Comp Cam Kit Advice

[Vette79]

So, this winter I am going to be purchasing a Comp Cam Kit and Edlebrock Performer Intake Manifold from Summit. I currently have dual chambered exhaust and headers installed. The Quad Carb has been rebuilt and tuned. Emissions removed. Stock L48 Heads and stock rearend. Transmission has been rebuilt and is stock. Compression on all eight cylinders is great. I need advice on which cam to go with with my current setup. I am looking at Xtreme Energy 218 cam. It is a dual pattern with 218 on the intake and 224 on the exhaust. Here's a link to this kit: http://store.summitracing.com/partdetail.asp?part=CCA-K12-238-2&autoview=sku Should I go milder or is this to aggressive?

 

[Art Jett]

That is the same cam I have in my 383. It is actually an XE262H if you look in the spec. I'm running Performer RPM heads with a custom TPI setup on my 383 and the cam is great! It gives it a real nasty idle and the power band is nice for a street car. I'm running a 3.08 rear which combined with the 700R04 is a little tall, but it has plenty of power. I can smoke the tires if needed and still have instant power for passing on the highway. It was about the most radical cam I could go with without messing with the computer. Art

 

[Vette79]

Then this cam is probably to aggressive for my Vette. I might want to look at:
COMP CAM High energy-designed for street engines with an 8:1 to 9:1 compression ratio.These cams offer good increases in both gas mileage and power throughout the rpm range for most street applications

1,500-5,500
Intake Duration at 050 inch Lift:218
Exhaust Duration at 050 inch Lift:218
Duration at 050 inch Lift:218 int./218 exh.
Advertised Intake Duration:268
Advertised Exhaust Duration:268
Advertised Duration:268 int./268 exh.
Intake Valve Lift with Factory Rocker Arm Ratio:0.454 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio:0.454 in.
Valve Lift with Factory Rocker Arm Ratio:0.454 int./0.454 exh. lift
Lobe Separation (degrees):110

 

[Hib Halverson]

The Comp cam with 218 at .050 is a bit much cam for a stock, low-compression L48 with a Performer intake and headers.

If you're not going to change or modify the heads, I think you'd be better off with something a little less aggressive. Also, 'cause I'm partial to Crane products, I'd switch manufactuers. I've used cams from both but had best luck with Crane. If you want to stay with a flat-tappet hydraulic, I'd go with a Crane 114132. It's got .440/.454 lift, 210/216 duration at .050 and a 114 lobe sep.

 

[fine69]

Then this cam is probably to aggressive for my Vette. I might want to look at:
COMP CAM High energy-designed for street engines with an 8:1 to 9:1 compression ratio.These cams offer good increases in both gas mileage and power throughout the rpm range for most street applications

1,500-5,500
Intake Duration at 050 inch Lift:218
Exhaust Duration at 050 inch Lift:218
Duration at 050 inch Lift:218 int./218 exh.
Advertised Intake Duration:268
Advertised Exhaust Duration:268
Advertised Duration:268 int./268 exh.
Intake Valve Lift with Factory Rocker Arm Ratio:0.454 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio:0.454 in.
Valve Lift with Factory Rocker Arm Ratio:0.454 int./0.454 exh. lift
Lobe Separation (degrees):110

I also considered this kit when I was doing mine.

Do you know your compression ratio with the stock heads?

Be careful this "cam change" project can EASILY turn into an engine overhaul project! Should you decide to go that route, you can use my engine cherry picker hoist, and engine stands (I have a stand for the block and another that holds the assembled engine and tranny).

Ralph

 

[Vette79]

Hi Ralph. Well, the last thing I want to do is a complete engine overhaul. I think I am settling with this Cam Kit. It is a bit milder. http://store.summitracing.com/partdetail.asp?part=CCA-K12-234-2&autoview=sku

Basic Operating RPM Range: 1,000-5,200
Intake Duration at 050 inch Lift: 212
Exhaust Duration at 050 inch Lift: 218
Duration at 050 inch Lift: 212 int./218 exh.
Advertised Intake Duration: 256
Advertised Exhaust Duration: 268
Advertised Duration: 256 int./268 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.447 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.454 in.
Valve Lift with Factory Rocker Arm Ratio: 0.447 int./0.454 exh. lift
Lobe Separation (degrees): 110

OR:

http://store.summitracing.com/partdetail.asp?part=CCA-K12-238-2&autoview=sku

Basic Operating RPM Range: 1,300-5,600
Intake Duration at 050 inch Lift: 218
Exhaust Duration at 050 inch Lift: 224
Duration at 050 inch Lift: 218 int./224 exh.
Advertised Intake Duration: 262
Advertised Exhaust Duration: 270
Advertised Duration: 262 int./270 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.462 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.469 in.
Valve Lift with Factory Rocker Arm Ratio: 0.462 int./0.469 exh. lift
Lobe Separation (degrees): 110

 

[Vette79]

Surprise no one has any opinions on this. Has anyone changed their cam?

 

[fine69]

Surprise no one has any opinions on this. Has anyone changed their cam?

Knowing the approximate CR with the stock heads would help in making a determination. It wouldn't make sense to cam-up your engine if you didn't have the components to utilize the additional flow, volume, etc.. that's why I asked in my earlier reply. So you see, if it turns out that you need other items (e.g., cylinder heads), this project can easily grow. My two cents.

