GMs HP RATINGS

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Re: GMs HP RATINGS

Post by pdq67 » Mon Oct 30, 2017 3:21 pm

Stan Weiss wrote:
Mon Oct 30, 2017 1:45 pm
Some Chevy cams from back in the day.

Stan

IMAG0212.gif
They forgot the old 350hp/327 hy-cam, the -151. (L-79 cam if not mistaken?)..

As well as the, "little-bitty", -097 Duntov solid lifter cam. I think that it was installed in the 250, 283, 290, and 315hp/283 engines(??) as well as the 340 and 360hp/327 engines(??). (2x4 carb. and early FI engines here?)...

Which mag. did the, "balls-out", 302/307 engine test? Seems that they finally got it, "dyno'ed", up to 515hp or thereabouts..

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Re: GMs HP RATINGS

Post by stangbuilder » Mon Oct 30, 2017 7:34 pm

I have had about 5 cars with the 302s and 350Lt 1s One was a low compression Lt1 9.1 deal in a 72 z28 I ran them all at local drags with street tires...all were 4 speed cars ...

69 Z28 with the 302 with headers on it . Only 1 run was around a 14 sec deal bad traction big time..at 109mph
70 Z28 Lt1 with headers Best i remember was 13 .5s at 105mph
72 z28 bone stock 14,2 at 99 mph with headers think i got in the 13s at 104 mph

Heres what i remember about these cars. were the 69z after i put headers on that deal that car came alive.It was fun to drive once you got it going,Had a 220 first gear with 373 gear.All i remember was that car halled the mail at the top end. i buzzed that motor to 8000 rpm . honestly that was my favorite one.. bitchin fun car.

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Re: GMs HP RATINGS

Post by Frankshaft » Mon Oct 30, 2017 8:39 pm

Which one ran low the lowest rpm? My guess the 72? And it was the slowest. :wink: :wink: wonder if anyone will catch the correlation, lol

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Re: GMs HP RATINGS

Post by MadBill » Mon Oct 30, 2017 8:47 pm

The '69 Z28 cam made more power with open headers than the '70 1/2 cam, but less with stock exhaust. In other words the early cam was optimized for open exhaust and the later one was more 'street tuned'. (Plus having to behave with an automatic.)
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Re: GMs HP RATINGS

Post by GARY C » Mon Oct 30, 2017 8:50 pm

There was a write up years ago about how the factory use to cheat their #'s, I don't remember all of it but it seems part of it was they would test the engine with all accessories and I believe at low rpm. It seems they were a few other things but most engines over the years have usually bettered there stock #'s.

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Re: GMs HP RATINGS

Post by pdq67 » Mon Oct 30, 2017 9:28 pm

stangbuilder wrote:
Mon Oct 30, 2017 7:34 pm
I have had about 5 cars with the 302s and 350Lt 1s One was a low compression Lt1 9.1 deal in a 72 z28 I ran them all at local drags with street tires...all were 4 speed cars ...

69 Z28 with the 302 with headers on it . Only 1 run was around a 14 sec deal bad traction big time..at 109mph
70 Z28 Lt1 with headers Best i remember was 13 .5s at 105mph
72 z28 bone stock 14,2 at 99 mph with headers think i got in the 13s at 104 mph

Heres what i remember about these cars. were the 69z after i put headers on that deal that car came alive.It was fun to drive once you got it going,Had a 220 first gear with 373 gear.All i remember was that car halled the mail at the top end. i buzzed that motor to 8000 rpm . honestly that was my favorite one.. bitchin fun car.
Now people can see why I liked my old, "junk301", so much!

She just went up and up AND up!!

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Re: GMs HP RATINGS

Post by pdq67 » Mon Oct 30, 2017 9:48 pm

MadBill wrote:
Mon Oct 30, 2017 8:47 pm
The '69 Z28 cam made more power with open headers than the '70 1/2 cam, but less with stock exhaust. In other words the early cam was optimized for open exhaust and the later one was more 'street tuned'. (Plus having to behave with an automatic.)

Right, imho..

The old 30-30 cam at 254/254 vs the -178 at 242/254 or thereabouts. (The old 30-30 cam would do 8,000 rpm but when done, usually the valves were bent if the valve springs weren't upgraded!)...

