Hispano Suiza V8

[RReid]

Boring for the second bank of cylinders went well today, loose nuts notwithstanding. That's the go/no-go gauge in place in one of the openings, not going beyond the no-go point.




Another WW1 pilot who flew behind a Hispano Suiza 8 was America's #1 Ace and squadron leader of the famous "Hat in the Ring" squadron, Eddie Rickenbacker. Before the war he had been a notable race car driver, and after the war became a notable businessman, among other accomplishments.

The seemingly odd spacing of the exhaust ports apparent in this photo is one of the easiest recognition features of the Hispano Suiza, but was that way for a perfectly logical reason. More on that later.

[RReid]

Thanks Art! You posted just as I was.

[RReid]

The next task on the crankcase was to bore for the future crankshaft. The plan here is to have bronze flanged bushings at either either end, with the internal bearing supports/caps acting as bearings directly. The center one has a bronze insert already installed, along with a bronze cap, while the other two are just plain brass.

The first step was to make a sort of cradle to mount the crankcase to from two bars of aluminum. These were drilled to take screws for mounting to the lathe or mill, and a step milled in to exactly the height of the lathe center above the cross-slide. The crankcase fits down onto this, up against the edge of the step to keep it square, and once screwed down on the lathe the lathe center is right at the crankshaft centerline. Then I drilled completely through with the biggest long drill bit that I have, about 0.150” diameter. This was done in stages, starting with the drill choked up so that only the first two were drilled, then lengthend out, taking advantage of the support provided by the previous holes until it was all the way through.


Next I opened up the holes in steps, drilling and reaming 3/16” and 1/4” until getting to the final of 5/16”. The last two reamers were also able to have the benefit of tail stock support for the final bit.


To open up the ends to accept the bronze bushings, I turned to my 'tween centers boring bar. Since I would be turning the bushings to fit, I didn't have to worry about a very precise setting of the cutter and more or less eye-balled it. It ended  up cutting a 0.364” diameter, which is just fine since the bronze stock has a 0.375” diameter, which leaves the desired flange.


Here's the final result, with the bushings and a surrogate crankshaft (actually the boring bar) in place. Turns nice and smooth and no play to be felt, so it seems that all went well!

[Dave Otto]

Great progress Ron!

Dave

[cnr6400]

 

[RReid]

Thank you both, Dave and CNR!

I've made a start on getting out the cylinders. I have two stubs of 1.125” 1144 steel and one of 1.25” 12L14, each long enough to get out two cylinders. The stub left from the bar of 1144 I still need to buy to make the crankshaft will give me the last two. This much turning and boring of steel on a light lathe takes awhile, so doing all eight will be a bit of a slog.


The other leading fighter of WW1 to be Hispano Suiza powered, beside the SPAD, was the Royal Aircraft Factory (RAF) SE5a. Like the SPAD SXVIII, it used the 200 HP geared version, either the H-S 8B or the license built Wolsely Viper. A group in New Zealand (https://thevintageaviator.co.nz/) built an accurate modern replica, except for using a direct drive version of the engine. Shown is the crankcase for one of the three engines they acquired and restored.

[Vixen]

Hello Ron,

There's a lot of work in producing eight identical cylinders. Whats the plan, complete them all, one at a time? or can you batch some of the work, like the bores and honing stages? I like the way you weave a little history in with the build, it makes a nice connection between the model and the real engine.

Cheers   

Mike

[RReid]

Whats the plan, complete them all, one at a time? or can you batch some of the work, like the bores and honing stages?

Hi Mike,

I will be completing all the OD turning as well as the boring for one cylinder before going on to the next one. After all the lathe work is done there will be little bit to do on the mill also.

That doesn't mean I can't remove the complete set-up to do something else on the lathe, like today when I realized I'd forgotten to turn a plug gauge ahead of time as I'd meant to. So I just unscrewed the chuck with the part and the steady-rest still in place and did the needed work in a collet. Of course I could do the same thing if I need a break from cylinders. Without power feed it does get a little tiring.


Then I put it back and could get on with boring the cylinder. Because I use Viton 0-rings on my pistons, I haven't found honing to be necessary.


This first cylinder came out very nicely, I must say. I hope I can do as well seven more times.


I hope others also enjoy my little history snippets.

[Kim]

Definitely enjoying the history AND the build!  Keep it coming!  The first cylinder turned out great! 

Kim

[wagnmkr]

I am also enjoying this build. I love to see history come alive.

 

Tom

[RReid]

Thank you, Kim and Tom!

While I chunk away on the cylinders, I've also been giving some thought to the connecting rods. After several iterations I think I've arrived at something that is close to the prototype while still being within my ability to actually make. After getting used to looking at these zoomed in on the computer screen, I'm always a bit surprised at how small they actually are!




This is a test record from the British Aeronautical Inspection Directorate for a Wolsely Viper of the type used in the SE5A. I think the hand written scratch-outs and  corrections add to the interest, but I have no idea what "siq" means. Dated Nov. 23, 1918, so tomorrow it will be a month short of 106 years old.

[AVTUR]

I think "siq" is actually S19 which was probably a steel specification. By that time stainless steels started to be used for the valve material. The valve timings are interesting.

It is possible that the UK National Archives could tell you which aircraft manufacturer used the engine. However given the date I guess it went for disposal

The conrods look very fiddly.

AVTUR

[Brendon M]

Hello, great work so far!

In particular I think the built up crankcase is really neat, would save a lot of machining compared to starting with a solid bar.

[RReid]

I think "siq" is actually S19 which was probably a steel specification.

That makes sense, AVTUR, thank you! As for the date, I completely missed the fact that it was less than two weeks after the Armistice.

As far as I know, that valve timing was standard across all the models until valve overlap was finally applied to the 300HP Model H; which seems was primarily manufactured by the US licensee Wright-Martin (later Wright Aeronautical Corporation).

Thank you, Brendon.
Yes, the built up construction not only saved a lot of  swarf, but also money since I already had the brass bar on hand, and it had been acquired at a much lower cost than would be likely today!

[Roger B]

Great work on the crankcase and cylinder     

I do like the little bits of history