Great thread!

We have lots of the same goals, except I think you are hoping for more power than I am. I think with the rpm limitations, HP will be no higher than ~425 at the rear tires.

But I've got the same parameters:
-10.xx:1 CR so I can run 93 octane
-2000-6000rpm rev-range

I assume you are getting a cowl induction hood of some sort to accomodate a hi-rise intake?

Everyone says oval ports are better below 6k rpms, and I'm sure you guys are right, but find me a decent intake manifold that will support flow to this type of rpm/HP level (looking for ~475-500flywheel @ 5800rpm) that will FIT under a stock '69 BB hood. :) Torker II? It's ok, but its a single-plane manifold...obviously better for high-end breathing, and more rpm than I'm really looking for.

My LS6 rect. port intake is a good one (according to knowledgeable guys like Chuck H), but then I obviously can't run an oval port head and optimize the combo. Several have suggested this can be done by working the intake port on the head to match to the rect. port intake, but another made a good point about losing port velocity by opening it up.

<---pulling my hair out. If its not one thing, its another.

I guess the _easiest_ thing to do is buy an aftermarket L88 hood, get some NON-raised exhaust port oval heads (Edels would work well, I think) and something that 69NOXRatt suggested like an Air-Gap intake.

To me, none of this stuff should be rocket-science, but I've been a bit frustrated with the limitations I've run into. Seems that you either go radical and make insane power, or you leave it pretty tame like mine is now.

 

I was thinking something like the Crane Powermax roller, 288*/296* duration and .587"/.610" lift :cheers:

 

110 LSA ?

 

For an intake, Edelbrock has a Performer RPM and RPM air-gap, both with oval or recatngle ports. But they only list them for 396-454ci, the air-gap just says BBC, no ci :confused:

 

Thisnis what I used:

427
oval port heads 2.19/1.90
dual plane
850cfm carb
10:5:1
large tube headers w/ mufflers
roller cam 288/296 .587/.610

.........HP / TQ

2000... 160 / 420
2500... 212 / 446
3000... 256 / 449
3500... 314 / 471
4000... 374 / 491
4500... 433 / 505
5000... 478 / 502
5500... 507 / 484
6000... 518 / 453
6500... 514 / 415

Keep in mind this is a stock head, just by pocket porting your peak # numbers would increase to: 554hp@ 6,000rpms and 521tq at 5,000rpms.

Let me know if I need to adjust for anything.

:cheers:

 

A big block intake is a big block intake they will fit them all.

396-540ci

 

Thanks Corey :cool: . I just went to the Edelbrock website, and I think a pair of oval-port Performer RPM's and a Performer RPM intake will do the job. I was 99% sure all big block intakes worked for all big blocks but Jeg's only had it listed to 454. The Edelbrock site says 396-502ci
If you could run it with the these Edelbrock's and use 496ci, and AFR 305's w/496ci I'd appreciate it:cheers:


[Modified by Ryan77, 4:14 PM 3/15/2003]


[Modified by Ryan77, 4:17 PM 3/15/2003]

 

Sure, I just need the air flow for each head.

Also, this is some good info on BB dyno numbers and cam choices.
http://www.72chevelle.com/lashword.htm

:cheers:


[Modified by Corey 68, 3:41 PM 3/15/2003]

 

The Edelbrock are 295cc intake runners, 118cc exhaust port, 112cc chamber volume, and 2.25"/1.90" valves.
The AFR's are rectangle ports but here's the #'s anyway, 305cc intake, 119cc chambers, and 2.25"/1.88" valves, but I can't find the exhaust port size

If you could run it with 427ci, 454ci, and 496ci that would be great.

Thanks :yesnod: :yesnod: :yesnod: :cheers:


[Modified by Ryan77, 5:00 PM 3/15/2003]

 

Ok but I also need the flow rate at
.200
.300
.400
.500
.600

 

AFR:

0.200 159/135
0.300 231/169
0.400 292/219
0.500 333/249
0.600 358/272
0.700 363/285
0.800 364/290

Edelborck #60459

0.100 74/71
0.200 143/128
0.300 207/153
0.400 250/178
0.500 284/200
0.600 309/218

:lurk:

 

Thanks 69stingray :cheers:

 

Ryan77, I would save your money on Aluminum Heads and have a set of Factory Oval ports worked over. I'm running the original Oval port heads on my 71 Ls5 (with work done to them of course) I just pulled 450 RWHP and 492RWTQ last week. So you can make good power with Factory Iron oval heads. It's all about getting the right combination of parts. Good luck.

 

Chuck:
I totally agree. That is why I only go racing on Tuesdays and Thursday (test & tune sessions). There is no head start like in bracket racing, there's no worrying about running faster than your dialed time...it's "run what ya brung" :) .

