compression

Old 01-10-2012, 07:35 AM
  #11  
bear4333
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The heads were cnc'd by a steve schmidt program. Not sure of the flow rate.
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Old 01-11-2012, 04:11 PM
  #12  
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Lessee, the question was about compression ratios with a BBC . . Then I added more to the same question . .

Is there anyone looking at this that has a clue? Not being a wiseass, but there is no such thing as "More heads" . . it's what you do to the heads and the corresponding valve train that improves your E.T.s . . Also compression has a hell of a lot to do with both 60' time and top end MPH . .

Currently, math and competiton tells us we're building somewhere between 650 to 690 HP. At this point, the heads are fine, but we're putting together a "Back up Bullet" which is the reason for the query . . We would like to know what the compression ratio should be ideally for a high altitude engine that can be taken to near sea level without changing pistons or heads . . and without beating hell out of it on top end . .

I'm a novice on Chevy Truck motors, although back aways I tuned and was crew chief to several Blown Alky cars . . Just never screwed with anything with doors or a carburetor on it . . Just thought some old hands that know some of the short answers might have something for us . .

Guess not . . .
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Old 01-11-2012, 04:20 PM
  #13  
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Originally Posted by roadkill2
Lessee, the question was about compression ratios with a BBC . . Then I added more to the same question . .

Is there anyone looking at this that has a clue? Not being a wiseass, but there is no such thing as "More heads" . . it's what you do to the heads and the corresponding valve train that improves your E.T.s . . Also compression has a hell of a lot to do with both 60' time and top end MPH . .

Currently, math and competiton tells us we're building somewhere between 650 to 690 HP. At this point, the heads are fine, but we're putting together a "Back up Bullet" which is the reason for the query . . We would like to know what the compression ratio should be ideally for a high altitude engine that can be taken to near sea level without changing pistons or heads . . and without beating hell out of it on top end . .

I'm a novice on Chevy Truck motors, although back aways I tuned and was crew chief to several Blown Alky cars . . Just never screwed with anything with doors or a carburetor on it . . Just thought some old hands that know some of the short answers might have something for us . .

Guess not . . .
Yep, guess not. You seem to have all the answers. What do you need from any of us? :roll:

Good luck on your backup "Bullet"

More head would be a head that flows more. :shock:

If you're not even going to make 700hp with a 632, why not just run it on pump gas? Just curious. I'm sure I'm not the only one wondering that.
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Old 01-12-2012, 04:54 AM
  #14  
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I asked what I thought was a simple question for someone with experience on a 632 cubic in motor. I currently run a 496 and am looking to upgrade to a 632. I assumed I could get some advice here, but only got aswers about the heads I have. I realy don't get the sarcasm about making 700 hp with a 496 at 5000 ft.
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Old 01-12-2012, 05:21 AM
  #15  
TS1955
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Originally Posted by BEAST477
Originally Posted by roadkill2
Lessee, the question was about compression ratios with a BBC . . Then I added more to the same question . .

Is there anyone looking at this that has a clue? Not being a wiseass, but there is no such thing as "More heads" . . it's what you do to the heads and the corresponding valve train that improves your E.T.s . . Also compression has a hell of a lot to do with both 60' time and top end MPH . .

Currently, math and competiton tells us we're building somewhere between 650 to 690 HP. At this point, the heads are fine, but we're putting together a "Back up Bullet" which is the reason for the query . . We would like to know what the compression ratio should be ideally for a high altitude engine that can be taken to near sea level without changing pistons or heads . . and without beating hell out of it on top end . .

I'm a novice on Chevy Truck motors, although back aways I tuned and was crew chief to several Blown Alky cars . . Just never screwed with anything with doors or a carburetor on it . . Just thought some old hands that know some of the short answers might have something for us . .

Guess not . . .
Yep, guess not. You seem to have all the answers. What do you need from any of us? :roll:

Good luck on your backup "Bullet"

More head would be a head that flows more. :shock:

If you're not even going to make 700hp with a 632, why not just run it on pump gas? Just curious. I'm sure I'm not the only one wondering that.
X2....You try and give people advise to make thier set-up more efficient and optimize horsepower, ( and some appreciate the advise ) but others don't want to hear that it could be better.

