Help with cam selection

[eedeutsch]

My new Backdraft came with a COMP cam # 35-000-9. Just an idea.

[olddog]

I don't understand why you didn't stroke it out - practically the same money.

I would use an air gap manifold.

With aluminum heads, I would have shot for 10 to 10.5 compression.

From what you have put together, I take it you are not trying to make a bunch of power. You have said nothing on the type of rpms you want to turn, nor have you mentioned you tolerance on a nasty engine with bad manors.

With the high 5th gear, you will either have to keep the cam tame enough to let it lug smoothly at 1500 rpm or you will have to gear it low enough to keep the rpm up over 1800 at 55 mph. That or not use 5th unless your on a 4 lane with a 65+ speed limit.

I have 236/242 duration @ 0.050 lift in a 347 cid, and it does not like to pull smoothly much below 1800 rpm. I lowered the rear end gears because of this. I cannot feel the torque drop off all the way to 6500 rpm by the seat of my pants (I'm sure it does but I do not feel it). If I ever pull my engine down, I would drop ~5 on the duration and go a little wider on the lobe separation.

You want to stay on the milder side of my cam to run that transmission. If that doesn't make enough power for you, then change other components to make more power. That's my advise, unless you love nasty engines with no manors.

[worksalot 2]

Sorry about lack of info. I should have mention my plan for the rear end gearing. I planned on 3.50 gears. With my tires and that rear/trans combo 2300rpm in 5th should be around 75mph. 4th should be about 51 mph. It is my hope to do the HotRod power tour in 06/14. The block and rotating assembly are already assembled so I am not stroking this engine. The reason for the tko500 is incase I want to stroke my other 351 block later....I have not owned a cobra for 10years...I need some seat time before I go very radical. And yes I want something with street manners. At 2400lbs it wont take much to have impressive performance so I am leaning toward driveable performance.

[blykins]

eedeutsch, that part number means it's a custom cam, on a billet steel core. You would have to look at the cam card to determine the specs.

worksalot 2, you need to be somewhere around 224/230 on the duration @ .050". With those heads, lift around .570-.600" would be optimal, and a 110 LSA would be good.

If you need a cam, let me know, I can help.

[worksalot 2]

BLYKINS if I am working in an area with good cell signal I will give you a call today. I have read good things about you. Thanks. And thanks everyone for your input.

[blykins]

Be glad to help. I can have a custom cam to you by the middle of next week.

[koupe377]

Originally Posted by olddog

I have 236/242 duration @ 0.050 lift in a 347 cid, and it does not like to pull smoothly much below 1800 rpm. I lowered the rear end gears because of this. I cannot feel the torque drop off all the way to 6500 rpm by the seat of my pants (I'm sure it does but I do not feel it). If I ever pull my engine down, I would drop ~5 on the duration and go a little wider on the lobe separation.

What lobe separation are you running now?

Originally Posted by RICK LAKE

Also watch the tko 500 trans, if yours has all the updates, There will no problems with it. Your motor with a little work will push this trans to it's rate limits of 500/500. The torque number will be higher. Get ahold of Joe craine and let him port the intake and heads to match, than go 1 step higher than the camshaft you are looking at, BUT stay under the 5,000 rpm range. This will give you the nasty exhaust sound and still be drivible. advancing or retarding the camshaft will move the power band around also. Torque is better than HP. Rick L.

Tremec's tranny's will actually handle much more power than they are rated for. Not to mention I believe those ratings are based on a 3000lb vehicle. Cobras are much lighter and because of that the TKO can handle much more than 500ftlbs in them.

I agree you should port the heads and intake to but I would also shave them to 58cc chambers to bring the compression up from that low 9.5:1.

However, I think you should run a cam that will let you pull to 5800-6000. There's lots of power to be had up there. These cars are so light not sure why you would want to build with so much emphasis on torque. Especially when traction is already an issue. It doesn't matter how much torque you have if all you're doing is spinning your tires not going anywhere.

Originally Posted by worksalot 2

Heads are box stock fast as cast trickflow 170s (which flow number like the afr185s because of valve placement...I think) and the intake I currently have is the performer. Nothing is port matched at this time.

