Dyno Numbers vs Cam Selection

[CJ428CJ]

I've been playing around with Desktop Dyno (an engine simulation program). I wish I had purchased this program prior to selecting the cam for my engine. I'm running a 428, 10.25 compression, Edelbrock heads and a dual plane manifold. Below (if I did it right) is a table showing the hp and torque of some of the cams for this engine. My engine is running cam #9. That's good for about 458hp@5500 and 493ft-lbs@4000. Looks like there are lots of other hydraulic cams I could have selected that might have been a bit better. But the ones that are really interesting are cams 22 and 24. 22 is a solid-roller that should pump out 502hp@5500 and 573ft-lbs@3000. 24 is a hydraulic roller that should be good for about 526hp@6000 and 534ft-lbs@4500. Wow! Is anyone else running a roller in their FE? Besides cost, are there any pitfalls I should be aware of? Of course, if I were to go with the hydraulic roller, I'd need the cam, lifters, new valve springs, keepers, etc and maybe pushrods. That's a lot of bucks but it shouldn't be too tough to do. Any words of wisdom?

[IMG]cam summary table[/IMG]

[CJ428CJ]

Okay, who can tell me what I did wrong? I tried to embed the table in the above post. I thought I knew how to do it but it doesn't look like it came out right.

[Don]

If using Explorer. hi-lite the table, data, verbage etc., by dragging over the fields of information by holding the mouse down from a singler click, release when all is hi-lited and then click on Copy in the Edit command of the top toolbar

When entering the posting, position the cursor where desired for the information to appear, click on Edit, then click Paste

Such as :

CJ428CJ_
Senior Club Cobra Member

Registered: Dec 2000
Location: Livermore, CA
Posts: 109
Cobra Make & Engine: ERA #629, 428, Richmond 5 speed
_

Okay, who can tell me what I did wrong? I tried to embed the table in the above post. I thought I knew how to do it but it doesn't look like it came out right.




Report this post to a moderator | IP: 12.32.89.121

06-13-2003 08:15 AM

[CJ428CJ]

Thanks Don. I can do what you suggest but that's just cutting and pasting. Since it's a table, the column alignment gets goofed up. I was trying to imbed the image within the message as either a pdf or tif file. Kind of like what some people do when they put photos within their post. Until someone can tell me what I did wrong, here's the data in its raw unformatted form:

# Mfg Part No. Type HP @RPM Torq @RPM Lift(Int/Ex) Dur Dur@.05 Sep.
1 Isky 351271 Hyd 443 5000 511 3000 .542/.542 280/280 232/232 108
2 Comp 33-519-3 Hyd 446 6500 420 4500 .580/.580 306/306
3 Comp 33-241-3 Hyd 448 6000 436 4500 .580/.580 305/305
4 Crower 16241 Hyd 451 5500 509 3500 .538/.552 280/286 222/228 112
5 Crane 344561 Hyd 453 5500 470 4000 .572/.572 236/236 108
6 Edel 7106 Hyd 453 5500 470 4000 .572/.572 296/296 236/236 108
7 Crower 16255 Hyd 456 6000 500 3000 .549/.550 280/288 224/232 108
8 Crane 343801 Hyd 457 5500 500 4000 .537/.537 288/288 226/226 112
9 Isky 351281 Hyd 458 5500 493 4000 .565/.565 232/232 108
10 Comp 33-240-3 Hyd 460 6000 482 4500 .560/.560 292/300 111
11 Comp 33-310-4 Hyd 462 5500 507 3500 .550/.550 276/284 110
12 Comp 33-230-4 Hyd 465 6000 502 3500 .530/.530 280/280 110
13 Comp 33-316-4 Hyd 465 6000 459 4500 .590/.590 296/305 110
14 Comp 33-317-4 Hyd 467 6000 476 4000 .560/.590 292/296 110
15 Lunati 00054 Hyd 468 5500 490 4500 .554/.554 292/292 230/230 109
16 Comp 33-314-4 Hyd 469 5500 501 4000 .560/.560 280/288 110
17 Comp 33-315-4 Hyd 471 5500 491 4500 .570/.560 286/292 110
18 Crane 344621 Hyd 475 6000 461 5000 .554/.563 296/300 234/238 112
19 Lunati 30507 Hyd 475 5500 485 4000 .563/.600 280/290 230/240 108
20 Crane 343801 Hyd 477 5500 499 4500 .548/.580 278/290 222/234 114
21 Comp 33-312-4 Hyd 483 6000 481 4500 .570/.560 286/292 108
22 Crower 16462 Sol-Rol 502 5500 573 3000 .580/.582 280/288 234/244
23 Crane 349541 Hyd-Rol 510 6000 471 4500 .632/.655 300/308 238/246 112
24 Crane 349521 Hyd-Rol 526 6000 534 4500 .584/.607 284/290 222/228 110

