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1932 Studebaker Indy car build


Gary_Ash

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We're sure the parts will go together because I sent an extra wheel center to China to be used as a gauge to check the fit of the splines. It was also used to assure that the spinners seated correctly and mated to the 10-degree taper on the outer end of the centers. Since the wheel centers were actually made in India to the original Dunlop drawings, that test piece will have traveled from India to England to Massachusetts to China and back to Massachusetts, all in the course of 3-4 months.

See my post from Feb. 23, 2014 on the previous page for notes on the 250 cu in straight 8 engine.

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  • 2 weeks later...

Finally, the splined hubs are finished. After cutting the splines on the hubs, the knock-off spinners got polished and chromed. The are some screw-in caps for the ends that serve as grease retainers. We made these out of brass, no plating, laser-etched the Studebaker logo into them. I'll have to polish them now and then, but I think they'll look just fine. My buddy who got these made in China went more than the extra mile to get these done right, now I will really owe him many favors.

The front tires arrived here, the rear ones were back-ordered. I'm using the new Excelsior Stahl radials from Coker that look like bias ply tires. They are speed-rated for more than enough mph. The tubes are "racing" style ones with brass stems to prevent a shifting tube from cutting off the stem at a critical moment, required for participation in any vintage racing events.

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  • 4 weeks later...

At long last, I finally managed to finish off a bunch of small but critical parts: rear spring mounts, shackles for front and rear springs, chassis cross-members, and the front spring mounts and crossbar. It was a little tricky to get the chassis bolted together with the springs in place because the springs have bronze bushings with no give anywhere. I was a little concerned about having welded all the parts together to keep everything square and perfectly aligned. However, it did go together. I got the front axle mounted with caster shim and rubber bumper, and the rear axle housing mounted with its shim (without the center section and axle shafts - much lighter to move). The NOS (from 1928) axle shafts got polished to remove a little shelf rust and will go in as soon as I fabricate the felt grease seals.

I pressed the new bearing cups into the front splined hubs and put old cones in temporarily. The 1963 Buick Riviera aluminum drums were mounted on the new front hubs, and the assemblies placed on the front spindles. Then the wire wheels were slid over the splines and spinners and brass hub caps put on. I'm still waiting for the arrival of the rear tires, due in a week or so. Then it will be a rolling chassis. I even put one of the firewall support hoops in place with a couple of C-clamps, just for fun. It's beginning to look like a car!

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  • 4 weeks later...

I got the parts together to reassemble the rear axle. I had to make the felt grease seals by using some pieces of exhaust tubing with sharpened edges to die cut 1/4" felt sheet into some doughnuts. The differential assembly was rebuilt with new bearings, aligned, and the backlash adjusted by WCD Garage in Northborough, Mass. The assembly weighs 90 lbs, so there was no way I could pick it up, hold it with one hand, and insert the bolts. I maneuvered the engine hoist into place, attached a chain, and picked it up. Fortunately, it balanced nicely in the right orientation. I managed to get a couple of bolts started to take the weight, removed the chain, and put in the rest of the bolts. If I have to do this again, I'll make a couple of long studs to guide the flange into place and take the weight temporarily.

Next on the list is to press the tapered-bore axle shaft bearings onto the axle shafts. The shafts are big: 1.625" diameter with a 1:12 taper at the ends. According to the bearing manufacturers, I'm supposed to place the bearing on the taper and then drive it on tight. The recommendation for this size bearing is move it about .016-.020" up the taper, expanding the i.d. by about .0015". My plan is to put a big hose clamp on the axle just inside the bearing starting point so that I can get a stack of feeler gauges between them, say about .060". I can just get the axle shaft and a 6" piece of 1-1/2" iron pipe under my Harbor Freight hydraulic press. Pushing on the pipe should drive the inner race up the shaft and I can keep putting the feeler gauges in as I go. I sure hope this works!

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  • 3 weeks later...

The axle shaft bearing installation fortunately went mostly as planned. I slipped the tapered-bore bearing on the shaft, placed a piece of 1-1/2" black iron pipe and a cap over the axle end resting on the inner race, and pushed with the hydraulic press. It was almost an anti-climax, as I didn't have to pump more than a single stroke to move the bearing about .020" along the shaft. I greased up the new bearings, inserted the inner felt seals, slid in the shafts, and mounted the hex-shaped end caps to push the bearings into place. Maybe the factory originally pushed the bearings on a little more or my NOS axle shafts were just a touch longer than the old ones, but I didn't have enough shims to get the .001-.006" free play in the shafts. I quickly drew up a CAD file, bought a roll of .005" steel shim stock, and had the laser-cutting shop down the road make some new shims. I would have cut them by hand from Mylar polyester sheets, but I wasn't sure how well they would stand up to heat and oil for the next 10-20 years or more. I wound up adding about .015" of shims to each side to get the free play I needed, but now I can just hear the click as the axle shaft moves in and out.

