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Discussion Starter · #1 · (Edited)
A few months back I built a 454 with the help of my dad to put in my 55 sedan. It is a 4 bolt block that has .030 over Speed Pro hypereutectic pistons with .100 dome and a stock cast crank. It has an Edelbrock RPM intake and a Holley 4150-850 cfm carburator. The heads are stock GM 781 castings. The headers are Heddman 1 7/8 full length. The cam is a hydraulic flat tappet Comp Cams XE268 with .515/.520 lift. It has Comp Cams 1.72 roller tip rockers. After the initial break-in and adjustments I noticed this cam just don't seem to talk to ya, if you know what I mean. I just thought it would have a little more bump to it. I have not been able to drive it yet due to other things not completed yet. What kind of performance will I get from this cam with the aforementioned combination of parts? The car also has a stock 8.5 from a Trans Am with 3.08 gears and a Saginaw 4 speed.
 

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Discussion Starter · #2 · (Edited)
A few months back I built a 454 with the help of my dad to put in my 55 sedan. It is a 4 bolt block that has .030 over Speed Pro hypereutectic pistons with .100 dome and a stock cast crank. It has an Edelbrock RPM intake and a Holley 4150-850 cfm carburator. The heads are stock GM 781 castings. The headers are Heddman 1 7/8 full length. The cam is a hydraulic flat tappet Comp Cams XE268 with .515/.520 lift. It has Comp Cams 1.72 roller tip rockers. After the initial break-in and adjustments I noticed this cam just don't seem to talk to ya, if you know what I mean. I just thought it would have a little more bump to it. I have not been able to drive it yet due to other things not completed yet. What kind of performance will I get from this cam with the aforementioned combination of parts? The car also has a stock 8.5 from a Trans Am with 3.08 gears and a Saginaw 4 speed.
Please save all the negative comments about my weak tranny that I'm going to break and my itty bitty valves on my heads or my tall gears needs to be lower. Believe me if my pockets were deep all that would have been changed too. I used what I already had or picked up cheap. I know we have all been there. Thanks all, Dearl.
 

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With that kind of reasonable build, you'll probably want an XE grind in the 270-278 adv. duration to give you a little bump. That won't out do the performer manifold by much. Your combo should be good for 400 hp and 450 torque, maybe a tad more and a moderate cam change won't do much to that, but you might enjoy it more, especially since it's a manual trans. Be careful about changing cams to more than .550 lift, unless you measured the valve to piston clearance you have now during the build so you can do the math. I'm kind of a fan of the Thumper line of cams for what it seems you want, but I'll probably get some grief for saying it.
 

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1956 chevy 210 del rey sedan
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your combo sounds great to me, should be a real respectable ride. i believe advancing the cam a couple of degrees would help with the rat a tat you are looking for. will also help it build a little more cylinder pressure.
 

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A few months back I built a 454 with the help of my dad to put in my 55 sedan. It is a 4 bolt block that has .030 over Keith Black hypereutectic pistons with .100 dome and a stock cast crank. It has an Edelbrock RPM intake and a Holley 4150-850 cfm carburator. The heads are stock GM 781 castings. The headers are Heddman 1 7/8 full length. The cam is a hydraulic flat tappet Comp Cams XE268 with .515/.520 lift. It has Comp Cams 1.72 roller tip rockers. After the initial break-in and adjustments I noticed this cam just don't seem to talk to ya, if you know what I mean. I just thought it would have a little more bump to it. I have not been able to drive it yet due to other things not completed yet. What kind of performance will I get from this cam with the aforementioned combination of parts? The car also has a stock 8.5 from a Trans Am with 3.08 gears and a Saginaw 4 speed.
I have the same cam and pretty much the same setup. Same heads but I have forged .100 dome pistons. Otherwise pretty much identical. It was a great match for the cam, heads, pistons, intake. I am running a 750 CFM Quick fuel carb on it. Found it to be the best I tested. I am getting 453 horse and 490 lbs/ft of torque.. I also experienced a smooth idle and wanted a bit more lope but decided to stay with it because the engine is a monster. Fast and very reliable. Here is a video of it running. This is when i still had the demon on it.

http://www.youtube.com/watch?v=Ye9rUGFPKcQ

Here is another driving it but I didnt get on it at all because I was holding a camera

http://www.youtube.com/watch?v=07lZgCi5xJs

I should mention this is a built up 700r4 with 355 gears.
 

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I think your setup is great, especially with the 3.08 rear, That will get you 60 mile per hour at only about 1850 rpm.

Make us a video of you driving, don't break the speed limit like I did ( That's Wrong ) :) :auto14:

It's great to have another big block guy.

Otis :)
 

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A few months back I built a 454 with the help of my dad to put in my 55 sedan. It is a 4 bolt block that has .030 over Keith Black hypereutectic pistons with .100 dome and a stock cast crank. It has an Edelbrock RPM intake and a Holley 4150-850 cfm carburator. The heads are stock GM 781 castings. The headers are Heddman 1 7/8 full length. The cam is a hydraulic flat tappet Comp Cams XE268 with .515/.520 lift. It has Comp Cams 1.72 roller tip rockers. After the initial break-in and adjustments I noticed this cam just don't seem to talk to ya, if you know what I mean. I just thought it would have a little more bump to it. I have not been able to drive it yet due to other things not completed yet. What kind of performance will I get from this cam with the aforementioned combination of parts? The car also has a stock 8.5 from a Trans Am with 3.08 gears and a Saginaw 4 speed.
To answer your question, a lot of TQ and on the street that makes for a great engine. To get that rumpity idle you'll need a bigger cam but that doesn't mean a better engine. I think that one is about perfect for a warmed up BB.
 

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Dennis as you know I have the very same setup in my 468 except i put the bigger valves in the 049 heads. What i was going for was good low end torque and crisp throttle response. I got both with this combination. It may not sound all that bad but you better be hangin on when i hit the go pedal. Many people over cam a motor for the sound but they don't run as well as a properly cammed engine.
 

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Discussion Starter · #11 ·
Thanks for all the replies. I'm sure it will run very well. It sure don't sound like my sb 350 did though. I've always heard that torque is king. In a few months I will find out.
 

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I think your setup is great, especially with the 3.08 rear, That will get you 60 mile per hour at only about 1850 rpm.

Make us a video of you driving, don't break the speed limit like I did ( That's Wrong ) :) :auto14:

It's great to have another big block guy.

Otis :)
I question your math my 72 Blazer, 72 Cheyanne, and 78 Vette all have 3.07 rear gears and turn about 1900 at 45 mph with 30x9.50s or 275/60/15s. Same goes for Dads 46 Chevy PU with 3.08s and 215/70/15s. All of the aforementioned units have TH-350s.
 
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