[Don]

Mis-read your e-mail, now I understand. While far from the best way, an approach used for another site was to have the document scanned and sent directly to me via e-mail , not as an attachment, then did the copy and paste from the body of the e-mail. Might be the format just happened to fit correctly.

Looking forward to having someone explain the details of the correct method

[decooney]

CJ428CJ,

IMHO, if you do decide to swtich your cam, really take your time on this and talk to those that have "actually tried" a few different cams in their 428s with different axle/transmission ratios. I've tried 3 different cams now in my last two 428s and there is a noticeable difference in usability, driveability, performance, and longevity just going up or down in the scale one or two levels. I ended up stepping back down on my last cam and like it much better now for the type of driving I do, and I have more power right where I need it. Also, if your E-Brock heads are not professionally blueprinted/ported to your intake by an FE specialist, you will definitely be able to pick up some there too. If you go roller in an FE, be careful. Hopefully you can work with someone that has successfully installed rollers in FEs without oiling problems... talk is cheap on this one and expensive if someone does not know what they are doing.

I can always recommend Tom at FE Specialties, he sure knows his roller cams in FEs, and is very helpful as a backup reference. Tom is at: 916-339-0427. Good Luck.

[HighPlainsDrifter]

Hi,
The desktop dyno is fun to play around with, but it is just that, a desktop- read not real.
Ditto to what the previous reply said, driveability goes out the window the bigger the cam.
Also, unless you are a serious racer , stay with a good street hydrualic cam. Roller cams have VERY aggressive ramps and lift rates, read Hard on valvetrain ! That means you would replace valvesprings and check heads completely after a few thousand miles.
Good Luck,
Perry.

[CJ428CJ]

This all sounds like good advice but I'd be curious to hear from people that are running roller cams. To me a roller cam just seems like it would be better. That sounds naive but what I'm talking about is the reduced friction and the ability to get "more area under the curve." The explanation I found here seemed to make a lot of sense: http://www.lunaticams.com/Camshafts/CamSpecs6.html

Besides, is cam 24 really much more aggressive than cam 9? Cam 24 has 222/228 @.050 while my existing cam (cam 9) has 232/232@.050. Of course cam 24 has more lift 584/607 compared to 565/565.

Crane's description of cam 24 is "Fair idle, moderate performance usage, good mid-range hp, mild bracket racing, 2800-3400 cruise, 9.5 to 10.7 compression ratio advised, basic rpm 2500-6000." That sounds about right to me.

Lastly, the Erson catalog (page 100) gives glowing revues to hydraulic roller cams. They claim that the only disadvantages are cost and heaver tappets which require slightly stronger valve springs. They claim the advantages are 1) a quiet and virtually friction free valve train which requires little to no maintenance, 2) more aggressive camshaft lobe profiles, offering more area under the curve for better cylinder filling capability and increased midrange performance, 3) no break-in period required eliminating the possibility of premature camshaft and/or lifter failure due to improper break-in.

All the literature I'm reading makes it sound like hyd roller cams are the way to go.

[PatBuckley]

I have used a solid roller cam in an FE and I would recommend it if you are either mechanically inclined or willing to pay someone to do your work for you because they do need attention.

The valves must not be allowed to go out of adjustment - if they do, this allows the lifters to get beaten up, reducing their life. When they "die" a whole lot of little needle bearings make their way through your nice engine....bad news.

I do NOT recommend a very aggressive race type roller for the street. Spring pressures need to be pretty high for these which puts a lot of pressure on the lifters and reduces their life....see comment above.

The distributor drive gear needs to be replaced about every 5000 miles (if installed correctly) and checked - which requires pulling the distributor out - at the 2500 mile mark.