With the rear axle assembled, I mounted the 1960 Buick LeSabre backing plates and adaptors, cleaned up the 1965 Riviera 90-fin 12" aluminum drums and pressed them onto the new inner hubs. I'm using the same aluminum drums front and rear, but the rear shoes are narrower to help balance the braking correctly. I had obtained copies of the original manufacturing drawings for the 1928 hubs from the Studebaker National Museum, so the new hubs were the same depth and had the 1:12 taper to match the shafts. My buddy who had the parts made for me in China used wire EDM (electro-discharge machining) to cut the taper and 1/4" keyway. The outer splined hubs slipped over the five studs pressed through the inner hub and lug nuts hold the assemblies together. The lug nuts are hidden by the wire wheel centers.

The Coker Stahl radial tires got mounted on the wire wheels, 6.00-6.50/18 in the front and 7.00/18 in the rear. Each wheel and tire weighs about 55 lbs. The hubs and drums are heavy, too. Today, I was finally able to get all four wheels and tires installed. I lowered the chassis onto four Walmart bathroom scales and added up the weights: about 950 lbs for the frame rails, axles, springs, hubs, wheels, and tires. The bare frame weighed about 150 lbs, so there is about 800 lbs of unsprung weight. Maybe I should only count half of the weight of the springs as "unsprung", but there is still a lot of it. The engine and transmission will be very heavy, about 750 lbs with accessories, but the aluminum body will probably come in at about 200 lbs.

The highlight of today's work was finally putting the tires on the ground and rolling the car forward and backward in the garage. It feels good to have a "roller"! Now I have to get the radiator shell mounted and refine my FoamCore radiator model so I can get the radiator built.

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I'm thinking of using The Brass Works for the radiator [http://www.thebrassworks.net]. I think the 1930s cars ran with zero pressure on the cooling systems, but a 4 lb cap with a modern-type radiator should be OK. The real limit may be the packed seal on the water pump. The original Indy cars may have used a Ford AA truck radiator core about 2-5/8" thick, but they didn't have fans since they usually drove at 110-140 mph. I'm planning on a 3.5" thick, 4-row core, about 18" wide x 18" high, plus the tanks. I'll use a fan, as the current versions of the Studebaker Indy cars have, since it's more likely that I'll be running at (much) lower speeds. I have an old 2-row radiator from my 1948 Studebaker M5 truck that is almost exactly the right height and width, but it's a radiator for an 80 hp engine, not 200 hp, hence my plan for a thicker core. It almost fits the radiator shell for the Indy car, except for the side brackets. The guy at The Brass Works (Lee), said to send them a foam model of what I want rather than drawings with 100 dimensions. He just confirmed my theory that the best craftsmen are bright, visually oriented, not paper-and-pencil math wizards, and probably dyslexic. My radiator model is made out of 1/2" FoamCore put together will Elmer's Glue. I can easily rip it apart, shave it down or add parts, and put it back together. It's light enough to ship to California at low cost. Lee claims his guys can build anything they can see.

Here's a photo of one of the cars with the 1933-style body and radiator shell but having the smaller 250 cu in straight 8 engine as I am using. The photo was taken as Studebaker was preparing for the 1934 Indy race, but they went into receivership and didn't make the race in May. The picture shows the engine and radiator, same radiator as used 1931-33., but different grille shells and surrounds.

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Edited by Gary_Ash (see edit history)
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Will, I've been using TurboCAD for some years now. I started off with TurboCAD Deluxe, the $129 version. It will do 2D and 3D modeling. Because I needed some additional features for work, I eventually upgraded to TurboCAD Pro. The Pro version has features like "lofting" to generate complex surfaces that follow an array of lines, good for body design. However, you can do a lot in the basic Deluxe version if you take a little more time to make surfaces, trim, and attach them together. A speedster body isn't like a Lamborghini, so the surfaces are simpler. See www.turbocad.com.

I'm currently working on rendering the grille shell. It's very difficult because of all of the complex curves. Getting the lower edges to the right shape and blending them in is proving to be a challenge. Here is the real thing plus the drawing version, so far.

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I got some work done on the frame for the cockpit skin. The frame is made from 1x1x1/8" angle iron, based on photos of the 1932 cars at the factory and some photos I have taken of the real cars over the years. Since the restorations of the existing Indy cars were done 30-40 years ago, I haven't found any recent photos of the cars with the aluminum skin off. I have a couple of photos of the 1962 restoration of the #22 car, done at the Studebaker factory to celebrate the 100th anniversary of the Studebaker company. The cockpit skin is a hoop of aluminum skin with aluminum angles at the bottom to snug it down tight to the frame rails, pulling it tight against the angle iron frame and the cotton webbing attached to the angle iron. Of course, the skin was formed to curl up for the top of the dash and outward to give space for the steering wheel. This will be work for the English wheel and planishing hammer.

