Did I pick the right cam ?

I'm more of a fabricator than engine builder, stuff like cam theory is way over my head, so I thought I would throw this out there for input from you guys who do know this stuff. Here is my combination:

Chevy 350 four bolt, just had it machined. .020 over TWR forged flattop pistons, balanced, etc. My engine guy says it should turn out to be a 9.5 compression motor with the combo I have.

Heads are World Product cast iron heads, 202 valves, 69 cc. Fresh from machine shop. Harlan Sharp roller rockers.

Intake will be Air Gap dual plane, maybe with 750 Holley (it came with the engine so I might use it or go to a 600 cfm Edelbrock that I usually use.)

I will be running a B and M TH350 I also have, with a 2400 hole shot convertor. I will probably run gears in the back in the 3.50 range.

This will be going into my 46 Ford when the time comes. Yesterday I ordered a cam and lifter set from Summit and wanted to try their house brand cam, so here is what I ordered :

Cam and Lifters, Hydraulic Flat Tappet, Advertised Duration 298/304, Lift .466/.487, Chevy, Small Block, Kit
(Mfr. #: SUM-K1105)

I went with the split duration and lift because I understand it gives more mid range and bottom end.......is that correct ? The rpm range of this one is 2400 to 6000, and that will be maybe a little steep for a street driven car, but I like a healthy sounding cam.

Thoughts anyone ?

Don

Sounds like a good combo to me...but keep the 750 carb. 600 is barely too small for the top end range. Good luck, Bill.

Don,
Are you gonna drive this car on the street?!

BoB

Yes, Bob, strictly street.

Don

donsrods said:

Yes, Bob, strictly street.

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This is just my .02 but I like a wider power band preferably 1500-5500. I've found it just takes too long to come up on the cam with a 2400-6000 but of course you know my propensity for lead footin'! I love LS motors for that reason... they typically have torque from idle to red line. You can actually feel 350's come up on the cam & I like ta git goin' asap... haha! Also depends on what kinda drivin' u plan on doin'! [ddd

BoB

The cam description says 2500+ stall, and gearing is recommended... Their tech line is pretty darn good, I'd ask some questions...

me

sounds like too much cam/carb for the driving you plan on doing with the 46 .


this is the cam l have in my SBC's and it works great with a matching aluminum dual plane with a 6OO CFM carb:

Performer-Plus Camshaft
1957-86 Chevy 265-400
.420''/.442'' Lift
278°/288° Adv. Duration
Idle-5500 RPM Range

Later

I guess it's all a matter of perspective. I have a much larger cam with a 780 carb, 3600 convertor and 3:73 gears and love it for tooling around town...not so much on the highway. Anyway, good luck with the build, Bill.

I think it depends on how you want it to act/perform. that is a bit on the big side but can be streetable.

I have a Comp Cams 292 cam in a 80 over 283. So a bit smaller cam in a smaller motor. I have a 2400 stall converter in a TH350 with 3:08's. It's got no low end but comes on real strong above 2800 to 6500. I used to have 4:88's and the lack of low end wasn't noticable, it was a lot of fun to drive around town but too much gear for the highway. Since the 3:08's I've put over 20K miles on it and it has decent drivability. The coolest thing is pulling up to a stop and hearing the cam through the flowmasters. In my case 3:73's would probably be the best gearing for all around driving...

I say go for it and if it ends up being too much cam, swap it.[dr

what is the biggest cam you can have without doing head job and stall converter ..? is it a simple answer ? or does a lot of other factors fall in ?

I would just want the sound .. no racing .. just driving and idling around, (350 sbc) And I'm not trying to steel your thread donsrods ..

I agree with Tripper, sounds a bit much for easing around in a street car. Like him, I prefer a lower powerband, 1500 or so sounds about right. I had a 272 in the 302 in the Maverick, supposed to be 1500-5500 RPM, and even at that, you could feel the cam really come in about 2500-3000 RPM. Anything lower than that, and it just had a nice lope.