TS1955
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Old 01-12-2012, 06:07 AM
  #16  
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Originally Posted by bear4333
I asked what I thought was a simple question for someone with experience on a 632 cubic in motor. I currently run a 496 and am looking to upgrade to a 632. I assumed I could get some advice here, but only got aswers about the heads I have. I realy don't get the sarcasm about making 700 hp with a 496 at 5000 ft.
Send us an e-mail [email protected]

We will be more than happy to answer any question you have about building the 632.

We have built 4 in the last 6 weeks for customers.
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Old 01-12-2012, 09:06 AM
  #17  
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Originally Posted by BEAST477

Yep, guess not. You seem to have all the answers. What do you need from any of us? :roll:

Good luck on your backup "Bullet"

More head would be a head that flows more. :shock:

If you're not even going to make 700hp with a 632, why not just run it on pump gas? Just curious. I'm sure I'm not the only one wondering that.
Lessee, What the initial question concerned was "Were Bear to buy a 632 BBC, what compression ratio would be a good one for high altitude racing?"

Answer, 14 to 15 . . Then I asked for more particulars concerning the same issue.

I never said we had or were using a 632, nor did I bring up any HP facts . . I did note that "More Head(s)" weren't an answer because there's no such thing. What you do (or might do) to a head might be a factual answer, but more head is just a pornographic request . . While it might be a good idea, it won't make you go any faster . . In the second post, I did mention an estimated HP figure(s) from the current engine we are racing, but never connected that to any 632 statements, nor did I give the CI . . Thus, any answer to that specifically, would have been less than a partial answer (had one been given) because you didn't have enough facts to build on . .

Apparently my critic is better at jumping to conclusions than giving specific and factual advice or answers . .

As I said, I've done this before, but not with the engines, tuning or modifications that a BBC responds to or likes . . I don't have all the answers but apparently enough to understand that specific heads and the way you use them require more than grabbing a roto rooter and making them "Bigger" . . Flow is very dependent upon the combustion chamber size, RPM range you intend to operate in and Valve sizes, duration etc . . Thus, "More head" is like saying "More Gear" or More Driver" . . Exactly "How much More" becomes the question . . and specifics becomes the answer . . :roll:

And thanks, CNC for your specific answers . . . They're appreciated.
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Old 01-12-2012, 04:02 PM
  #18  
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Nowhere was anything mentioned about a 496BBC making the 700hp.

Sorry for the misunderstanding. I'm done.
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Old 01-12-2012, 04:16 PM
  #19  
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Default Re: compression

Originally Posted by bear4333
what's the best compession ratio for a bbc 632 that would make the best power? I'm looking to purchase a short block, my heads are dart 360 cnc.
I swear that says 632bbc dart 360s :wink: followed up with
Currently, math and competiton tells us we're building somewhere between 650 to 690 HP
:P

Back to the questions on compression 15.5 on gas and 114 octane isnt enough... if alky 14.5 is enough. The dart 360s will be a major hold back unless you get one of the TPS guys to work on them.
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Old 01-13-2012, 06:12 AM
  #20  
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Thanks Guys, we're just trying to see what our options are before getting froggy and buying this coming year's backup short block, which, will end up being next year's Bullet if all goes well this coming season . . As I said, I'm not closely familiar with Big Inch BBCs and the Boss was just getting his feet wet this last year . . We ask questions because we want the shortest learning curve available and it's a hell of a lot easier (and cheaper) to get answers from those of you who might have them, than to learn them the hard way . .

Not that we're lost, as we've been in the money twice last year . . We just wanna do it as easily as possible . . Hell, I'm an old guy, I'm tired of climbing mountains and fighting thunderstorms . . There's a bunch of know how here and I'd love to share what I've learned about other classes of drag racing with guys who're successful in the brackets . .

Bracket racing is a whole hell of a lot different than either heads up or index racing . . But most of you know that . .

On the Headwork, they've been massaged by Steve Schmidt (former Pro Stocker and engine builder) and are all CNC . . At this point the heads aren't close to their potential, I believe, as we've had other glitches. Those, as far as we can tell, have been cured and we're just waiting to get the car to a race and see what the results on the present setup will be . .

Thanx again to both CNCMotorsport and Hammertime . . serious discussion with factual info . .
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