I copied the dimensions as well as I could, tacked the pieces together while they sat on the chassis, then finished the welding and ground down the lumps and bumps. I had welded the angle iron hoop for the dash and steering support on the garage floor so that I could get the 20 degree tilt of the dash and the inward slope of the legs correct. It was a brain-numbing task to get all of the angles and dimensions about right. In most cases, I think my parts are within 1/16" to 1/4" of the actual cars. Some bolts through the frame rails will secure the skin and angle iron to the chassis. It feels very stiff, even now. Even so, I would hate to be in a roll-over accident in one of these cars.

I had a CAD mockup of the instrument panel, printed it out on 8 sheets of 8.5"x11" paper, and taped the bits together to see how the dash will look. I need to make a few adjustments for actual sizes and shapes, but it's close.

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Edited by Gary_Ash (see edit history)
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  • 4 weeks later...

On projects like this, even the small parts take a lot of work. To operate the throttles on the four Stromberg EX-23 carbs, the factory mounted short arms on the throttle shafts. The arms may have been a standard Stromberg part in the 1930's, but also remember that Stromberg, a Bendix subsidiary, was located in South Bend, Indiana along with Studebaker, so special parts would not have been too difficult to get. The carb arms coupled to stamped-steel links and then to another arm located on a 1/2" diameter shaft running the length of the engine. See the photos in post #21 of this thread. Using the old photos I had, plus a visit to one of the original cars, I drew up the arms and links in my TurboCAD program. The throttle shaft arms were machined for me in China by a friend who makes parts there, but I made the other parts here. I created a solid model for stereolithography 3D printing of the carb arm and had one made by Shapeways.com in acrylic plastic. The acrylic master was used to make a silicone rubber mold and a then a bunch of wax masters. These were mounted together, dipped in a plaster mix several times, then investment cast in silicon bronze at a local art foundry. The foundry shook them out of the plaster, tumbled them for surface finishing, then I had to drill several holes, machine a clamping slot, and tap for the 10-24 clamp screw. The silicon bronze turned out to be easy to machine, fortunately, as I only have a small mill.

The blanks for the links were laser-cut from 16 gauge (0.060") steel sheet by a nearby shop. Blanks were about 2.5" long x 1/2" wide. I made a simple die from 1/2" steel bar to stamp the double bends in them using my little 12-ton hydraulic press. Two stamped blanks were then spot-welded together to make each link.

Arms and links then went to a local plating shop for zinc plating with clear chromate overcoat for corrosion protection and to make the silicon bronze parts the same color as the rest of the parts. Now they look like the Studebaker factory engine parts used in the 1931-33 races and the engines being developed for the 1934 race. I still have to make the special throttle shafts from 1/4" brass rod. Cutting the .060" slots for the throttle plates and threading one end will be tricky. Each throttle plate got two tiny screws to hold it in place; I haven't yet figured out how they peened over the ends of the tiny screws to keep them from loosening.

I have some extra carb arms and links for sale if anyone needs something like this.

I always try to keep a bunch of things progressing in parallel so that in case I hit a barrier with something or get frustrated on a part, at least something is getting done all of the time. There is still a lot to do on this car!

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Edited by Gary_Ash (see edit history)
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  • 2 weeks later...

The 57 lb flywheel got dragged off to the local auto parts shop for resurfacing. The recessed surface makes it slightly more difficult to do, but not significantly - they charged $60 to grind it, including the surface where the clutch case attaches, to keep the spacing correct. Apparently, the car that the engine came from had been parked many years, so the clutch disk had glued itself to the pressure plate. The lining was torn off the disk at some point. I cleaned up the mess with a flat scraper, then sent the remains of the disk and the pressure plate with case to Ft. Wayne Clutch. The 20 lb assembly went into one of those US Postal Service flat-rate boxes: "If it fits, it ships!". I've sent starters and generators this way, too, an inexpensive way to move heavy parts. The people at Ft. Wayne Clutch did a great job rebuilding the pressure plate assembly and re-lining the disk, plus new springs, and returned the parts in about 10 days.

I've been thinking about lightening the flywheel, but I think I'll try it the way it is. The transmission is a 3-speed Borg Warner T85-1B with R5 overdrive. I may need to modify it to be able to lock-out the overdrive/freewheel at times.

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We've lost all of our local platers due to the cost/environmental restrictions so I'm curious how your zinc plating compares to chrome in cost. If I ever get my new shop set up I'm seriously thinking about setting up a tank to do my own small parts if I can source the products.

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Zinc is for corrosion protection, not for bright and shiny like chrome. It is not long-term durable outside.

It is easy to do your own zinc plating, but messy. I have just done some nuts and bolts. My "tank" was a 5 litre bucket and the zinc was zinc bars from a boat shop (sacrificial anodes). I used this paper for guidance: http://home.comcast.net/~rt66tbird/website/zincplating.html#

It is written by a person with some chemistry background. In this country, zinc phosphate is used to treat footrot in sheep. My first attempt did not work well - I had too much current. So I added all the items I wanted to plate at the same time and it worked very well. Take note of the current requirement - it is low. I will be looking for an old radio volume control (a potentiometer) to add to the circuit to reduce current.

