OK school me on a 327 sbc cam selection

Oh how I remember these days. Spending days and nights pondering a camshaft selection only to get jammed up at the end trying to decide between two cams.

I'm building a .030" 327 with Edelbrock E-Tec 64cc chambers 170cc runners, Edelbrock Performer EPS Vortec intake, 600 or 650 holley square flange (I haven't bought it yet), headers and exhaust undecided, Flat top hypereutectic pistons, compression figures out to be around 9.5:1. It's going in a 2900lb car with a tremec TKO 600 5 speed with a .64 overdrive going to a 3.73 limited slip rear. I'm looking to drive this car A LOT, so I can't have it guzzling gas, but would like it to sound nice, pull really well through the gears, be done at 5500 rpms with a set redline of 6000. I figure I want the most torque between 2000 and 4500rpm.

The camshafts that I narrowed it down to are both roller cams, with specs as follows:

Lunati voodoo 60111 roller
duration at .050 219 int, 225 exh
lift .515 int, .530 exh
LSA 112 (6 degree advance)

or

Comp Cams 12-422-8 xtreme roller
duration at .050 218 int, 224 exh
lift .495 int, .502 exh
LSA 110

I remember 327's in my past loving to rev up and my memory could be rusty but I thought big bore, short stroke engines (everything relative) liked short stroke, high lift cams.

I have read till my eyes bled, and at this point am going in circles.

What's your opinion? Does anybody have desk top dyno?

PS if I'm way off on this combo, please chime in.

 

tHey are midrange and topend motors ,I think number 2 is your best choice ,Get more opinions though

 

Anybody else?

 

I ain't touchin' this one!! One thing about a small block chevy is, there's so many cam grinds out there... I wouldn't know where to start.. If it were me, I'd try for a roller that's close to the L-79 flat tappet grind specs... Then that's just me... Let's see what the other guys like......

 

I ain't messes with sbc much for a loooong time but we used to love those 350 horse hydraulic cams, a little more radical was the solid Z/28 cam and the 30/30 Duntov would wind like a bad boy but didn't have much down low.

 

That's a fun cam also.... When the lash is adjusted perfectly....

 

you have narrowed down two good cams. I vote for the Lunati. The heads are where your power is. Those rollers reach 5 grand REALLY quick especially in a 327. If gas mileage is a major factor you need to go further. My opinion. peace

 

Thanks for the input, it is appreciated. What did you mean by "go further"? Is that go further mileage or go further with research or...?

 

Not sure how you got to where you are on your selection, but Comp Cams has a free download you can play with to run different specs. I happen to like Lunati cams - they seem to have more selections using 1.250" spring diameters whereas the Comps mostly seem to use 1.44". That only may be of interest depending on how your heads are cut.

 

I would use the lunati cam, heavy steel flywheel, 4.11 gears and wind it to 7000. The heavy flywheel should help in O.D. and the lower rear gears will get you into the power curve. If you want 2000 to 4500 power build a 383 or 400. I like the direction you're going.

 

Neither of those cams will make power to anywhere near 7K in a 327.

 

My only recommendation is that you don't use the lunati lifters. I have a very good friend who is a machinist, he informed me of a defect involving the diameter of the lifters. they are apparently slightly larger than spec. causing them not to turn. which leads to cam failure before you ever leave the garage. the problem could have been something that was isolated to a particular model, but I am not for sure. if you use the lunati and use their lifters, just be sure that they are free to rotate.
i do have a lunati bracket master II, cam only, in my hunting rig. it works great so far with no problems.

just trying to inform you of a problem that could potentially screw up an engine build. I am no expert, by any measure, just thought that you would want to have the heads up.

Good Luck with whatever you choose.

 

I run the XR 264 HR (12-412-8) in my 355. It will idle smoothly to 600 rpm in gear with the TH 350 auto trans. Pulls from idle all the way to 5000 plus. I run 9.5 cr and a tuned port injection setup with a 3.36 gear.

Very pleased with the camshaft.

 

Well that would be unfortunate if that was true. I'm probably going to use a cast 307 crank. I don't think it would like that too much. The specs say 5800 rpm it drops off, but I'm guessing that that is most likely in a 350. I never did know what engine they make all these speculations for.

I'm leaning towards the Lunati, but haven't pulled the trigger yet.

Any more input anybody?

 

A couple of things to watch for--

If you buy the Comp roller, MAKE SURE it is on a billet core, not cast. Most of their "shelf" rollers are cast cores which can't take the spring pressures a roller needs. The other thing to watch for is the springs they recommend, which are very light to match their cast cams, but will float the valves as soon as you blink.

I just went through this on my own engine, pulled the Comp cam and installed a Lunati, with Isky springs.

