Help picking a cam

4

4doorscooter

Active Member
Hello everyone I am looking for opinions on camshafts. My build is in a 65 nova. The engine is a 355 9.25 to1 compression and will hopefully have vortec heads if they check out at the machine shop. Exhaust is headers connected to an x pipe and dual MagnaFlow mufflers. The transmission is a tko 600 with . 64od and the rear end is an 8.5inch 10 bolt with an Eaton posi and 3.42 ratio and 26" tall tires. I drive the car at least 3 times a week and it has power brakes so I need street ability and some vacuume. Please give me some suggestions as I'm trying to get as many suggestions as possible so I can pick a middle of the pack cam. I would love to go roller but I'm not sure it's in the budget but I will take roller and flat tappet suggestions. Thanks guys!!!
 
If it means a few less packs of smokes, a few less lunches at McDonalds and selling some junk you don't need, to go for the Gold and get the Rollers now rather than later, you'll be glad you did!
 
You can still use a flat tappet camshaft today if you use oil that has ZDDP or use the additive.
Most important is to use quality lifters. And to make absolutely sure that the valvetrain is proper.
I used this cam in my 334 SBC (16" vac at 850 rpm):

ISKY Grind No./Type: 264-MEGA HYDRAULIC FT**
Application: Tremendous torque & good mid-range power.
9-10.5:1 compr., good idle, stock converter.
3.23-3.70 axle ratio. Up to 625 CFM Carb.
RPM-Range: 2000-5800
Valve Lift Int/Ext: .450/.450 (1.5), .480/.480 (1.6)
Valve Lash Hot Int/Ext: .000/.000
ADV Duration Int/Ext: 264/264
.050 Duration Int/Ext: 214/214
Lobe Center: 108 108° LSA /108° ICL = straight up

Seat-to-seat timing (Wallace) (IN .007”, EX .010”) ISKY
IVO is 24.0 ° BTDC (- indicates ATDC)
IVC is 60.0 ° ABDC
EVO is 60.0 ° BBDC
EVC is 24.0 ° ATDC (- indicates BTDC)
Overlap is 48 °

.050” Valve Events – IN Opens 1 ATDC IN Closes 35 ABDC
EX Opens 35 BBDC EX Closes 1 BTDC

I also recently found these similar ROLLER cams on the internet:

There is also another cam that's tried and true and that's the 213/219 .493/.502 HR112 74216.
The 219/219 .560/.560 HR112 74219 is not bad either.
215/218 dur, .490/.490 lift, 112 LSA full roller cam.
 
both the flat tappet,cams posted above are valid choices, both will make decent power, and personally but both will be on the edge of producing a bit less manifold vacuum than the power brakes may like to operate correctly (but will work ok in most cases)
a roller cam like any of those listed above potentially has some marked advantages, in less friction and a much lower potential for break-in lobe failure issues.
Ive used a crane 114142 flat tappet cam for similar builds when I wanted to save cash,many times. it also pushes but does not exceed the limits on manifold vacuum.
all those cams benefit from better valve springs than the stock factory springs and use of 1.6:1 roller rockers
crane114142.png


the crower 00482 and crane 119561 roller cams also fit the application
and if you can swing the cost a roller cams the better choice (don,t forget to check clearances, use the correct matched valve springs and degree in the cam, and 1.6:1 roller rockers will help produce more power)

crower00482.png

crane119561c.png


why not call the tech dept at all five cam manufacturers linked below, and get their input,
(without discussing or letting anyone at those individual tech departments,know you talked to other sources
.what any other cam manufacturer might have said in any way)
write down the cam specs they suggest, lift duration and lsa,

then average the results and
select the cam thats the closest match, to that average , of the 5 cams that were suggested.

crane (386)310-4875

crower 619.661.6477

erson 800-641-7920

lunati..662-892-1500

ISKY 323.770.0930

what your basically trying to do is to maximize operational compression,
over the useful rpm range
(this maximizes the torque curve efficiency,)
but, while keeping that cylinder pressure under the detonation threshold

related info
http://garage.grumpysperformance.com/index.php?threads/semi-fool-proof-cam-sellection.82/

http://garage.grumpysperformance.com/index.php?threads/how-to-read-a-cam-spec-card.1477/

http://garage.grumpysperformance.com/index.php?threads/the-mechanics-of-adv-ret-a-camshaft.4532/

http://garage.grumpysperformance.co...d-high-spring-pressures-don-t-work-well.1489/

http://garage.grumpysperformance.com/index.php?threads/valve-train-clearances-and-problems.528/

http://garage.grumpysperformance.co...e-springs-and-setting-up-the-valve-train.181/

http://garage.grumpysperformance.co...-the-charts-calculators-and-basic-math.10705/

http://garage.grumpysperformance.co...lsa-effects-your-compression-torque-dcr.1070/

http://garage.grumpysperformance.com/index.php?threads/limited-oil-choices-for-cam-break-in.13602/