GM used the 30-30 cam in the mule 350 LT-1 engine to get their 370 hp rating and then switched cams to sell the car to the public --- and equipped with A/C and P/S.

pdq67

PS., oh, and btw, a real 302, Z-28 engine has a certain sound to it that a person that knows them can tell in a heart-beat if it is stock 30-30 cammed!!

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Re: GMs HP RATINGS

Post by stangbuilder » Mon Oct 30, 2017 10:48 pm

pdq67 wrote:
Mon Oct 30, 2017 9:48 pm
MadBill wrote:
Mon Oct 30, 2017 8:47 pm
The '69 Z28 cam made more power with open headers than the '70 1/2 cam, but less with stock exhaust. In other words the early cam was optimized for open exhaust and the later one was more 'street tuned'. (Plus having to behave with an automatic.)

Right, imho..

The old 30-30 cam at 254/254 vs the -178 at 242/254 or thereabouts. (The old 30-30 cam would do 8,000 rpm but when done, usually the valves were bent if the valve springs weren't upgraded!)...

GM used the 30-30 cam in the mule 350 LT-1 engine to get their 370 hp rating and then switched cams to sell the car to the public --- and equipped with A/C and P/S.

pdq67

PS., oh, and btw, a real 302, Z-28 engine has a certain sound to it that a person that knows them can tell in a heart-beat if it is stock 30-30 cammed!!
what i remember was the 69 sounded bad ass bone stock..And yes it had a sound .Fyi the cams in the 70 @72 Lt 1s were the same part number. The only difference in the two engines were one has a 202 head small camber think a 64 cc the 72 had a 72 cc camber and flat top single valve relief..

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Re: GMs HP RATINGS

Post by pdq67 » Tue Oct 31, 2017 12:36 am

Nobody talks much about the, 222/222(?), .450"/.460" -962 hy-cam that I think was installed in the 330 hp/350 engine. I think it was supposed to be a more modern version of the old, 221/221, -151 hy-cam?

From Kendrick Automotive, San Antonio, TX

Chevrolet Factory Cam Specs

Chevrolet Factory Cam Specs by part number
Part # Lifter type–duration at .050 In/ex–Lift in/ex–centerline–description
Small Blocks
3849346 Mechanical – 254/254 – .484/.484 – 114 – 327 365HP& Z-28 302
3863151 Hyd. – 221/221-.447/.447-114 – 327-350HP, L79
3896929 Hyd. – 195/202 – .390/.410 – 112 – 327 300 HP
3896962 Hyd. – 222/222 – .450/.460 – 114 – 350 L-46, L-82
3927140 Mechanical – 257/269 – .493/.512 – 112 – Off Road
3965724 Mechanical – 262/273 – .488/.509 – 112 – 2nd design road race, short track
3972178 ? --- (See the -182 specs below but subtract hot lash). pdq67
3972182 Mechanical – 242/254 – .459/.485 – 116 – 70 LT1 360 & 370HP, 71 LT 330 HP
10134334 Hyd. Roller – 235/235 – .480/.480 – 114 – 350ZZZ and ZZ2 Crate Motor
10185071 Hyd. Roller – 208/221 – .474/.474 – 112 – 350 345, ZZ3&4 Crate Motor
10224241 Hyd. Roller – – 92-94 GenII, LT1, 350
10243779 Hyd. Roller – – 94-96 Gen II, L99 265 V-8
12353914 Hyd. – 180/194 – .378/.401 – – GM Crane Lo speed Hi torque
12353915 Hyd. – 194/204 – .401/.423 – 104 – GM Crane street
12353916 Hyd. – 204/214 – .423/.446 – 110 – GM Crane 305-350 street legal 50 states
12353917 Hyd. – 204/214 – .420/.441 – 112 – GM Crane nan-emissions vehicles & off road
12353918 Hyd. – 214/224 – .442/.465 – 112 – GM Crane marine & off road
12353923 Hyd. – 224/234 – .465/.448 – 114 – GM Crane off road
12364050 ?
12364051 ?
12364052 ?
12364053 ?
12364054 ?
12370845 Hyd. Roller – 214/224 – .488/.509 – 112 – Off Road, lobe for mech fuel pump
12370846 Hyd. Roller – 222/230 – .509/.528 – 112 – Off Road, lobe for mech fuel pump
12370847 Hyd. Roller – 232/242 – .539/.558 – 112 – Off Road, lobe for mech fuel pump
12551142 Hyd. Roller – 203/210 – .476/.480 – 115.5 – 96 350 LT4 w1.6 roller rockers
12551705 Hyd. Roller – 201/208 – .447/.459 – 112 – 95-96 Gen II, LT1, w center dowel pin
14088843 Hyd. – 202/206 – .403/.415 – 115 – 305 HO, 83-86
14093643 Hyd. Roller – 202/206 – .403/.415 – 115 – 87 350 Corvette, IROC Camaro
24502476 Hyd. – 121/220 – .435/.460 – 112.5 – 350 300 crate motor
24502586 Hyd. Roller – 218/228 – .525/.525 – – 96 LT4 H.O.T. crate motor, use with 1.6 roller rockers
NA Hyd. Roller – 202/210 – .472/.478 – 111 – 97 Gen III LS1 Corvette 350 uses 1.7 roller rockers

