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1936 Buick High Way Speed Question


Buick36-49

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So even with slightly truckier gearing in your above junior Buicks, Oldsmobiles, Pontiacs, et al, if you can't hold 50-55 mph, something's seriously amiss.

I'm not saying that my Pontiac can't do the speed, I just hate the sound of the high RPMs. I was looking over the service manual for my car last night, and I noticed that for my car (6 cyl) the peak HP is at 3600 RPMs, and at those RPMs, the car should be traveling at approx. 65 MPH. With the lower gear ration, I believe that running this car at these RPMs would NOT be good for the car, especially if I intend on keeping it to drive for a while.

It's funny, there was nothing in the book about the different gear ratios with these cars. How would I be able to find out about this? I would like to a better gear ratio to keep the RPMs down during higher speeds.

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You'll have to check with various experienced members in the Pontiac-Oakland Club to see what later, taller rear pumpkins you can use, perhaps something out of an early '50 Hydramatic Pontiac, if it'll fit, bolt right in. You'll lose some of your low end snap, but cruise with less drama. That, or an aftermarket overdrive.

Or just enjoy it as is, and be content to stay in the right lane or backroads. Be glad you don't have an MG-TC, wide open and buzzing at 78 mph razor-tuned with a tail wind.

All these old cars are survivors, and nice, yours among them.

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I should add a caveat to the 1933 Graham 64 Cannonball Baker run. The Model 64 Graham had the preproduction 1934 Supercharged 140HP straight eight, not bad for a 245 cid engine. Graham did not publicize the new engine during the run. Cannonball did say he would have been faster if he had not taken a 20 min nap. As far as I know the record stands for a single driver.

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My '38 is strictly around town. I don't have anywhere I really wanna go on the highway with it. But occassionally I might be, or on a high-speed secondary road, and sometimes I'll get all "courageous" (Ha!) and take 'er up to 60, or just a little over. It really smooths out and honestly rides so nice at that speed, and engine RPM too. Through the firewall things sound much more like a high pressure rush of air, not moving parts. Buuuuut then I get to thinking of those long rods flying around at that speed, and listening close it sounds "busy" as others have said. Then I slow the hell down.

I can't believe peak HP is at 3200. I don't think I've ever spun mine that fast once. So what's the redline, 4 grand? Ha! See ya later connecting rods!...

I'd love to build up a hot-rod straight 8 with a stout bottom end JUST so I could rev it to 4-5 grand like an engine 30-40 years newer. That alone would help with acceleration, and top end cruising speed, provided you don't mind listening to it. It's not funky noises that bother me....it's knowing they are symptoms of something BAD that bothers me!

There is a world of difference between a 248 cid Special and a 320 cid Century. For 1939 the factory rear was 4.44-1, and the alternate was 3.9-1 in a Special. The Century came with 3.9-1 with an optional 3.6-1. I suspect the '36 was similar, but I haven't looked. In 1939 a Century couple, driven by Mark Light, won the first stock car race at Langhorne Speedway in PA. The Century was a very fast car. The 1936 Century was so named, because Buick said it could do an honest 100 mph.

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As posted earlier, I like to cruise my 36 Chevy with 4:11 differential at 50. I will cruise it at 55 for awhile, and would be willing to do 60 or so for several miles. We live in the Appalachian mountains with a lot of scenic, twisting roads, so it is my intent to drive on those, not interstates. The high torque engine is excellent at pulling around on these type roads.

So my intent in having an old car is to take it easy and not push it too hard. Yes, it could probably maintain 60, but the long-term pounding with the long stroke rods and heavy pistons couldn't be too good long term at that speed. The engine was recently rebuilt with NOS GM rods, NOS main modern type insert bearings, and NOS GM crankshaft, and I hope to keep the car running a long time.

I would be willing to bet that Cannonball Baker and other record setters didn't care about the long-term durability of the vehicle they were driving--they were simply trying to set speed records. So if they needed to have the engine screaming away at maximum rpms for long periods of time, so be it.

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My '47 Super had the original 444 rear end when I first bought it and it I could feel the engine working pretty hard above 55 mph. I switched to a 390 and it's a different car. I can easily maintain freeway speeds here in So CA without worrying about the effect on the engine. Back in the 30's and 40's cruising speed was 45-50 mph. The original gearing on these cars was never designed to cruise all day at freeway speeds. I find the car to be very comfortable at 60-65 mph. At only 50 mph you become a road hazard on the So CA freeways. Switch to a 390 or even a 360; driving will be much easier.

