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Username Post: Comp cam gm350        (Topic#355678)
Kmat 
Poster
Posts: 2

Reg: 03-18-19
03-18-19 07:03 PM - Post#2762430    

Hello i have a gm350 bored 0.30,flat top pistons,world product sportsman2 heads,2.02 1.94 64cc and 200 intake chamber, question is will i have to do any special modifications if i put a 12-210-2 comp cam in?

COMP Cams 12-210-2 Details
Chevy 262-400ci Small Block 1955-98

*Note: 50-State Legal for 1987 & earlier carbureted V-8 Small Block Chevy 262-400 C.A.R.B. E.O. #D-279-3, D-279-5, D-279-6.



Good street performance with stock converter, choppy idle.

Operating Range: 1500-5500 RPM
Duration Advertised: 268° Intake / 268° Exhaust
Duration @ .050'' Lift: 218° Intake / 218° Exhaust
Valve Lift w/1.5 Rockers: .454'' Intake / .454'' Exhaust
Lobe Separation Angle: 110°

heres some info you forgot



 


Mel Foye 
*VIP* Founding Member
Posts: 4917
Mel Foye
Reg: 09-29-00
03-18-19 11:24 PM - Post#2762445    
    In response to Kmat

1) ??2:02 1:94
2) Compression ratio
3) Use of vehicle, describe car, redline, trans and gear ratio.



 
rumrumm 
"18th Year" Silver Supporting Member
Posts: 2087
rumrumm
Loc: Macomb, IL
Reg: 10-18-01
03-19-19 04:59 AM - Post#2762455    
    In response to Kmat

Have you called and spoken to a tech at CompCams? If not, I would suggest you give them a call and see what they recommend. That is a small cam for the heads you have.

Lynn

"There's no 12-step program for stupid."


383 sbc, Eagle, AFR, SRP, CompCams, Edelbrock, FiTECH. Dyno #'s: 450 hp @ 5700, 468 lb. ft. of torque @ 4300.



 
busterrm 
Frequent Contributor
Posts: 1230
busterrm
Loc: Wichita Falls, Tx
Reg: 08-30-10
03-21-19 07:54 PM - Post#2762631    
    In response to rumrumm

I agree that is a small cam for 200 cc heads, I would look for 225-230 duration with .525-.550 lift. Those heads will need the added duration as well as the higher lift to reach their flow potential! But to get that lift with that duration you might need a roller cam!

==== BOB ====
If I can't smoke the tires I want more!

1976 Chevy Nova
2007 Chevy 1500 1/2 ton
2017 Harley Davidson XL1200 Sportster
2018 Nissan Versa Note


 
scrambldcj8 
Silver Supporting Member
Posts: 2507
scrambldcj8
Loc: Belchertown, MA
Reg: 04-06-03
03-22-19 03:25 AM - Post#2762643    
    In response to busterrm

I agree with the others...a smaller cam. But by the sounds of it's....intended use >>> by the description of the cam you posted. "good street manners and stock Tq. convert...I am guessing a street car.

So......maybe different heads with something around 180cc intake ports?

You tried, but more info is needed for better guidance.



 
1983G20Van 
Super Senior Member
Posts: 3792

Loc: Bedford, Texas, USA
Reg: 11-13-02
03-22-19 05:02 AM - Post#2762650    
    In response to scrambldcj8

  • scrambldcj8 Said:
I agree with the others...a smaller cam. But by the sounds of it's....intended use >>> by the description of the cam you posted. "good street manners and stock Tq. convert...I am guessing a street car.

So......maybe different heads with something around 180cc intake ports?

You tried, but more info is needed for better guidance.



If he has 200cc heads at his disposal I would just run them. 180cc vs 200cc will not effect the powerband nearly as much as the cam choice will. The 180s will make a few ft/lbs more torque down low and the 200s will a bit more peak HP assuming the 200s flow better than the 180s.

He can always keep the duration mild on the cam and run 1.7 rockers.

I have 200cc aluminum heads that were ported by Lloyd Elliot and CC'd right at 215cc runners. 2.02/1.60 valves, 7/16" screw in studs, double springs.

Flow @ 28 in/h20

LIFT------INTAKE-----EXHA UST
.200----------138-------10 7
.300----------192-------13 8
.400----------241-------16 4
.500----------274-------18 3
.600----------291-------19 3
.700----------295-------19 9

I am running them on a 9.6:1 350 with a custom grind roller cam.

270/284 @ 0.006
215/224 @ .050
.578/.578 lift w/ 1.7 rocker
110 LSA
106 ICL

Running a marine port fuel injection manifold for a L31 that was ported to match the heads, doug thorley tri-ys, factory dual 3" exhaust to the muffler, single 4" out tail pipe, with a 4L85E and the stock torque converter stalling 2,400 rpm and 5.13 geared rear end. Its all in a 1997 Express 1500 with 3500 suspension and running gear. I tow my 6,000 lbs travel trailer behind the thing in OD down the highway at 2,700 rpm @ 70 mph. When you spin it up to 6,000-6,200 rpm it requires approximately 475 hp worth of fuel from the injectors.