Of the 2 cams listed, I'd be more likely to choose the Lunati due to it's specs, the 112 lobe centers will build more low speed vacuum and help with that overdrive which is going to be very deep. You will effectively have a 2.38 gear in overdrive. A little more lift never hurt anything either, as long as you have the piston to valve clearance.

Devin

 

I have a Y block Ford, about the same cubes, same rear gear, similar ratios for my five speed, and close to the same numbers on the cam. You will like this combo on the street. Its easy to go to big on the carb, stay with a 600 or 500 or you loose throttle response. You will find you can drive all day and never exceed 2500 at legal speeds to get your fuel mleage, yet when you wind it up you have an exciting ride.
Have fun!

 

Be careful that the cam will not be below the powerband in overdrive. You will need to do the math w/tire size etc. It may be tough to get an agressive idle and good mileage. Call Comp and ask about the small Thumper.

 

Call the cam maker and ask what they suggest.

 

Excellent recommendation, but doesn't go far enough. Call at least three or four. By the time you have talked to that many, you may be a little confused (everybody thinks their stuff is the best), but you will probably have an idea about what specs you need for the application.

 

Of the two cams you have listed I like the lift on the Lunati better. I would still like to see the exact #s on the valve timing. For the task at hand of what your asking of this engine the Intake valve opening and the exhaust valve closing are the TWO MOST IMPORTANT #s to know >>>>.

 

well i think they both have too much lift. anything over 480 lift starts to push the valves sideways in the guides which incresses guide wear.

i used 480 lift cams in the dirt track cars made plenty of power. one guy i built a motor for changed to a 512 lift knocked the guides out in one season.

 

are you buying the retro lifters or converting your block to use the 3.1 lifters?

 

I have never had this happen.

 

Here are the specs on the Lunati 60111 voodoo cam.

http://www.lunatipower.com/Product.aspx?id=1988&gid=289

and here are the specs on an alternate smaller Lunati 60110 voodoo cam

http://www.lunatipower.com/Product.aspx?id=1987&gid=289

What do you think?

 

I'd be getting a cam and lifter set. They call them retro fit. Never heard of the 3.1L lifter trick, but it sounds interesting.

 

I calculated the 65mph cruise RPM to be 1792. Now I'm leaning towards the smaller Lunati 60010 voodoo roller camshaft listed above to get within the rpm range listed.

duration at .050

int 211
exh 219

lift

int .507
exh .515

LSA 112

I'm hoping it doesn't sound too soft at idle. Any last input before I heat up the paypal account?

 

Any cam that has the low torque range you seem to be looking for won't have a real radical idle. Based on the displacement of your engine, cylinder head intake runner size, and what it looks like you want to accomplish, you might be even better off with the Lunati 60110 VooDoo.

 

Ok, I am going to push the envelope a little bit. I would up the cam a little bit. With the 60112. I think your motor is more than capable of handleing it with good driveability. Plus this cam would ad a little bit more sound to your engine. I still think in overdrive this cam will be fine. You should still call Lunati and talk to them. I have talked to them before and they are really nice and helpful.

 

I just got off the phone with Lunati. I purposely just fed him information and let him decide which cam. He chose the 60110 roller. Then when I had asked if it would have a nice sounding idle he said I could go with the 60111 roller. Soooo, I guess it's down to talking to people to make the final decision.

I also spoke to Comp today and they recommended the cam that I listed in the beginning of this thread. That falls in between the 2 Lunati cams, but I thought that design didn't produce as much "area under the curve" as the Lunati voodoo rollers.

I'm still not certain what to do.

...Looking for more opinions...

 

This seems fitting here - If in doubt go for the one with the higher RPM potential. I never get tired of winding one out

cams are a lot like women

example - big flashy cam with impressive numbers - requires high maintenance, additional money to me spent on other parts to keep it happy

stock cam - not so flashy - still does good things for you, has good torque in her bottom end, may not rev as high but runs good with little to no maintenance. No additional money is required to be spent on other things.

The farther you go above stock cam the more you'll have to invest in the whole set up and them keep after it to keep the set up happy.

Then there is only one way to know how a cam works. Try it out. You can read all you want about them and you'll never know until you stick it in and try her. Then there is a wide variety of cams we all want to try every one we see. Hydraulic, solid flat tappet, solid roller, hydraulic roller. But it is expensive to change cams just like women. You usually have to stick with the one you have. But then you always wonder and dream - what if I had a really hot flashy roller cam with all the goodies. Woo that is really cost you to try it out. But then you would have a trophy cam!

Then you have other guys opinions about cams, they are all different. One guy likes them huge, the next guy likes them lumpy, and the next says he needs a lot of vacuum. It just all depends and there is still only one way to find out. Try them out.

Some guys even like to try used cams. Now that is a whole nuther story that can be expensive and dangerous.

You also don't usually get to try out new cams just for fun. The one you have usually needs to go bad first.