Sid Munger

I think you'll find that was a 4.54-1. They were still higher after the War; why? I have no clue except maybe the car was heavier.

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As posted earlier, I like to cruise my 36 Chevy with 4:11 differential at 50. I will cruise it at 55 for awhile, and would be willing to do 60 or so for several miles. We live in the Appalachian mountains with a lot of scenic, twisting roads, so it is my intent to drive on those, not interstates. The high torque engine is excellent at pulling around on these type roads.

So my intent in having an old car is to take it easy and not push it too hard. Yes, it could probably maintain 60, but the long-term pounding with the long stroke rods and heavy pistons couldn't be too good long term at that speed. The engine was recently rebuilt with NOS GM rods, NOS main modern type insert bearings, and NOS GM crankshaft, and I hope to keep the car running a long time.

I would be willing to bet that Cannonball Baker and other record setters didn't care about the long-term durability of the vehicle they were driving--they were simply trying to set speed records. So if they needed to have the engine screaming away at maximum rpms for long periods of time, so be it.

With insert bearings you should be able to run the car as hard and as long as you want or need to do, or not to do. Insert bearings are also the answer for all 1937-49.5 Buick 248 engines. It's the only way to go. 1950 Series 40 rods are the same, and 1950 factory insert bearings work wonderful. You have to use only 1950 Series 40 rods, because the 1950 Super and all 1951-53 Special and Super used the 263 cid engine and the rods are shorter. If you tear apart a second series '49 Series 40-50 engine and find inserts, those rods will work too. The 320 Buick, I think, switched over at the beginning of 1949, unlike the Special and Super which switched mid-year.

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Regarding Dynaflash 8's comment in post #44 above, Buick never "said" the '36 Century would do 100. See my post #40 above, second paragraph. Buick's Harlow Curtice and Buick's new ad agency (Art) Kudner, knew how to market, promote.

Century was chosen for the new model with its debut engine both to suggest 100 and the high-speed luxe of the then most famous express train in the nation, the New York Central's 20th Century Limited, just as Buick's top model on the long wheelbase was christened Limited.

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I'll have to go back and research my notes for my 1971 Buick Straight 8 article, and/or the article itself. It's been a long time since I wrote it, but I still think I found where Buick did say that.....but, after almost 40 years, I could be mistaken. Earl Beauchamp Jr.

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BTW, in response to JPage's question about '36 Buick Century. GM knew how to market automobiles. No way would a stock '36-37 Century do an honest, observed 100mph. A '38 Century did manage 100 briefly with a phalanx of anxious Buick engineers looking on with bated breath at the GM Proving Grounds. Buicks sorely needed the rare, no-cost option 3.6:1 "economy axle" available 1939-42, but only on the senior Buicks.

The 1936 Buick Century sedan was credited with a top speed of 95.6 MPH and in all likelyhood the lighter bodied coupes and convertible coupe could manage 100MPH.

I recommend an article written by Michael Lamm titled PAST MASTERS : MUSCLE CARS OF THE THIRTIES AND FORTIES which appeared in the April 2009 edition of Collectible Automobile.

The article includes a comparison chart of road tests conducted by various motoring magazines of the day and interestingly rates the Buick Century amongst some very illustrious company.

The Century as we know was a standard sized vehicle with the largest available motor ( sounds like a muscle car!! ) but there were also other differences. One was the rear end ratio. The 1936 Century had aratio of 3.9-1 while the Special was 4.444-1 and the larger series 80 and 90 were 4.222-1 and 4.555-1 respectivley.

Obviously being a Buick owner I am a little biased so I do suggest anyone with an interest in early high powered cars obtain a copy of this article - I'm sure it will produce plenty of comment!!

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That 95.6 mph top speed observed at the GM Proving Grounds for the new '36 Century rings a bell. I read that years ago. Thanks. However, a coupe or convertible would be no faster. Actually, a convertible would be a trace, perhaps a couple hundredths of a mph, slower due to drag from the cloth top.

