327 Build

[Horder]

I’ve lurked on this forum for years. Learned a ton and will continue to. I hope I am not out of line asking for some advise on a street only build. If so, I understand.

Car is a 66 Nova, 2 door hardtop. Muncie 4 speed, Centerforce clutch, Hurst Comp Plus shifter, Moser 12 Bolt housing a 3.73:1 Posi. Street tire. 245/60/15. No power options, No AC. I drive it a couple times a week in the summer month, May - end of September....Canada! Lol Fuel is 91 Octane pump fuel. Building a recessed oil filter Nova block that matches my car and it’s theme as an L79 clone. Not looking for the fastest car or it wouldn’t be a 327. I want good street power and some lope to the idle. I’d like a car that’s not dismal to drive at low speed, yet can still make power to 6000 ish RPM. I would like some camshaft advise.
I was thinking hydraulic roller. But not set on anything really. The 327(331) I just pulled out had 461 double hump heads, 10.3:1 compression, Comp 280 Magnum. It seemed soggy to me. Here are the specs so far

327 bored .040. Torque plate honed
Forged flat tops with 4.9 cc valve reliefs
Forged crank and rods. ARP bolts, balanced
Zero decked, align honed
Trick Flow DHC Heads. 175 cc intake runner 60 cc Chambers
Plan to use .039” head gasket with 4.166 bore (suggestion on gasket welcome)
This “calculates” to 10.25:1 static compression
650 Holley DP, Dual plane (I have an L79 and Z28 Winters factory Dual planes) could be convinced to use something else?
Typically use a 4 hole 1” spacer
1 5/8” full length headers, 2 1/2” exhaust with H-pipe, exits behind rear tire

Although I had planned hydraulic roller and have zero issue spending the extra cash, if solid or hyd flat tappet cams make more sense in this type of build I’d love to hear that logic.

Head Flow is as follow, I have not bought full roller rockers yet as I want the ratio to be part of the camshaft spec.

.100 65 53
.200 133 104
.300 192 136
.400 233 180
.500 258 198
.600 255 107

Thanks in advance

[lefty o]

in a hyd roller, id think something in the 230-235degr with a 106-108 lsa and about .550" lift will get you where you want to go, but better off talking with the camking for better specs.

[Horder]

Thanks for the reply. In a hydraulic roller I was considering smaller durations than that. Maybe my compression is too high for these smaller ones like the 270 or 272 intake lobes? I have never used a roller cam, only hyd and solid flat tappet, so I am possibly wrong on my considerations.


Cams like
270/276 218/224 .330”/.335” lobe 110 LSA
272/278 219/225 .350”/.350” lobe 110 LSA or 112 LSA
278/278 225/225 .350”/.350” lobe 110 LSA or 108 LSA

I had previously done some reading that mentioned because of a hydraulic roller’s slower acceleration off the seat that in lower duration cams, a flat tappet made more power. Of coarse that makes a guy think that it must be an aggressive flat tappet lobe destined for failure so the appropriate route would again be a roller.

I would also like to know opinions on my head gasket thickness. I’m at .001” deep to 0 deck. It’s a forged flat top.

As well, are these old “winters” intakes boat anchors by today’s standards? I have read/been told the L79 intake is not a good choice but the Z28 intake is very similar to the edelbrock RPM.

[steve316]

With .040 over bore on a 327 (4.040) a .035 to .040 compress gasket would work. A cam with 224 to 236 intake & run 6 to 8 degrees
spread on exhaust. Run 109 to 112 LSA ; 109 for a lope idle 112 for a smoother idle.

[Walter R. Malik]

With your standard shift, I would use a smallish cam, (probably around 220@.050"), with a tight separation and as much lift as you dare, (usually a hyd. roller will attain more lift), so it will idle rough but, get smoother as you drive higher than the idle speed.

[cgarb]

Have you looked at any of the street solid rollers? Some of the more mild stuff you don't need a ton of spring pressure and a good set of lifters would last a long time. The solid roller lifters are usually cheaper than hydraulic ones and can be less fussy in my opinion. You hear of some unhappy people with valvetrain noise hydraulic rollers. Going over the valves once a year isn't a big deal to me. I went roller a few years back in my bracket car and havent looked back. I know I have about 8 seasons of racing on the very 1st set of Herbert brand roller lifters I bought. I'm putting new in this year just for piece of mind, but they still look good and the rollers turn smooth. I've had good luck with thier stuff, but I wouldn't advise buying cheap Herbert lifters and try running them on a camshaft ground for a 410 sprint car. Everything has its limits.