One thing though. Tom mentions denatured alcohol which is white meths, here. It contains a bittering agent. I tried storing cleaned bolts in it and they still rusted. It must have contained had some disolved oxygen.

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In the U.S., the Environmental Protection Agency (EPA) and the Occupational Health and Safety Administration (OSHA) set very stringent health and safety rules for many industrial activities, especially plating. Historically, chrome plating has used a hexavalent chromium compound to deposit the chrome coating. Rules are tough on exposure of humans to the plating solutions and also to disposing of spent solutions. There are newer processes that don't use hexavalent chrome, but you still can't dump chrome or copper compounds down the drain - and you don't want to dump them in the back yard where the solutions get into your well water or someone else's well. I once worked at a company that got in trouble for the amount of copper flowing down the drains into the town's sewer system. When the quality of the incoming town water was tested, there was more copper in it than was in the discharged water - the town stopped pursuing the case.

Bright zinc plating is nowhere near as corrosion resistant as true copper/nickel/chrome plating, but it works OK in protected areas, like under the hoods of cars that will never get driven or parked in the rain. Also, it's not very expensive. I paid $50 to get about 60 parts plated, but that was the minimum charge and they could have done 5-10 times that many parts for the same money. They finished with a clear chromate layer for extra corrosion protection. For many functional parts, I would prefer electroless nickel plating in .0003 to 0.001" (8-25 microns) thickness for corrosion protection and hardness. The electroless nickel covers all surfaces uniformly, coats into holes and recesses, and covers corners. It's available in both bright and dull finish, stands up to long-term exposure, not as shiny as chrome, but pretty good. The local plating shop says they will get into nickel plating in a few months. The shop is 10 minutes from my house, the people are friendly, and they delivered good quality in 24 hours - it doesn't get better than that.

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Is electroless nickel porous? "Normal" electroplated nickel is, which is why it should have copper under it - copper is not porous. I believe chrome electroplating is also porous.

I am reliably informed that all nuts, bolts, washers and screws on my 1930 Dodge DC were cadmium plated. Almost all of them were painted on assembly. When not, they have lasted quite well, although the cadmium discolours over time.

Edited by Spinneyhill (see edit history)
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Under the right conditions, electroless nickel is not porous and is very corrosion resistant. See http://en.wikipedia.org/wiki/Electroless_nickel

I designed parts for industrial applications that saw exposure to corrosive gases, repetitive cycling to cryogenic temperatures with weekly returns to room temperature wet environments and the parts never showed corrosion after 10-20 years.

I believe that electroless nickel is superior to cadmium - but it's very difficult to find anyone to do cadmium plating now. I looked at the Caswell Plating kits for "CopyCad", but there is a significant investment and it's basically zinc, anyway, and you need to set up a chem lab to do it. I'm content to send the parts out and let them worry about the details. I had a similar reaction to looking at anodizing aluminum parts - yes, you can do it, but why bother?

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Car #46 presents an interesting mystery. Let's start at the beginning of a long, complicated story...

We need to cover what we do know about the Studebaker Indy cars. In 1931, Studebaker was interested in participating at Indy but did not want to get involved "officially". So, car #37 was built using many parts from standard President sedans, such as the engine, transmission, steering, front axle, and gauges. The rear axle came from a 1928 Studebaker GB or EW roadster or Victoria coupe because it had an available 3.09 ratio, standard was 3.31. Brakes (12", cable operated) came from a smaller Studebaker sedan, a Dictator or Commander. The chassis was built by the Hermann Rigling shop in Indianapolis, pure race car. The body was made by "Pops" Dreyer in Indianapolis. Many other Indy cars of the 1930s used Rigling chassis and Dreyer bodies, including the Shafer 8 cars with Buick straight 8 engines. The #37 car was owned by Ab Jenkins and George Hunt, a Studebaker engineer. The car did well enough in the 1931 race that the factory authorized building four copies of the car and raced them as a team of five, though #37 continued to be privately owned. Also , there were a number of other privately-owned cars with Studebaker engines that raced from 1930 and as late as 1939, including the ROMTHE Special, Art Rose Special with front-wheel drive, and several cars by John Snowberger, who started using Studebaker engines about 1930.

The cars - except #37 - got new bodies in 1933 to gain speed through streamlining. Some of the cars got new racing numbers for 1933. It isn't clear what happened to the 1932 bodies, but some of them survived in storage. The Depression hit all of the car makers hard, and Studebaker went into receivership in 1934. They had discontinued the 337 cubic inch straight 8 after 1933, had planned to use a racing version of the 250 cubic inch straight 8, but had to cancel racing plans before the 1934 race. They then proceeded to sell off the 250 cubic inch racing engines for $750 each. They also sold all of the race cars.

