My engine builder is taking my 548 back to the dyno tomorrow, he was not familar with this particular dyno. He was very unhappy with what the numbers showed him. Question. What kind of hp can a person expect out of a streetable, pump gas 548. It is a Merlin block, Brodix heads, Victor Jr, intake 950HP Holley carb, and I do not know the specs on the cam yet. Do not say "do a search". I can never ask the right questions to get a response like what I want. What do you boys think? Edd

My 540 dynoed 696 HP @ 6100, 690 TQ @ 4900 on pump gas...Merlin III block, Dart Pro I 325 heads, UDHarold designed mild solid roller.

It really depends on what compression, heads and cam you have, but i would say at least. 550Hp

Originally posted by BillsCamino:
My 540 dynoed 696 HP @ 6100, 690 TQ @ 4300 on pump gas...Merlin III block, Dart Pro I 325 heads, UDHarold designed mild solid roller. 690 TQ @ 4900

My 540 dynoed 719 HP @6000, 671 TQ @ 5200 on Sunoco 94. Merlin II block, Dart fully ported oval ports, Crane solid roller

Undee70SS,
What are your cam specs?
Thanks.

Originally posted by undee70ss:
</font><blockquote>quote:</font><hr />Originally posted by BillsCamino:
My 540 dynoed 696 HP @ 6100, 690 TQ @ 4300 on pump gas...Merlin III block, Dart Pro I 325 heads, UDHarold designed mild solid roller. 690 TQ @ 4900 </font>[/QUOTE]You're right...sorry for the typo! graemlins/clonk.gif
How'd you know??

So what numbers did he come up with??

Way too many unanswered questions that will skew the numbers.

Which Brodix heads? CNC? Ported?

Pump gas...but what compression?

Gotta know something about cam. Streetable is a relative term. Flat tappet? Solid roller? Hyd roller?

Carb spacers?

Headers?

Water pump belt driven or not?

Not trying to be picky, but I could tell you anything from 500-800+ and still be accurate without more input.

My 540 with Merlin block has had two configurations. 10.4 compression, out of the box Brodix 2Xtras (non CNC), 262/273 solid roller on a 112 LSA with .675.672 lift, and ancient Team G (small plenum) and a 1050 Dominator. Using 2 1/8" headers and a belt driven water pump it made 732hp and 678 ft lbs at 6200 and 4900 rpm respectively. Killer street motor with unreal midrange, but poor above 6500 rpm. This version made 565 RWHP capped up with Flowmasters and 615 RWHP uncapped.

Second version has same shortblock, fully ported heads, a Super Victor, same carb and a new cam. 272/278 on a 110 with .731/.731 lift. It made 825hp and 676 ft lbs at 7400 and 5300 rpm respectively. Definitely an RPM lover but lost bunches of mid range. Actually good because it helps car hook. This testing was done with 3 different sets of headers, a 1" spacer and an electric water pump. The worst case had it making 778 hp with 2" headers, no spacer to give you an idea. The 2" headers were actually much better up to 6000 rpm. Then they killed 50+ hp by 7000 rpm.
Never did chassis dyno it..just engine dyno on a Superflow.

Since then I've tried a flat tappet cam in it.A Crane .600/.620 lift 266/276 on a 110 LSA. Ran well but of course is down on that killer power of the roller. But not bad..still an awful fun reliable motor without solid roller headaches.

I just stuck in a 266/273 roller on a 112 LSA with .712/.731 lift this last weekend. No track times yet, but buttometer tests are good. I'll let you know how it turns out.


A buddy of mine has one with ported Brodix -2's, ported Holley Strip Dominator, a 250'ish solid roller with .670 or so lift. He made almost identical power to my version one using a 1020 cfm 4150 carb. He recently bored it to a 548, added a 266/272 cam on a 112 and CNC AFR 335's. We'll get chassis dyno numbers this weekend.