 

[TMPJoe]

So, this winter I am going to be purchasing a Comp Cam Kit and Edlebrock Performer Intake Manifold from Summit. I currently have dual chambered exhaust and headers installed. The Quad Carb has been rebuilt and tuned. Emissions removed. Stock L48 Heads and stock rearend. Transmission has been rebuilt and is stock. Compression on all eight cylinders is great. I need advice on which cam to go with with my current setup. I am looking at Xtreme Energy 218 cam. It is a dual pattern with 218 on the intake and 224 on the exhaust. Here's a link to this kit: http://store.summitracing.com/partdetail.asp?part=CCA-K12-238-2&autoview=sku Should I go milder or is this to aggressive?

the power lies in the heads... with stock heads and pistons... you just are strangling the car....

if you don't have a particular combo in mind then consider getting a head, intake and cam package complete from somebody like holley or edelbrock... you will need pistons too in your case .... its not as expensive as you think and will really be the right way to go..

making mods with the stock restricted heads and low grade compression just isn't worth that much..... no offense meant by that.. but you won;t see much HP when all is said and done with a cam from where you are now....

 

[Vette79]

the power lies in the heads... with stock heads and pistons... you just are strangling the car....

if you don't have a particular combo in mind then consider getting a head, intake and cam package complete from somebody like holley or edelbrock... you will need pistons too in your case .... its not as expensive as you think and will really be the right way to go..

making mods with the stock restricted heads and low grade compression just isn't worth that much..... no offense meant by that.. but you won;t see much HP when all is said and done with a cam from where you are now....

Basically, I am not trying to get much. This winter I am replacing my water pump and timing chain cover gasket as well as valve seals anyway. I will already be in the area with pieces and parts removed so I figured why not just get a cam kit and do an upgrade. I am replacing my intake manifold regardless. A couple of recent posts upgrading to a larger cam then what I had specified shows that there is success with stock components...

 

[Curtis]

by the time you do a performance valve job on the old heads you have nearly spent as much money as new vortecs, and you are planning to buy a new intake anyway with a cam... why not put better port technology out of the box to work for you and get some real power? the old heads are the pinch point for airflow anyway unless you dump gobs of cash in a high grade port effort.

 

[L88 crazy]

Comp Cams K12-211-2

I got a Comp Cam 268 High Energy cam in my 72 small block stock rebuild. Duration at .50 is 218 and .454 lift intake and exhaust. The perfect cam in my opinion for stoplight to stoplight action. Last time I took it to Atco I squealed even with the 3.36 rear ratio, turbo 400 and 1500 rpm powerbrake launch! I would go with Comp Cams K12-211-2 Magnum Cam kit .470 lift and 224 duration at .50. A good blend street strip cam.

 

[Vette79]

I got a Comp Cam 268 High Energy cam in my 72 small block stock rebuild. Duration at .50 is 218 and .454 lift intake and exhaust. The perfect cam in my opinion for stoplight to stoplight action. Last time I took it to Atco I squealed even with the 3.36 rear ratio, turbo 400 and 1500 rpm powerbrake launch! I would go with Comp Cams K12-211-2 Magnum Cam kit .470 lift and 224 duration at .50. A good blend street strip cam.

I agree. I need to replace the timing chain cover gasket so why not replace the timing chain and cam? Makes sense to me. I will only improve performance. Thanks for the input.

 

[Crimson Thunder]

I agree with Curtis.If you are going to do a cam/timing chain/intake change,go ahead and spend a little more and get some new Vortec heads.The 64cc chambers in the Vortec's will help out your comp. ratio and the stock springs will work with all the cams you are thinking about.I would go with that first Comp cam you were thinking about.

 

[Vette79]

I agree with Curtis.If you are going to do a cam/timing chain/intake change,go ahead and spend a little more and get some new Vortec heads.The 64cc chambers in the Vortec's will help out your comp. ratio and the stock springs will work with all the cams you are thinking about.I would go with that first Comp cam you were thinking about.

OK, what type of Vortec heads and where? Can someone point me in the right direction?

 

[GerryLP]

OK, what type of Vortec heads and where? Can someone point me in the right direction?

You have fallen into the most common and infamous trap in the realm of Vette modifications. You are up to your neck in "while-I-am-at-it-I-might-as-well-do-this-other-thing"

For example, the change to Vortec heads will trigger a change for an intake manifold with Vortec bolt pattern.

Have fun!

 

[Curtis]

My son and I chose Scoggin Dickey for our head supplier.. http://www.sdparts.com/categories/e...heads/SDPCVortecCylinderHeadsandHeadKits.aspx You can purchase the entire kit containing bolts, gaskets, intake, absolutely everything you need to go vortec..

 

[Vette79]

You have fallen into the most common and infamous trap in the realm of Vette modifications. You are up to your neck in "while-I-am-at-it-I-might-as-well-do-this-other-thing"

For example, the change to Vortec heads will trigger a change for an intake manifold with Vortec bolt pattern.

Have fun!

Yea Gerry. This small project is getting bigger and bigger. Fine69 (Ralph) warned me of this earlier. Maybe I should leave well enough alone and just repair or replace what is needed. Thanks Curtis, I will look at the link you provided.

 

[Glensgages]

OK, what type of Vortec heads and where? Can someone point me in the right direction?

Vortec heads will need a vortec-style intake manifold:
Scoggin-Dickey Performance offers head/intake/gasket kits for a decent price.

http://www.sdparts.com/product/SD8060AKIT/UpgradedVortecHeadKitEdelbrockPerformerIntake.aspx


This will raise the compression from a typical L-48 from 8.2:1 to 9.3:1, which will still run on a good-grade of pump-gas (Sunoco-94/Amoco-93 ), and work better with a larger cam in the .480"-lift, 230*-duration range, which would be the max for the OEM bottom-end, in my guesstimation.

 

[Curtis]

This article talks about the engine build you may be considering..http://www.superchevy.com/technical/engines_drivetrain/completebuilds_testing/0312sc_dm15_copy/ Test 15. I now have a street and fuel friendly motor with enough power to smoke the Mustangs around here. No vacuum problems.