So, the car that was #18 in 1932, got a new body in 1933 and a new number, #9. That car was eventually sold to A.E. Small, a Studebaker dealer in South Africa. The car was raced, sold a couple of times, and stayed as a race car until about 1959. The chassis and body went to a scrap yard, but the engine block went into a 1928 Studebaker 7-passenger limousine, perhaps in the 1970s. The limousine survives, was recently purchased by Peter Gillespie, a Studebaker enthusiast in South Africa. The serial number on the block matches the records for the race cars and the modification for installing a magneto for racing is there. At least we have the engine from #18/#9.

The history for the other cars, except for #46, is pretty well documented. Car #25 in 1932 got a new body and number 34 for 1933. Somehow the 1933 body got separated from the chassis, and is now in California, owned by a collector. A new, replica body was built for Brooks Stevens when he owned #34. The car is now owned by August Grasis III in Kansas City and is regularly raced in vintage events. It is white and carries #34, as it did in 1933. It's the only existing Studebaker Indy car with a 1933-style body.

The original body and grille from #18 emerged from a back-alley garage in Chicago in the late 1970s and was bought by Mike Cleary, who restored it with the assistance of Darrell Dye. It got a new chassis and engine, along with many other mechanical parts, to complete the car. It, too, races regularly in vintage events, has a blue paint job and wears #18. The #22 maroon car somehow wound up with its original body, though considerable restoration had to be done at the Studebaker factory in 1962 for it to appear at Indy events that year. It had raced as #6 in 1933 and as #53 when it ran Indy in 1937 with its original body. Today, the car is at the Indy Speedway Museum. The #37 car ran as #47 in 1933 with its original body, wound up in the hands of Ab Jenkins' son, converted to a sports car. It eventually was bought by Stan Smith Sr. about 1972 and was restored over a long period to its original configuration, color, and number. It is now owned by Robert Valpey in New Hampshire.

So, what about #46? We can accurately account for all the other cars, but there is a big, 50-year gap in the history of #46. It may have gone to Argentina in the 1930s because there are no records or photos of it appearing at car events in the U.S. from the 1930s to the 1980s. I have emailed a number of car hobbyists and racers in South America asking if they have photos, magazines, newspapers, or any documentation of the car appearing at events in South America - so far, no luck. I did correspond with the family of a Mercedes dealer in Germany who apparently imported the remains of some kind of race car from Argentina in the 1980s, nominally car #46. I can't find any records of who the Argentinian seller was. Eventually, the car wound up in the hands of Alfred Weber who had the car "restored" in Indianapolis with the help of some key people at the Indy Speedway Museum and shipped back to Germany about 1994. I talked to "Junior" Dreyer, grandson of the original body builder, who said he made a body for the car, working from old photos. Apparently, the Dreyer family does not have original drawings for the car bodies. I was told that the car came back to Indianapolis again for repairs and upgrades. Today, the car is owned by Ronald Springer in Germany, and has raced at Nürburgring the last couple of years in vintage events. One of the things that lends some credence to the chassis and many other parts being original is the assortment of spares that are clearly from an original car. The current engine is not an original Indy racing engine, but it is a 337 cubic inch one. There is a spare engine, pictured below, that has the magneto installed and the unique tach drive adapter in the head where the distributor originally sat. I have no reason to doubt that this started life as the #46 car, but I sure would like to know where it was for 50 years. It may have been sold by the factory with a 1933 body, and a new 1932-style body may have been created for the 1994 restoration. There is no truth to the rumor that one of the Studebaker Indy cars was lost in the sinking of a ship bound for South Africa or South America, according to Richard Quinn, Studebaker historian of great renown.

So, a long story and interesting mystery!

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Edited by Gary_Ash (see edit history)
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More work on the carburetors and linkage! I'm using four Stromberg EX-23 carbs from 1936-37 Studebaker sedans, similar to the ones used by the factory. However, the sedan carbs had stamped throttle arms that were peened onto the ends of the throttle shafts. Some of the old carbs I acquired had the shafts completely frozen in the base or the peened brass had split, leaving the arms loose. The stamped arms were all wrong anyway, so I had made new arms and links, but I also needed to make new shafts. The shafts are 1/4" diameter brass with a 1/16" wide slot cut in it for the throttle plate. Two tiny 6-32 screws secure the plate to the shaft. One end is threaded for a 10-32 nut, then milled on two surfaces to locate the throttle pump lever. I'm not a very experienced machinist and the task looked pretty daunting. Since I needed four shafts for me and eight more for carbs for some other guys, the estimate I got of $60 each made the potential cash outlay pretty high for a few small parts. So, I did it myself on my Harbor Freight 7"x10" "toy" lathe and my used Rong Fu mill/drill.

Starting with 1/4 brass rod, I cut the pieces to 4.000" long, then turned down and threaded one end. With some old aluminum scrap, I made up a fixture with alignment stops to hold the shafts in the mill. I bought a 1/16" wide x 2.5" diameter slotting saw and arbor from Victor Machinery (good supplier for drilling/milling bits and cutters, etc.). With a shaft in my fixture, I leveled the shaft parallel to the bed, centered everything up, and cut the slot part-way through the shaft, then flipped the shaft over and did the slot from the other side. This left room to slide the throttle plate in. I kept a close watch on where my fingers went with the saw blade spinning at high speed! Next, I drilled and tapped the two 6-32 holes crosswise on the shaft, drilling right through the fixture. I finished up with and end mill to cut down the small shoulder and 10-32 threads to mount the throttle pump arm, using the cross holes to align the 180 degree rotation.