Another buddy has one that was built mild for literally daily driving. It used 9.0 compression, slightly ported GM/Edelbrock rectangular ports, an LS-6 dual plane and a 232/236 hyd roller. It was making just over 400 rwhp with 1 7/8" headers. He added a ported Holley Strip Dominator and picked up 30 RWHP. He then replaced 850 DP with a 1000 HP and picked up 16 more without affecting driveability. He then pulled heads and had them profesionally ported along with a cam change to a 245/250 on a 110 LSA. He made right at 500 RWHP. He is currently replacing heads with a set of CNC 357 AFR's (planning on a 632" later!) and installing some 2" headers. This should raise HP significantly. Numbers to come.

Anyway, as you can see there are some vastly different numbers based on the combos. All of these run on pump gas and have made 2000 mile cross country trips with no issues. Different degrees of streetability of course, but they all drive regularly on the street.

Let us know what you've come up with so far and what he gets the next time.


JIM

Originally posted by BillsCamino:
You're right...sorry for the typo! graemlins/clonk.gif
How'd you know?? Have your dyno sheet that you once posted saved on my computer.

Originally posted by Doug F.:
Undee70SS,
What are your cam specs?
Thanks. Crane cust solid rollor .695 lift 272@.050 112LSA installed at 104.25 ICL

Edd, It looks like 675+ for horsepower, Jim's right, the cam, heads and compression are needed to make a good guess.

Well boys, here is some more info that I did not have at the time of the original post. Merlin III block Brodix Weld Tech BB1 Comp Cam hyd roller with 646 lift and 254 duration, I do not know the compresion. This test he used a 1050 Dominator and you boys were just about right on the money.720 hp @6000 and 657 lbs of tourque @ 4900. This is with Quick Trip 91 octane gas. All conditions were not perfect there might be a little left, but I am well pleased. I enjoyed reading the posts. Thanks for the response. Edd

May I suggest asking the builder to give you your CAM CARD!!

Then come back here and tell us what it says and I am sure somebody will know what you have and how it should generally run even if we don't know everything about your combination!!!

pdq67

PS., and if he doesn't have a cam card that you paid good money for if he bought your cam for you, then I would ask him to ask the cam supplier for one AND then get another Motor Man!!!

He has the card and offered it to me when I left but I was in a hurry. He has a computor sheet with head flow, and the details on every part he used. I pick it upp on Tuesday.

Edd, I too would recommend getting the cam card. More for future reference than anything and the headflow sheet. Can't have too much information. It sounds like he did a pretty fair job on the engine. Give us strip junkies more updates when you get to run it at the strip. Sounds like mid to low 10s in a average weight Chevelle. Good luck.

540Hotrod...can you post some of your time slips along with the changes made?.
That would help alot, thanks

Check and see if you can't build a standard height block, 588"er for about the same money as a 540"er??

4.625" b x 4.375" s...

Just use 6.4" or slightly longer custom rods to help hold cylinder wall side-loading down is all...

You know, the bigger, the easier to make power is all.....

pdq67

Originally posted by 540Hotrod:
A buddy of mine has one with ported Brodix -2's, ported Holley Strip Dominator, a 250'ish solid roller with .670 or so lift. He made almost identical power to my version one using a 1020 cfm 4150 carb. He recently bored it to a 548, added a 266/272 cam on a 112 and CNC AFR 335's. We'll get chassis dyno numbers this weekend. I'm the buddy Jim referred to. Just back from the chassis dyno and made 676 RWHP @ 6400 and 612 RWT @ 5200 on pump gas. These new AFR heads are all they're made out to be!

Mark

676 RWHP!!! :eek: :eek: Thats insane power to the wheels on pump gas out of "just" 548 ci.

Originally posted by -SS454-:
676 RWHP!!! :eek: :eek: Thats insane power to the wheels on pump gas out of "just" 548 ci. It does merge well into traffic...

ML67, What kind of tranny does it have?

Originally posted by Harold Sutton:
ML67, What kind of tranny does it have? Harold, it has a G-Force prepared Richmond Gear road race 5-speed. This is the synchro version -- not a crash box. And its in a stock appearing 67 Corvette coupe.

