listening to it accelerate became addicting. That's why I am going with something completely different this time around, a torquey BB, with 450# + TQ at idle. I am going for that almost flat 500# TQ band from 1500-5000. That's almost double, at idle, vs the 350, and will make it so much easier to just drive / cruise around. And it will still smoke the SB in a drag race. The SBC ran low 13s at 106 mph. Shifting at 6700. This one should be way quicker and way faster. Maybe low 12s at 114mph. Shifting at 6000. And it'll cruise way better! On the street I won't have to downshift, or wait for the revs to climb up, for it to just "go". A 425 HP SBC and 500HP BBC do not sound all that far apart, until you consider that one has double the TQ, at idle.

Does that help?

 

This is great real world help!. Thanks so much. I think I scared the builder a little with my insistence on idle and vacuum. I'm going to see what else is out there around t230-232 with a little wider separation than 110. I suppose I could have CC do a custom grind but that will just add $$$. Out of curiosity, anyone know approximately what custom grinds cost?

This one off the shelf might be a winner? https://www.summitracing.com/parts/HRS-120205-14

 

Custom Billet Steel Roller with iron everwear distributor gear welded on $570

You will never catch me using one of those "austempered" cast iron roller cam cores
Aren't they $400 anyway?

My previous custom Erson Billet was $400

 

not as bad I thought. About $100-$150 depending on shipping.

 

The cam in my 496 is 240/245@.050” hydraulic roller. 10:1 496 with Dr J’s heavily ported Edelbrock heads. The car will idle at 850 rpm in neutral no problem. I do have EFI but the Hooker sidepipes are probably costing me 50+ hp even with the STS baffles.

Here is my rear wheel dyno from 2014, running a T-56 Magnum and Toms 12 bolt diff. (3.73) so I am sure there was some drivetrain loss. (Ignore the 427 on the chart, it is a 496).

 

Until we narrow down exact heads etc I could t give a cam recommendation.

But I can tell you the 388” I did for my buddy has a 248* solid roller on a 108 LSA. Over .600” lift. The thing idles great and will
literally idle away from a red light with a 4 speed and 3.36 gears. He has 3.70s in it now and it’s even better.

A 240ish cam in a big block isn’t even close to L-88 manners. But again the heads make the difference. The better the heads the less can you typically need for X power….but that just means you can make that power at a lower RPM with the better heads. More cam would still make more power with more RPM.

Do some searching on builds by VORTECPRO here on the Forum. He’s a wizard with iron oval port big blocks and routinely makes 650 hp out of 496s on pump gas with only a 238* HR from Isky. They peak around 6000 rpm and pull like a freight train.

You can also look at Straub Technologies. Chris has a line of HR cams specifically geared to your type of build. His specs may look a little rowdy but the shape of the actual lobes makes a difference and there’s a lot of people that will vouch for results.

Jim

 

Umm ....I thought we were talking duration of hydraulic cams here for the OP.
Throwing in solid cam duration numbers really muddies things up.
So I am afraid we just confused the heck out of the OP.
I was trying to keep it simple.
You absolutely can not compare the quoted duration of a solid cam, to a hydraulic cam, because of the valve lash effect.
For reasons unknown, except to the cam mfgrs, they specify hydraulic and solid cams differently. Solid cams duration is spec'd at zero lifter movement, but they have up to .030" lash before the lifter actually moves. So you get less duration than what they advertise, and it is hard to compare to hydraulic, unless you account for it.

I think we can all agree something in the mid to high 230s* duration, in a hydraulic cam, is near the max for even a rowdy street cam.
Cranking the idle up to 1000-1100 tames these down quite a bit. So they idle better with more vacuum.
That 248* solid roller mentioned has net duration (after lash) around 238-240* depending on the lash. Perfect. But big.
High 230s* is really pushing it. At 230* and lower you can idle it at 850.

I saw SWDuke's results online where he did actual cam profile measurements to be able to directly compare solid lifter cams with hydraulics. You basically take off 6* duration (@.050") for .012" tight lash, or 15* duration for chevies old .030" loose lash. This gives you the net duration of a solid cam, above the lash point, and lets you compare it directly to a hydraulic. He measured it, so this is not a guess. Jeff and I had been estimating this for 30 years, just based on experience, and degree wheel measurements, and SWDukes testing validating our experience.
I gave up caring about mfgrs quoted solid cam duration figures decades ago, we just converted them to net duration. For street cams anyway. And things made much more sense. You change the lash, you change the duration, simple. We could advise a customer on how similar "X" solid was to "Y" hydraulic. And we sold thousands of cams at Jeffs shop.

