A retarded setting for any cam will castrate the torque and magnify the hp, as a rule. Those low-comp engines came with 350-360 ft. lbs. from the factory, and the Crower level 2 cam would only increase this. As mentioned previously, torque doesn't change a whole lot, while the hp is the main increase seen on performance engines in this range. That's my take on it anyway, based on what we see with all the Buick 350's dyno'ed and tested. My 'educated guess' was just that: a guess. The numbers may be off a bit, but probably not all that much. Don't forget those low numbers (sub 200 hp and sub 300 ft. lbs.) are SAE figures, not flywheel. Divide those SAE numbers by .8 or .75 to get a more accurate depiction of flywheel figures. 280 SAE ft. lbs. equates to 350-373 ft. lbs. depending on what was configured within the SAE protocol on that vehicle model the SAE torque figure was calculated for. This was factory post '75 figures too (the weakest 350 ever built)
Good memory for Andy remembering Steve's dyno posting! In Gary's defense, Steve's engine was the only engine dyno sbb 350 results in a VERY long time, with not many real engine comparisons to reference, hopefully that will change in the near future? Derek
Not to make it a debate . Just don't think a 7.5 static would get those numbers without boost. It's more like the formula they used before sae standard in 72. Where the 68-69 350 made 280 hp-410 lbs torque. But 1977 2 barrel engine was an anemic 140 hp flywheel no accessory rated. Just think the 7.5 static even with a crower level 2 will be there with the 140 hp engine. I think rated at 270 lbs?
I got curious so I looked it up, '68 and '69 sbb 350 engines that were rated for 280 HP were rated for 375 ft lbs. I thought the 410 sounded a bit high, close and not to bad from going off memory. To look up the '77 spec I will need to find my '73 to '81 Chilton manual. The '70 only, GS 350 was rated @ 315 HP were the one that had 410 ft lbs rating, it was down hill from there starting in '71 when they neutered the compression ratios for just about every muscle car engine platform from then on! :af: The above specs are from my '67 to '73 Motors manual. Derek
Not sure if this GSCA article was ever discussed here, I seem to remember someone mentioning it, but in any case, thought you guys would find it relevant.
According to my Motors manual in 1970 there are 2 different 350 4bbl engines listed with one that is listed to have 10.25:1 which is the GS 350 with 315 HP and 410 ft lbs, the other 4bbl engine is rated at 9:1 compression and rated to have 285 HP and 375 ft lbs. So that article looks to have misinformation in it, perhaps so people call the number at the end of the article? It was dark when I looked at my Motors manual earlier and made a mistake, in 1971 is when the muscle car engine platform compression ratio was neutered to all be rated @ 8.5:1 in the Buick line up anyway!! I will have to edit my previous post to correct that. Derek
Yup, my Steven Dove book says the same thing. I think it is safe to say that the actual compression wasn't 10.25:1 and 9.0:1 respectively, it was less. And yes, Richard Lassiter has an interest in Wildcat Performance, so yeah, they want you to call Didn't even notice that.:grin:
Nice info there. 270 ish hp on 9.4 compression. About 40 hp below rating and almost a full point of compression drop. Seems most engines are down 30-40 hp over rated. Does that hold true to the 77 model year that would make the 140 hp engine about 110 hp?
The power figures for the Buick 350 were all over the place, which only exacerbates the confusion of what one can actually do. I have seen several other dyno results from built engines with lopey cams (not sure what all else was done), and the torque figures range from 369-377. Steve's torque figures were actually very good for a retarded set cam (it peaked at 380 ft. lbs., not 370 btw) and he tested it with different tune settings to finally end up with 340 hp out of iron manifolds, which is outstanding. From everything I've seen and based on my own memory, torque for these engines doesn't vary much unless you wind them up or force more air through them to get in excess of 400 ft. lbs. According to the dyno program I use, you can get well over 400 ft. lbs. and around 330 hp out of even a stock cam (with moderate compression and using the Federal Mogul cs647 or Melling sbc-5 cams) when using headers and open exhaust, but that's not realistic for the street or cars using iron manifolds. Jim's dyno tested and tuned 350 turned out 398 ft. lbs. and 349 hp with the TA 212-350 cam, ported heads and 1 3/4" headers. The real power gains are from using headers---or so we thought, until Steve pulls a rabbit out of his hat with 340 hp and iron manifolds... Try to bear in mind not to dwell so much on the raw numbers, as the trends we see in the numbers from engine to engine. I know for a fact that they perform way better than anything the books say, at least on the street vs other cars--though this info is old it still applies to the older generation of cars. Cars nowadays are way out of its league. All power figures after 1971 were SAEnet figures, with all accessories installed and operating, measured at the end of the transmission. This is why you see hp less than 200 and torque less than 300. Depending on what all accessories came with that car, which exhaust it used, and the transmission (TH350 or TH400, which took off 36 hp and 44 hp respectively just by themselves), you could end up with numbers ranging from 155 hp (the 140 hp version was a 2 barrel I believe) to 195 hp. The torque figures even here didn't change a whole lot, ranging from 270 to 290 for the SAEnet figures, and those include 2 barrel and 4 barrel variants. The most powerful SAEnet Buick 350 recorded in the books had 195 hp and 290 ft. lbs.--using 8.5:1 compression (book value). That's a lot when you consider how much has been removed from them from the taxable calculations. If you figure 20-25% power loss you end up with 244-260 hp with 363-387 ft. lbs. from a factory assembled low comp stock engine. Hp's not all that impressive, but the torque is. Boost compression, put in a larger cam, port heads, use headers, and you'll see torque go up some, but not much--but the hp will soar off the chart (vs what it used to be). This was my point to all this. I've said in the past that even though we all tend to dwell on maximizing numbers, I think it's more important to see where those numbers occur, and to try and get them as wide as you can without hurting performance too much. The OEM replica GS cams do a fine job at doing this. (for street machines, of course) It's all good to get this info out here on the boards. Maybe we can get others to chime in with their findings if they come across this so we can add to the information pool. Gary
The 1970 figures were sexed up for sales. This was just before they started using SAE figures and were playing around with adding numbers to the flywheel figures by calculating in what they figured the induction hood would give. lol That's conjecture on my part, not actual fact (though it may very well be!). EDIT: just noticed the article Larry posted said pretty much the same thing lol They wanted to go out with a bang. It's also why the 'standard' 455 in that year also had 2 figures for hp, 350 and 370, with the Stage1 having only 360. This played into the limits placed on cars to be restricted to 10% power to weight ratio for insurance purposes. (3600 lb. car = 360 hp)
Here's the Federal Mogul 455 cam card specs for analysis/comparison: ...and for the 350: There's more to these cams than meets the eye...
As noted the 1970 "315 HP" engine didn't quite make it to the advertised rating. However, if blueprinted to the full advertised compression ratio I'll bet it would be very close. That 10.25 compression is really about 9. I had the SP engine with all stock parts and calculated by zero decking the block the compression was spot on at 10.25. Should tell you the stock cam can make power as Gary has pointed out. When he builds his blueprint special we'll see that's true.
