THE HISPANO-SUIZA V-8 718 & 1127c.i. CRANKSHAFT PROBLEMS

[baldeagle]

Originally Posted by m9a3r5i7o2n

Starting the Hisso is usually a fairly straightforward procedure, although if the engine is hot and the magnetos are weak you can wear out your prop-swinger in no time as the big V-8 obstinately refuses to fire up. Normally, you give the engine a couple of shots of prime, call, "Switch off!" to your helper, and wait while the propeller is turned through three or four revolutions. Then the booster mag comes into play. This is a small, hand-cranked magneto at the lower right corner of the instrument panel that sends extra current to the spark plugs for starting. If the engine is juiced up just right, and the propeller is in just the right position, you can put the mag switch to Both, crank the little handle on the booster mag, and the engine will start instantaneously. Usually this doesn't work, and you have to call the prop-swinger back to his task. You call, "Contact!", wait until after you see him start to swing, never before, and then start to crank the booster. Hopefully the Hisso catches and settles into a low, rumbling idle. It will idle below the last mark on the tachometer, but it's better to bump it up to 650 rpm or so to keep some cooling air moving through the radiator. This is especially true when the engine is warm, like in between rides.
M.L. Anderson

From; PilotWeb

Not sure I can add much to the discussion, but I wrote the above as part of a pilot report on a Travel Air 3000 w/180 Hisso (E?). I had the good fortune to fly another Travel Air 3000 yesterday, and from a pilot's point of view the Hispano-Suiza is a magnificent piece of equipment, great sound, smooth, and lots of power. Probably the closest I'll get to flying a H-S powered SPAD, unless Butch gets on the stick.......

[m9a3r5i7o2n]

One of the things I am looking for is the post that stated that the Wolseley had Crankshaft problems. I can’t find it anywhere and it is really bugging me as what he may have meant to say was about the Gear and Pinion. I have figured out, I believe, that the Lubrication of the Gear and Pinion was by a spray into two holes in the Gear from the pipe that supposedly broke and caused most of the problems in the 8B engine. If this is true then the Gear may have been insufficiently cooled by not having enough lubricant to cool and lubricate the teeth in the pinion. Cooling by the lubricate may have just been even more important than the actual lubrication process itself. This may be true if the Gear and Pinion were not being cooled enough before re-engagement. Some times the reason to spray the oil on the disengagement side of the gear and pinion to allow the oil a full rotation of the gear to cool its teeth.

I am now in the stage where the machining of the Blade Rod with its dual Outside Diameters for the mating of the Fork Rod and am trying to fine out if Birkigt had access to Optical Tooling for the alignment of the machines to aline the I.D, and the O.Ds to one another but have been unable to find exactly when such equipment was available to do this highly precise exercise in machining.

Did Birkigt have access to Precision Inspection Precision?
The Optical Inferometer had been invented some time before and I believe it was one of the optical devices used by Johansson to make Jo blocks.

The gauge block set, also known as "Jo Blocks", was developed by the Swedish inventor Carl Edvard Johansson. Johansson was employed in 1888 as an armourer inspector by the state arsenal Carl Gustaf Stad's Rifle Factory in the town of Eskilstuna, Sweden.

Carl Edvard Johansson - Wikipedia, the free encyclopedia

M.L. Anderson

[m9a3r5i7o2n]

Having just finished the sketch of the oil pump shown on pages 19, 20 and a part of 21 of the document (Written in French) plus the translation of the text (Using Free Translation Online), “Description Technique du MOTEUR D’AVIATION Hispano-Suiza”. one must arrive at some conclusion as to it’s effectiveness in a troubled lubrication system. Unfortunately the sketch in the book is very small, as is the type of the text, that a redrawing is necessary to understand just how the mechanism operates. Firstly it is a two lobe system of offset partial diameters. No dimensions are given.

The operating, revolving part is called a shutter (Pallette) and appears to be three pieces. The two pieces are spring loaded and slide against one another as the variances of the two partial diameters (circles) change in relation to the axis of the rotating shutter.
The one side of the chamber is shaped similar to a crescent and is the part that produces the extension of one side of the paddle.

This reason, paddle extension, may be the cause of Birkigt’s failure of putting an Oil Pressure Relief Valve in the system was the spring loading of the Paddle, he may have had cause to believe the spring would supply some pressure relief. However a simple test with heavy oil should have disproved this or he may have simply ignored the test. We will never know unless French documents are available to see if any tests were made of this type of pump.

Yours, M.L. Anderson

[jumpinjan]

I can't follow the explanation (could you provide a picture of the pump?). When you say a crescent shaped chamber, could it look like this automatic trans pump below?

[m9a3r5i7o2n]

I'll give it a shot. One of the reasons is the sketch is so small, the reason I had to make a much larger sketch of it to understand how it was supposed to operate. The principle is the same as the picture you show but a spring is in there and there aren't any toothed wheels of any kind inside the chamber. I'll see what I can do. I’ll have to make 3 new sketches!
M.L. Anderson

[m9a3r5i7o2n]

I don't believe at this time. after making the first sketch, that he would have made this mistake as there is not enought surface to force the paddle to open with any reasonable oil pressure even if the Castor Oil were at it's worst. The opening would have to be about 300 lbs.p.s.i. to do this. He may have made mistakes but I doubt this was one of them.
M.L.Anderson

[m9a3r5i7o2n]

From and old post by mossie I find that the use of methylated spirits were used in Rotary-Radials to allow the Castor Oil to flow for fast warm -ups. Since in an engine as the Hispano-Suiza the addition of this to the Castor Oil would allow the lubricant to also flow better, from a cold start, I am wondering if anyone has found that denatured alcohol, a methylated spirit, to be used in any regular piston engine such as the Hispano-Suiza?