So with that in mind the LT-1 and L72, L71, LS6 solid cams all have a net intake duration (after lash) @ .050' of 231. The L88 is a 247/257* split. (It's pre-lash numbers are 262*/272*) We can agree it is extremely rowdy. All the max effort street cams, come in at 230* intake, post lash. Straubs, Comps, Cranes, Iskys, GMs, etc. Solid or Hydraulic. The overlap is growing, vac is diving, and that is about the limit, around 12-13" vac at idle. Down to 10" if you go to 235-238*

There are very few Hydraulic cams of any kind with more than 230* dur, because the hydr lifters have issues dealing with the over 6000 rpm potential of the cam profile.
Here are two, and notice what they say about the idle. The last two sort of split an L88 profile.



Here are some of my notes after 30 years of cam comparing, on profiles we are talking about. 230* duration at .050" lift, (net) is a tipping point. Even a couple extra degrees makes a huge difference at that level.

 

I won't disagree with the differences between HR and SR's......but your list also includes flat tappets for comparisons. An L-88 or LS-7 flat tappets "manners" will be much different than either a SR or HR. The ramps are vastly different. And as mentioned the tight lash SR's change things even more. It's really hard to compare .050 numbers unless you're looking at similar lobe profiles.....as things quickly change as you move to .200" and beyond on various lobes....and whether symmetrical or not.

Agreed...something like VortecPro's 238" HR is pretty rowdy, but works with a relatively tight converter and headlights and brakes will work.

I did a 254* HR in a pump gas 555" that made 800 HP with enough intake/carb on it....against a larger (on paper-but similar overall) solid flat tappet....the flat tappet made much less power under 4000 RPM....but similar with smaller intake/carb...but 20+ more on the top end with large carb and intake since it could rev higher. But again...while easily street drivable in an engine that large...it WAS rowdy and not smooth like the OP is looking for. BTW...a similar SR made 850 HP in same engine and was the best driving one of all.

If looking for simple and for sure relatively smooth...go with the 220"ish cam...but decide what you really want and whether the investment in heads is worth it if you're not going to use the power they can make. Good ones WILL make more power with the smaller cam than stockers for sure....you just have to decide what you want.

BTW...some of those Straub HR's do amazingly well with the tight LSA's. As I mentioned..it's the total lobe shape. One of the best running solid flat tappets I've used on SBC's with iron double hump heads is a Crower circle track cam with a 108 LSA. Runs great, idles and drives clean and sounds wicked.

JIM

 

Great info Jim!

I have always believed that the .050" intake duration sets the basic rev range.
Then all the other things come into play like: advertised duration, exhaust duration, LC, ICL, IVC, overlap, advance, ramp speed, lobe shape, lift, etc. etc. which enable you to tweak different parameters a bit, here or there. And sometimes those things can really add up.

The #1 most common issue in the speed shop was 80% or more of the guys that came in, always came in asking for too much duration for what they wanted to do. The whole "bigger is better" syndrome. They handicapped themselves by a bad selection from the start. When they listened, the car always ran better, smoother, and faster.

 

I think I can put this one to rest. I had a great conversation with a very experienced tech at Howards Cams. We talked at length about duration, lift, and valve events in the context of my heads and goals. I might be leaving RPMs on the table and higher peak HP, but I value friendly idle and vacuum. Here’s where we ended:

cam - 120245-12. 225/231 duration; .567/.578 lift; 112 LSA.
heads - Brodix 270cc intake, 119cc chambers
pistons - forged 38cc domes. 10.6:1 compression.
Intake - Edelbrock Performer (dual plane).

Assuming a properly tuned carb (or EFI) and electronic ignition, he estimated horsepower to be about 575 at the crank. I would have been happy at 540-550.

thanks again to everyone for the opinions, education, and examples of various combos…even the solid cam versions.

 

Double ck on valve size vs pistons. Are those 2.25" intakes? Gonna need a wide valve pocket for radial clearance.

Sounds like you'll be happy with that cam considering your needs for idle and smoothness. It will still thump a little.

You might look at Brodix intakes also......they make some nice flowing dual planes also. A regular Performer might be a restriction. How many cubes did you decide on?

JIM