Absolute or top speed= coefficient of drag (CD rating)/horsepower/final gearing

Acceleration=weight/torque/final gearing

And even if Buicks defied the laws of physics, Flint would still publicize the absolute highest speed they could wring out of their new car, regardless body style.

Thanks, sir, for confirming that figure.

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since Buick used the torque tube for years ( I believe into the 60s ), can't you guys find a complete rear or just gears with suitable ratios that might interchange with your older cars ???...yes 4.44s and 4.33s are fine for chugging around town,the freeway is another thing....I think that mid to late 50s Buicks used a highway friendly 3.64 and 3.36 ratios...look into these gearsets.

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Seems to me people are often substantially out of proportion in their expectations of higher gear ratio obtainable from swapping the ring and pinion gearsets. The factory rear end for ford (model A) correspond to a 3.78 (OEM) ring-divided-by-pinion ratio. A weekend and several hundred dollars later, you can have the 3.54 ratio, if you are lucky enough to find the gearset. Stop and think about difference in these two ratios. Easiest way is probably just to divide 3.78 by 3.54 to find that 1.068 the high speed rear end is only about 6% gain! Say you are going 60mph with the lower ratio. Then, preserving the same rpm, you are only able to go only 3.6 mph faster, or about 63.6mph! I believe the reason for over-rating the effect of these ratios probably stems from drag racing, where a small change can lead to many thousandths of a second in elapsed time, which makes the change seem much more meaningful than it is with respect to engine rpm. Perry

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The Buick differential gear sets (pumpkins) are interchangeable from 1940 to 1955. When installing a taller ratio gear set you may need to use slightly longer bolts to hold the case into the rear end housing. The ratios that were made for the later years were 3.9, 3.6, 3.41, 3.36 and perhaps one or two more. You need to re-use your original drive shaft and torque tube. The rear cover needs to be positioned so the drain plug is at about 4 or 5 o'clock as the gear lube level should be about about 1/2 way up or just touching the bottom of the axle shafts.

Pay attention to the fact that while you can usually improve road speed with a gear change, you still have to stop these old Buicks, so leave enough room to stop.

Joe, BCA 33493

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As far as my Pontiac goes, since this car was (until I purchased it) in the mountains, then that would explain why the RPMs are so high when at 50. All I would be interested in, would be to find the higher-speed ratin that would have originally come with my car. This of course would be the gears that were designed for flat-ground driving. No mountains in Florida, so that wouldn't be a problem. I know that these cars were (for the most part) not designed for the highway speeds of today, but if I could drop the engine RPMs just a bit, going 55 mph wouldn't be such a strain on the old engine.

I spoke to a guy that also owns a 37 Pontiac with a 6 cyl, and he told me he has no problem going 55-60 MPH at a constant speed. His car has the flat-land gear ratio.

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when these cars were new, there wasn't any road called a "freeway". around town and country roads were all there was....40-50mph would have been just fine....now with every car equipped with overdrive, overhead cam high revving aluminum engines, every driver just suums to be in a great hurry to get to their destinations....why??...because they can !!...our old cars are now just "rolling roadblocks" to modern vehicles.

'

'

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Dynaflash I must admit that would be a ratio change wide enough to be highly noticeable, as you say. You gain better than 12% more roadspeed at any high-gear RPM. I think that is along the same lines as some overdrive units.

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A gear swap won't come close to matching an overdrive for RPM reduction. As someone pointed out above, the effect of a modest gear change isn't very big, but the overdrive in my Cadillac, for example, is a 30% reduction (the Cadillac's final drive ratio goes from 4.75 to approximately 3.33 with the overdrive). At a real 60 MPH, the engine thinks it's going 42 MPH. I don't think there's any real-world gear ratio out there that can deliver that much of an improvement.

This isn't to say that a gear swap isn't a worthwhile improvement, because even a 300-500 RPM reduction is nice peace of mind when you hear it thrashing away under the hood. I have a 3.60 gearset for my '41 Century that I intend to use in place of the original 3.90s, but that's really only economically smart because I already have the whole car apart. If I had a complete, running, driving car, I don't think I would have made the investment in money or effort for that small of an improvement. I believe The Old Guy has a set of 3.54 gears from a Dynaflow car in his 1940 Super, which is probably the ideal choice for any '30s or early '40s Buick, which have plenty of torque to pull a lower gear. If you can find a set THAT would definitely be a worthwhile upgrade.

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