Just how many aircraft engines were treated with gasoline in WW-2 in a similar way is unknown but we do know it was done and I believe it was even in the engine manuals and just how and when and the restrictions that applied to it.

http://physics.slss.ie/downloads/ph_...tedspirits.pdf

Yours, M.L. Anderson

[m9a3r5i7o2n]

Fine picture of the 8B Hispano-Suiza engine with one shot of the Helical Gear and Pinion but I failed to see the Pipe that seems to be in question. If it is on the engine it must be on the opposite side of the cut away. Some other pictures of WW-1 engines also! After it comes up, probably slowly, go to # 3 then to the 8B engine!

M.L. Anderson

Deutsches Museum

[m9a3r5i7o2n]

Figure # 8, Page # 12 of the French 200 H.P. Hispano-Suiza Aero Engine, Instruction Handbook. June 1917

We know, by observation, that the large oil pipe goes up the left side of the crankcase, pilots view, and extends forward to the front edge of the crankcase where a hole extends upwards to the bottom edge of the crankcase main bearing. The sketch on page # 12 Figure # 8 shows a passage way (H) up to the propeller shaft and then the oil goes into the center of a large weight reduction hole of the propeller shaft in which it appears to have four holes drilled. Then it is passed into the center web of the gear wheel and into the holes drilled into the gear, there is no mention of how many of these holes are drilled into the gear. Arrows also show the oil is directed into these holes and also into holes lubricating the front ball bearing.

There is no explanation of this process in the written text that I have been able to find except this text written herein, above and below
In the document that I have of the, “ Report upon Troubles with the 200 H.P. Hispano in Service”, was the following on page #3 I believe, as I haven’t the complete document. As follows is the statement.

It is necessary that the diameter of the lubricating jet of the reduction gear be 10/10 mms. (some are still 6/10). No other thing is mentioned as to the location of the jet or any other placement of the jet.

The only place I found that even closely resembles the description if the jet and the copper oil pipe is a projection into the propeller shaft from the front of the engine into the and sprays oil into the propeller shaft and then into the four holes in the shaft and the gear wheel where centrifugal force throws it into the tooth area of just the one tooth per hole. One must remember that there are only four holes that I can see in the sketch.

1.0mm diameter = .785square mm
.6mm diameter = .287 square mm
A difference of .498 square mm or an increase of 49.3% on the square area, just why this was done I don’t know and isn’t revealed in the text. Was it to increase the oil flow to the gear and pinion or was it to decrease the pressure in the piping, which was the primary purpose I don’t know and they who did know didn‘t reveal the true purpose.

We do know that the oil that was forced into the teeth which are on the outer side from the gear wheels web. The driving but smaller pinion wheel does not get any direct spray of oil and seems to get the lubrication only from indirect sources. Remember that it is on the bottom side of the two wheels and gravity may take care of it’s lubrication most of the time altho this may not be sufficient lubricant in combat maneuvering.

Page # 11 Lubrication Paragraph # 5; From the front end bearing housing of the crankshaft oil is forced under pressure through an oil duct H in the crankcase upward to the propeller inside diameter. The shaft is hollow for weight reduction and just how many of the teeth are drilled for oiling I cannot state for sure. I don’t believe every tooth can be drilled due to a weakening of the hub area of the larger gear. Visually imagine 41 or 59 holes drilled thru the hub area for each tooth!
Is this just a bad design? It doesn’t seem to provide enough oil spray on the teeth to cool the gear and pinion sufficiently under all circumstances of maneuver. Of course this gets into the real reason that Wolseley took off the reducer which we really also don’t know for sure. Possibly the Oil Pressure Relief should have been directed into the Gear and Pinion box area near the tooth disengagement area.

After finishing a sketch of the Oil Pipe I believe that this must be the pipe of the, “Broken Copper Pipe Story”. It seems to be less than half the diameter of the steel pipe which is given as ½”. and around 2” long and projecting out of the front face of the upper crankcase. The only mention in the Manual is the resizing of the jet mentioned above. The sketch is very bad on this view and I had to increase the magnification 500 to see a two very faint lines showing the tube itself.
Yours, M. L. Anderson

[m9a3r5i7o2n]

#8 (permalink) 7 July 2005, 02:40 PM
Quote from an_San_Abbott
Forum Ace of Aces
Contributor
Join Date: Aug 2001
Location: Ceres, California
Posts: 6,742
The sweet sound of a Hisso.
Retread:
My friend Lee Branch and I were discussing the gear problems with the Hispano-Suiza 8Ba engine. I had thought the problem was improperly heat treated reduction gears. Lee said, "No, it was design failure in the copper feed pipe that brought oil to the reduction gears, the wall of the copper tubing was too thin and it failed under pressure, thus depriving the reduction gears of the necessary lubrication. Hispano-Suiza did not want it known that it was a design error, so they put out the story of the improper heat treating of the reduction gears."

Yours, M.L. Anderson