Recently we were asked about the existence of 1955-57 Chevy frames with one-piece 'rails. Frankly, we knew about one-piece California bumpers, but had never heard of one-piece framerails.
As with most cars of the era, the typical frames under Tri-Five Chevys used two-piece 'rails—basically two U-shaped sections with the open ends facing each other that were welded together.
The story we were told (and is evidently often repeated) was that a California law in force at the time required automotive framerails to be one piece. Having owned cars with two-piece framerails that rolled off California assembly lines in those years the explanation didn't sound right and there is no evidence that there was such a law. This is, however, another explanation for the creation of one-piece framerails, which also make it easy to understand why they are so rare.
With the introduction of the new 1955 Chevrolets general manager, Ed Cole, was intent on altering the perception that Chevys were cars for old men. He was after the youth market, knew performance was the way to attract a younger clientele and stock car racing was one way to prove the new car's potential. When Herb Thomas won the NASCAR Southern 500 race at Darlington, South Carolina, on Labor Day 1955 and seven of the new cars finished in the Top 10, Cole's point was made and buyers headed to the showrooms.
To get the story on one-piece Chevy frames we contacted Gene Bruner at Danchuk Manufacturing (danchuk.com). Bruner has spent years accumulating information on Tri-Fives and was familiar with the one-piece frames. As he explains it, they were lighter and stronger than the standard two-piece design and the Chevy brass wanted to use them for racing but NASCAR homologation requirements meant that a certain number of parts had to be used in production to be legal for competition (the Dodge Daytonas and Plymouth Superbirds were a more recent example).
As Bruner explains it, these frames are rare, but owing to NASCAR regulations may be found under a variety of production cars, including six-cylinder 210s, and all the Black Widow cars produced by the Southern Engineering and Development Company (SEDCO) had one-piece 'rails.
Where's the Painter Guy?
Q. Another question about my 1932 DeSoto three-window coupe project. I don't know who to direct this question to, as you guys don't have an "ask the painter" guy. I am smoothing my 354 Hemi motor block and heads. There are a number of spots where I would have to grind too deep to remove the pits and casting defects. What do you fill the pits, gouges, casting flaws, and grinding marks with that will withstand the repeated hot and cold cycles the motor will go through and still stick to the cast iron?
Thanks for your help (again!),
Tom and Tina Keyes
A. We don't have a "painter guy" but we'll try to help anyhow.
Ironically, we just looked at a Hemi that was painted with single-stage polyurethane enamel and we'd settle for a paintjob on any of our cars that looked as good. Used in commercial and industrial applications, polyurethane enamel is available in single-stage and basecoat/clearcoat.
Tough stuff, this material is very resistant to chemicals, which makes it great for engines. We had a block that was painted with single-stage polyurethane enamel and when it was time for a rebuild not even a trip through a hot tank removed the finish (although it was dull afterward).
Another option is single-stage acrylic urethane, we've used it with good results and it can be mixed in a color to match your car. Of course some builders go all-out and shoot their engines with basecoat/clearcoat acrylic urethane. In either case the gloss retention is excellent.
If you're looking for a simple method to make your engine look good Eastwood has an engine kit that included their 2K Ceramic Engine Paint. This urethane finish can be sprayed or brushed. The complete engine kit includes paint, cups with lids, three foam brushes, and 15 "Pig Mats" to keep your garage floor clean.
As for filling imperfections one builder who has detailed lots of engines tells us he uses polyester body filler with excellent results. Once the filler is set and sanded he shoots a light coat of PPG epoxy primer followed by PPG single-stage acrylic urethane.
It seems everyone we talked to on the subject had an opinion about engine paint, one engine builder swears by acrylic enamel and our buddy John Beck at Vintage Hot Rod/Pro Machine favors Hammerite Rust Cap (it provides a unique "hammered finish" that's extremely durable). But regardless of the product used, the real secret to a great looking, long lasting finish on an engine is the same as any other paintjob: preparation.
Prepping an engine for paint can be a challenge, especially if it has many miles on it. Obviously, removing all traces of oil and grime is necessary, but don't think that because an engine is new it's ready to paint, as no doubt there will be machining and assembly lubricants left behind. Use a good prep solvent to clean all the surfaces, then follow up with a thorough scrubbing with hot water and dish washing detergent (making sure not to get any water in the engine). Sheetmetal components like rocker covers and pans can be bead blasted or sanded, again make sure that any abrasive material is removed, as you certainly wouldn't want it to find a way inside the engine.
High Voltage Hemi
Q. I've been collecting Chrysler Hemi parts for quite some time. I never have been able to come up with a complete engine, but I have quite a few short-blocks, lots of heads, stock and aftermarket intakes, several stock flywheels, two different aluminum flywheels (one has 146 teeth, the other has 172). I've also got a number of starters, both 6 and 12V, but I'm confused about starter/ring gear compatibility.
Now to the question. The aluminum flywheel with 172 has a scored insert where the clutch disc rides, the one with 146 teeth is brand new so I'd like to use it. Is there a 12V starter that will work with the smaller-diameter flywheel? What happens if I use a 6V starter on 12V?
Via the Internet
A. As far back as 1933, Chrysler used starter ring gears with 146 teeth and they continued doing so through 1956. In 1957 the change was made to a 172-tooth ring gear, which would also be used the following year.
Chrysler Hemi starters are as follows: 1951-55 use a 6V starter (146-tooth flywheel), 1956 uses a unique starter that is 12V but is compatible with a 146-tooth flywheel, and 1957-58 use a 12V starter (172-tooth flywheel).
You have several choices with your collection of starters. You could use a '56 starter, the identification plate will read MDF 6001, PN 1642140. Another option is a 6V starter on 12V. It may come as a surprise but this is a common starter solution when converting a car from 6 to 12V. If the starter is in good shape to begin with it will run on 12 V for a long, long time with no adverse effects.
Another option is a gear reduction starter from Powermaster. They offer two Hemi starters in their XS Torque line that produce 200 lb-ft of torque—PN 9530 is used with 146-tooth flywheels, PN 9531 is for those with 172 teeth.
Finally, if you opt for an adapter to attach a late-model automatic to your Hemi, you will find many use a late-style Chrysler starter (check with the adapter manufacturer for exact specifications).