I understand that motors were sometimes unpainted when they were installed in the T's, and sometimes painted. If someone had their motor rebuilt and wanted it "unpainted", would you have to apply any sort of sealer on the unpainted engine? I've seen engines in restored vehicles left unpainted and they don't look rusty. Why is that? It's my understanding that once you sandblast something down to bare metal, you have to apply some sort of primer right away to avoid rusting, but unpainted engines look pretty clean. What's the secret?
Might be this cast iron look paint that's out there. Other's will follow with the name which I don't recall.
Lol Bill I think the T's propensity for leaking oil all over the place has a lot to do with the engine staying rust free. It might be more maintenance to keep it looking nice, but really a naked engine is like a shotgun or rifle - just keep it wiped down with oil. Heck, you throw some Marvel Mystery Oil on a rag and keep it in a ziplock and your engine will smell as good as it looks. You can just make a point to wipe it down occasionally.
"Cast Blast" paint.
Sandblasted metal will start rusting immediately. Moisture from your fingers and air will start the rust process. Bare metal would need some sort of oil or application to keep air/moisture from the bare metal. Not a permanent solution or recommended. The best way to have your "T" engine look unpainted is to paint it with a good quality- hi temp "cast iron" paint. This is what most all restorers do. It gives the look of unpainted cast iron and keeps the rust away. Apply the cast iron paint directly to the bare metal. NO primer is needed.
You could probably even put the MMO in a small spray bottle so that you really get the oil everywhere (just preferably not on the exhaust manifold) and then use your rag to wipe any runs and even everything out. It's kind of a neat idea the more I think about it.
An MTFCI judge (I don't remember which one) once posted on here that the engines were originally painter with a black wash (or green paint for the '26-7's), or they were left bare. They were NEVER originally painted with "cast blast" paint. FWIW.
After removing 3 layers of paint (green)off a '23 engine I came to that black wash. As I'd read here that was normal plus the fact that it didn't come off as easily as the other stuff I left it on.
From the Club's webpage Encyl.
This paint was F-142 Black Slush Paint. It was probably the fastest air drying paint used in the Ford Motor Company, and it certainly was the simplest in composition. It was made from 50% Gilsonite and 50% petroleum spirits (paint thinner). Crankcases were dipped in this material and would air dry in an hour or less. Parts painted with F-142 would have appeared to be “dense black” in color, but probably not very glossy or shiny.
1915 'Ford Shops'
A dull black on engines is better than modern 'cast blast' finish IMO, 'cept on the aluminum hogshead, leave that un-painted.
Here's a bit from the encyclopedia about engine paining and lack thereof:
Little written evidence exists that indicates engines were painted any color. If painted, early cars (1909) were probably painted chassis (body) color, and all were probably black if painted after the early production. Early Ford records do not seem to indicate any engine paint.
The oil pan (crankcase), after the very early production, was painted black. Transmission covers were probably also painted if the engine was, except in the case of the aluminum covers, which were always bare.
I assume you're asking about your 1916, so I'm skipping the part about 26-27.
Other records at the Ford Archives list the amount of black paint used on the engine assembly. Unfortunately these records do not say just where this paint was applied; to the entire engine, or to just the crankcase which was definitely painted. Notes also give a paint number which was the same as the black paint used on the radiator, a thin sort of a “wash.” This could be consistent with the black “paint” found on parts of the engine of the “Rip Van Winkle” 1917 Ford which had just twenty-six miles of use.
To add to the confusion, factory photos of the chassis and engine seem to indicate no paint on the engine block, while the crankcase was definitely black.
Perhaps some engines were painted, and some were not. It's an open question.
There's also a long dissertation on Model T paints and painting in the encyclopedia, some of which I think also describes engine paint.
My own personal preference for the pre-26 engine is black satin finish Rustoleum because it's durable and not expensive. I think that today NO Model T receives authentic original paint. I'll bet even the most pure of purists doesn't concoct a "Gilsonite wash" for his engine. I'd say there are two choices that come closest to simulating the original look. One is black paint, and the other is clear or "cast iron" paint.
Since I am the one that wrote the Model T paint articles originally for the Vintage Ford, this is my 2 cents worth.
Bruce and I had a long standing argument over engine paint. He would challenge me, and I would have to go back to the Research Center and dig up more evidence. I finally did come up with enough stuff that he eventually accepted my arguments. Prior to August 1925 and the appearance of the Improved Cars, Model T engines were painted with M-142 Black Slush. It was made up of Gilsonite and paint thinner in a 50/50 mixture. This was a very poor excuse for a coating and it either was washed off by hot oil, burned off by engine heat, or was amalgamated into the grease typically found on most original, unmolested Model T engines.
I have seen only two bonafide examples of the original black slush on original motors in low mileage cars. One was the Rip Van Winkle Ford, and the other is a VERY low mileage, well-preserved '16. In both cases the paint was more of a dis coloring preservative than it was a paint.
Personally, I use a black semi-gloss paint on my engines, preferably Bar-B-Que paint. In my opinion (yours will probably be different) it most closely resembles the Reflectiveness of Black Slush, while providing much better protection of the underlying surface. If some engines were untainted, it probably was unintentional. In any case, Cast Blast paint was never used on Model Ts. I hate that stuff almost as much as Ron Patterson hates #%+=<¥>^*+s.
Respectfully Submitted, and with wonderful memories of Bruce,
Trent your description of the engine "paint" is the best I have seen yet.
A few years ago I acquired a very unmolested '16 engine that had been in a car owned by the same ranch family since new. When the original oily crust was removed from the engine, I found no trace of paint on the engine block, which when cleaned of oil and dirt showed bright cast iron, now slightly dulled with oxidation.
The valve covers, however, showed patches or thin smears of black staining. The "finish" appears to have been applied with a wet mop as opposed to a stiff bristled brush, and were coated as if the engine was assembled when "painted"... Just a few quick dabbs here and there. The finish or stain is impervious to paint thinner, lacquer thinner and acetone and presents itself more like a metal stain or gun bluing chemical. The finish appears to have been a very thin wash which must have evaporated quickly after application, as there is no film build or signs of runs or flow at all where applied.
Thank you for your thoughtful research into this matter.
Trent, it's great to see you on the Forum again, even if only occasionally. A number of years ago your "List of My Model T Pet Peeves" (paraphrased title) appeared somewhere, and two of them have stuck with me. They were: fork-mounted 1915 headlamps and unpainted engines. I think a third one was the "1915 Klaxon". You had about 6 or so on the list and I got a kick out of it.
I think prior to 1914 the engines were painted after being installed in the chassis as part of the engine install line procedure. From 1914 on, the engines were painted at the end of the engine assembly line as Dan Trace quoted.
Source: There's a factory photo, labeled 1913, that clearly shows an unpainted engine being installed in a chassis. In the background there's another parallel engine install line showing the engine in place but painted black. The worker in the background is holding something that appears to be an oval brush or dauber. Or small "mop" as Trent noted. There is a third line but the details are not clear.
For those looking for the unpainted cast iron look, there's a new product out called RPM (Rust Prevention Magic), sold by ecsautomotive.com. I've never tried it, but the Mopar crowd loves it on their OE Gold restorations. It is supposed to be 100% undetectable on bare cast iron.