Getting the exact alignment for all of these operations was tough. My results weren't perfect, but good enough to reassemble a carb, tighten down the new throttle plate screws, and do a test assembly of the rest of the linkage. The throttle arms and stamped links had been zinc plated with clear chromate overcoat at a local shop. The parts look very much like the original cars (see photo below). It was a lot of work for some small details, but worth the effort. I still have to strip all the carbs, de-gunk them, paint the bodies flat black, and reassemble with new gaskets.

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Edited by Gary_Ash (see edit history)
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  • 4 weeks later...

Yes, I'm still having fun! Today, I finally hoisted up one of the engine blocks and lowered it into the engine compartment to check the fit and figure out how to mount it. The original cars had the engines solidly bolted to the chassis rails. The sedans of that era were that way, too. Since I'm using a 1937 block, a few "refinements" came along in the 1932-37 period, especially rubber mounts for engines. Studebaker adapted a Vee frame to the front of the engine with a small rectangular rubber pad under it. The rear mounts were two rubber donuts with vertical bolts through the rear of the bell housing. Of course, they changed the basic engine casting, too, so there are no longer the threaded bolt holes to do something different. It seems I will have to cobble up a couple of strong cross members to use front and back. The engine won't be so solidly mounted, but maybe giving up a little chassis stiffness for less vibration isn't all bad.

The good news is that I have plenty of room and can still keep the engine in the right place. The race cars didn't have fans - and now I see why! The original fans in sedans were mounted way up high, driven by a fan belt from the front of the crank, and the radiators were tall. There is no way to fit a belt-driven fan under my hood, so it looks like I'll have to use an electric "puller" fan behind the radiator, but that is OK. If you are driving 100-140 mph, you don't need a fan, but I'll be going more slowly, so I need something.

I'm still working on solving the shock absorber issues. I did get two Houdaille front shocks when I bought the old 1929 Studebaker President front axle. They had sat out in the rain for 30-40 years, were very rusted, but Five Points Classic Shocks did eventually get them apart and rebuilt. I acquired two more of the big Houdaille shocks, though it isn't clear what kind of car they came from, and they don't match exactly. The arms are 10.5" long, center-to-center, and I need them to be about 5.5". Apple Hydraulics says they can rebuild the shocks and cut the arms down, bend them to the right position for me. Apple says they can supply the shock links, too. However, if anyone has some big Houdaille shocks from the 1929-33 period, 4" diameter rounded domes, 5.125" bolt hole spacing, I'm interested in buying some.

Here's the engine hanging in the chassis and a shot of one of the original cars showing the shocks with short arms, as well as a Photoshopped image of what I need to do with the long arms.

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Edited by Gary_Ash (see edit history)
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With the engine block in place, I wanted to mount the bell housing and possibly the transmission. The engine blocks I got were a mixture of parts, not sure how they came apart or went together again. There is a thin steel plate between the block and bell housing that would not go on unless I pulled a 3/8" dowel pin from the block. I thought I could just grab it with some ViseGrips and twist, but no joy! I checked on line for dowel pin pullers and found sets for $200, nothing much cheaper. But, I did see how they were designed. I have a bunch of R8 collets for my Rong Fu milling machine, so I grabbed the 3/8" collet and a 4" long piece of 1" steel pipe. The collet nested just right and the pipe length seemed right, so I bought a 1" pipe cap and a 7/16-20 bolt at Lowe's, and a couple of hardened washers. I had a hub puller with a long shaft and a strange threaded end, which turned out to be 5/8-18 thread, took a couple of tries at local stores to find a steel nut.

I welded a washer into the i.d. of the 1" pipe and a 5/8-18 nut to the pipe cap. The R8 collet went into the other end of the 1" pipe and the bolt pulled it in a bit. I shoved the assembly over the dowel pin, tightened the bolt to grab the dowel pin, then screwed on the pipe cap/nut and threaded in the puller shaft and sliding weight. I guess I got lucky: about three taps with the sliding weight yanked the dowel pin, just like a rotten tooth. I felt much better that I had only spent about $5 for parts to make a puller, and my other collets in the set can be used for other sizes if I ever need some.

I was then able to get the plate on and the bell housing mounted. I think I can make a front and rear cross member for the engine with 3" x 1.5" x 1/8" wall rectangular tube. I'll need to order the rubber/steel engine mounts to figure out the exact heights, but I'm encouraged. There will be one flat rubber mount in front and two donuts in back with 1/2" vertical bolts through the bell housing.

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Hello Garry. Is that dowel you pulled eccentric? Apparently they made them in various forms to help fit the bell housing to line it up with the crankshaft, so the gearbox input pinion would be central in the clutch bush. I am sure I have read about it in my 1939 literature.