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Re: GMs HP RATINGS

Post by novadude » Tue Oct 31, 2017 9:32 am

stangbuilder wrote:
Mon Oct 30, 2017 7:34 pm
I have had about 5 cars with the 302s and 350Lt 1s One was a low compression Lt1 9.1 deal in a 72 z28 I ran them all at local drags with street tires...all were 4 speed cars ...

69 Z28 with the 302 with headers on it . Only 1 run was around a 14 sec deal bad traction big time..at 109mph
70 Z28 Lt1 with headers Best i remember was 13 .5s at 105mph
72 z28 bone stock 14,2 at 99 mph with headers think i got in the 13s at 104 mph

Heres what i remember about these cars. were the 69z after i put headers on that deal that car came alive.It was fun to drive once you got it going,Had a 220 first gear with 373 gear.All i remember was that car halled the mail at the top end. i buzzed that motor to 8000 rpm . honestly that was my favorite one.. bitchin fun car.
109 mph sounds like a lot for a stock 302 ci and what I would assume to be a ~3500 lb car with driver. NHRA Stocker-prepped Z/28s were only running 116 mph in 1968, and we know those weren't "stock" factory builds. Not saying it didn't happen, but that is really flying for a stock 302 with headers.

http://z28camaro.com/old-reliable/

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Re: GMs HP RATINGS

Post by dr5375 » Tue Oct 31, 2017 9:43 am

I had a 1971 Z28 with a 330 horse 350 stock except headers, TM1 intake and 700 DP holley. It had the 178 mechanical cam. I do not know if the rating was correct but it would redline the tach at 6500 and the speedometer at 150 at the same time and it was not done there. It turned 7000 in high gear many times. Never had it on the track, it was my daily drive anywhere car. Later I had a 1974 Z28 with the .450 .460 hydraulic cam and that car was a big disappointment over the 71.

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Re: GMs HP RATINGS

Post by Frankshaft » Tue Oct 31, 2017 10:19 am

novadude wrote:
Tue Oct 31, 2017 9:32 am
stangbuilder wrote:
Mon Oct 30, 2017 7:34 pm
I have had about 5 cars with the 302s and 350Lt 1s One was a low compression Lt1 9.1 deal in a 72 z28 I ran them all at local drags with street tires...all were 4 speed cars ...

69 Z28 with the 302 with headers on it . Only 1 run was around a 14 sec deal bad traction big time..at 109mph
70 Z28 Lt1 with headers Best i remember was 13 .5s at 105mph
72 z28 bone stock 14,2 at 99 mph with headers think i got in the 13s at 104 mph

Heres what i remember about these cars. were the 69z after i put headers on that deal that car came alive.It was fun to drive once you got it going,Had a 220 first gear with 373 gear.All i remember was that car halled the mail at the top end. i buzzed that motor to 8000 rpm . honestly that was my favorite one.. bitchin fun car.
109 mph sounds like a lot for a stock 302 ci and what I would assume to be a ~3500 lb car with driver. NHRA Stocker-prepped Z/28s were only running 116 mph in 1968, and we know those weren't "stock" factory builds. Not saying it didn't happen, but that is really flying for a stock 302 with headers.

