Guys,

I just had the following big block 454 built:

- Brodix aluminum RR-O heads (316/188 @ .50 lift, 270cc runners)
- Edelbrock Performer intake
- Holley 770 Carb (out of the box)
- Comp Cams hyraulic roller 218/224 .510/.510
- 9.25 static compression
- Dyno headers were 2 1/8 inch, will be smaller in the car

The car is a 100% street machine and I wanted a smooth, powerful cruiser with lots of "seat of the pants" feel in real world driving. It will be mated to a T56 six speed tranny and 4.11 gears. Of course, it is going in a 2gen.

Here are the preliminary results. No time was spent tuning the carb or playing with the ignition, just set it to 36 degrees at 3,000 rpm and let it rip:

RPM TQ HP
2400 572 266
2600 574 291
2800 573 311
3000 569 332
3200 564 350
3400 557 370
3600 554 379
3800 547 395
4000 537 419
4200 534 427
4400 526 440
4600 515 451
4800 503 460
5000 479 456
5200 455 451
5400 443 456
5600 438 468
5700 427 463

The engine builder thinks it ought to rev a bit better. Initially we got poor results at anything over 4,200 rpm or so. After speaking with Comp Cams he shimmed the springs to 160 seat and 360 open then got consistent pulls as shown above. However, he thinks the hydraulic rollers simply don't want to rev. We are both concerned with valve float and the wonderful things it can do to the engine. I suppose I can always set the rev limiter on the ignition box to 5,200 and call it good. At that point the horsepower is almost level; the torque is dropping off almost as fast as the rpms are increasing anyway.

He wants me to be happy with the results and we agreed to sleep on it. Of course, the first thing I did after hanging up the phone was to post here to see what you guys thought. Perhaps someone will be kind enough to run a desktop dyno just for grins to compare it to the actuals.

BTW, thanks to Marv and Jody for their two cents each after I consulted them privately after the first disappointing dyno runs.

So, whaddya think?

FWIW, here is a pic on the dyno:

http://members.aol.com/MikeM79/454dyno.jpg

[This message has been edited by MikeM79 (edited February 24, 2005).]

Impressive numbers, that thing is a torque monster.

Screw the desktop dyno, I think you have all the info you need Mike, right off the printouts. If you can post the dyno printout with all the data like EGT's, brake specifics, manifold vacuum readings, air fuel (if recorded), VE and CFM I'll give you some feedback.

Also, does the dyno report say what correction factor was used? I suspect standard correction.

Here is one thing I do know, take the Performer off and bolt up an RPM, you'll see a significant increase on the top. Then bolt a 1" spacer under the carb and see if you pick up another 10 HP.

Of course you may not fit it under the hood with the RPM but basically the Performer just doesn't cut it on the top end with a big block.

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70 SS 454 CI Dynoed 684 HP, 702 TQ All Aluminium Fuel Injected Small Block , plus 200 - 500 HP NX nitrous system.

[This message has been edited by Rick WI (edited February 24, 2005).]

Ungodly torque numbers, but the shortish duration is gonna lop off some top end naturally. I love the combo! Lotsa torque, let the HP fall where it may, it isn't a slouch by no means!

That thing is making huge TQ down low. My gut tells me it's running out of breath. Is that carb big enough?

Ditto on the intake. As stated above, a spacer might help you out....even with the current intake manifold. At least that would be very easy to try out.

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2000 Corvette hardtop black, 6 speed, Halltech Tric cold air intake w/nylon MAF ends, Corsa Touring cat back exhaust w/pro tips, Taylor wires, 1/4 mile: 12.918 @ 111.29 mph on stock EMT's 330 rwhp, 342 rwt on MTI's dyno, 3075 lbs

79 Camaro 355 CID, Edelbrock intake, Edelbrock 600 cfm carb, Edelbrock performer 64 cc alum cyl heads, comp cams extreme energy 262 cam, erson roller rockers, hooker headers, Mallory Comp 9000, 3.42 posi, 700R4 rebuilt w/ B&M kit, 2400 stall converter w/ TCI lockup kit, energy suspension f.e. rebuild, 1-1/4 front sway bar, 5/8 rear bar

67 Camaro, 327 w/ a 'glide , waiting on "funding"

Why would you even consider running a 4.11 with a T56? You'll be in 3rd gear before you get out of the intersection.

I'd go with a low 3 and take advantage of the gearing.

A 12 bolt 4.11 rear is what is in the car at the moment. Your point is well taken though. I imagine this engine could cruise highway speeds at little more than a fast idle.

Gotta love that torque you got going. Remember, torque is what moves you. Looks damn good to me. Should take care of any tires you put on it!!!

