H.O.Rider

I am finally getting around to building a new 327 for my 66 Chevy II. I like to post my 327 questions here as there is a tremendous amount of knowledge on these forums.

Car is a 2 door hardtop, 4 speed Muncie M-21, Moser 12 bolt with an Eaton 3.73:1 Posi. Tire is 235/60/14 street tire.

Block is a recessed oil filter Chevy II block 3791362
2680 forged crank
Scat 4340 forged floating rods
Wiseco Forged flat tops, 2 VR @ 3 cc
461 Double Hump Heads, 2.02/1.6 stainless valves
Deshrouded, pocket ported, screw in studs, guide plates, new guides, hardened seats, Magnum roller tipped rockers.
Heads cc at 62-63
SCR is 10.1-10.3 with .040" quench
I have two intakes to choose from. L79 or LT1 winters
L79 dual snorkel air cleaner
600 Holley vacuum, 4 hole spacer?
1 5/8 Headers, 2 1/4 duals with H pipe
Stock distributor with Pertronix module

Now I ask for your opinion on cams. I think the L79 cam would run well with the true compression I have. But I would love to get input on other choices including 30-30, 178, 097, XE solids, Voodoo, etc...
Car will be street driven only.

BADBIRDCAGE

JMHO. Street driven only? Retro-fit hydraulic roller or standard hydraulic performance camshaft such as GM 327/350 HP cam would be my choice. If you were tracking the car maybe solids but not for street use only. You arn't going to see any benefit.

MikeM

Given your choice of cams. L 79 first, 097 cam second choice. Either is durable and very streetable with good power for the street. No problem with 10-1 compression with these cams.

Junk the spark advance curve in the L 79 distributor and get a quicker curve in it.

PS. the LT1 intake is generally regarded as a better intake than the stock L 79.

H.O.Rider

I was thinking solid as I have read with a correct sized solid I would have more torque throughout the RMP range.

The CamQuest program I was using seems to support that.

With the GM cams will I have tom worry about a lobe going flat? That's the only way I would consider a retro roller.

What brand of L79 cam would you buy? Speed Pro?

65tripleblack

What is the deck clearance and head gasket you plan to use.

Vintage flat tappet cams are terribly inefficient, and will run like a turd compared to a modern cam. The poor running will be exaggerated unless you have the proper static compression ratio.

It already looks like you want a vintage cam. If that's the case, then be sure to deck the block. Use an online calculator, or give me the vitals and I'll do it for you. You're leaving a lot of power on the table if you continue in the direction you seemed to be heading in.

H.O.Rider

Thanks for the replies! Much appreciated.

I am not against a modern cam. I would love to hear what you guys think.

In terms of DCR, I did the calcs based on .040" over, 3 cc piston valve reliefs, .012-.014" piston depth, 62-63cc heads as measured. .028" gasket.

65tripleblack

As stated, the Z28 intake is far better. The L79 is junk.

You should use a steel shim gasket (about .018 - .021) to get the highest SCR that you can.

I would never build an engine using a flat tappet cam, but a roller will require extra money for valvetrain components, as well as head modifications. Probably cost you an extra 400-500 dollars.

If you want a vintage solid cam, then look at the Duntov. Believe it or not, the 097 cam will run better than the L79 with lower compression! I LIKE the 097, with it's relatively tight lash. The only "problem" is the low lift, designed for the 283 engine and 1.94/1.50 valves. I always recommend the 097 cam for those wanting a vintage cam for a 327 or 350, but with the added lift provided by TRUE 1.6:1 rockers. This will yield valve lifts of .412/.4084 (with .008/.018 lash). You can run it a few degrees advanced beyond spec for added DCR at low RPM's.

The best hydraulic is the L46/L82 (962 cam) as it has slightly more lift and duration than the 151 cam. You can install this cam slightly more advanced than spec to make up for your lower compression ratio.

In ALL cases, design your engine for no more than about 8.5:1 DCR. This will give you enough margin to use 91 octane (or 93 depending on location) with a very aggressive spark advance program (for low/midrange torque) while running detonation free.

H.O.Rider

Based on what I have what cam would you recommend in a Hyd or solid roller?

toddalin

This is the cam you want. You get everything else right and with your combination you can put 275-300 hp to the rear tires.



http://www.summitracing.com/parts/crn-967601/overview/

hundriver

As stated above, Crane makes great cams for the SBC. I used a Crane solid flat tappet in a SBC engine I built several years back. I also used Crane roller rockers.

Bowlerdude

If you're set on having a solid lifter cam then the LT-1 cam works pretty good, it has good street manners and some people prefer it over the 097.

There has been a lot of discussion on this subject here and if you were to do a search of the forum you'll find lots of info on it and a few heated discussions to boot.

H.O.Rider

Not really set on anything...solid/hydraulic/roller/flat...

