Astrodokk

Everything has changed after slipping a rod bearing. New motor here: http://forums.corvetteforum.com/c1-a...383-build.html

I decided to post in here rather than in the drag racing section because I think it's pertinent to engine mods vs general racing info.
I recently drag raced and finished with a 13.9 secs @ 103.32 mph. This is typical of the 1970 LT1 350/370 engine that I have in my '65 right now. However, I've been told that the heads are the '73 heads (330545) which are 74 or 76cc combustion chambers with 2.02-1.6 valves. It has an unknown mild cam and a Holley list 4779-9 double pumper with 4 corner idle screws, sitting on an Edelbrock Torker single plane wide mouth intake manifold. As you can see, this is old school stuff that is period correct for a car that has been modified in the early seventies and configured for drag racing (Can Am flares and big rear wheels) during that era. I'd like to improve upon this.
Besides all the safety stuff that has been replaced with new (tires, fuel line, shocks, steering rod, et cetera), I also have an Edelbrock C3BX dual plane intake that I could install. My question to you motorheads out there is: In order to get more power, what heads should I look for and maybe even what other carb and or intake manifold could I use to keep my car a sleeper (has the small block hood) yet kick major behind when I'm up against those Fords and Mopars that show up at the track?
I appreciate any advise.

cardo0

Well lets be truthful. If you have '73 heads on a '70 motor u no longer have a '70 350/370. U can get an idea of cam and compression by measuring cyl press with a compression test. If you have cyl press between 180psi to 210psi u have a good street performance combo. I would be happy with that.: : More than 210psi means engine life will be short on pump gas. Less than that has room for improvement.

For performance improvements u need to tune the carb and ignition to achieve optimum results. Yes even just changing to headers or a new intake will require tuning changes to make them work correctly.
What do u have for a timing curve? When does the curve start and when is full timing in (rpm)? Are u using vac adv? When does your vac adv full (manifold vac at idle) and when is out (WOT)?
Now for new school, can u install a $150 Air/Fuel mix gauge with O2 sensor? Then tune using your carb metering rods or jets (what ever your running) for rich 12.5:1 WOT and lean 15:1 cruise?

Now lets talk parts. Plenty of great heads sittting on the shelf for <$1500 - just bolt'em on. Pull the heads to measure quench height and compression (piston volume). Choose heads that will nail your compression ratio and a head gasket for quench height. Now find a cam to match this combo. Headers - yes. Intake last, try a few - they're cheap.

Well that's a very quick summery but i hope it helps point u in the right direction. Too many details to list but we'll be here for you when u need'em. And really everyone has they're own preferences so build it for what u want to do.

Hope this helps ya'
cardo0

Astrodokk

Thanks for the reply. I'm printing it out to take to a hot rodder and see what he can do for me. To be even more truthful, I would like to use the dual plane that I have and just fit some better heads than what's on now. The 492's are the LT1 heads that should be on it. I know that not having the original components makes it not an LT1 any longer , but using that premise, since my car doesn't have the original 327, it doesn't make it less of a '65 Vette neither
Nonetheless, your point is well taken and still, I appreciate your insight into making more power for this motor. If I can bring my time down to in the 12's. I'll be happy!
By the way, I want my 350 to look like your 350

mayordaly

Sounds like your heading down that old path of chasing horsepower with the least amount of money. Beware that slapping mismatched heads, cams, and carbs may cost you more headaches in the long run.
Edelbrock has some good combinations Cam, heads intakes and carbs. that will compliment each other is the best way. You can chose if you still want to use pump gas, low or midrange H.P. and torque etc..
But then you need a good Hurst competition shifter, heavy duty
competition clutch, heavy duty Universal Joints, higher volume fuel pump, 411 rear end etc.. do you have a T10 tranny,(not so good for racing). After the first 400HP it gets pretty expensive. So set your goal and figure how much to get there. You car looks fast already,
ain't that half the fun already?

cv67

To keep up with them guys look into an aftermarket head such as an AFR and a stout roller cam, minimum.

BLOWNBLUEZ06

Just sneak a line in the back of the intake and spray it from underneath and hide your bottle. That way it is period correct and everyone will be wondering what the hell this car's got. I don't know of any V8 that wouldn't take a 100shot.

