Camshaft change opinions on a stroker

[washMO66]

I've had the 347 for two seasons in the car and it runs great but as always I am looking for a few more .10's and I was considering stepping up to the next size bumpstick.

Right now I have the Comp Cam XE274HR which only spins to 6200RPM. I need opinions to see what you all think I might gain by going up to the XE282HR.

The XE282HR has the following specs;232-240 duration @.50 and 565 - 574 lift and 112 dgree lobe seperation. It's rated up to 6500RPM.

My specs are listed below and I have my head flow chart numbers at home which I'll add later. Bottom line is that if I change to this cam what can I expect? Will I need to change gears, stall speed? Also I am only running a Mighty Demon 650 and I think my motor can handle more, I'll be trying out a friends 850 race demon next weekend on my current set up.

I do drive this car on occasion on the street with no problems. Your opinions are greatly appreciated.

• Lunati Iron Crank, Lunati street / race rods
• KB hypereutectic flat domes w/ 6.5cc reliefs
• Clevite bearings
• All ARP hardware
• BHJ billet crank damper
• Pioneer flexplate
• Probe girdle
• Canton 7 qt pan
• Comp cams aluminum roller rockers 1.6:1
• Holley laser shot 9mm plug wires
• Comp cam Xtreme Energy 35-518-8 hydraulic roller Cam Duration @.050 224 – 232, valve lift .555 - .565, lobe separation angle 112 degrees
• AFR 185 heads ported and polished by Joe Mondella (documented flow charts)
• MSD Pro billet distributor
• Hooker super comp ceramic coated long tubes 1 5/8” primary, 3” collectors
• Weiland aluminum water pump
• Port Matched Victor JR Single Plane intake manifold (Plenum opened up big time)
• Elgin high volume pump and timing set
• Holley blue fuel pump w/ regulator
• Mighty Demon 650 carb (flows 753CFM wet)
• MSD 6AL, blaster 2 coil
• Currie 9” w/ 3:70 Detroit true trac
• TCP Upper control arms w/ 620lbs Mustangs Plus 1” coils
• Sway Bars (front removed)
• TCP Sub-frame connectors
• TCP Solid Motor mounts
• 2500 Stall, C-4 massaged tranny
• Street Wheels – Vintage Wheel Works 16X8 Vintage 50’s w 245/50/16 & 225/50/16 Comp T/A
• Strip wheels Drag light w/ Hoosier 26X9.0X15
• 10.8:1 COMPRESSION

 

[allcarfan]

change to that cam...without a doubt

 

[washMO66]

Here are the head flow #'s. Not sure if this is good or bad or what.

I'll start @ .500

Intake - 265.6
Exhaust - 193.1

@.600

Intake - 270.5
Exhaust - 196.8

@.700

Intake - 276.2
Exhaust - 200.4

It goes higher but you guys that know heads get the picture. I also have swirl #'s too.

TB

 

[washMO66]

change to that cam...without a doubt

Dude,

elaborate please. Can I expect significant gains?

 

[ratio411]

You need to make a couple checks first, but I would run your current cam with 1.7 rockers.

Some things you need to check:
Call Comp, make sure the cam lobe is compatible with more rocker ratio.
Some lobes are too aggressive for more ratio, the manufacturer will tell you if this is the case.
You will need to know if your springs can take a little more lift.
You will need to know that your piston/valve clearance can stand a little more lift.

I think the larger cam will put you in a position of needing more gear and stall.
If you want a little more power up top, without destroying the bottom, where your gears and stall are, you should pump in a little more lift with 1.7s.
The swap is easier than a full on cam swap, and you can change your mind and be out a lot less dough.
Good luck
Dave

BTW: You do need more carb IMO. Nevermind... Just sunk in that your carb flows well over rating.

 

[cobra232]

best thing to do is scrap the 3.70 gears for a set of 4.56's. this will utilize the high rpm power better

 

[2bav8]

I'd rather spend a few extra bucks and get the "right" cam by getting a cam custom ground.

 

[66P51GT]

Another thing to consider when in the upper RPM range is making sure your valvetrain matches your cam. Above 6500 RPM you may begin to experience valve float. If you go the custom cam route, make sure the springs match the grind.

Have you considered going to a solid lifter vs. hydraulic? I'm no expert but most of the writups I have seen for race motors have solid roller lifters - especially for hight RPM small blocks.