Sounds like a really nice combination when you get done with it. One thing to point it though is that the AFR 185's will out flow the TW 170's all day long. The 170's flow less and that's WITH Trickflow using a 4.150 bore. AFR uses a smaller 4.060 bore and yet still has more flow. Your engine is only .030 over, so you wont be getting anywhere near the 170's advertised numbers. The AFR's would be a little more accurate being the bore is closer to .030 but it still wont be the same as what they advertise

Trick Flow 170's flowed with 4.150 bore
Intake:
.400 - 233
.500 - 251
.600 - 251

AFR 185's flowed with 4.060 bore
.400 - 255
.500 - 285
.600 - 297

AFR's - more flow with a smaller bore. You can also see that from .500 - .600 the 170's pick up no airflow at all, however, the AFR's from .500 - 600 pick up 12 cfm. Anytime you're looking at flow numbers always find out what bore was used. Most manufactures use bigger bores to inflate their flow numbers. But with that said the only true way to compare two sets of heads is to flow both sets on the same flow bench at the same bore.

This is a mild motor you are building so there is no reason for the extra cost of a custom ground cam, something off the shelf will be fine. I also think you should ditch the Performer and go with the RPM of even better the RPM Airgap. More power plus the AirGaps look cool for when you pop the hood.

Also as mentioned have the heads ported a little and shave them down to 58cc, higher compression is free horsepower. You're leaving lots of torque and power on the table running the 9.5:1. Even if you don't port them, shave them.

Originally Posted by blykins

John, I have a left-over cam from Cliff Rosson's 331 SBF that I did for him several months ago. It has about 5-6 dyno pulls on it, but other than that, I ordered it brand new for his engine. It's a 228/232 duration, a little over .600" lift with a 1.7 rocker. Standard base circle, so you'd have to use link bar lifters with it. I'll make you a deal on it that you can't refuse....

John, this sounds like it would be a good cam for your combo. Personally I would run 1.6's as your heads flow no more at .600 than they do at .500. Even with 1.6's your lift will be around .565.

Not trying to step on anyone's toes just giving my thoughts on it.

[olddog]

Originally Posted by koupe377

What lobe separation are you running now

Here's my Comp Cams - cam card:

Part # 35-000-8
Engine: FW Ford 351W/302/HO HR/SR

Grind# FW 3316F / 3317F HR110+4
SPC INSTR 1:
SPC INSTR2:

----------------------------Intake Exhaust
Valve Adjustment ----------- HYD --- HYD
Gross Valve Lift ------------ 0.555 -- 0.576
Duration @ .006 Tappet Lift - 287 -- 293

Valve Timing @ 0.050 -- Open ----- Close
Intake ---------------- 12 BTDC -- 44 ABDC
Exhaust -------------- 55 BBDC --- 7 ATDC
These specs are for cam installed @ 106.0 Intake Center Line

---------------------------- Intake --- Exhaust
Duration @ .050 Tappet Lift--- 236 ---- 242
Lobe Lift ------------------- 0.3470 ---0.3600

Lobe Seperation 110

[koupe377]

Originally Posted by olddog

Here's my Comp Cams - cam card:

Part # 35-000-8
Engine: FW Ford 351W/302/HO HR/SR

Grind# FW 3316F / 3317F HR110+4
SPC INSTR 1:
SPC INSTR2:

----------------------------Intake Exhaust
Valve Adjustment ----------- HYD --- HYD
Gross Valve Lift ------------ 0.555 -- 0.576
Duration @ .006 Tappet Lift - 287 -- 293

Valve Timing @ 0.050 -- Open ----- Close
Intake ---------------- 12 BTDC -- 44 ABDC
Exhaust -------------- 55 BBDC --- 7 ATDC
These specs are for cam installed @ 106.0 Intake Center Line

---------------------------- Intake --- Exhaust
Duration @ .050 Tappet Lift--- 236 ---- 242
Lobe Lift ------------------- 0.3470 ---0.3600

Lobe Seperation 110

Yea a 114 LS will clean it up some and help with driveability.

Originally Posted by worksalot 2

Thanks for all of the input. F.y.I. I have the r.p.m. airgap on its way...found a good deal on a used one on ebay. I do appreciate the info on the afr heads. I didn't know they measured flow differently. I will be using the trickflows even though there are better options, because that is what I have. I have not made a decision on the cam yet. I have been busy with interior designing, air and heat options and body work. Thanks for the help...I will keep checking this thread.

Cool you got the airgap. If you have any extra cash in your budget have those tick flows ported. 170's are kind of on the small side for 357 cubes.