BBO vs BBC

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Oct 3, 2013 | 07:05 AM

#41

dfire25

"Trying to fix her right"

Joined: Oct 2012

Posts: 749

From: Bartlett IL

Quote:

Originally Posted by drjr56

dfire25 your car/engine look awesome good luck with it. As for power #'s you can look for combos here or on the other Olds forums and compare specs.Gives ya an idea where your at. It's another reason why builders posting accurate results helps...

Thanks! Like I said I would have loved to dyno it to post an actual number.

Oct 3, 2013 | 08:50 AM

#42

oldcutlass

Administrator

Joined: Oct 2009

Posts: 42,475

From: Poteau, Ok

You still can, all you need to do is find a chassis dyno and let her rip.

Jun 11, 2021 | 03:19 AM

#43

Amplitude

Registered User

Joined: Mar 2021

Posts: 59

From: Overland Park, KS

Quote:

Originally Posted by cutlassefi

I understand some of the comments, some I don't.
I'm doing these dyno sessions with different combinations with the blessing of the owners, and sometimes the cost for the additional time is out my own pocket. If any of you that posted less than stellar feedback want to do this then have at it. Dyno all the combos you want, but you'll have to pay for it.

As mentioned, if you want to then disregard the BBC reference and just compare the DX build with the iron headed 455. Similar carbs, same headers, same dyno on the same day, cam difference was only 3 degrees and .030 lift. But with 29 less cubic inches it made the same torque and 58 more Hp than the iron headed 455. Take it for what it's worth.

I completely understand and agree with the assessments you made. That's why my 67 400 BBO will be coming out of my 68 442 before I damage what is a good running engine. My 439 BBC with AFR 265 CNC Ovals, forged internals and custom hydraulic roller cam will be going in-between my frame rails. Hopefully it will also get a MPFI Terminator X or HP system at the same time.

Jun 11, 2021 | 04:43 AM

#44

VORTECPRO

Registered User

Joined: Aug 2012

Posts: 1,878

From: Thousand Oaks Ca

Quote:

Originally Posted by oldcutlass

I agree on the aluminum heads for an Olds, however the comparison is not apples to apples on your dyno test. I bet even with iron heads your BBC will show better numbers.

My 10.1 compression 467 BBC with ported production GM iron oval port heads and a 228 @ .050 hyd roller on a 111 LS with a Performer RPM intake, 15 inches of vacuum makes 600-605 verified HP @ 6200 RPM and 600 TQ @ 4200 RPM and will be over 600 HP for a 600 RPM spread. This type of engine runs 10.20s in my 3600 + pound Chevelle with a 800 RPM idle.

Last edited by VORTECPRO; Jun 21, 2021 at 06:20 AM.

Jun 11, 2021 | 12:42 PM

#45

70cutty

Beer Connoisseur

Joined: Aug 2008

Posts: 2,092

From: Daly City, California

Quote:

Originally Posted by Amplitude

You realize you revived this 8 year old thread just to talk about your439 Chevy.

That being said if I was to have a BBC engine built, I'd have Vortecpro build it.....just sayin.

Jun 11, 2021 | 01:29 PM

#46

Amplitude

Registered User

Joined: Mar 2021

Posts: 59

From: Overland Park, KS

Quote:

Originally Posted by 70cutty

You realize you revived this 8 year old thread just to talk about your439 Chevy.

That being said if I was to have a BBC engine built, I'd have Vortecpro build it.....just sayin.

I was somehow oblivious to how old the thread was. I think it just popped up in Related Topics and caught my attention.

I've already spoken with Vortech Pro a couple months ago. Waiting for him to get fully settled in his new location before I might just take it down there for a once over and a slight refresh.
We'll have to see, as there have been allot of unexpected costs come up with the car that have really eaten into my reserves.

Jun 12, 2021 | 06:55 AM

#47

Grayghost

Registered User

Joined: Jan 2021

Posts: 292

If the Aftermarket for example Edelbrook. cast the same heads in both Alum, and iron. same ports, same chamber, same valves, same eveything.

Iron will make more power every time.
Alum wins in it is lighter and easier to cast/machine (read cheaper).
heat rejection matters

Jun 12, 2021 | 04:19 PM

#48

cutlassefi

Thread Starter

Registered User

Joined: Nov 2008

Posts: 8,477

From: Central Fl

Quote:

Originally Posted by VORTECPRO

The Dyno I used back then was a 901. He always said it was “stingy”. I later realized in designing and building my own Dyno room that it wasn’t his Dyno that was the issue, it was the fact that his room was for shyt. You’d stink to high heaven after a day there. Carbon monoxide will kill power.

Last edited by cutlassefi; Jun 13, 2021 at 10:24 PM.

Jun 17, 2021 | 10:11 AM

#49

Amplitude

Registered User

Joined: Mar 2021

Posts: 59

From: Overland Park, KS

Quote:

Originally Posted by Grayghost

A few magazines have tested that over the years. But the most comprehensive test I've ever seen was done by David Freiburger in 2009.
Iron vs. Aluminum Heads

But then why did manufacturers switch to Aluminum?

It's lighter. So the car is lighter, performs better and in theory gets better MPG because of weight reductions all around. It is also cheaper to transport because it is lighter.
Aluminum has a much lower melting point, so it is cast at lower temperatures than cast iron, which in mass manufacturing means that they can be cast more quickly and using less energy.
Aluminum is much softer and thus easier, faster, and again cheaper to machine.

The aftermarket has adopted it for many of these same reasons. It means that smaller companies like Texas Speed, AFR, RHS among others don't need their own foundry. They can machine a complete cylinder head from a solid biller, or from a cast 60% complete blank manufactured to their specs.
Plus porting Aluminum is so much easier.

Last edited by Amplitude; Jun 17, 2021 at 10:17 AM.