327 buildup questions?
Thanks for the help guys.
Peak SAE gross power on a lab dyno was 359@6400, the imposed redline for the testing, and it was still climbing. It also made 80 percent peak torque at 2000, with just a slight drop down to 1500. The top end of the 80 percent torque bandwidth was beyond the redline.
Duke
Duke

heads $1000
Manifold, $220
Carb, $125
Cam $200
pistons, $250
bolts, $200
WP $50
Used Block with rods, cam , pistons, oil pump, crank, etc... $200
block prep and balncing assemblies, $550
Misc $ 400
stuff i bought and didn't use, $400 (carb, cam )
ended up using the crank, rods and timing stuff i bought with the block, a 350 4 bolt main one.
To me this was budget but i am not unhappy with the stuff i bought, weather i am putting it together right is another question that time will tell. i used friends, e bay, the forum here and the local speed shop as a parts/ info source. i obviously squandered $400 by changeing my goal after i started. i wold suggest you don't do that. good luck
PS i am sticking in a rev limiter with the MSD. probably at the 6500 mark maybe lower. depends on what the dyno tells in the end.
Last edited by panchop; Aug 6, 2004 at 01:17 PM.
* AFR 180 heads.
* Have your engine blue-printed for a zero-deck 10:1 compression ratio (high quench).
* If you have the money, use a hydraulic roller cam with specs of 110 lobe seperation/218 intake duration & 223 exhaust duration @ 0.05 lift.
* 1-5/8" Headers
* Edelbrock Performer RPM manifold and 750 cfm carb.
This combo produces approx 430 HP in a 350 according to the AFR website. Should be able to produce 350 HP in a 327 I would think.
The Best of Corvette for Corvette Enthusiasts
This is why 327s and more so 302s are known as "revvers".
I seriously doubt the claim that the configuration you quoted will produce over 400 SAE gross horsepower, but whatever the peak power in a 350 CID version shortening the stroke to 3.25 will result in about the same peak power about 500 revs higher.
Duke
327 cu in
AFR 180 heads
10:1 compression
Dual plane intake
750 cfm carb
Small-tube Headers w/ Mufflers
Comp Cam 270HR (hydrallic Roller - 218/224 duration 0.495/0.502 LIft)
RPM HP TQ
2000 128 336
2500 165 346
3000 205 358
3500 251 376
4000 295 387
4500 335 391
5000 365 383
5500 383 365
6000 385 337
6500 374 302
7000 351 260
It's important to note that this applies to engines that are identical other than stroke. For a longer stroke engine you can go with a slightly longer cam and a larger carb without increasing the beginning speed of the 80 percent torque bandwidth, so you can usually get a little more power out of them at a slightly higher mean piston speed than a short stroke engine, especially if you have really good heads.
Duke





1. The Vortec heads require a vortec-specific intake, which is not compatible with the AFR heads.
2. Out of the box, Voretc heads are only good for .460", without the rist of retainer to guide interference. The Vortec heads can be modified to accept larger cams, or can be purchased at a higher price already set-up for high lift cams. Both options will add considerably to the cost.
3. Properly set-up Vortec heads will probably run you close to $600 by the time you're done, then you need to purchase the intake. You'll be into this combo close to $800. At this point there are aftermarket heads that out perform the Vortecs, for not much more money. TFS 23* heads are a good, budget choice, and they use a traditonal SBC intake. Speaking from experience, it's a lot cheaper in the long run to plan for and ultimately build the combo you want the first time.
4. A while ago, in the C1-C2 forum, they were discussing manifold height with Vortec heads. The consensus was that the Vortecs placed the carb slightly higher than traditional 23* SBC heads for a given intake. If you have hood clearance concerns, this is something to consider.
Personally, I think the Vortec heads are great on the street, but if your ultimate plan is to step up to a better head in the future, I'd by-pass the Vortecs altogether. JMHO Wes
Personally, I think the power is coming from the way in which the heads were hogged out and pocket ported. The stock 1.94 valve heads have a higher velocity to promote torque than the stock 2.02 heads and porting these out to 2.02 gives them the flow while retaining the velocity. The fact that they are iron better keeps in the heat of combustion than aluminum heads.
My combination:
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, nickle plated
1" Aluminum open spacer, exterior polished
Edelbrock Performer RPM, port matched, exterior polished with all extraneous castings and lettering removed
Homemade lifter valley splash shield to keep hot oil off manifold bottom
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
Comp Cams 1.52:1 roller-tip rockers
Crane Cam Vintage Muscle 327/350 hp cam, 222 degrees @ 0.05, 0.443" 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
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
Champion plugs
37 degrees total ignition advance
Carter high-volume fuel pump
Melling high volume oil pump
Polished aluminum GM high flow water pump
Flex fan with polished aluminum spacer
Polished aluminum one-wire 100 amp alternator
Muncie M-20 CR 4-speed
3.70:1 positraction
Car recently did 293 ft-lb and 293 hp @ 5,500 rpm at the wheels on the chassis dyno. Engine pulls to 6,200 rpm and does over 200 ft-lb from 1,900 rpm. This was prior to some clean-up work around the junction of the carburetor and base of the air cleaner that smooths the flow through this area and should be good for a few ponies. Car has run 107 mph in the high 13's (bad tires) at the quarter and is probably faster now. Car is extremely streetable and could probably even run 87 octane if it had to. (I can't get the engine to ping no matter how far I advance the ignition.)
I've just done some modifications in the area of the carburetor/air cleaner base interface that substantially smooths the flow through this area and I would now expect about 300 hp at the wheels. (I took lots of pics and am considering doing an article.)
The secret to power is in the details and air flow. For example, when an intake and heads are matched to a gasket, and each other, there is still some "slop" in how the manifold lays on the heads such that you can end up with a ridge at the interface. However, if one really takes the time and knows how to do it, the interface can be seamless. Most shops won't take this kind of time.
That's why guys are always quoting some awesome et for their favorite muscle car (and believe they came that way from the factory). While the typical factory stock `60's -early `70's muscle car might be hard pressed to get into the 14's, we're always hearing about 12 sec GTO's. Z28's, etc.. There's a lot of power to be had in the "details" and there's also a lot of et reduction to be had in gearing and chassi prep.


