Nice puller, too! Very cost effective.

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The dowel pin is round, 1.975 inch long and 0.375 inch diameter over most of its length. The end which was pressed in was ground down to 0.343 inch diameter for about 1/4 inch length. There is a groove about 0.020 inch wide and 0.016 inch deep along the length, probably as a vent during assembly.

Studebaker's general practice on pinning things was to line up the transmission pilot hole, say 4" diameter, in the bell housing with the crankshaft assembly, then drill and pin the bell housing. Once located, standard bolts went in the other holes. It frequently means that swapping bell housings requires dial indicating the new housing and drilling two new holes for the pins. I had to do this on my 1948 Studebaker pickup - tedious and difficult with the engine still in the truck and me without a car hoist. I used a magnetic base on the flywheel to hold the dial indicator and pulled the flywheel around with a pry bar while the indicator tip rode on the i.d. of the hole in the bell housing. I got the runout down to below 0.005 inch.

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I've been laying out the cross members that will act as supports for the front and rear of the engine. The engine came equipped with a heavy (~.164" thick) Vee-shaped stamped steel front frame that has a rectangular steel/rubber/steel isolator under it. As the old isolator is now 77 years old and has been soaked in oil all those years, I ordered a new one. I also ordered the two pairs of rubber donuts that go at the rear under the bell housing, secured with 1/2-inch bolts. I need those in hand to figure out the height needed for the cross members. Isn't it nice to know that replacement parts can be ordered for engines this old!

I'm currently planning on using 1.5 x 3 x 0.12 inch wall type A500, grade B, rectangular tubing to make the cross members. I'll have to cut some pieces and weld the butted right angle joints. To prevent weld cracks from stress, I'll also add some 3x3 or 4x4 triangular gussets from 1/8th inch plate on front and rear surfaces of the butted joints. I'm figuring the lap welds of the gussets will prevent flexing of the butted joints. The engine, transmission, and accessories will weigh about 750 lbs. My calculation of the bending at the center of the cross members shows about .010-.015" for the case of both ends fixed, i.e. 1/4-inch mounting plates bolted through the chassis rails. Stress levels should be 3000-4000 psi, which is way below the yield strength of 46,000 psi of the steel.

The only thing making me pause at this point is that my cross member designs are not pretty. I thought about having the tubes bent, but bending rectangular tube this large is tough and the radius needed is too tight - the tubes would wrinkle and collapse. I could make curvy cross members by plasma cutting the front and rear faces and bending 3" wide strip to fit the contour. I'd be welding for a week and I don't think I could get it as strong as drawn tube. With the hood closed, the cross members won't show, and they'll still be hard to see with the hood open. Maybe someone else has some suggestions for alternate concepts or methods, though.

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Edited by Gary_Ash (see edit history)
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Personally, I think you're over thinking things. The parts that aren't out front won't be a big deal in the long run... but if it really concerns you, I've always found that lightening holes we're a good addition. They break up the visual of large structural beams.

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From the structural point of view, you would be better to have single diagonal members from the chassis attachment to the lower horizontal member. That way you only have two knee joints, at more than 90°. Think of a truss - they don't have that inefficient rectangular shape. It will also be cheaper to make this way - fewer joints - and there will be fewer welds with the possibility of failure. The forces will be more axial with less bending moments in the joints.

The car manufacture would have bent something up. The 1939 Commander has an inverted U-shape front cross member with a "sag" in it, but not to the degree you appear to be looking at. The chassis on the Commander is an open channel as yours is and the cross member is rivetted to the top and bottom flanges as well as the web of the channel. You will need to use high strength friction bolts at least, with no threads in the connection; it should really be rivetted. (A car with bolted chassis like that would probably not pass the low volume vehicle safety inspection here.) You will be applying torque to the chassis with the mounting you propose and the chassis will probably deform in time and crack.

I think you are way short in your design loads. You have a heavy engine (= inertia) with a chassis bucking (up, down, left and right) and twisting under it. The engine will also rock quite a bit on that single front mount - the rear mounts will reduce the rocking, but the engine is long as well so will twist. (Were the racing engines on a single front mount?) The dynamic forces will be considerable - could they be 5x as much as the static force? The "rubber" mount will soften some of the movement but absorb little of the energy so the engine will still move relative to the chassis. In building base isolation we use "rubber" for springs and lead or steel plugs to absorb energy (i.e. like a shock absorber) and thus reduce movement between the ground and the building. The original cross member was substantial for a reason and not to just hold up the engine.

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Whtbaron and Spinneyhill: You guys continue to be very helpful and knowledgeable observers and constructive critics of my efforts, as well as others. I appreciate it. It isn't easy to find people who can discuss this stuff with knowledge and experience. I was looking for your input.

So, am I overthinking it? Yes, I am guilty, but that's part of the fun. I would make an exact replica of the 1931 car (the #37 car of Bob Valpey) but it isn't practical and I have some of my own ideas tempered by the fact that 83 years have passed since the car was created. We must have learned SOMETHING in the meantime.

