Looking for a HP estimate... - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Chevelle454 · 11-15-2003, 01:15 AM

I am in the process of finishing my motor up. I did a total engine rebuild in school, and I was wondering what kind of horsepower I will be getting. It is a '72 350 with hypereutectic pistons, moly rings, CraneCam 266, and stock rebuilt heads. For now I will just be using the stock intake, exhaust and 2 bbl carb. What do you guys think the horsepower will be for this motor? And what would you estimate it to be with a Holley 770 street avenger carb, street avenger intake, hooker headers, and true dual exhaust with flowmaster 40 series mufflers? You probably have no idea and wonder what I'm smoking for even asking, but I'll try anyway...

Hooter · 11-15-2003, 01:19 AM

if it is around 9.1 compression Id have to say 250-310 range, but thats just a real rough guess

cableguy0 · 11-15-2003, 01:54 AM

with all the stock stuff maybe 260 horsepower. with the goodies probably 280 maybe 300

*redbowtie* · 11-15-2003, 02:55 AM

Yup, that sounds about right...

gonebad2 · 11-15-2003, 05:56 AM

I just posted a thread titled Vin Decoder. It doesn't list a 350 with a 2 BBL Carb. But a 350 with a 4BBL carb in '72 put out 175 to 210 HP...We can thank the Government for that. I looked up my '70 and it put out 255 hp stock. A new intake, headers and flowmasters should make a big difference for you. BTW..stock compression ratio in '72 was 8.5:1

Chevelle454 · 11-15-2003, 10:41 AM

I plan to add aluminum heads sometime in the near future. I hope the stupid thing puts out more than 200 hp after all the money I have stuck in it so far...

Class of 69 · 11-15-2003, 11:19 AM

The 72 HP ratings were for "net" HP. Prior to 71 the ratings were for "gross" HP. The net ratings are actually closer to flywheel horse, rather than bare crankshaft horse. I recommend finding a stock 4 bbl carb, and intake, as the 2bbl is going to really restrict the performance with the pistons and cam. If you can't find a stock setup cheap around home, I have one on a vintage 69 motor you could use till you up grade. I won't be needing it for a while, but will want it back when you change over. PM me if you are interested.

bigjimzlll · 11-15-2003, 12:03 PM

Quote:

Originally posted by Chevelle454
I plan to add aluminum heads sometime in the near future. I hope the stupid thing puts out more than 200 hp after all the money I have stuck in it so far...

first of all...aluminum heads will not make more HP than cast...They will make more than stock however. You are probably around 260-285 HP. This is what the most powerful SBC had in the late 50s early 60s from the factory. This 285HP is what 90% of people will say that their engines is making 350-400HP. With 285HP you can run mid 14 second 1/4 mile times. It is expensive to make a lot of HP. Remember...GM with all of its resources could only make 360HP with a 350...This was a solid cammed 11.5-1 100+octane no lowend power no power braked facory drag engine...and this was with the old school HP raitings...the new ls1s make big power...but they are very HI tech. If you want to make a true 400HP+ 350...email me..I have the info...but expect to run race gas...

junkyardjohn · 11-15-2003, 01:05 PM

BIGJIMZIII -- TRUER WORDS WERE NEVER SPOKEN. IT SEEMS NO ONE UNDERESTIMATES HORSEPOWER..... OR GAS MILEAGE.

JOHN

PanelDeland · 11-15-2003, 01:13 PM

The equation for HP is

" Speed cost's money.How fast can you afford to go?"

Chevelle454 · 11-16-2003, 01:35 AM

Thanks for all the info everyone. I forgot to mention that I had the motor bored 30 over, but that probably doesn't make much, if any, more power. What is the displacement of a 350 bored .030 over?

bigjimzlll · 11-16-2003, 01:52 AM

355

11-15-2003, 01:15 AM	#1
Chevelle454 Registered User Join Date: Aug 2003 Location: MN Posts: 380	Looking for a HP estimate... I am in the process of finishing my motor up. I did a total engine rebuild in school, and I was wondering what kind of horsepower I will be getting. It is a '72 350 with hypereutectic pistons, moly rings, CraneCam 266, and stock rebuilt heads. For now I will just be using the stock intake, exhaust and 2 bbl carb. What do you guys think the horsepower will be for this motor? And what would you estimate it to be with a Holley 770 street avenger carb, street avenger intake, hooker headers, and true dual exhaust with flowmaster 40 series mufflers? You probably have no idea and wonder what I'm smoking for even asking, but I'll try anyway... __________________ 1972 C10 1972 C20

11-15-2003, 01:19 AM	#2
Hooter My other Love Join Date: Aug 2001 Location: Castlegar B.C. Canada Posts: 4,085	if it is around 9.1 compression Id have to say 250-310 range, but thats just a real rough guess __________________ Castlegar B.C.The great white North (Canada Eh!) Hooter_5@hotmail.com First generation Monte Carlo club pictures of my life

11-15-2003, 01:54 AM	#3
cableguy0 Senior Member Join Date: Apr 2000 Location: Delta,Pa Posts: 14,950	with all the stock stuff maybe 260 horsepower. with the goodies probably 280 maybe 300 __________________ Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member.

11-15-2003, 05:56 AM	#5
gonebad2 Merciless Butcher Join Date: Oct 2003 Location: CC Nevada Posts: 1,447	I just posted a thread titled Vin Decoder. It doesn't list a 350 with a 2 BBL Carb. But a 350 with a 4BBL carb in '72 put out 175 to 210 HP...We can thank the Government for that. I looked up my '70 and it put out 255 hp stock. A new intake, headers and flowmasters should make a big difference for you. BTW..stock compression ratio in '72 was 8.5:1 __________________ Your Bought And Sold....I Got Your Soul!

11-15-2003, 10:41 AM	#6
Chevelle454 Registered User Join Date: Aug 2003 Location: MN Posts: 380	I plan to add aluminum heads sometime in the near future. I hope the stupid thing puts out more than 200 hp after all the money I have stuck in it so far... __________________ 1972 C10 1972 C20

11-15-2003, 02:55 AM	#4
redbowtie Account Suspended Join Date: Nov 2003 Location: Fort Worth, Texas Posts: 0	Yup, that sounds about right...

11-15-2003, 11:19 AM	#7
Class of 69 Registered User Join Date: Mar 2003 Location: Stillwater MN Posts: 1,166	The 72 HP ratings were for "net" HP. Prior to 71 the ratings were for "gross" HP. The net ratings are actually closer to flywheel horse, rather than bare crankshaft horse. I recommend finding a stock 4 bbl carb, and intake, as the 2bbl is going to really restrict the performance with the pistons and cam. If you can't find a stock setup cheap around home, I have one on a vintage 69 motor you could use till you up grade. I won't be needing it for a while, but will want it back when you change over. PM me if you are interested. __________________ 69 GMC K10 ..some restoration required....still..

11-15-2003, 01:05 PM	#9
junkyardjohn Registered User Join Date: Aug 2001 Location: SOMERSET KY. Posts: 6,427	BIGJIMZIII -- TRUER WORDS WERE NEVER SPOKEN. IT SEEMS NO ONE UNDERESTIMATES HORSEPOWER..... OR GAS MILEAGE. JOHN __________________ junkyardjohn 69 1 TON TOW TRUCK // 84 4WD CUCV BLAZER// 85 1 TON 4WD STAKE TRUCK// 86 M1031 5/4 TON 4WD CUCV// ALOT OF OLD TRUCKS FOR ONE OLD MAN TO DRIVE. THERES ROOM FOR ALL OF GODS CREATURES RIGHT NEXT TO MY MASHED POTATOES// LIFE MEMBER OF P.E.T.A (PEOPLE EATING TASTY ANIMALS) DON'T RENT U-HAUL ALWAYS TELL THE TRUTH IT WILL AMAZE PART OF THE PEOPLE & ASTONISH THE REST

11-15-2003, 01:13 PM	#10
PanelDeland I am a Referee of life. Join Date: Jun 2000 Location: Greensboro N.C. Posts: 13,993	The equation for HP is " Speed cost's money.How fast can you afford to go?" __________________ The 47-present Chevrolet and GMC Truck Message Board Network,it's owners,moderators,members,and associates of any type should not be held responsible for my opinion. You can't fix stupid,not even with duct tape. "My appearance is due to the fact that "GOD" does punish you for having too much fun!" Barrett-Jackson has perfected alchemy,they make rust into gold! "You can lead a horse to water but you can't saddle a duck" "Cleverly disguised as a 'Responsible Adult' "Sometimes your Knight in shining armor is just a retard in tinfoil"

11-16-2003, 01:35 AM	#11
Chevelle454 Registered User Join Date: Aug 2003 Location: MN Posts: 380	Thanks for all the info everyone. I forgot to mention that I had the motor bored 30 over, but that probably doesn't make much, if any, more power. What is the displacement of a 350 bored .030 over? __________________ 1972 C10 1972 C20

11-16-2003, 01:52 AM	#12
bigjimzlll Senior Member Join Date: Dec 2001 Location: Redding,CA...USA Posts: 4,736	355 __________________ It's called "drag racing" if they called it "tic..tic..WHAM!..BANG! F*&K!!!", they'd have to keep the magazines under the counter with the other men's publications click the clicky to join the site.... http://67-72chevytrucks.com/vboard/payments.php 67 lwb..first hotrod in 25 years..540 best ET is 9.45 @ 141.44 Anderson,CA



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