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03-04-2004, 03:59 PM | #31 | ||
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Re: Re: Re: Re: z28
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I would not call the Boss 302 cam radical with only .477 in. lift at the valve, and 290 degrees duration. Sure the duration is more than your average 302, but a 93 Mustang Cobra 5.0 motor has .477 lift. The Boss 351 used nearly the same cam, and no one claims that it even made 400HP. The Cleveland 4V heads are on the large side for a 302, and this cam is a compromise for the street. It would take alot more cam to get 400HP out of the Boss 302, although the heads are cpable of it. Show me where it is documented that the street Chevy 302 made 400HP. I highly doubt it. |
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03-04-2004, 04:13 PM | #32 | ||
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Re: Re: Re: Re: Re: z28
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290 duration doesn't mean anything, it's duration at .050 that counts. I don't know those specs. The cobra 302 probably has a roller cam correct? Roller cams have MUCH more lift than any other cam and you cannot compare them. HUH? The 351C in 71' probably made about 450 HP. It was faster than the BOSS 429 rated at 375, not to mention 450 ft/lbs. And the 351 was faster, HMM? The boss 351 had 11.7:1 compression, and you think all it made was the rated 330 HP? Please. I've read lots of books that say although the 302 was rated at 290 HP, it was closer to 400 HP. But there was no torque of course.
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03-04-2004, 04:32 PM | #33 | |
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OK found the specs of the factory boss 302 cam. 228 duration @.050'', .477 lift and 114 ICL. So you are right that it's not very radical, but still large for 302 cubic inches.
I plugged all the data into my desktop dyno with NO porting whatsoever, canted valves/stock ports-and with small tube headers open exhaust it came out 418 HP at 6500 RPM and 405 ft/lbs at 4500 RPM. With the small tube headers and mufflers options it comes out 393 HP at 6000 RPM, and 391 ft/lbs at 4500 RPM. Even with the ''high performance manifolds and mufflers'' option it comes out with 353 HP at 6000 RPM and 358 ft/lbs at 4500 RPM. One other thing, for some reason these engines came with dual plane manifolds. With the small tube headers open exhaust option, and a single plane manifold selected it comes out to be 459 HP at 6500 RPM and 423 ft/lbs at 5000 RPM. Add pocket porting, and it comes out to 500 HP even. You don't need a huge cam to make big HP. So, using the exact same cam ,I put in the 302 chevy specs. Wedge/stock ports and valves-202/160 valves, 11:1 compression small tube headers open exhaust and it show 371 HP at 5500 RPM and 393 ft/lbs at 5000 RPM. Smaller valves, no cant to the valves=less power even with more compression. Now of course I'm using the same cam, I'm not sure what the actual specs are for the chevy 302.
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03-04-2004, 04:43 PM | #34 | ||
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Re: 69' BOSS 302 VS Camaro Z28
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Pull out some of the old magazine reviews and tests even. |
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03-04-2004, 05:07 PM | #35 | ||
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Re: Re: 69' BOSS 302 VS Camaro Z28
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Why don't you find the reviews? I know there is no possible way that this engine only made 325 HP. And the boss 351? LOL what a joke that it only makes 330. If it can eat the 429 for lunch, it MUST have well over 400 HP. Like I said the 429 was rated at 375 HP and 450 ft/lbs in 71'.
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03-04-2004, 05:30 PM | #36 | ||
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Re: Re: 69' BOSS 302 VS Camaro Z28
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Here is the imput into desktop dyno: 69' 302 ford-4.002'' bore X 3'' stroke-301.9 CID heads-canted valve/stock ports and valves valve sizes-2.23 intake/1.71 exhaust compression ratio-10.5:1 induction flow-780 CFM intake manifold-dual plane exhaust system-small tube headers open exhaust camshaft-solid lifters, 228 duration @.050'', .477 lift, 114 ICL peak HP-418@6500 peak torque-405@4500 RPM 69' Chevy 302: 4'' bore X 3'' stroke-301.6 CID heads-wedge/stock ports and valves valve sizes-2.02 intake/1.60 exhaust compression ratio-11:1 induction flow-780 CFM intake manifold-dual plane exhaust-small tube headers open exhaust cam-same as ford 302 peak HP-371 at 5500 RPM peak torque-393 at 4500 RPM 71' BOSS 351C 4'' bore X 3.5'' stroke- 351.9 CID heads-canted valves/stock ports and valves valves sizes-2.19 intake/1.71 exhaust compression ratio-11.7:1 induction flow-780 CFM(not sure about CFM, carb is Autolite 4300-A) intake manifold-dual plane exhuast-small tube headers open exhaust cam-same peak HP-440 at 5500 RPM peak torque-466 at 4000-4500 RPM
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03-05-2004, 07:09 AM | #37 | |
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Re: 69' BOSS 302 VS Camaro Z28
I guess that the Desktop Dyno is a neat tool, but the hard facts are that even with open high flow headers, the Boss 351 did not make even 400HP and 400Lb-FT of torque, and the Boss 302 made less torque/horsepower than did the Boss 351.
