Thread: 327 Build Cam Selection

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Hey Guys

Getting the 327 done and need to pick a cam soon. The car is a 66 Nova 2 door hardtop. Small journal 327, .030" over, Muncie 4 speed, 12 Bolt 3.73:1 Eaton with around a 24.5" rear tire.

The car is a going to be a cruiser with the odd mash of the throttle..lol
No power brakes.

Using flat top Speed pro hypers, decked block, .040" quench, around 62 cc domes in 291 double humps. 2.0/1.6 valves. Guide plates, screw in studs. Running a holley 600, L79 490 winters intakes, 1.5" headers with duals and an H-pipe. Electronic ignition.

Static compression is between 9.85 and 10 depending on exactly where the heads come in at.

Looking at the following cams. My builder likes the old Comp 270H. I was thinking it might build a little too much dynamic compression with an IVC of 61
With the 10.0:1 compression the 270H comes in at 8.14 dynamic. Too high?
I like the XE274 with IVC of 63 bring the dynamic right to 8.0 if I hit right arout 10:1. Comp tech line which originally told me to go XE268 is now saying XE 274 or Comp 280..

Thoughts are appreciated.

I did some cam checks on this engine . Now it's going to be for street Performance . So you will want a Camshaft that will give you good H.P but max Torque .

The XE268H showed to be that cam 359.2 H.P 398.7 Torque

The XE274H shows 364.7 H.P 392.8 Torque

Now that L-79 Intake is ok and a well set up 600 Holley would work ok . But when I plugged in a Better Dual Plane intake and a 700 cfm carb the H.P up-ed 25 Horses and the Torque 13 Lbs on either Build . I would go with the XE268H with a Better intake and carb = 386.3 H.P 411.0 Flbs Torque .

I am worried about dynamic compression being too high with the XE268. Could end up as high as 8.2 with the iron heads??? Thoughts??

I am trying to keep this build period correct as the car is done as an L79 clone. That is why I am going with the Holley 600, winters aluminum 490 dual plane, correct valve covers without holes, dual snorkel air cleaner, oil tube with the correct PCV valve. I picked the small journal 327 with the road draft opening at the back of the block to do this.

I don't plan on changing to an RPM intake but for 25HP??? I wouldn't have though a change in carb and intake would help that much below 6000RPM. I was told the 600 is plenty big enough below 6000???

I like the Magnum cam line, and I ran a 270 Magnum in a 327 some years ago and really liked it. The one thing you have to check is the DCR. A Magnum cam will allow you a little more static compression than an XE cam because the intake valve closes later. To give you an example, when I was choosing a cam for my 383, I was looking at the XE-274, but with 10.6:1 static compression, it pushed the DCR to 8.64. But with the 280 Magnum, the DCR was 8.44 which is acceptable for aluminum heads and 91 octane. Because you want to stay under 8.0 DCR with iron heads. Your best bet is the XE-274 or the Magnum 280 or something comparable from Crane, Crower, or Lunati. Because you have a 4-speed, you can go bigger on the cam and still have decent street manners. I don't think either of these cams would be good with an automatic transmission.

I'm with Lynn - especially in light of the four speed as your left foot can regulate your stall speed if you will.. In that he (Lynn) has real life experience with a motor that's similar I don't think you can go wrong with his recommendation..

If stock appearance wasn't important, Tango's got it nailed and trust me - you'd definitely notice another 50 ft/lb of torque in a 66 Nova.

Let us know what you decide - I'll be curious to get your reaction after your initial test ride..

Regards,
Glenn

Much appreciated guys!

Oh yes, I know I would notice another 50 Pounds of torque. I know I might get a bit more with the newer dual plane designs but I think my 600 Holley and the winters L79 dual plane will work well.

Does anyone think a Comp 280 is toooo bigggg??? With a light car, 4 speed, 3.73:1, and a small tire(23560r14), I have friends telling me the 280H from comp is the ticket.