If your ordering any cam, be very sure you explain what year block and what cylinder heads will be used as there are differences in the cams. between early and later SBC, block s and the cams they require,and on big blocks theres similar issues, a mark VI cam is different from a MARK IV cam
 
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Thanks for all the help so far guys! So if I were to go roller cam I was looking at a company called Howard's cams that seems to be good American made stuff but a bit more affordable for the conversion then the others. Do you guys have any experience with them or good cams the make for my application?what do you guys think of this cam I hear allot of good about lunati voodoo cams. http://www.lunatipower.com/Product.aspx?id=2324&gid=287
 
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Whichever way you go and whatever you choose, go for reliability.
And certainly DO NOT make a choice based on, "I want my car to sound like ______."
If that is what you really want, then look to CompCams Thumpr line.
For a flat tappet, you are better off using higher ratio rockers with a less aggressive lobe profile.
Aggressive lobes equal a shorter lifespan, and when the camshaft and lifters fail the resultant
metal chips will destroy your engine. Ask me how I know.
 
I'm definitely not trying to chase any type of sound. I really just want a good pulling motor that's fun to drive. Ive been reading reviews on that isky 264 mega, seems like a nice option. So those 1.6 rockers really make a big difference? Anyone care to chime in on Howard's cams experience?
 
1.6 rockers CAN make a difference IF your engine needs the extra lift and few degrees of added duration.
If your camshaft is already big enough to take full advantage of your heads, then you will not gain anything.
The same can be said for installing a "bottom of the page" race camshaft along with using stock heads.
I don't have any experience with Howard's cams. It is the quality of the lifters that is more important, IMO.
 
4 Lifter Manufacturers Breakdown.jpg Crane Old & New.jpg pushrod seats right side up sbs.jpg reflection.jpg side by side comparison.png worst.png

ISKY has good lifters - they are the Johnson type.
Old Crane lifters (before they closed) were good also. They were the Eaton type.
Not sure about what they are using now. But the last set I got from (new) Crane were the Stanadyne type.
GM (Delphi type) lifters are good also. They are the type that has the hardened bases.
Not many people can say they have ever seen this type wear on the base.
But DON'T make the mistake I did and buy what was promised to be real GM Delphi lifters for a great price
and were really imported Chinese knock-offs. The pictures show what happened. To read the whole story:
http://garage.grumpysperformance.co...help-i-might-have-no-oil-to-the-rockers.3397/
http://garage.grumpysperformance.co...e-parts-dont-come-in-plain-white-boxes.11940/
The pushrod seat inside of the Chinese knock-off was thicker than the GM, which effectively disables the lifter's ability
to pump oil to the rockers. By the time I figured it out, 1 lobe was already on its way to becoming round.
ISKY 264 Mega camshaft & lifters is in there now. So far - so good.
 
okay thanks for all the good info on lifters 302chevy!! I plan on setting everything up right on this engine and I have two questions in regards to measuring push rod length. How do you account for the collapsing of the plunger on hydraulic lifters to get an accurate push rod length? and how much do i tighten the rocker arm when checking pushrod length? thanks again for all the help so far!!!!
 
prctool.png


You will not have to if you use this tool.
If there is a gap on the pushrod side, you need a longer pushrod.
If there is a gap at the valve stem tip, you need a shorter pushrod.

For engine running, set rockers 1/4 to 1/2 turn down after pushrod clearance is removed.
 
It doesn't get any easier. Just make sure the cam is on the base circle of the lobe you are checking.
 
NO! its all pre-calculated , into the tool design,,if both the valve tip and push rod tip just touch the tool surface with the cam lobe, base circle, sitting on the lifter base
prctool.png
 
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Okay so the machine shop said my heads are good! So taking note of how much a roller cam would be a benefit I contacted Howard's cams and they recommended this cam any thoughts? Howard's cl110245 The duration seems kinda high to me please let me know what you think.
Basic Operating RPM Range:1,600-5,400


Duration at 050 inch Lift:225 int./231 exh.


Advertised Duration:278 int./284 exh.


Valve Lift with Factory Rocker Arm Ratio:0.500 int./0.510 exh.

Lobe Separation (degrees):110
 
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