Small cam with big heads that flow is better than a big cam with small heads that don't flow any day of the week!

Years ago I also ran Dart Iron Eagle 215s with 2.08/1.60" valves on a TBI 350 in my old G20 van. They were on a 18cc dished piston 350 TBI engine. Even with a thin .016" compressed head gasket the compression was 8.9:1 With a stock 1996 LT4 corvette cam, 1.7 roller rockers, thorley tri-y headers, 2.5" dual exhaust, edelbrock performer RPM intake, marine 2" TBI unit and matching TBI to square bore adapter that engine put down 320 RWHP and over 330 RWTQ. I had over 300 ft/lbs of torque at the tires at 1,500 rpm.

1983 G20 Van, 350 TPI, Ported 906 Vortecs, Edelbrock 3817 Base, ASM oversize runners. Reed Custom Roller cam, 700r4, 12 bolt with 3.08 gears, Doug Thorley Tri-Y headers, true duals


Edited by 1983G20Van on 03-22-19 05:10 AM. Reason for edit: No reason given.

 
scrambldcj8 
Silver Supporting Member
Posts: 2507
scrambldcj8
Loc: Belchertown, MA
Reg: 04-06-03
03-25-19 08:43 AM - Post#2762843    
    In response to 1983G20Van

Too little known info....carb'd vs EFI? Carb'd will be more sensitive to a port vol too large.

A port a little too small will be a far better deal to drive than one that is a little too large. Just 20cc too big can easily cost 20 lbs-ft at a point in the rpm band that is most often used for a true street driver.

A little too small is much better than a little too big. If the OP already has the 200cc heads, go for all the compression ratio the fuel intended will stand, as this will, to some extent, compensate.




 
1983G20Van 
Super Senior Member
Posts: 3792

Loc: Bedford, Texas, USA
Reg: 11-13-02
03-29-19 02:30 PM - Post#2763205    
    In response to scrambldcj8

  • scrambldcj8 Said:
Too little known info....carb'd vs EFI? Carb'd will be more sensitive to a port vol too large.

A port a little too small will be a far better deal to drive than one that is a little too large. Just 20cc too big can easily cost 20 lbs-ft at a point in the rpm band that is most often used for a true street driver.

A little too small is much better than a little too big. If the OP already has the 200cc heads, go for all the compression ratio the fuel intended will stand, as this will, to some extent, compensate.




Compression is your friend anytime you are trying to build torque. Have to pay attention to the dynamic compression ratio more than anything.

We also know nothing about the rest of the driveline.

Higher stall converters and deeper gears will also mask ports that would otherwise give up some bottem end torque. Kinda pointless to build power at 1,500-2,500 rpm if you have a 3,000 rpm stall speed and gearing that puts you at 3,500 rpm at 70.

Modern booster designs are also less prone to losing as much low-end torque from loss of off-idle intake velocity. I would put money on a 200cc port head making more average torque from 2,000-6,000 rpm than a 180cc on a 350 which is a realistic street driven powerband for a well built 350. I bet the ports in those heads are a good match for a performer rpm intake as well.

I would also run a 1.7:1 rocker to get as much lift and under the curve duration as I could out of that cam. That cam would be more like 222/222 @ .050 with a 1.7 rocker and .514" lift.


1983 G20 Van, 350 TPI, Ported 906 Vortecs, Edelbrock 3817 Base, ASM oversize runners. Reed Custom Roller cam, 700r4, 12 bolt with 3.08 gears, Doug Thorley Tri-Y headers, true duals


Edited by 1983G20Van on 03-29-19 02:35 PM. Reason for edit: No reason given.

 
scrambldcj8 
Silver Supporting Member
Posts: 2507
scrambldcj8
Loc: Belchertown, MA
Reg: 04-06-03
03-30-19 04:36 PM - Post#2763281    
    In response to 1983G20Van

Perfect then. With all the unknowns, we can willfully advise the OP.

OP, you are good to go. Enjoy your new ride......



 
1983G20Van 
Super Senior Member
Posts: 3792

Loc: Bedford, Texas, USA
Reg: 11-13-02
03-31-19 08:26 AM - Post#2763316    
    In response to scrambldcj8

  • scrambldcj8 Said:
Perfect then. With all the unknowns, we can willfully advise the OP.

OP, you are good to go. Enjoy your new ride......



For certain!

I have had a Lunati version of that same cam in a 305 Vortec in a 1999 Tahoe. Cruised down the road at 1,700 rpm @ 70 mph all day and would get 22 mpg highway. Dropped it to 3rd and ran it 2,600 rpm pulling around trailers with an issue as well.


1983 G20 Van, 350 TPI, Ported 906 Vortecs, Edelbrock 3817 Base, ASM oversize runners. Reed Custom Roller cam, 700r4, 12 bolt with 3.08 gears, Doug Thorley Tri-Y headers, true duals


 


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