 

[allcarfan]

Have you seen the numbers on AFR's website using box-stock 185 heads and an xe282hr????

 

[washMO66]

Ratio411 - As always sound advice, I will call Comp Cams and as far as the gears/stall, I anticipated that I would have to change these out.

2BAV8 - I was hoping you would chime in as I've noticed in the past your build is similar to mine. With your Ed Curtis custom grind how high are you spinning that stroker?

66P51GT - I have looked into solid roller and I am trying to stay away from that for a few reasons, 1 - I don't want to have to adjust these things all the time and with a solid roller I will. 2 - essentially the same reason, the car is also driven on the street and is not 100% race

I run on pump gas and can sit and idle in traffic all day long, drive to and from work when I want and not worry about breakdowns/reliability.

I know I'm walking the line between street and race but I figured I could get away with a little more with a more aggressive hydralic roller.

ALLCARFAN - I'll check it out on AFR to see the numbers.

Going to go call comp now. 1.7 sounds attractive, we'll see what they say.

 

[66P51GT]

66P51GT - I have looked into solid roller and I am trying to stay away from that for a few reasons, 1 - I don't want to have to adjust these things all the time and with a solid roller I will. 2 - essentially the same reason, the car is also driven on the street and is not 100% race

You are taking the right approach. With your build sheet, it looked more Strip/Race than Street.

302 with AFR 185 with CompCam 282

455HP @ 6,100
398TQ @ 5,500

326TQ at 3,000

Expect bigger numbers with 347!!!

Nice!

 

[dannydoo]

I like that hp rating.

455hp with a 282 and afr 185?

Whooosh....I gotta get to a dyno

 

[washMO66]

Holy old thread! I've actually sold the car, bought a Saleen E car, sold it and bought back my 66 in the time since I started this thread in 04'...

and did the cam swap.....

 

[gjz30075]

Did it meet your expectations? What other changes were made to accomodate?

 

[dannydoo]

So how did you like this combo w/the 282? Did it make all that power?

 

[dannydoo]

Im asking cause my combo is about the same except it has dometops a lil more compression ,and efi

 

[57fairlane]

IMO, a brand new 282hr is $100 less than a custom from Jay Allen/Ed Curtis etc . . . you might as well spend the extra money to know exactly what is going in your engine will work the best with what you have.

At any rate, in a 347 with untouched but slightly milled Victor Jrs (10.5:1), ported Holley systemax put down 418/406 to the tires with a 3550. It made max power at 6200.

I would stick with the 3.70s you have now but definetly look into getting a bigger converter. Check with a custom company . . . I had a great experience with Edge Racing Converters for what its worth with my c4.

 

[washMO66]

Well I have no new numbers from the track but I like having a little more RPM, it definitley pulls harder up top. The stall has been changed from a 2500 to what I think is around a 3800 to 4000. The mighty demon 650 has been swapped for a race demon 775RS-DR. My old C-4 bit the dust and I put in a PA super comp C-4 (rev manual vb with a brake) this summer. This winter I am doing a 3.70 to 4.11 gear swap which should round out my combo...

I just got the new moly cage installed and I expect to be back to the track in the spring. It ran 11.28's before so I am hoping it will pick up a couple of .10's with the new gear, stall, carb and cam.....

As far as my expectations, this motor has always ran great but I am never satisfied and I'm getting a little bored with it. I am going to run it this season and start to plan a new build, just not sure what yet but it will be wicked.

 

[washMO66]

At any rate, in a 347 with untouched but slightly milled Victor Jrs (10.5:1), ported Holley systemax put down 418/406 to the tires with a 3550. It made max power at 6200.

I would stick with the 3.70s you have now but definetly look into getting a bigger converter. Check with a custom company . . . I had a great experience with Edge Racing Converters for what its worth with my c4.

With the new cam and a loose converter on an auto my combo made 380/400 to the wheels. 3.70's were not enough for my set up before as I went through the traps at 119MPH at only 6K RPM. The 4.11's are going to help and should be perfect....

 

[dannydoo]

Definitly do the 410s
Thats what I have and I cant imagine less than 410s

That xe282hr cam in my combo is pretty wild.It shakes my car nice and it pulls for what seems like forever.

IM only runnin 8deg of base timing "long story" but its wild like this and I know theres plenty more to be had w/race fuel and timing.