Racingjunk Forums

Racingjunk Forums (https://www.racingjunk.com/forums/index.php)
-   Engine Tech (https://www.racingjunk.com/forums/forumdisplay.php?f=9)
-   -   cam size (https://www.racingjunk.com/forums/showthread.php?t=24033)

txhunter69 04-27-2009 02:34 PM

cam size
 
im buillding a 468 street/strip and i was wondering what cam size yall thibk i should run im thinkin abou a 274/286 duration with 552/ 555 comp extreme energy flat tappet

sound good?

Tod74 04-27-2009 03:32 PM

IMPOSSIBLE TO ANSWER WITHOUT COMPRESSION, HEADS, INTAKE, INTENDED RPM range etc

bowhay 04-27-2009 05:08 PM

his heads are gonna be stock, but ported with a calce job, and milled a few cc down
its prolly gonna be anywhere from about 9.5 to 10.5
rpm airgap dual plane
and 2500 to 6500 thereabouts

this is just from what i was told he was gonna do, he might have changed his mind

Tod74 04-27-2009 05:35 PM

IT DOES NO GOOD TO HAVE A BIG Cam that the heads won't support.

Duration @ .050 is what you need to look at, rather than advertised duration. If it were me I'd keep that in the 230 -240 range. The more duration you have the more compression you will need. Too much camshaft duration will bleed off a lot of cylinder preasure at low rpm. Not a good thing with a street driven vehicle with low compression.

BUT....
Since it's a big block it will have torque on the botton so you will probably get away with a little more... Just my opinion...I'm no camshaft guy by any means.

txhunter69 04-27-2009 06:04 PM

ya stock heads good port and valve job flat top pistons and either airgap or rpm performer and yes 2500 to4500 rpm so you think im goiong with too high of a duration

Tod74 04-27-2009 08:31 PM


Originally Posted by txhunter69
ya stock heads good port and valve job flat top pistons and either airgap or rpm performer and yes 2500 to4500 rpm so you think im goiong with too high of a duration

I don't know...what is the duration @ .050? NOT advertised duration...if that IS @ .050 then YES MOST DEFINITELY TOO MUCH.

txhunter69 04-28-2009 09:24 AM

this is the specs off summit
Brand: COMP Cams
Product Line: COMP Cams Xtreme Energy Cam and Lifter Kits
Part Type: Camshaft and Lifter Kits
Part Number: CCA-CL11-246-3
Cam Style: Hydraulic flat tappet
Basic Operating RPM Range: 1,800-6,000
Intake Duration at 050 inch Lift: 230
Exhaust Duration at 050 inch Lift: 236
Duration at 050 inch Lift: 230 int./236 exh.
Advertised Intake Duration: 274
Advertised Exhaust Duration: 286
Advertised Duration: 274 int./286 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.552 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.555 in.
Valve Lift with Factory Rocker Arm Ratio: 0.552 int./0.555 exh. lift
Lobe Separation (degrees): 110
Intake Valve Lash: 0.000 in.
Exhaust Valve Lash: 0.000 in.
Grind Number: CB XE274H-10
Computer-Controlled Compatible: No
Lifters Included: Yes
Lifter Style: Hydraulic flat tappet
Valve Springs Included: No
Retainers Included: No
Locks Included: No
Valve Stem Seals Included: No
Timing Chain and Gears Included: No
Assembly Lubricant Included: Yes
Pushrods Included: No
Rocker Arms Included: No
Gaskets Included: No
Quantity: Sold as a kit.

Cam and Lifters, Hydraulic Flat Tappet, Advertised Duration 274/286, Lift .552/.555, Chevy, Big Block, Kit

bowhay 04-28-2009 06:41 PM

ok see it right there
it has the duration and it has the duration at 50
which is mid 230s which it good
easy mistake to make though
cam specs can get confusing sometimes, to many numbers make head hurt lol

Tod74 04-28-2009 08:28 PM

That should be good for what you have in my opinion.

desoto30 04-29-2009 09:20 AM

your combo is quite similar to mystreet rod engine which has a cam like the one you are thinking of using.It works well.


All times are GMT -8. The time now is 01:10 AM.