Traction is &lt;ahem&gt; challenged as I can only fit 255/60R15 Comp R1 road race radials. Needless to say, it doesn't launch very hard. But it does keep the IRS from fragging.

Take care,

Mark

ThatIS insane isn't it???

Mark has been working on this combo for several years now, and I believe this most current version is by far the best! No doubt the AFR CNC 335's are making some power. I can't get over the amount it makes at the rpm is does it at!

He'll be going to the track in a few weeks to get at least some MPH numbers...not sure about traction....he'll have to be working the pedals pretty well to get it moving!

I'll have some new track numbers next week. Hoping to do much better than my previous mid 10's@133. Had lots of issues that day....hopefully they are all in line now.

New cam with lower power band, new trans I can actually shift under power with new gear ratios to get it in the powerband, new taller slicks, new headers, new ignition......

My luck none of it will help....but I'm going to try!


JIM

Originally posted by 540Hotrod:
ThatIS insane isn't it???

I'll have some new track numbers next week. Hoping to do much better than my previous mid 10's@133. Had lots of issues that day....hopefully they are all in line now.

New cam with lower power band, new trans I can actually shift under power with new gear ratios to get it in the powerband, new taller slicks, new headers, new ignition......

My luck none of it will help....but I'm going to try!

JIM Talk about insane -- you're making more power than me and in a convertible to boot! As long as you don't break anything (and you've beefed the whole driveline) I'm guessing you're good for low 10's and maybe even a 9 at high 130's. Wouldn't it be great if you hit the trifecta: run a 9, break 140 and win!

Looking forward to seeing you run next week.

Take care,

Mark

Looks like the vette guys are taking this place over ;)

I have watched the transition of Jim and Mark's cars over on the Vette forum for three years. Ya gotta admit 800+ hp 540's in stock looking stick shifted 67 vettes is very cool.

Makes me wish mine was done. Hopefully by March

Not sure if weather will cooperate..it's pretty warm here still....but hey it will be fun trying!

Now talk about crazy...when you get that beast of yours done John.....I wanna go for a ride! With ALL the N20 going!

Mine and Marks are just little pump gas cruisers...yours is just going to be sick!

JIM

All Big Block Chevy stuff is great, no matter which platform you choose. My son's going to up the bar a little more Jim. He put a nitrous converter in his Chevelle and started spraying it lightly a while back. Going 8s soon. Keep us posted on your progress, Jim & Mark. (How about 9.22 @ 147, lifting, to control tire spin). (888 RWHP with a little juice).

Originally posted by Harold Sutton:
All Big Block Chevy stuff is great, no matter which platform you choose. That is the truth! Your son's car is a beast. BTW I made the choice for Borla XR-1 mufflers based on feedback from both you and my head porter, Bernard Mondello. Great choice -- they're loud but have a deep basso profundo sound that reeks of power w/o being obnoxious.

And John, your just raising the bar to an entirely different level. What is your guesstimate from completion?

Take care,

Mark

Not to steal a thread. graemlins/beers.gif

The backhalf has been delivered. We think we will get a 15x33 in. tire under the car. I am going to order some 13.5 to 1 pistons for the 454, after I cc the heads. I plan on running the 454 with upwards of 350 hp through the Fogger and or plate or maybe a staged system. We will see how the traction issue goes. It would be nice to give it all the NOS right off the transbrake. Should be good for right at 1000-1050hp. I am still collecting parts for the 572. I want to run the 454 for at least a year to cut down on the chances of an expensive mistake with the 572.

Going with a full aluminum (anodized black) interior (with Z06 seats smile.gif ) The goal is to get the car down to around 2600 lbs. I hope to have the car at the track with the 454 by March.

Going to run the cam I bought from you in the 454. Other than maybe a little small on the exhaust side for a 350 shot, it sure was a good cam for the 454. Last thing is I decided to run aluminum rods in both motors.