Originally Posted by rumrumm

I like the Magnum cam line, and I ran a 270 Magnum in a 327 some years ago and really liked it. The one thing you have to check is the DCR. A Magnum cam will allow you a little more static compression than an XE cam because the intake valve closes later. To give you an example, when I was choosing a cam for my 383, I was looking at the XE-274, but with 10.6:1 static compression, it pushed the DCR to 8.64. But with the 280 Magnum, the DCR was 8.44 which is acceptable for aluminum heads and 91 octane. Because you want to stay under 8.0 DCR with iron heads. Your best bet is the XE-274 or the Magnum 280 or something comparable from Crane, Crower, or Lunati. Because you have a 4-speed, you can go bigger on the cam and still have decent street manners. I don't think either of these cams would be good with an automatic transmission.

well...I decided on the 280H... its 230/230 @.050" .480" lift, 110 LSA. It should get me 7.85 -7.9 DCR. Hopeing that will be safe with the iron heads. Might be a little softer on the bottom end but should sound great. I had the old L79 cam in there before with less static compression, poor squish, and it bleeds off a lot more compression than the 280H. I thought it ran well so this should be a good cam. Thanks for the help boys...

I think you'll be real happy with the 280H - it should open and closes valves in the sweet spot of your engine build / combination and with the four speed and a 3:73 rear end, as mentioned earlier, you'll quickly get the feel for good RPM ranges to start mildly or launch a bit and with as light as the Nova is the first time you hit second at WOT you'll see God and have to change your shorts - Have fun and please let us know the results!

Regards and Happy Thanksgiving,
Glenn

280H with your L79 Intake and 600 Carb is 359.3 H.P with 386.8 Lbs of Torque your giving up 12Lbs of Torque over the XE268H and will have a worse Idle as well .

I was First thinking about the 270H but it gives up a Lot of Horse but the Torque is up 348 H.P with 399 Lbs of Torque . This was done with Comp Cams on Line Info .

Here is a 280H in a 355 with a bit more Compresion then your 331 has . It will be more grumpy in your Engine and if you get into some traffic and your Ign is not were it should be Like with no MSD it more then Likely will Load up . With what your Running for heads and Intake I think the 280H will be a Bit to Much Cam

Tango...thanks for your replies and I do agree in a sense. Using camquest, the obvious cam is the XE268. Makes similar HP to the best cams plus the torque is greater. That was my choice from the start. Then when we started running DCR calculations the dynamic was ending up as high as 8.3 with the XE268's 60 degree intake valve clsoing. This way too high in most peoples opinion for pump fuel. The 270 wasn't much better with an IVC of 61. So even though I was giving up 2HP and 10 Tq(according to my numbers on camquest) the desicion was to be safer. No forged pistons to battlle detonation either. I have read numerous posts with guys running the 280 in similar 327's with less compression etc... and they have been happy. Hope I will be...lol You believe an MSD will be valuable in the running quality of my 331?

Yes an MSD would be very Valuable to your Engine as it is to Most Street / Strip Builds . That 280H would make it's self more usefull with a Better intake and carb . I have ran that Intake as well as the camshafts above . It turns on at about 1500 and shuts off at about Max 5400 . You build that 331 right and have the valves set right it will go well over that . Sure the 280H will blow off some Compression in Doing so it also Lets go of some Torque . Any how you Look at it your going to have to run 92 octane fuel . I just built a 327 same Like yours / Better intake and Carb and had a camshaft ground for it Should run on 89 octane Fuel and not Load up and have Torque Like a 350 .


http://oi56.tinypic.com/ixz2hz.jpg

An MSD will be on my Xmas list then! I was thinking I would spin this 327 to around 6000. Used ARP bolts on the bottom end. What intake carb would you suggest? Edelbrock RPM and Holley 750DP?

If your going with the 280H and want Max H.P then go with a Edelbrock RPM Air Gap with a 700 D/Per Holley . If you want it to have more Low end Torque and better Throttle response then use the Regular Edelbrock RPM with a 650 Performer AVS Carb .

Is it possible the L79 intake will make more torque than either of those?
My engine builder thinks that intake is great for torque and HP bleow 5800RPM?? The cam show max HP @ 5500. I wasn't planning on spinning above 6000?

His thought was that if I wanted an aftermarket intake, that the Edlelbrock EPS was ideal up to 55-5800 on a 327??