[Horder]

I plan on keeping my front sump oil pan on the Chevy II. Oil pumps are quite limited and my understanding was that solid rollers needed more oil volume???

[novadude]

Just my $0.02. I've got a similar car (65 Nova, M20, 3.36), and I am using a Howards 270/278, 217/225, 108 LCA hyd roller cam in a 9.6:1 355 with Vortec heads. I would think something similar would work real well for you. My car traps 108 mph (ET was a slow 12.9x, but that was due to a poor 60 ft as I was launching easy). I am also using the stock Chevy II L79 pan with the factory windage tray (reproduction from chevy2only).

My cam is pretty similar to what you were looking at. I would stick with 108-110 LSA. JMO.

PS: the rest of my combo is a GM 'performer' style intake (not RPM), dougs tri-y headers with 2.5" exhaust and x-pipe, quadrajet, 1.5 rockers. Just a simple street engine that has a slight lope at idle and delivers decent highway mpg.

[1980RS]

Put a 268H can in the 327 you will be much happier and the little engine will be a lot snappier. A 280 is pretty big for that, I have used both.

[FuelieNova]

My first engine in my 66 Nova was a well machined 327 with nothing more than the Edelbrock Performer RPM kit, (heads, cam and intake). Compression was 10:1. Muncie 4 speed.
This engine ran amazing and was a great combo for the 66, Mine had Ford 9" with 3.73 gears at the time.
Tom

[PRH]

I guess I’ll be the outlier here.......

I’d run a fairly small tight lash SFT cam, single pattern or maybe 4* split, 108lsa.

[mt-engines]

Just my $0.02. I've got a similar car (65 Nova, M20, 3.36), and I am using a Howards 270/278, 217/225, 108 LCA hyd roller cam in a 9.6:1 355 with Vortec heads. I would think something similar would work real well for you. My car traps 108 mph (ET was a slow 12.9x, but that was due to a poor 60 ft as I was launching easy). I am also using the stock Chevy II L79 pan with the factory windage tray (reproduction from chevy2only).

My cam is pretty similar to what you were looking at. I would stick with 108-110 LSA. JMO.

PS: the rest of my combo is a GM 'performer' style intake (not RPM), dougs tri-y headers with 2.5" exhaust and x-pipe, quadrajet, 1.5 rockers. Just a simple street engine that has a slight lope at idle and delivers decent highway mpg.

Thats the same Cam I was going to suggest. Great for pickups, vans cars. Good power to 5500.

[Horder]

Really appreciate the responses.

Yes the 280 Magnum was a weak cam in a 327 until 3000 RPM. Sounded great. With a good tune I could get 10” of vacuum and a cool 650-700 RPM idle. The engine had a real 10.3:1 compression with 59 cc (shaved so much the intake wouldn’t fit lol)461 double hump heads. I went with a bigger cam on that build because of compression and iron heads It never pinged once. But it was never right, if you know what I mean

This engine has the benefit of aluminum heads, forged pistons, good machine work including balancing. Hoping for better performance with what I feel is a well flowing small runner head, CNC chamber, etc

I haven’t put much thought into a solid roller. But a smaller solid flat tappet has been something I have looked at such as the Xs268s and the Lunati VooDoo 266. Not being worried about a cam going flat makes me lean roller, but is it really an issue if good parts are used and break in is followed

[Horder]

With the head flow dropping from 258 to 255 between .500 and .600” lift, where would you like to see intake lift?
Exhaust port is solid to .600” lift flowing 198 at .500” and 207 cfm at .600”

[tenxal]

If it was mine, I'd keep the head gasket bore much tighter (think Cometic gaskets ), stay away from a hydraulic roller cam (use a solid roller with as much lift as the valve reliefs allow) and for sure use the Z28 intake....the L79's are not that great. Really, about the only way to muddy up the results are by not keeping the compression up, too big a camshaft/carb and a poor intake.

Nice project!