I'm working through a project and was curious what kind of rear end gear ratios were available to the dry lakes racers during the late thirties and through the forties. I'm trying to estimate what some of the record holders were running for RPM. I have tire sizes and speed, but unclear on gear ratios. Here are some ratios I have found for that time period. (could be wrong) 3.27 3.54 3.78 4.11
Bull, I know my old man had a set of 3.54 and 8.00 16 tires and twisted his flathead A-V-8 well over 5,000 in outlaw runs in about '42. I think he wounded the engine.
3:27 was available, and also available was the overdrive real axle, the Columbia. some used 18" indianapolis tires and wheels, etc.,m Trader Jack
i think halibrand started making quickchange rears in 46 or 47, there were others well before them as well as the mentioned columbia rear ends. the everyday racer just swapped out to larger tires once at the lakes, mostly using 18 inch wires or kelsey hayes high clearance wheels (divco) and indy tires or just the tallest tires they could find. one old timer who started racing just after the war and worked at a hospital told me they'd "borrow" the rear wheels/tires off the ambulance
hey Jack, do you remember what year Fords came with the 3:27 ratio? also. was it fairly easy or common for a guy to locate a set of used Indy tires?
I feel like you didn't really see those indy tires show up a lot until the Lakesters became more prevalent but I know nothing since I wasn't born until 1982. It's a cool fact to know when Halibrand started making quickies since I was teetering on the idea of running one in my '33 eventually but I always thought they were sort of High Dollar for the day and I like the idea of building a car for the average dude from back in the day. I'll probably run the '39 rear with 3.78's as planned, but '32 18" wires might be an option maybe....
Post the speeds and tire size, then we can give you an rpm..Rough example: 29" tall tire, 3.78 gear = 4381 rpm @ 100mph.. not as much rpm as one would think..
Thanks Seb I have the formula for getting RPMs. I'm wasn't clear on the racers gear options for the time period.
I think what I was saying is that if the speeds [what were the speeds in the years?] were around the 100 mph mark, and they wanted to be at the 5000 rpm level then the 3.78 or 4.11 would have been fine..I don't know how high they wanted to run the engines, which was your question.. and the most common [for Ford] rears was the 3.78 and I think it would have been acceptable..I read somewheres that Ford had even lower gears than 4.11; like 4.44, 4.57, 4.86 in cars that were delivered to mountain areas [maybe in just the v8 60 and 4cyl]..
------------------------- It may be a Vega, but Packard power and running at Bonneville makes it HAMB-friendly enough for me! Mart3406 =====================
What a cool lesson in land speed times. I love the story about using the ambulance wheels and tires, what a guys gotta do sometimes! Thanx! ~Sololobo~
As a side note here, I was checking out Chet Herbert's Beast III at the Crouse shop in Colorado a couple of years ago after it had just emerged from hiding. At one point in its history they had installed a huge diesel (425 c.i. 6-71 GMC I think) with twin superchargers on a home made manifold. The engine was laying next to the car and it was huge looked like it wouldn't even fit under the body ... Anyway, it ran a preposterous gear ratio/tire combination that would move the car something like 12 ft for every turn of the engine. The motor would only turn maybe a couple thousand RPM's but had enough torque to pull it close to 200 mph and set some diesel records for the day..... .
If you or anyone else likes it enough it's available for loan as a HAMB type club endeavor to take to the salt and run. Anyone contemplating such a thing would have to show up with a trailer that I will let my car and tires on. They should show up pretty early (Like around now) in order to get the between meets maintenance done and any changes to suit them. That's about it.
I know that Ford made a 3.54 gear in 1946. I just sold the gear set last year,and it came out of a 46 Ford half ton pickup,barn find. I am sure it was original,it had the Ford script logo. I have another 3.54 in my 27-T,that also says Ford on it. It came out of a 36 Ford hot rod that was built in the late 40's,early 50's. The guy from Yesteryear Ford told me that Ford built some cars in 35-36 with 3.54's to take advantage of the new smaller 16" wheels.
Here are some more speed records and their years. Schenck's Golden Submarine 118.57 mph (1940) Jack Lehman 123.96 (1942) Arnold Birner 124.65 (1942) Arnold Birner 125.69 (1942)
The Jalopy Journal
