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As some of you know I am fascinated with the Olds 350s performance, however meager it may or may not have been. So I am constantly trying to better understand it. For example I have been searching online for an automatic TH350 road test for 1969 and 1970 310 HP for about 6 years with no luck. In that never ending journey I have come across one very odd set of specs, for a 1971 W31. Now of course this car never existed. So its either a misprint, or a 1970 that was tested in 1971. Or maybe a 1971 Cutlass that had a W25 option and the article simply implied that it was like a W31, and the results info was skewed ?
I am a original road test fan, came across a fascinating page online many years ago. Someone went to great lengths to put a list together and credited the source of information for every single models performance specs. From obvious ringers to mythical models, they covered the original muscle era like a proverbial blanket from 1964-1972. I really appreciate the effort. I have verified many of the models performance specs via other sources. But the 1971 W31s is odd on many levels, I have seen the same specs somewhere else over the years but so far have not relocated it.
Now with that said I would like some input from you guys if possible. This is the source http://roadtests.tripod.com/ and here are the listed specs from that page.
This cannot be a W31, so what is it ? Is anyone familiar with HPC which according to the legend, stands for Hi-Performance Cars. I am not really familiar with the publication. Is it similar to a HotRod or CarCraft where they often seem to have better performance than other mainstream publications ? Likely do to tweaking ? advancing the timing, removing air filter elements, running with a 1/4 tank, etc, ?
Now I am assuming the 260 that's listed is gross HP rating while it's net rating is 200 HP.
Also assuming its a Cutlass S the best available gearing option for 260 gross HP version with automatic is 3.23 ?
Only the manual shift versions could come with a 3.42 rear which was the G92 package ?
Even the performance does not make sense vs HP. While 15.15 @ 90 HP is tremendous performance and is 3rd best of all time for a factory small block. Only lagging behind the 4 speed 310 HP Cutlass / Rallye 350 and of course a real W31. When you run those specs you are close to a perfect pass. That is that both the mph and et show an almost even amount of HP production. Problem is according to a calculator, the engine is producing around 215 HP net which is too much if it is indeed the 260 gross engine. And close to how much an inefficient drive train can leave on the table if its actually 260 net HP, but 3.42s make for an efficient drive-train.... so what gives ?
Has anybody seen the actual road test ? if so what is it really ?
You've got a random website put up by someone nameless that claims this drag test is from Hi-Performance Cars but doesn't provide an issue number of date.
Good question, pretty sure there was only one 350 available for 71. What did the 70 350 4spd run in the 1/4? Also what gearing did it have?
1970 Rallye 350 4 spd manual ran 15.27 @ 94.33 MPH rear 3.42 and 2 passengers onboard weight unknown. Car Life magazine May 1970.
1970 Rallye 350 3 spd manual ran 15.4 @ 89 MPH rear 3.23 approximate weight 3500 lbs (whether test or curb unknown...) Motor Trend magazine February 1970
Obviously a big difference in MPH. My 69 performs similarly to the 3 spd and far away from the 4 spd. Rallyes are automatically dual exhaust. My Car is dual exhaust. Made me wonder if the 3 spd manual has the automatic 310 HP cam, but the article clearly states the Rallye received a manual 442 cam. http://wildaboutcarsonline.com/membe...ye_350_1-3.pdf
You've got a random website put up by someone nameless that claims this drag test is from Hi-Performance Cars but doesn't provide an issue number of date.
I know Joe, all I can say is that page has been up on the internet for a very long time. Maybe before some realized how important it would be to tie yourself to posted information. I may have first come across it in the mid 2000s. As I mentioned I can verify several of those road test results that are posted. Having the month would of been great, but some of those tests are so legendary you can locate matching articles rather easily.
Doesn't make sense to me that they would totally invent non eye opening stats for a somewhat obscure / non existent model like a W31 / 1971 ... But obviously something is amiss.
Would love to know if its a total botch job, or if its some customer special order Cutlass that HPC decided to call W31 like ?
Originally Posted by 69HO43
IIRC, the 71 PIM has "Cancelled" stamped all over the W-31 reference pages.
That says a lot.
Originally Posted by 69HO43
Too bad, as that was a car they should have at least attempted.
So CARS version of a 1971 W31, they close to max optioned a 71 S 350 for performance, then called it that. Options took price from $3021 to $4264, surprisingly they ordered a stereo but no W25 ... Took 2 months from order form to car delivered. Performance excellent for a post 1970 350 Cutlass.
I don't think it would have been very much fun with an 8.5:1 compression ratio. Which may have something to do with why it was cancelled.