Those numbers are pretty much what I would expect. That isn't much cam for a 454, so I'm not suprised it dosent wanng go past 6K.
Be happy Mike that thing is doing everything you want

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1971 Camaro
383 stroker ~500HP
M21 4spd
12" brakes
16x10" Wheels
Autocross competitive
Engine Designer - The Speed Merchant, San Jose, CA
http://www.speedmerchant.com/

<font face="Arial,Verdana" size="2">Originally posted by Lowend:
Those numbers are pretty much what I would expect. That isn't much cam for a 454, so I'm not suprised it dosent wanng go past 6K.
Be happy Mike that thing is doing everything you want

</font>


CAM screams at me. short duration, and low lift... a lot of small blocks run 510 lift cams. I've never messed with dual plane intakes so I won't ocmment on that, but I'll definitely say that the cam is tiny. Since you've already go hydraulic roller valvetrain, I'd yank that cam out in a heartbeat and put a .587/.610 232/236 @ .050 crane cam in there and watch the hp climb way higher.

I think the problem then Cale would be he'd run into valve toss even worse. Also that intake would REALLY be a resitriction as will the carb. He doesn't have a lot of compression to work with either.

I'm thinkin Mike wants a great driver with lots of snap, gets good mileage, and cruises in double overdrive smoothly, but would like it to simply carry better when it revs up. Somthing the wife won't get all freaked out with when it starts up. That's where I think simply changing the manifold would help a great deal.

We did a big block Pontiac on the dyno a couple of weeks ago that did not have as good of head specs, slightly bigger flat tappet cam and 462 cubes. It loved the Performer RPM with a 1" spacer. It made all the difference on the top end.

Those Holleys work pretty nice out of the box don't they Mike? We love using those things.

Mike,

First off you need to look at a few numbers on your dyno sheet. Look at the bscf. Next look at the air sensor factor. Most are at 9.0 and a ratio of 1-1. Next should be egts. In looking at the photo, you may not have that option. Like the others have stated, look at the correction factor. Most conservate dynos will only correct to 29.5 inches Hg and 60 degrees in dry air. Obiously if it is 90 degrees and 80% humidity, you numbers will be grossly out of wack. Now what suprizes me is the drop in power at 4800-5200 then back up by 9 a few hundred later then almost 10 a few hundred later. Could be a carb problem or tune. The torque seems awful high at such a low rpm. If I did my bar graph correctly., your torque and hp curve cross at 4000 rpm. That should be closer to 5250 or thereabouts. Please correct me if i did it wrong.

If it were mine knowing it is a street motor, I would refine the crankcase ventalation (PCV) or something like that. Look to see that you have the right heat range plugs. I would also hook up the water pump as it is going to be used. Lastly double check the valves and leak it down. Not saying there is a problem, but it sure is easy to do while it is bolted down like that. I would be happy with the results myself. I think that with a bit of tunning you will be right there. If you can scrounge up a set of headers that will be run in the car, bolt them on and then repull.If your dyno guy will let you, I would try the other mainfold and spacers and such. For sure I would dyno it as it is going to be in the car with the belt drives and headers that way I could tune it as it will be ran and not be so fixated on the numbers. With a t-56 and 4.11's, you have other things to worry about, like tires and ben gay to treat your carpel-tunnel from shifting so much.

Yeah, my concern was valve/lifter control. You've got a heavy hydraulic roller lifter, heavy BBC valve/steel retainer, and a light hydraulic rated spring trying to control all of it. Even with the mild cam the upper rpm's are going to beat up on the valve train considerably.
BUT,,, with what I see here who needs RPM's! For Pete's sake you could set this thing on high idle, use a tight convertor and idle your way into the 12's And STILL set a full glass of wine on the hood and never spill a drop (like the old Dodge commercials)!! You freeking BBC guys just don't appreciate how easy you have it! http://www.nastyz28.com/ubb/wink.gif

Guys,

Thanks for the excellent feedback and sanity check.

Rick has pretty much nailed it concerning my design objectives. I built a 383 for my 79Z a few years ago and was never really happy with it because I tried to do everything with it. I simply did not want to acknowledge the fact that torque curves are only so wide. Ended up with an engine with too much static compression (trying to recapture low end torque) and too much runner volume (trying to scream at the top end). I have to mix in about 10% of 103 octane along with pump 93 to keep it from pinging. Fun the first time, PITA after that. The engine is fun once it spools up a bit but has no throttle response under 3,400 rpm or so.

This time I decided to go with an engine that fits how I really drive.

These heads seem like a real find. They are new on the market but the builder is a real believer in anything Brodix puts out. 600+ peak horsepower looks easily attainable with more cam and compression if you are looking for more of "top end" engine.

I will call the builder today and tell him to get an RPM intake on it and to have a spacer handy. Rick makes a persuasive case and it is a relatively easy thing to do. Once that is done we will do the full blown dyno session with all the sensors hooked up, etc. I will post the results when I get them.

I'd also look for a bigger carb too.

Since its a manual trans behind it, I'd try a double pumper 800-830-850 just to 'compare'.

And of course, with a healthy build up, why'd yopu even waste your time on a plain performer? http://www.nastyz28.com/ubb/wink.gif I have one on my 'not even' 8:1 compression smog motor...lol.

If it was me http://www.nastyz28.com/ubb/smile.gif....I'd change cams (go a little bigger into the 530 lift range) and get heavier springs. That is...to max out everything.