http://z28camaro.com/old-reliable/
Was at an NHRA divisional in August, hanging out with a buddy of mine from Canada. We both love the stock, super stock, and comp stuff. He says, there is a 68 Camaro, 302 dz car in stock running 10.40's. I said, you mean superstock, he said no, stock. Hmm, sure enough he went 10.42 at like I 126 or 127. I said, wow. Then I thought about it. Smaller cubic inch, they had dome pistons, so, with "blueprinting" they end up at a decent compression ratio, they come with a higher lift solid flat tappet cam, and, a pretty decent intake, and a holley carb. And, they rev much higher, allowing more gear and a wilder converter. I wonder if anyone will get the correlation? lol

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Re: GMs HP RATINGS

Post by Stan Weiss » Tue Oct 31, 2017 10:41 am

Frankshaft wrote:
Tue Oct 31, 2017 10:19 am


Was at an NHRA divisional in August, hanging out with a buddy of mine from Canada. We both love the stock, super stock, and comp stuff. He says, there is a 68 Camaro, 302 dz car in stock running 10.40's. I said, you mean superstock, he said no, stock. Hmm, sure enough he went 10.42 at like I 126 or 127. I said, wow. Then I thought about it. Smaller cubic inch, they had dome pistons, so, with "blueprinting" they end up at a decent compression ratio, they come with a higher lift solid flat tappet cam, and, a pretty decent intake, and a holley carb. And, they rev much higher, allowing more gear and a wilder converter. I wonder if anyone will get the correlation? lol
:shock: :?

In '68 they only came with a 4 speed.

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Re: GMs HP RATINGS

Post by stangbuilder » Tue Oct 31, 2017 11:07 am

novadude wrote:
Tue Oct 31, 2017 9:32 am
stangbuilder wrote:
Mon Oct 30, 2017 7:34 pm
I have had about 5 cars with the 302s and 350Lt 1s One was a low compression Lt1 9.1 deal in a 72 z28 I ran them all at local drags with street tires...all were 4 speed cars ...

69 Z28 with the 302 with headers on it . Only 1 run was around a 14 sec deal bad traction big time..at 109mph
70 Z28 Lt1 with headers Best i remember was 13 .5s at 105mph
72 z28 bone stock 14,2 at 99 mph with headers think i got in the 13s at 104 mph

Heres what i remember about these cars. were the 69z after i put headers on that deal that car came alive.It was fun to drive once you got it going,Had a 220 first gear with 373 gear.All i remember was that car halled the mail at the top end. i buzzed that motor to 8000 rpm . honestly that was my favorite one.. bitchin fun car.
109 mph sounds like a lot for a stock 302 ci and what I would assume to be a ~3500 lb car with driver. NHRA Stocker-prepped Z/28s were only running 116 mph in 1968, and we know those weren't "stock" factory builds. Not saying it didn't happen, but that is really flying for a stock 302 with headers.

http://z28camaro.com/old-reliable/
I read this then i started thinking shit it was in 1975 at orange county drag strip in ca.So i looked in my box of time slips cound not find it call my friend that was at there track that night with me,, He remembers 108-109..Ran that car out the back door in 3rd gear

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Re: GMs HP RATINGS

Post by Stan Weiss » Tue Oct 31, 2017 11:17 am

pdq67 wrote:
Mon Oct 30, 2017 3:21 pm
Stan Weiss wrote:
Mon Oct 30, 2017 1:45 pm
Some Chevy cams from back in the day.

Stan

IMAG0212.gif
They forgot the old 350hp/327 hy-cam, the -151. (L-79 cam if not mistaken?)..

As well as the, "little-bitty", -097 Duntov solid lifter cam. I think that it was installed in the 250, 283, 290, and 315hp/283 engines(??) as well as the 340 and 360hp/327 engines(??). (2x4 carb. and early FI engines here?)...

Which mag. did the, "balls-out", 302/307 engine test? Seems that they finally got it, "dyno'ed", up to 515hp or thereabouts..

pdq67
They can only put some many lines on a graph before you cannot tell what is what.

Stan
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