MLCZ51

gkull

I was able to build a very consistent 12.70's bracket racer out of my 355 ci 79 Vette and still get 20+ mpg on long trips.

Weiand single plane. 200 cc iron heads with 2.055/1.6 valves 10.7 compression Balanced and blue printed motor Crane 278 H-flat cam with 1.6 RR 1 3/4 headers true dual W/O cats.

I drove that motor for about 60,000 miles and it could do over 7000 rpm

larrywalk

This takes me back about 30 years ago when I put an LT1 (350/370) in a '65 vert and went to the strip once to see what it would do. I had a close ratio Muncie and 3.70 gears; 492 heads (11:1 CR) and a 780 Holley vacuum secondary carb on an LT1 intake manifold, and street tires. My best time was 13.26 at 106 mph.

With much hindsight and a lot more experience, the best things you could do to improve would be (1) tires (MT Street ET radials), (2) a better cam than the LT1 cam which only had .435 intake valve lift on a lazy 116.25 lobe separation angle (try a roller, or if too expensive, then a hydraulic flat tappet cam with 230/235 degrees duration on ~110 degree lsa), a steeper first gear ratio such as the BW Super T-10 with a 2.64:1 first gear ratio, or if you have a close ratio Muncie, a 4.11 rear end gear. Get a good dual plane manifold - the stock LT1 high rise is fine, or an Edelbrock Performer RPM.

Astrodokk

Larry,
Thanks for reviving this thread. I was going to start one in the C2 section with a complete description of components after I get my new engine, so for now all I'll say is that after I slipped a rod bearing, rather than just repair it, I decided to go with a hydraulic roller 383 stroker with 64cc aluminum heads, Edelbrock dual plane intake, Holley 750 DP, but no idea what hyraulic roller cam to use yet. The combo so far should give a 10.1:1 compression ratio. Since this will be a newer block with the single rear seal, I'll have to get a newer '87 & up balanced flywheel for it too. I'll still be using the M-21 4 speed and the 4.11's in rear. Right now I have BFG's all around. What does MT stand for? I assume ET is elapsed time? Thanks, and any cam suggestions are much appreciated.
BTW, the old 350 had "PowerPak" 2.02/1.60 valves ported and polished 76cc heads, flat pistons, Crane Fireball 286 flat tappet cam with a Torker single plane and Holley 750 DP. I think I'll improve my 1/4 with the new set up!
Carlos

larrywalk

Sounds great. Be sure to use an online compression ratio calculator, also check the dynamic compression ratio. Here's a good one:
http://kb-silvolite.com/calc.php?action=comp

MT = Mickey Thompson ET Street Radials (drag radials) - they are soft and hook well.
http://store.summitracing.com/egnsea...5&autoview=sku

Keep us informed!

a1231212

sounds like shes beggin for a bottle...

lackomotorsportsllc

I have several questions. Your mile per hour is 103 in the quarter, but ur running a 13.90. What are your 60 ft times? Do you run street tires? What rear gears are in this car? I love the old school original Torquer Intake. I have 2 myself. Those intakes are good for 7500 RPM. As pointed out before not knowing the camshaft you have is a key component to making HP/TQ. I would match the cam to the intake and heads your running. The heads are probably not enough with a small lift/duration camshaft with this intake manifold.

If you want to improve 1/4 times the cheapest route. GEARS, and getting out of the hole! A gear ratio change will change your top end a little bit, but when drag racing if your not getting outta the hole your left behind! You need to be tach'n that car up and hammerin on that 4 speed. Im assuming you have street tires on at the track and your babying that car off the line.

If your not running slicks or drag radials I would get some first. Im not sure what rearend you have, but a stocker WONT like Drag Slicks for long!!! Drag radials are easier than the slicks, and street tires are not gonna help you get off the line.

IMO

beautiful car btw!!

a1231212

Curveit

You "spun" a bearing... It's ususally a good idea to stay on the small side If you're not sure how big a Cam you can live with. 224/230 or 230/236 with 110 LSA should work well with a 383. Get all the Lift you can; a Roller would be nice. AFR Heads are a proven HP maker. A Dual-Plane like the Edlebrock RPM would be best, but I'm not sure it will fit under your hood. The old Edlebrock is easily bested by todays Intakes, and the Torquer was horrible according to Joe Sherman; who was working at Edlebrock when they were introduced.