Otherwise....hell....you'll chirp the tires as soon as the clutch is out and you touch the gas http://www.nastyz28.com/ubb/wink.gif You've got more than enough Tq to change to a 3.42 to 3.08 rear since you have 6 gears to play with....

But this is just me http://www.nastyz28.com/ubb/wink.gif

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73 LT 454

http://www.cardomain.com/id/rscamaro73

One other quick tidbit as an FYI. Brodix specs a 140 closed 400 open, 1.950 installed height spring for hydraulic rollers.

[This message has been edited by Rick WI (edited February 25, 2005).]

Rick brings up a good point about the springs. If I had to take a guess from a thousand miles away I would say that you are trying to use a set of hydraulic flat tappet springs with a hydraulic roller cam. Perhaps you could let us know what valve springs you are using. Are they the exact ones recommended for the cam? Are they installed at the exact recommended installed height? ANYTIME you work the valvetrain harder the more critical it becomes to use the EXACT right springs at the EXACT right installed height.

Agreed, the Performer RPM intake would probably be a much better choice for that motor. If it's not worth an easy 10-15 ft/lbs everywhere in the RPM range I'd be surprised.

I'll lay another idea on you as well.... you've got a small cam, we know that. Maybe wishing you had gone bigger at this point, but it is what it is. What to do?? INSTALL IT 4* RETARDED! I checked out your cam specs and it's Comp Xtreme Energy 270 hydraulic roller (grind 11-422-8), right?

If so, that cam's got 4* advance ground into it already (106* intake centerline on a 110* lobe sep angle). All you'd really be doing by retarding it is bringing it back to true "stright up" (110* ICL on the same 110* LSA). What you would trade away on the bottom end would be almost nothing, and even if you gave up a few ft/lbs below 3000 would you really miss it?? What you'd gain on the top would probably be another easy 10-15 ft/lbs and raise the useable RPM range of the combo by about 300 RPMs. ALL WITHOUT WORKING THE VAVLETRAIN ANY HARDER THAN IT IS NOW!

BTW- I think that motor is a MONSTER. You're already making over 1 HP/ci with a small cam, small intake and ZERO tuning. I bet with a better intake and some other tweaks you can be pushing dangerously close to 500.

What about stepping up the rocker ratio as well ?

You could certainly do that, if the springs could take it. Another FYI, those heads flow over 340 cfm above .550. Room to grow in the future.

The higher ratio rockers would exacerabte the valve float problems as it is also snapping the valves open and shut at a faster rate, right?

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1973 RS Z28: Littlefield race series 6-71 supercharger on a 355 w/ AFR 195 heads, 10-12 lbs boost, 7.6:1 static compression, CompCams hydraulic roller (276/288 advertised, 224/236 @.050 duration, .510/.530 lift w/ 1.52 rockers on a 113 lobe separation), AFR Hydra-Rev kit, Eagle 4340 Forged Steel crankshaft, ARP studded bottom end, Eagle ESP H-beam rods, TRW forged reverse dome pistons, Comp Pro-Magnum 1.52 roller rockers with 7/16 studs, twin 750 Edelbrock carbs, 1&3/4 inch Hooker Super Comps, 3" dual exhaust with cross over pipe. MSD 6AL ignition & Pro-billet distributor, Tremec TKO-500 5-speed, Moser 12 bolt with Eaton posi, 33 spline axles & 3.42 gears.

That's correct.

Just found out something interesting while browsing through the Comp Cams catalog.

Turns out they offer two types of hydraulic roller lifters: "high energy" and "pro magnum". Quoting from the catalog:

"Pro Magnum hydraulic roller lifters are specifically designed to perform at higher engine speeds."

Chances are the less capable lifters are in the engine now. I hope so, should be an easy fix if that is the case. I'll find out Monday morning.

In all of my research that is just hype.
One company makes all of the hyd roller lifters

TTT http://www.nastyz28.com/ubb/smile.gif

Damn!! 572 lbs. of torque at 2400 rpm? (Are you sure that's right?) That combo sounds perfect for the street. It probably will have good vacuum and decent mileage too. You probably won't rev over 5000 rpm on the street very often, but you'll feel that 500+ lbs. of torque every time you leave a stop light.

I was thinking about going with the Performer RPM cam/heads/intake/carb combo, but I just might just go with this combo instead!

And for those occasional 5,000+ rpm runs, just give it a shot of nitrous!

Update:

We added a once spacer to the Perfomer intake and played with the jetting and timing some and got to 487 peak horsepower. Changing the intake to an RPM, upping the carb size to 870 cfm and running synthetic oil instead of the old school stuff would probably nudge it to 500hp, but that will remain unknown because we are done. I don't recall the new peak torque figures and I left the dyno sheet with the engine at the shop. I will post up the final results after I go pick up the engine.

It will probably end up with aftermarket fuel injection anyway, so I didn't feel the need to get an RPM intake just for a cheap thrill on the dyno(well, not so cheap not that I think about it).



[This message has been edited by MikeM79 (edited March 15, 2005).]

Plenty of power to keep you occupied, for a month or two!