It may have. It would have been nice to see them try it, at least. I can't see all the bean counters saying it wasn't worth it, but I wasn't there and have no say in what happened. I had a few 71 non-W-30 442s with 455s and 8.5:1 compression and they were still hella fun to drive even through the factory exhaust. I'm sure a 71 W-31 would have been similar fun. With pretty much everything a W-30 would have except the engine/transmission, how expensive would it have been?
I read somewhere it may have been that the 350 W-31 wouldn't pass the newer emissions testing requirements, but that doesn't make much sense to me. Still, unfortunate they didn't somehow pull it off. It was a neat concept of big brother/little brother muscle pairings.
I read somewhere it may have been that the 350 W-31 wouldn't pass the newer emissions testing requirements, but that doesn't make much sense to me. Still, unfortunate they didn't somehow pull it off. It was a neat concept of big brother/little brother muscle pairings.
That is exactly the problem. Between the lower CR and the milder cam, any post-70 "W31" would have been a disservice to the heritage. The BBO had enough torque to cover for the W30. An SBO would have needed a cam good to higher RPM, which was not an option for early-70s emissions technologies. Keep in mind that the automakers were struggling to meet the relatively easy emissions requirements of the time. Coupled with crushing insurance rates on musclecars, there wasn't a lot of incentive to pump development effort into such a small sliver of sales.
So CARS version of a 1971 W31, they close to max optioned a 71 S 350 for performance, then called it that. Options took price from $3021 to $4264, surprisingly they ordered a stereo but no W25 ... Took 2 months from order form to car delivered. Performance excellent for a post 1970 350 Cutlass.
back in the mid 80's i had a 70 w-31.took it to my grandma's one sunday where all the relatives used to meet every 2 or 3 weeks.well my cousin saw it and said a buddy of his had one.i asked if it was for sale and he didn't know but gave me his number.so i called him.went to look at it.he said he special ordered the car it was a 71 cutlass w-25 hood 4spd manual brakes gauges tach and wing.was gold with kind of cream colored lace stripes on the hood.had the aluminum w-31 intake and he said it had 3:91 gears.it had an emissions tag under the hood i have never seen before.it had the firering sparkplug on it.well we kinda went back and forth on price and he said he would think about it.well his wife kinda made up his mind to keep it.last i heard it got passed down to their son and he restored it.that is one car i wish i would have got bought.
back in the mid 80's i had a 70 w-31.took it to my grandma's one sunday where all the relatives used to meet every 2 or 3 weeks.well my cousin saw it and said a buddy of his had one.i asked if it was for sale and he didn't know but gave me his number.so i called him.went to look at it.he said he special ordered the car it was a 71 cutlass w-25 hood 4spd manual brakes gauges tach and wing.was gold with kind of cream colored lace stripes on the hood.had the aluminum w-31 intake and he said it had 3:91 gears.it had an emissions tag under the hood i have never seen before.it had the firering sparkplug on it.well we kinda went back and forth on price and he said he would think about it.well his wife kinda made up his mind to keep it.last i heard it got passed down to their son and he restored it.that is one car i wish i would have got bought.
Ah, the "special ordered" story. The W31 intake didn't exist for the 1971 model year so someone installed that after it left the factory. Same for the rear end. 3.91 gears were not an option for the 1971 corporate 10 bolt. You COULD get dealer-installed 4.10s but not 3.91s. The hood, wing, four speed , and even the 4.10 gears were all regular production options that just required checking the boxes on the order form. Manual brakes were standard equipment on the Cutlass S; you had to pay extra for power brakes. There were no factory lace stripes, so again someone did that after delivery.
That is exactly the problem. Between the lower CR and the milder cam, any post-70 "W31" would have been a disservice to the heritage. The BBO had enough torque to cover for the W30. An SBO would have needed a cam good to higher RPM, which was not an option for early-70s emissions technologies. Keep in mind that the automakers were struggling to meet the relatively easy emissions requirements of the time. Coupled with crushing insurance rates on musclecars, there wasn't a lot of incentive to pump development effort into such a small sliver of sales.
My point exactly, but I'll just play devil's advocate for a minute and argue against that point by observing that Chevy was able to get pretty respectable performance from the '71 LT-1 with its 9.0:1 CR.
So it could be done, but whether it was economically viable within Oldsmobile's corporate culture at the time is another question altogether.
This is an interesting topic. I actually have a olds w31 intake from Oldsmobile engineering that was obtained by a friend in the early 1970s. The intake I recall correctly was casted April 1970, has the large 71/72 rear heater fitting, lots of machining dye, with numbers stamped in the front. It is not casted 405114 on the rear of the intake. There was probably an intent to have the w31 in 1971, but as mentioned was scrapped. To further the conversation, your GM parts book refers to a 1971 w31 in one area.
Last edited by joesw31; January 13th, 2024 at 02:03 PM.
July 5th, 2020, 05:55 PM