Just want to keep the engine looking "the part" so to speak. I know the LT1 is a better intake and may use it over the L79. Just want to keep the double hump heads, old school intake, etc. But, I want a good sounding, streetable engine that is reliable.

Again, your thoughts are much appreciated. Especially if you have run a similar setup in a car weighing similar to my Chevy II...

H.O.Rider

Using CamQuest the Comp 270S or XS268S make good power but may be a touch small for my DCR. XR276HR looks good in a Hyd Roller and 268AR looks good in a solid Am I off base on where I should be?

I have a set of 26918 Beehives that would work for a roller.

troutster71

toddalin

Your set up is similar to mine and I use the Crane cam that I included in the link.

BTW, last Friday I had my mechanic change out the valve springs trying to get a little more RPM out of the engine, even though I'm already making max power at a hair over 5,500 RPM and the cam card notes it at 5,200 RPM. But the card shows valve float at 6,500 and I'm not/wasn't getting close to that.

The old springs were 10#+ light on the seats and 20#+ light when open and there was far more variability between them, so the next dyno pulls should be interesting.



331 CI, pump-friendly 9.5:1 CR
K&N 14"x4" air filter, Corvette drop base and lid
Holley 600 dp, choke horn milled and blended, Primary - 69, Secondary – 74, Squirters - 21
1/2" Aluminum open spacer port matched to manifold, exterior polished
Edelbrock Performer RPM intake manifold, port matched, exterior polished with all extraneous castings and lettering removed
Homemade lifter valley splash shield to keep hot oil off manifold bottom
Manifold heat riser crossover blocked
Camel hump 1.94/1.50 heads hogged out to 2.02/1.60, pocket ported, port matched, pump-friendly hardened seats, 3-angle valve job
Cylinder bores clearanced to unshroud the valves
Comp Cams 1.52:1 roller-tip rockers
Crane Cam Vintage Muscle 327/350 hp cam, 222 degrees @ 0.05, 0.447" lift (with 1.50 rockers)
Doug Thorley headers, dechromed and ceramic-coated
2.5" mandral-bent exhaust (including tips), 2" cross-over just before rear axle
DynoMax stainless Ultra Flow mufflers
Millerspeed 1-1/2” Gilmer under drive belt drive system
Mallory Hyfire IV CD ignition box triggered off Accel points
Mallory high voltage chrome coil
Mallory spiral-wound coil wire
Mallory solid copper plug wires, ends soldered to wires
Champion plugs
37 degrees total ignition advance
Carter high volume fuel pump
Melling high volume oil pump
Open breathers
Polished aluminum high flow water pump
160-degree thermostat
Flex fan with polished aluminum spacer
Polished aluminum one-wire 100 amp alternator
Header Power Bracket
Keisler TKO600 5-Speed
Hurst shifter
3.70:1 positraction with Big Block yokes
225/60/15 Firestone Firehawk SZ50s on 7”-wide Western 30-spoke Turbine Wheels

mrg

LT-1 cam is a good choice for a street cam, also IMO. I'm running one in a .040 over 327 with flat tops. Good low/mid range with decent higher end performance.

MikeM

I ran what I recommended in a Chevy II and still run it.

It would run mid 12's/110-112 or high 7's in the 1/8 on 7" tires.

I just recently tore the engine down for a look after nearly 50 years and it was all there with little wear. Almost none on the cam/llfters.

If you want more performance/durability than that, by all means spend the big bucks and go for the roller cam and rewoked/replacement headsl

Otherwise, save your money as you said it was going to be street only.

H.O.Rider

Are you running the L79 cam or the Duntov 097? Flat tops or domes?

427Hotrod

I've had really good luck with the Crower #350 cam in engines like this with double hump heads.

http://issuu.com/crower.com/docs/che...768832/5605531

268/274 ADV 238/244@.050 .497/.503 lift on a 107 LSA.

It idles great with a good lope...incredibly throttle responsive...drives fine and will wind 7000+ if you want to. Plus it doesn't hurt parts. Don't be scared of the 107 LSA...it idles better than many of the factory cams with longer durations and wider LSA.

I'd get rid of the vacuum secondary carb. Lots more fun with a double pumper. I'd use the LT-1 intake also.

JIM

MikeM

That was a factory stock L 79 engine with domed pistons. The first few years I ran the 097 cam and the 30-30 cam. The timed runs were with the L 79 cam and the Lt1 intake.

This is all old time stuff. It ran good, held up well and was cheap. And very streetable. Still, today, that combo will get it's doors blown off by any number of new cars on the street.

If you're trying to be the fastest guy on the street, take another road.

PS. If you haven't done your machine work yet, a 350 crankshaft will slide in that Chevy II block pretty easily and cheaply too. If you stick with either of the Chevy camshafts, I do with the domed pistons and bump the compression up. I could run 89 E 10 in the engine I described in the first paragraph.