Yankee, I'd go out on a limb and say something in the 272 range would work for you, too. I ran mine with a stock C4 and stock converter, stock D5 iron heads, a Offy 360 single plane intake with a Ford 600 cfm Holley and a set of Hooker headers. It would lope real good, and had a great powerband. I never ran it at a strip, so I don't know what kind of times it would run, but I do know it was still pulling at about 125 mph!

Thanks for all the input guys. I kinda threw a dart at the catalog and settled on this one because all the milder ones petered out at 4500 or so. I called Summit for advice but it was after the tech line closed for the day and the salesman helped me pick this one.

So what is the deal with the split overlap or whatever it is called ? How does that affect the performance ?

Don

Yankee Transplant said:

what is the biggest cam you can have without doing head job and stall converter ..? is it a simple answer ? or does a lot of other factors fall in ?

I would just want the sound .. no racing .. just driving and idling around, (350 sbc) And I'm not trying to steel your thread donsrods ..

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Don't worry about asking anything in my threads, YT. That is how we all learn.

Don

This is my all time favorite cam for this engine and setup
Comp Cams extreme Energy 268H
Camshaft Part # 12-242-2 Designation XE268H-10
Duration @ 0.006": 268° / 280°
Duration @ 0.050": 224° / 230°
Max Lift w/ 1.5RR: .477" / .480"
Lobe Separation: 110°
Lobe ID#'s: 5443 / 5203
Intake Centerline: 106°
Engine Type: Chevrolet 350 Small Block
Bore: 4.040"
Stroke: 3.480"
Displacement: 356ci
Compression: 9.25:1
Intake: Edelbrock Performer RPM Air-Gap Intake Manifolds 7561
Carburetor: Holley #3310 Vac. Sec.
Exhaust: 1 5/8" Headers
Max Torque: 413 ft*lbs @ 3800 RPM
Max Power: 342 HP @ 5000 RPM
Manifold Vacuum: 15.5" Hg @ 800 RPM & 17" Hg @ 1000 RPM w/ no load.

I ran a cam with a similar profile as old iron in a street truck. It was very pleasing....

Old Iron said:

This is my all time favorite cam for this engine and setup
Comp Cams extreme Energy 268H

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This IS an awesome cam. I've had it in 3 engines, A 307 a 350 and a 283. Great low end and mid range with a little on the top end. For a street car, daily driver, cruiser this cam is hard to beat. But I'll go back to what I said in my previous post and that it depends on what you want. I traded the 268 for the 292 cam in my 283 because I wanted the the very lopey idle that the 268 didn't. Now the 268 is far better all around cam but it's hard to beat the idle of a big one like the 292 or the one you ordered. Again, depends on what you want. I traded the all around performance for how the damn thing idles - probably not the wisest choice but it is f-ing cool...

I fully understand about the rough idle thing, I like a car to sound like it has one in there too. That was part of my rationale for ordering this one, the other below it seemed to mild and the ones above it too radical.

I guess we'll see when I get it fired up some day, and if I don't like it I can pull it out and throw in another one.......small block Chevys are easy that way.

Don

I ordered a cam. threw a race car man . I told him I wanted to hear it ,, didn't care about racing , if anything Id rather have the pulling at the bottom end . not the top end .. well It will rock the truck when you punch the gas , but you can't even hear it thump ,, very disappointed in that one ,Its in my big block 65 Ford truck . so its going to stay where it is for now , Fords aint easy like that I don't even know what he ordered me , I have a step up from a street cam in my 31 right now . It sounds ok, not wild but ok. It seems like I remember something about a 280 lift ??? IDK. I'll try the 272 range this go around for the 50 rat.. Thanks for the imfo Bamamav

Don, I think the split thing you were asking about is called a dual pattern cam where the intake and exhaust lobes have different specs. I hope that helps a little.

Dual pattern cams really work good on small block Ford's that need help breathing on the exhaust side.