When you are talking factory stock motors and parts, the cookie cutter guess (calculated estimation) of the Desktop Dyno software program is not always accurate. This is a case where it is off by a bunch. The data you inputed does not differentiate between the factory iron Cleveland 4V heads of the Boss 302/352, and a head with specs like the Yates aluminum head which has smaller ports and valves than the 69 Boss 302 head, but makes it look like a 221 head in relative flow comparison. |
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03-05-2004, 03:18 PM | #38 | |
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True I would need actual flow bench data to punch in to be completely accurate.
However, I'll say this one more time-The BOSS 351 was FASTER than the boss 429 in 71'-the 429 was rated at 375 HP, engines were usually underrated. Plus the 429 has 450 ft/lbs of torque. Now, you think a 351 with less than 400 HP is going to beat the 375 HP 429? NO
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03-05-2004, 05:32 PM | #39 | ||
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Re: 69' BOSS 302 VS Camaro Z28
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I'll say this one more time.............look at the real world, not your software and your guesses. |
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03-05-2004, 07:27 PM | #40 | ||
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Re: Re: 69' BOSS 302 VS Camaro Z28
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03-06-2004, 07:11 AM | #41 | ||
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Re: Re: Re: 69' BOSS 302 VS Camaro Z28
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There are magazine tests for the 429SCJ Torino in the 13.60's range, and a 429SCJ Mustang even quicker. The Boss 351 had a best magazine time in the 13.80's. The thing about a Boss 351 is that it only came with a 3.91 axle and the 2.78 1st geared wide ratio 4-speed. With over 200lbs less weight over the front tires, it was much easier to launch. The 4-speed 428's fared better because it was a lighter engine in a lighter car, and the 428 with nearly a 4" stroke had a pile more low end grunt than did the 429 with its 3.59" stroke which was not far off of the 3.5" stroke of a Boss 351. The Boss 429 was designed for a Nascar oval, not street racing. I have seen a pile of old Ford musclecars at both local tracks and at NMRA and World Ford Challenge races. I have personal experience with a 1970 429SCJ 4-speed Cyclone Spoiler. |
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03-06-2004, 08:45 AM | #42 | ||
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Re: Re: Re: Re: 69' BOSS 302 VS Camaro Z28
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Anyway, I think I remember someone saying that 1/4 mile did not mean much. Oh that was you! Since the boss 351 came with 3.91 gears I would say it's pretty hard to get it to hook up too. The higher gears of the 429 make it easier to launch without spinning, what are you talking about? Plus how do I know those times you gave aren't from ''tweeked'' cars?
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03-06-2004, 08:49 AM | #43 | ||
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Re: Re: Re: Re: 69' BOSS 302 VS Camaro Z28
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A ''pile more low end grunt'' combined with a lighter car would make it MUCH harder to launch. Do you have any clue to what you are talking about?
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03-06-2004, 03:02 PM | #44 | ||
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: 69' BOSS 302 VS Camaro Z28
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I will give you a break. I can see that you haven't had much experience in the area of big block cars on limited traction. When you launch on factory of smaller Drag Radials, you do not want to launch at a high RPM or you will overpower the tires. The 2.40 first gear ratio combined with a 3800-4000lb car is a prescription for bog when launching at a low RPM. It is a fine line between bog and lost traction without abusing your clutch every time. This is why automatic cars are easier to launch when talking about these animals. Do yourself a favor and get out to the tracks where the old musclecars run. It is a blast to watch, and people are pretty friendly and easy to talk to as well as willing to discuss their cars. I have been fortunate to have seat time in both newer "stupid 5.0's" and early small and big block muscle. I have had 351C powered early Mustangs and big block powered cars. Like I said already, I can talk abouty personal experience when launching an early 4-speed powered big block car. How about you? |
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03-06-2004, 03:28 PM | #45 | |
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To sum it up, the Boss 351 made more power than the Boss 302, and the 429SCJ made more power than did the Boss 351. Pretty simple concept. Bigger engine, more power. Especially when both Bosses used essentially the same heads.
You can't make horsepower without torque since horsepower is quite simply a function of torque and RPM. With less torque at the same RPM, the smaller engines make less horsepower. Basic stuff here. |
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