Ryan:
I agree with what Chuck has said. My motor is putting out around 475-500 horsepower at the flywheel. Traction is miserable at best on street tires. I have since switched to ET Streets. The problem you run into when you start reaching radical horsepower and torque levels is putting it to the ground. When you try to put that power to use (i.e. slicks) stuff starts breaking (it's not a matter of if, it's a matter of when). I know this and still put the slicks on my car today. I'm prepared for stuff to start breaking.

If you are going to be running Hooker Side Pipes, raised exhaust ports create a problem. To my knowledge the best flowing aftermarket head with standard exhaust port location is the Edelbrock Victor Jr. CNC ported. I believe that Dart, AFR, Merlin and Canfields all use raised exhaust ports. So as you can see your head choices are limited if you are running Hooker Side Pipes. The side pipes can be modified to fit raised exhaust port heads, this entails cutting, lengthening and welding the primaries.

Cory:
You are so right. I have stock style pullies and have thrown a belt or two in my day. :)

WA 2 FST:
I really don't care for the Torker II intake, I have the right to say this because I experimented with it (I wanted to use the stock hood). The Torker II reminds me more of a dual plane then a single plane (even though it is a single plane). It really did have nice bottomend grunt. The reason was because of the port design. The ports are 2 different sizes on the Torker II. This helps with port velocity and works kind of like a tune port. All in all just by switching to my Strip Dominator intake and changing nothing else I gained .5 tenths and 5 MPH down the 1/4 mile. It's a decent intake if hood clearance is an issue, but it will choke the motor some.

 

I'm running a stock hood so I pulled the performer RPM manifold off my new 454 and am putting on a polished Torker 2.

I will sell the big block Performer RPM manifold, in very nice shape, for half of what it goes for in Summit.

 

Other interesting notes:

Between 0.200-0.600, Edelbrock heads breath 0.82 CFM/cc (average) and AFR breath 0.899 CFM/cc (average). Very close.

In regards to Intake/Exhaust Ratio, between 0.200-0.600, Edelborck averages 76% I/E Ratio, while AFR averages 77% I/E ratio. BUT, if you take between 0.300-0.600, the ratios become 71% Edelbrock and 75% for AFR.

 

Ok the same engine I ran above but changed to the edelbrock heads:
peak numbers are: 548hp @ 6,500rpms and 517tq @ 5,000

The same engine but with 454ci made: 552hp@ 6,000 and 541tq@4,5000

And with 496ci: 555hp@ 5,500 and 577tq@ 4,5000 (w/ tq 500+ at 2,000rpms :eek: Fun, yet serious traction problems)

Now the 427 w/ AFR heads: 578hp@ 6,500 and 529tq@ 5,000

454: 588hp@ 6,000 and 577tq@ 4,500

496ci: 593hp@ 6,000 and 592tq @ 4,500rpms.

I was really impressed w/ the AFR but they ver very pricey and I can't use them w/ my side mount headers.

:cheers:

 

Thanks Corey :yesnod: :yesnod: :thumbs:

I too am really impressed with the AFR heads on the 496ci, 593hp@6,000 and 592tq@4,500 :eek:
I will definately be going with a 496ci, I found the rotating assembly that I want at SDPC. The AFR heads will be pricey ($1,000 more than the Edelbrocks) but you get what you pay for :eek: .

I still have a few more questions though. I will be using roller rockers, should I go with the 1.7 or 1.8 ratio? For the exhaust, what are you guys running? I currently have Hedman headers, 2.5" pipe, X-pipe, and Flowmaster 40's, but I know this will not be adequate for a 496ci. I plan on using Hooker headers either way, but, should I try and squezze 3" pipe under the car, or buy the sidepipes and modify the headers to fit?

 

IMHO, (and this is not from BB experience, but just engine experience in general), I'd run whatever rocker the cam is designed for. Since you're building the engine from scratch, you can design the cam any way you want, so I'd run a 1.7 rocker. Less potential for coil-bind, etc.

I would not mess with 3" pipe under the car. It will offer much less clearance. Get the sidepipes and modify them. I would be interested in who can do this effectively and not butcher them, so they still fit right as they exit to the side.

The AFR heads do look really good, but I can tell you that there is no way a stock set of side-mounted Hookers will work with the raised exhaust ports. :(

 

Well a 3in exhaust will have to be shoe horned in, plus you will have clearance issues. The best exhaust system as for as performance and clearance is the hooker sidemounts. BUT with the hookers you are limited on head choice because most have raise exhaust ports which will NOT work w/ the headers. So if you want aluminum heads AND side mounts you will have to either get the GM aluminum heads or the Edelbrocks.

:cheers: