Any thoughts on what I'm making?
Thread Starter
Racer
Joined: Nov 2003
Posts: 342
Likes: 0
From: Felton De
Any thoughts on what I'm making?
I've always liked to assume it was around 380-390, but i'm starting to think more like 320-340 
My heads are really restricting flow and have larger combustion chambers than i'd like. How much do you think i'm making?
71 350 2 bolt bored .030 over
3x14'' K&N airfilter
Holley 650DP
RPM performer intake
9.5.1 Forged TRW flattop .030 over
Crane Energizer 284H12 cam- 228 duration, 480 intake/exhaust, more if you need it.
Comp cams 1.5 roller rockers
Dart Iron Eagle SS's. 165cc intakes with 72cc combustion chambers
Dynomax headers and full 2 3/4'' exhaust with x-pipe, flowmaster mufflers.
Also, what do you think my weakest link is? I know the carb is only a 650, but i'm told thats plenty for 350's that push 400-415hp.... and i know i'm not there.
My heads are really restricting flow and have larger combustion chambers than i'd like. How much do you think i'm making? 71 350 2 bolt bored .030 over
3x14'' K&N airfilter
Holley 650DP
RPM performer intake
9.5.1 Forged TRW flattop .030 over
Crane Energizer 284H12 cam- 228 duration, 480 intake/exhaust, more if you need it.
Comp cams 1.5 roller rockers
Dart Iron Eagle SS's. 165cc intakes with 72cc combustion chambers
Dynomax headers and full 2 3/4'' exhaust with x-pipe, flowmaster mufflers.
Also, what do you think my weakest link is? I know the carb is only a 650, but i'm told thats plenty for 350's that push 400-415hp.... and i know i'm not there.
Melting Slicks
Joined: Feb 2003
Posts: 3,053
Likes: 4
St. Jude Donor '03,'11
Originally Posted by DJ Dep
I think you are looking through rose-tinted glasses. More like 270-300HP.
Dep
Dep
Le Mans Master
Joined: Oct 2002
Posts: 5,714
Likes: 6
From: Silver City NM
St. Jude Donor '05-'07
Originally Posted by turtlevette
you should know, a guy who thinks he's gonna build a race car with a 302. Now THAT'S funny.
http://www.z28camaro.com/oldrel.html
The Old Reliable: 1969 Z-28 Camaro
TECHNICAL DATA
VIN number 124378N411100
Build Date 04A (first week of April)
Color Corvette Bronze
Interior Code 712, black standard
Car Shipper Shipped on April 11, 1968 to Ammon R. Smith Auto Company, York, PA
Engine Data Cubic Inches, 302
Cylinder heads #3917291, completely stock, no porting allowed!
Stock rocker arms & valve springs
Intake 302 aluminum intake, casting #3917610
Carburetor Holley, #4053, 780 CFM 4bbl
Camshaft Crane, .480 inches lift, 272 degrees duration, valve lash, .016-.016
Pistons GM 302, .030" oversize
Horsepower 456 @7700rpm
Rear Tires 9" x 30.0" Hoosier's
Rear axle & ratio 12-bolt, 5.57 Richmond Pro Gears
Clutch 10 inch, three finger from Advance Clutch Technology
Shift Points 8200 RPM
BEST ET 10.80 @122.30mph
Still laughing?
Dep
Le Mans Master
Joined: Oct 2002
Posts: 5,714
Likes: 6
From: Silver City NM
St. Jude Donor '05-'07
Originally Posted by turtlevette
what did that Z-28 weigh. There was nothing to them.
you are going to have a hard time hauling the heavy C3 down the track to the tune of 10s.
We will see. Maybe a small wager?
you are going to have a hard time hauling the heavy C3 down the track to the tune of 10s.
We will see. Maybe a small wager?
When it get's done a small wager sounds great to me
Dep
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Thread Starter
Racer
Joined: Nov 2003
Posts: 342
Likes: 0
From: Felton De
270-300 at the crank? Eh, what can i say, i'm a little disappointed. I have run her with the old th400 tranny and 3.08 gears and managed a 14.03, cant remember the et. Switched out to a 700r4, and swapped my gears to 3.55's. Gonna get it dyno tuned first thing after i work out some current tranny issues. Wow, i must say, i'm disappointed if it is only putting out 270-300 crank, so like 220-240 at the wheels. Anyone else? Its just so much lower than i expected, considering it was rated 270hp from the factory to begin with..... sad 
Last edited by BrandonS; Apr 29, 2005 at 10:38 PM.
Race Director
Joined: Sep 2004
Posts: 11,874
Likes: 263
From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
i'm alittle more optimistic then the 270-300 numbers, i think you will see 270 at the rear wheels....what does your cam specifiation sheet say?
Pro
Joined: Sep 2002
Posts: 690
Likes: 1
From: near Memphis TN
If you got 14.03 then the HP calculator says you have 236 HP at the rear wheels assuming you and the car weigh 3300 pounds. Of course a trap speed would be a better indicator since time is so dependent on traction issues.
Gears make no difference to HP but they are good to have nevertheless, a 700r4 robs a little more horsepower than your old 350 transmission, and I run a 650DP in a low 13 second car so that shouldn't be an issue.
Your weakest link? You seems to have all the right parts in place although I know nothing about those heads. Even with flat tops your compression may be too low with the big chambers.
Gears make no difference to HP but they are good to have nevertheless, a 700r4 robs a little more horsepower than your old 350 transmission, and I run a 650DP in a low 13 second car so that shouldn't be an issue.
Your weakest link? You seems to have all the right parts in place although I know nothing about those heads. Even with flat tops your compression may be too low with the big chambers.
Thread Starter
Racer
Joined: Nov 2003
Posts: 342
Likes: 0
From: Felton De
The HP calculator is crap for calculating hp on our cars, at least my opinion. Cars are just too different to be compared using such basic numbers. My old TH400 tranny robbed outrageous amounts of power, and i'm sure the new 700 will be a little better. Also, my new gears will certainly help. I wonder what the calc would say if I had my car tuned and pulled off a 13.4-13.5 with the new combo, a run that isn't totally out of question from other 700 swap owners i've spoken to.
Le Mans Master
Joined: Oct 2002
Posts: 5,714
Likes: 6
From: Silver City NM
St. Jude Donor '05-'07
Originally Posted by turtlevette
if its still got the body on, its still heavy.
1972 Corvette Weight: 3,305 lbs
Oops...looks like you stepped in turtlepoop
Dep
Pro
Joined: Sep 2002
Posts: 690
Likes: 1
From: near Memphis TN
Actually I think an HP calculator using trap speed and car weight is even more accurate than a dyno for estimating horsepower, or at least your maximum horsepower. Too many variables with a dyno - type of dyno, operator, high stall speeds give it funny readings, etc.
For ET time, like I said, an HP calculator would not be accurate because traction would be too much of a factor.
Gearing will get you going faster but have no effect on horsepower one way or another.
For ET time, like I said, an HP calculator would not be accurate because traction would be too much of a factor.
Gearing will get you going faster but have no effect on horsepower one way or another.
Instructor
Joined: Apr 2004
Posts: 166
Likes: 0
From: Troy MO
Just my 2 cents, but I agree that the old 69 Z-28 302 was an excellent engine, and often wonder why they didn't continue its production or offer it in other models. Don't get me wrong, its hard to beat the raw HP of the big blocks, but for HP from CID, the 302 was one hot mama (with its decent bore{same as 327 I believe} and high revving short stroke {same as 283 I believe}), and I wish I had one to put in my 67 Camaro. I am also a big fan of the 327 also... and have had quite a few. All in all.... my favorite chevy engine is the 427 and love to drive my dad's 67 427 conv. / hard-top vette. I have one on my floor (427), but has a valve pushed through a cylinder wall and will need to be sleeved. My 65 Impala SS is 396 powered and is nothing to sneeze at, but its nowhere near a stock engine either. I think a LAUGH is someone building a 307 to race. But then again... at least there is a wide variety of sizes, bores, and strokes out there that everyone out there can find what they like to build and run. I personally do prefer the very high revving motors probably because of the sound they make more than the HP created, but with the right drive-train combination, just about anything can be built to compete.
Well that was probably more like my $3 than 2 cents. lol
Take Care All,
Loren
Well that was probably more like my $3 than 2 cents. lol
Take Care All,
Loren
Drifting
Joined: Sep 2004
Posts: 1,959
Likes: 1
From: North Bend Ohio
Originally Posted by TLChydraulics
Just my 2 cents, but I agree that the old 69 Z-28 302 was an excellent engine, and often wonder why they didn't continue its production or offer it in other models. Don't get me wrong, its hard to beat the raw HP of the big blocks, but for HP from CID, the 302 was one hot mama (with its decent bore{same as 327 I believe} and high revving short stroke {same as 283 I believe}), and I wish I had one to put in my 67 Camaro. I am also a big fan of the 327 also... and have had quite a few. All in all.... my favorite chevy engine is the 427 and love to drive my dad's 67 427 conv. / hard-top vette. I have one on my floor (427), but has a valve pushed through a cylinder wall and will need to be sleeved. My 65 Impala SS is 396 powered and is nothing to sneeze at, but its nowhere near a stock engine either. I think a LAUGH is someone building a 307 to race. But then again... at least there is a wide variety of sizes, bores, and strokes out there that everyone out there can find what they like to build and run. I personally do prefer the very high revving motors probably because of the sound they make more than the HP created, but with the right drive-train combination, just about anything can be built to compete.
Well that was probably more like my $3 than 2 cents. lol
Take Care All,
Loren
Well that was probably more like my $3 than 2 cents. lol
Take Care All,
Loren
BigBlockk
Later.....
Racer
Joined: Sep 2004
Posts: 298
Likes: 0
From: Comstock Park Michigan
I think HP numbers are somewhat useful, in order to give you an idea how your engine will perform. But in the end, I feel that you only need to ask yourself..."Does my engine/car do what I want it to do?"
Racer
Joined: Nov 2004
Posts: 422
Likes: 0
From: Owensboro Ky
Originally Posted by meangreenie
I think HP numbers are somewhat useful, in order to give you an idea how your engine will perform. But in the end, I feel that you only need to ask yourself..."Does my engine/car do what I want it to do?"
Build the car to your preferences and dont worry what anyone else thinks.
