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Old 07-20-2010, 02:35 PM   #16
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Default Re: BBC CAM SUGGESTIONS

With a bigger cam, more CR wouldn't hurt either. Have you actually measured your compression ratio or do you just have 12.5:1 pistons?
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Old 07-20-2010, 04:19 PM   #17
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Default Re: BBC CAM SUGGESTIONS

I have 12.5 to 1 pistons,. I did not do any actual measuring. No I did not degree the cam when I installed it.
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Old 07-21-2010, 01:20 AM   #18
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Default Re: BBC CAM SUGGESTIONS

Did you flow your heads? If not, you're throwing darts at a dart board and leaving plenty on the table with off the shelf stuff. I did a 12.4:1 467 quite e few yers ago with some Canfield 310's that honestly, I went backwards with on the flow, but with the flow numbers and build specs, I had Chris Straub spec a roller for it, and with a TR and pair of 1050's it made 821 @ 7100, 680 @ 5500, and had a very flat curve. Here's the kicker...the cam was 717/663 261/266. Not much of a cam for the power. No need to scream the engine to make good power.
If you want the most out of your combination, flow the heads and get the right cam.
JMO
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Old 07-21-2010, 07:09 AM   #19
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Default Re: BBC CAM SUGGESTIONS

Getting the heads flowed for true numbers and measuring for correct compression ratio may be the best place to start. Thanks
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Old 07-21-2010, 09:46 AM   #20
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Default Re: BBC CAM SUGGESTIONS

like scott said^^^^^^ it 's the ONLY WAY!! comp cams would be one of the last i called. theres intake valve timing, exh valve timing, lifter of the cam and profile i.e how fast the lift accelerates this is why no two cam will ever make the same power unless there form the same company ground the with the all same spec.
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Old 07-21-2010, 09:57 AM   #21
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Default Re: BBC CAM SUGGESTIONS

Here is what I would do;

1) Degree cam - VERY IMPORTANT
2) Measure ACTUAL compression ratio, you are probably lower than you think
3) Flow heads
4) Select proper cam for combination
5) Make sure torque convertor and axle ratio match accordingly
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Old 07-22-2010, 09:28 PM   #22
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Default Re: BBC CAM SUGGESTIONS

Quote:
Originally Posted by scott foxwell View Post
Did you flow your heads? If not, you're throwing darts at a dart board and leaving plenty on the table with off the shelf stuff. I did a 12.4:1 467 quite e few yers ago with some Canfield 310's that honestly, I went backwards with on the flow, but with the flow numbers and build specs, I had Chris Straub spec a roller for it, and with a TR and pair of 1050's it made 821 @ 7100, 680 @ 5500, and had a very flat curve. Here's the kicker...the cam was 717/663 261/266. Not much of a cam for the power. No need to scream the engine to make good power.
If you want the most out of your combination, flow the heads and get the right cam.
JMO

very good advise here,also many factory chevy bbc heads have flow issues past 700 lift thats what the backing up is that is talked about so just jaming in more lift as others have recommended is a big mistake without a flow bench first.
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Old 07-26-2010, 12:21 PM   #23
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Default Re: BBC CAM SUGGESTIONS

did you like the way the 270 -280 cam worked .... with a roller you can go bigger and still gain power through the entire power band..... I too agree go bigger and you will go faster.... at least 6-8 degrees.
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Old 07-27-2010, 08:06 AM   #24
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Default Re: BBC CAM SUGGESTIONS

Pulling the motor this coming weekend . Car ran excellent with the 270/280. I screwed up with the roller selection thinking the steeper lift angle made the valve full open quicker so not as much duration was needed. Thats why I didn't question Comp Cams online selection.
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Old 07-27-2010, 10:55 AM   #25
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Default Re: BBC CAM SUGGESTIONS

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Originally Posted by 69camaro View Post
I have 12.5 to 1 pistons,. I did not do any actual measuring. No I did not degree the cam when I installed it.
I really think you need to degree it. Some of these cams coming off the shelf are off more than 4 degrees depending on a bunch of factors. Just my 2 cents.

Rick
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Old 07-30-2010, 10:15 AM   #26
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Default Re: BBC CAM SUGGESTIONS

Intresting Thread , I too have a 3800+lbs car with a 454 with too big Dart Race Series 320's and a cam with less than .600 lift and 245-250* of duration. I know I do Have a Honest 12 to 1 comprerssion tho. I am looking at this winter going too a bigger roller and was recommended 274*/278* .435 .435 LL on a 108 and if there is room and Cash I want to go to a rocker shaft . I Have 28 inch tall tires and a 4.56 gear all I need is a new Convertor to match the rest of the set up
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Old 07-31-2010, 10:31 PM   #27
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Default Re: BBC CAM SUGGESTIONS

look into the Comp 11-702-9...its a great piece that is easy on valve springs..

271/282 with .680 lift on 110 LSA...

i will be on the dyno with this cam in about a week in a 522..i will let you know how it turns out...

there is also the old Crane standby, 274/284 with .737 int and i cant remember on exhaust...on 110..also easy on springs and makes great TQ and HP...IIRC #134751...

i personally would not go over 274 on intake...
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Old 08-03-2010, 09:23 AM   #28
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Default Re: BBC CAM SUGGESTIONS

Quote:
Originally Posted by TR Chassis View Post
I really think you need to degree it. Some of these cams coming off the shelf are off more than 4 degrees depending on a bunch of factors. Just my 2 cents.

Rick
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Old 08-19-2010, 02:35 PM   #29
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Default Re: BBC CAM SUGGESTIONS

Something I forgot to ask, I'm running 2, 08an lines from cell to y-block then to mallory 180gph pump then a single 1/2 fuel line to regulator on fire wall with (2) 06an lines to each bowl on a dominator,(1050) . I do not have it set up to return it dead heads at carb. Queastion is : is it better to have a return setup also is line size large enough for engine.
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Old 08-20-2010, 09:26 PM   #30
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Default Re: BBC CAM SUGGESTIONS

I think your cam is fine for your application. Degree it and put the intake centerline at 106*. You dont need big duration with those heads as their ports are slower than your oval ports. Going with a bigger duration cam than what you have will destroy what little low to midrange torque you have.
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