Pat

[Mr.Fixit]

Hydraulic rollers are great, but yopu need the rest of the valvetrain setup for them. (Sometimes even means drilling and tapping the block) The two cams you compared #9 and #24 are pretty close, pay attention to duration at .050 and overlap, those are the biggies as it concerns drivability. I promote small duration cams, everybody wants to go bigger, just to find out there car gets slower, drivability goes away, all that just from moving the powerband up 1000 rpm. If your motor doesn't really come on until 3000 rpm, it takes forever to get to 3000 rpm.

[Chaplin]

CJ428-
I think you and I have pretty much the same set up, except that I have cam #10. Could you run the figures with cam #10 and tell me what desktop dyno shows for that cam? I'd be interested to find out, because I don't even have the engine in the car yet, soon though, very soon . . .

Thanks,
Mike

[CJ428CJ]

I just posted some power curves and cam set up sheets to my gallery. I posted cam 9 vs. cam 24.

Chaplin, cam 10 comes in at 460hp@6000 and 482ft-lbs@4500rpm. I'd be happy to send you the complete graph, table showing hp and torque vs rpm, and the cam specs if you want to give me your email address.

Chris

[Chaplin]

Chris-
That'd be great, I really appreciate it.
Mike.

[CJ428CJ]

Mike, you've got mail.

Chris

[Chaplin]

Thanks!

[concobra]

The desk top dyno makes some assumptions that are misleading when looking at Hyd. roller cams. It assumes all roller patterns are a fast and aggressive ramp design as seen on racing cams. This does not hold true for street design roller cams whether hyd. or solid. To consider an accurate HP & torque number you need to reduce the desk top dyno figures by 25 the 30 HP & ft. lbs. of torque.

I have used the 349541 grind. It produced power until 5100 RPM then went into valve float ( typical for hyd rollers pushing heavy FE valves.) When going to heavier valve springs the hyd lifters began to collapse at 5400. Either way the motor signed off to early for the size of the cam. I pulled the hyd. roller and went with a solid roller over 248 degrees of intake @ .050 lift. This pulled power up to 6000 RPM which was my goal. Using a roller cam with less than 240 degrees of intake is a waste of money as the benefits of the aggresive ramp are lost by the low duration numbers.

Hope this helps.

[CJ428CJ]

Thanks Concobra. That's good information. It's always nice to hear from someone that has actually run the cam in question. Based on your feedback and similar feedback from someone else that was running a Crane hyd roller, I've pretty much ruled that cam out.

I'd consider going with a solid roller but when I built the motor I didn't tap the oil gallies that need to be blocked off to run solids. Taping the gallies without tearing down the motor would be a big no no since I wouldn't be able to clean out the resulting metal shavings. Anyone know of another way to block off the lifter gallies without having to thread the passage?

[concobra]

I know of a way to do this. Not perfect but works. It would take too long to explain on the thread. You are welcome to call me if you wish. 541-447-1398 my name is Phil.

[Cracker]

I was close to opting for a solid roller in my S/O just for the fact that it is the latest technology but the actual performance gains in HP/TQ are not that terribly significant in street trim. Mike LeFevers at Shelby Enterprises said he has never seen more than a 25HP gain using a roller and that was verified by my engine builder as well. Lots of money vs. limited performance gain and less maintenance - I kept the solid mechanical cam. Best of luck!

Tony Hull
Cracker

[Barry_R]

I've run solid rollers in my past two FE engines. These have been a bit "silly" for street driven cars - - I run them in a 3600 pound '69 Torino street racer that I fool around with. One was a 12:1 452" stroker, the other an 11:1 439" CJ based engine. The first went 10.30 with a 1050 Dominator and a 175HP nitrous hit, the second ran 11.10 w/ EFI. Both engines have since "expired" as a result of serious abuse by myself - - we're talking well over a thousand strip passes between them.

I could use a "fixable" 428 block.....nothing pretty.....

The rollers have made great power, the distributor gears have held up extremely well (remember though - I don't put many miles on these), and the setup/maintenence has been no more difficult than installing any other solid cam. No break-in period is even necessary, and the lifters can be inspected and re-used. Valve springs should be checked - - especially if you over-rev the engine.

My next FE (13.5:1, 505 inches) will also be solid roller cammed - - I don't think I'll ever go back.