And, Spinneyhill, I did try the diagonalized approach but I couldn't get it to wrap around the generator and other accessories unless the angles were already beyond 70 degrees, hence the rectangular approach. Also, the sedan engines sat much higher with respect to the frame rails than in the race cars.

You are correct: riveting would be the right way, as the engine cradle is currently formed and fastened. However, the race cars were made to be driven, crashed all too frequently, and disassembled to be repaired. Hence, the chassis is bolted together. These days, we do have Loctite compounds of blue and red types to lock things in place. Hardly any young engineers know the virtues of rivets, and modern cars do seem to live without them, truck frame rails particularly excepted. A rivet properly applied will never loosen and the parts will be clamped tightly enough that they never slide with respect to each other. One rivet-ignorant engineer I used to work with was afraid that a riveted joint would loosen with time and thermal cycling - I told him to stare out the window on the next airplane flight he took and watch to see if any wing rivets were rotating.

What has driven me to make these cross members different from the original cars is that the 1931-33 engines had "wings" cast on the blocks above the crankcase line, both in front and at the back of the block. My 1937 engines don't have those and depended on steel/rubber isolators at lower elevations and the stamped steel frames. The 1931-33 Indy cars had the engine block wings tied solidly to the frame rails, increasing the torsional stiffness and resistance to rocking motions. Of course, the vibrations were awful and the comfort was zero. I guess I am erring on the side of sedan comfort. On the other hand, the original cars have survived for 80 years without significant issues of frame or engine mount cracking, in spite of racing, crashing, road use, and who-knows-what over all that time. Heck, I'm already so old that joint failures in the car would occur long after any lawyer can come after me.

My calculations of the static loads resulted in stress levels that are <10% of the yield strength. If we now consider dynamic loads, it does add to the stress. My calculations show I might get as much as 300 lb-ft of torque from the engine, so let's pretend that I can get all 300 lb-ft transferred to the engine mounts at some point, perhaps even on a regular basis. I'll assume (incorrectly, of course) that the front and rear cross members will share equally in the torque transfer. So, I get 150 lb-ft of torque being restrained by two 1/2-inch bolts about 9 inches apart. This should generate 100 lbs of lift on one bolt and 100 pounds of compression on the other mounting pad. The front bolt spacings are similar. But, I won't double the stress on the cross members, and I'll stay well below my normal guideline of 1/3rd of the yield strength as the maximum load. Even cyclic loads of 1,000,000 cycles or more (i.e., infinite life) should be OK at these loading levels. Even if I add forces for bumps and jolts, I should still stay way below the yield strength. Of course, I don't want to be driving down the road at 70 mph and hear the "ping" of a weld failure as the car veers off the road. Do you think my 1.5x3x.12 rectangular tube has less moment and stiffness than the original sedan cross members? Mine are 26 and 31.5 inches wide. I don't have an old one to look at.

I do agree that this is an issue to be concerned about, both for me and anyone else building a speedster, etc. It's not just static loads, it's the repetitive flexing of parts that eventually cracks welds. Frequent inspections are critical on one-off machines. As a private pilot, I learned to walk around the plane before every flight looking for loose bolts, cracks in metal, and other signs of failure. In modern cars, people rarely open the hoods to check the oil or check the tire pressure. We've become complacent and lazy because the cars we drive every day are so safe and reliable. Just don't transfer that thinking to driving old cars or speedsters we build.

I will take your good advice and review the designs. Thank you!

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Another wildcat thought for you. My 1930 Dodge Brothers Eight has the front engine mounts formed from a plate bolted to the front of the engine under the timing gear cover. It is bent up at the ends to form bolting points to the chassis and to brackets attached to it. There is maybe 5 mm of "rubber" body mounting under the mount. The car is very smooth - you can balance a 20c piece on edge on the top of the engine while it is idling. The plate is 5 mm thick. The crankshaft (as denoted by the crank handle hole in the bottom of the radiator) is below the chassis.

I would imagine road roughness bumps would put significant loads on the engine mounts. The chassis moves upwards and downwards rapidly at speed so the forces on the engine could be significant. I would try to make some allowance for them, but I don't know how at the moment. With fairly stiff springs (e.g. for some attempt at racing handling) you will get forces and movements more than you might expect.

For transmitting shear, how does the cross-sectional area of steel of your proposed RHS compare with the original mounting cross member? I wonder if 3 mm wall thickness is too thin. What is the chassis made of? Is that 0.164" (about 4 mm)?

Could you improve the knee joints' bending moment capacity if you use the RHS with the long dimension vertical across the bottom and for the chassis mounts and laterally for the sub-vertical members? This will, however, reduce the longitudinal resistance to movement of the engine and transmission.

Have you checked deflections (strains) as well as stress? The design might turn out to be governed by deflections rather than stresses.

No doubt you are familiar with steel structures design code(s). I just thought they might be a useful reminder of what you need to consider.

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